pollution article essay

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Essay on Pollution: Samples in 100, 150 and 200 Words

• Updated on  
• Apr 27, 2024

As the world embraced urbanization, mother nature witnessed the greener lands getting transformed into modern cities and metropolises. What followed is a trail of natural disasters signalling that something is wrong with the planet Earth. Pollution is increasingly asked under the writing section in school and college tests as well as competitive exams . This is because it is a relevant environmental issue today. This blog aims to help you with the necessary knowledge as well as tips and tricks to draft a well-written essay on pollution.

What is Pollution?

Pollution is the introduction of harmful materials into the environment. These materials are called pollutants. They can be created by human activity like trash and natural like volcanic ash. Pollutants damage the quality of water, air and land. Pollution is a global problem. Air and water carry pollution into the ocean currents and migrating fish. Pollution is among the many things that harm our planet- once greener and healthier than it is now. Pollution is a dangerous phenomenon that is contributing to an array of health issues.

Types of Pollution

In simple terms, pollution is defined as the contamination of the physical and biological constituents in the earth’s atmosphere. It affects human life and the natural environment to a very great extent. It degrades our natural resources, from the water we drink to the air we breathe. While writing an essay on Pollution, you must mention the major four types of pollution which are as follows:

• Air Pollution : Air pollution is the contamination of air in the atmosphere when harmful or excessive quantities of substances such as smoke and harmful gases from industries, CFCs and oxides produced by automobiles, the burning of solid wastes, etc. are introduced into the environment.
• Water Pollution : This refers to the contamination of natural resources of water, due to the addition of harmful chemical, biological or physical materials, which includes industrial wastes, oil spills, domestic and farm wastes, pesticides, as well as mining and agricultural wastes, to water resource which make it unusable.
• Soil Pollution : Land/Soil Pollution occurs due to the degradation of the earth’s surface by different commercial, industrial, agricultural and domestic activities. Causes of soil pollution also include mining, deforestation, dumping of e-waste and other industrial wastes, usage of harmful chemicals such as insecticides, pesticides, etc.
• Noise Pollution : Excess noise due to sounds created by machines, loudspeakers, microphones, loud music, noise from industries, construction and civil engineering works etc. lead to noise pollution.

Causes and Health Effects of Pollution

You can include various causes and health effects in your essay on Pollution from the following table:-

Sample Essay on Pollution in 100 Words

Pollution is the addition of unwanted substances which are incorporated into the environment that can damage our Earth. There are mainly four types of pollution, these include water pollution, air pollution, soil pollution, and noise pollution. One should note that any form of pollution is the result of careless activity carried out by man. We, humans daily dump waste directly into water bodies which leads to water pollution.

Vehicle emissions of smoke into the atmosphere impede the ability of all living things to breathe, leading to air pollution. Our garbage is dumped into landfills directly, which results in soil pollution. Although it cannot be seen, noise pollution is a severe type of pollution that can harm our ears.

Sample Essay on Pollution in 250-300 Words

The biggest threat planet Earth is facing is pollution. Unwanted substances leave a negative impact once released into an environment. There are four types of pollution air, water, land, and noise. Pollution affects the quality of life more than any human can imagine.

Due to air pollution, even teenage kids have developed various respiratory diseases. Water pollution has led to diseases in children. The waste we humans dump on the land or chemical fertilisers which are put on the land for agricultural purposes causes land/ soil pollution.

If the soil quality deteriorates due to such practices, the soil will become infertile and no crops could be grown in future. The government has launched various schemes over the years to fight pollution but individual efforts can also play a vital role.

Start by replacing plastic bags for shopping with cloth bags, stopping littering on roads and stopping wasting water are some of the basic things to start with that can lead to big changes in the environment.

Also Read: Essay on Green Energy PDF: 150 and 250 Words

Sample Essay on Pollution in 300-350 Words

One of the most critical threats faced by our planet in the present-day scenario. Environmental pollution is a global issue affecting people around the world. It is occurring in different forms, whether by affecting the air we breathe or the water resources we utilise for several purposes.

Air pollution came into being with an increase in the level of carbon dioxide, with the increase in pollutants which are contaminating the air and causing breathing discomfort as well as skin diseases to human beings. Talking about the other aspect, there is no life without water.

The water bodies are polluting and becoming unsafe for drinking or any other use because of industrial development, rapid urbanisation and various other reasons. Due to air pollution, diseases that can occur in human beings are asthma, various skin diseases, cancer, etc. Therefore, it is the essential need of the hour to take serious steps to reduce pollution to its core.

At a personal level, we can minimise environmental pollution by taking public transport or carpools to reduce vehicular smoke, avoiding firecrackers at festivals and celebrations can also cut down on air and noise pollution, and not using fertilisers and pesticides which can cause both water and soil pollution, and switching over to organic farming. The government can also bring strict rules and regulations to lessen industrial pollution.  

To sum up, any type of pollution is harmful to the environment with serious consequences like global warming, uneven climatic changes, etc. Due to our greediness and illegal human activities, the innocent lives of animals are lost. The time has come to join hands and work towards preserving and protecting the environment for the present as well as future generations.

Also Read: Essay on Environment: Examples and Tips

Short Essay on Pollution in English

Find a sample of a short essay on pollution below:

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Nikita Puri

Nikita is a creative writer and editor, who is always ready to learn new skills. She has great knowledge about study abroad universities, researching and writing blogs about them. Being a perfectionist, she has a habit of keeping her tasks complete on time before the OCD hits her. When Nikita is not busy working, you can find her eating while binge-watching The office. Also, she breathes music. She has done her bachelor's from Delhi University and her master's from Jamia Millia Islamia.

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• Published: 17 June 2020

Half the world’s population are exposed to increasing air pollution

• G. Shaddick   ORCID: orcid.org/0000-0002-4117-4264 1 ,
• M. L. Thomas 2 ,
• P. Mudu 3 ,
• G. Ruggeri 3 &
• S. Gumy 3  

npj Climate and Atmospheric Science volume  3 , Article number:  23 ( 2020 ) Cite this article

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• Environmental impact

Air pollution is high on the global agenda and is widely recognised as a threat to both public health and economic progress. The World Health Organization (WHO) estimates that 4.2 million deaths annually can be attributed to outdoor air pollution. Recently, there have been major advances in methods that allow the quantification of air pollution-related indicators to track progress towards the Sustainable Development Goals and that expand the evidence base of the impacts of air pollution on health. Despite efforts to reduce air pollution in many countries there are regions, notably Central and Southern Asia and Sub-Saharan Africa, in which populations continue to be exposed to increasing levels of air pollution. The majority of the world’s population continue to be exposed to levels of air pollution substantially above WHO Air Quality Guidelines and, as such, air pollution constitutes a major, and in many areas, increasing threat to public health.

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Introduction.

In 2016, the WHO estimated that 4.2 million deaths annually could be attributed to ambient (outdoor) fine particulate matter air pollution, or PM 2.5 (particles smaller than 2.5 μm in diameter) 1 . PM 2.5 comes from a wide range of sources, including energy production, households, industry, transport, waste, agriculture, desert dust and forest fires and particles can travel in the atmosphere for hundreds of kilometres and their chemical and physical characteristics may vary greatly over time and space. The WHO developed Air Quality Guidelines (AQG) to offer guidance for reducing the health impacts of air pollution. The first edition, the WHO AQG for Europe, was published in 1987 with a global update (in 2005) reflecting the increased scientific evidence of the health risks of air pollution worldwide and the growing appreciation of the global scale of the problem 2 . The current WHO AQG states that annual mean concentration should not exceed 10 μg/m 3  2 .

The adoption and implementation of policy interventions have proved to be effective in improving air quality 3 , 4 , 5 , 6 , 7 . There are at least three examples of enforcement of long-term policies that have reduced concentration of air pollutants in Europe and North America: (i) the Clean Air Act in 1963 and its subsequent amendments in the USA; (ii) the Convention on Long-range Transboundary Air Pollution (LRTAP) with protocols enforced since the beginning of the 1980s in Europe and North America 8 ; and (iii) the European emission standards passed in the European Union in the early 1990s 9 . However, between 1960 and 2009 concentrations of PM 2.5 globally increased by 38%, due in large part to increases in China and India, with deaths attributable to air pollution increasing by 124% between 1960 and 2009 10 .

The momentum behind the air pollution and climate change agendas, and the synergies between them, together with the Sustainable Development Goals (SDGs) provide an opportunity to address air pollution and the related burden of disease. Here, trends in global air quality between 2010 and 2016 are examined in the context of attempts to reduce air pollution, both through long-term policies and more recent attempts to reduce levels of air pollution. Particular focus is given to providing comprehensive coverage of estimated concentrations and obtaining (national-level) distributions of population exposures for health impact assessment. Traditionally, the primary source of information has been measurements from ground monitoring networks but, although coverage is increasing, there remain regions in which monitoring is sparse, or even non-existent (see Supplementary Information) 11 . The Data Integration Model for Air Quality (DIMAQ) was developed by the WHO Data Integration Task Force (see Acknowledgements for details) to respond to the need for improved estimates of exposures to PM 2.5 at high spatial resolution (0.1° × 0.1°) globally 11 . DIMAQ calibrates ground monitoring data with information from satellite retrievals of aerosol optical depth, chemical transport models and other sources to provide yearly air quality profiles for individual countries, regions and globally 11 . Estimates of PM 2.5 concentrations have been compared with previous studies and a good quantitative agreement in the direction and magnitude of trends has been found. This is especially valid in data rich settings (North America, Western Europe and China) where trends results are consistent with what has been found from the analysis of ground level PM 2.5 measurements.

Figure 1a shows average annual concentrations of PM 2.5 for 2016, estimated using DIMAQ,; and Fig. 1b the differences in concentrations between 2010 and 2016. Although air pollution affects high and low-income countries alike, low- and middle-income countries experience the highest burden, with the highest concentrations being seen in Central, Eastern Southern and South-Eastern Asia 12 .

a Concentrations in 2016. b Changes in concentrations between 2010 and 2016.

The high concentrations observed across parts of the Middle East, parts of Asia and Sub-Saharan regions of Africa are associated with sand and desert dust. Desert dust has received increasing attention due to the magnitude of its concentration and the capacity to be transported over very long distances in particular areas of the world 13 , 14 . The Sahara is one of the biggest global source of desert dust 15 and the increase of PM 2.5 in this region is consistent with the prediction of an increase of desert dust due to climate change 16 , 17 .

Globally, 55.3% of the world’s population were exposed to increased levels of PM 2.5 , between 2010 and 2016, however there are marked differences in the direction and magnitude of trends across the world. For example, in North America and Europe annual average population-weighted concentrations decreased from 12.4 to 9.8 μg/m 3 while in Central and Southern Asia they rose from 54.8 to 61.5 μg/m 3 . Reductions in concentrations observed in North America and Europe align with those reported by the US Environmental Protection Agency and European Environmental Agency (EEA) 18 , 19 . The lower values observed in these regions reflect substantial regulatory processes that were implemented thirty years ago that have led to substantial decreases in air pollution over previous decades 18 , 20 , 21 . In high-income countries, the extent of air pollution from widespread coal and other solid-fuel burning, together with other toxic emissions from largely unregulated industrial processes, declined markedly with Clean Air Acts and similar ‘smoke control’ legislation introduced from the mid-20th century. However, these remain important sources of air pollution in other parts of the world 22 . In North America and Europe, the rates of improvements are small reflecting the difficulties in reducing concentrations at lower levels.

Assessing the health impacts of air pollution requires detailed information of the levels to which specific populations are exposed. Specifically, it is important to identify whether areas where there are high concentrations are co-located with high populations within a country or region. Population-weighted concentrations, often referred to as population-weighted exposures, are calculated by spatially aligning concentrations of PM 2.5 with population estimates (see Supplementary Information).

Figure 2 shows global trends in estimated concentrations and population-weighted concentrations of PM 2.5 for 2010–2016, together with trends for SDG regions (see Supplementary Fig. 1.1 ). Where population-weighted exposures are higher than concentrations, as seen in Central Asia and Southern Asia, this indicates that higher levels of air pollution coincide with highly populated areas. Globally, whilst concentrations have reduced slightly (from 12.8 μg/m 3 in 2010 to 11.7 in 2016), population-weighted concentrations have increased slightly (33.5 μg/m 3 in 2010, 34.6 μg/m 3 in 2016). In North America and Europe both concentrations and population-weighted concentrations have decreased (6.1–4.9 and 12.4–9.8 μg/m 3 , respectively). The association between concentrations and population can be clearly seen for Central Asia and Southern Asia where concentrations increased from 29.6 to 31.7 μg/m 3 (a 7% increase) while population-weighted concentrations were higher both in magnitude and in percentage of increase, increasing from 54.8 to 61.5 μg/m 3 (a 12% increase).

a Concentrations. b Population-weighted concentrations.

For the Eastern Asia and South Eastern Asia concentrations increase from 2010 to 2013 and then decrease from 2013 to 2016, a result of the implementation of the ‘Air Pollution Prevention and Control Action Plan’ 21 and the transition to cleaner energy mix due to increased urbanization in China 23 , 24 , 25 . Population-weighted concentrations for urban areas in this region are strongly influenced by China, which comprises 62.6% of the population in the region. Population-weighted concentrations are higher than the concentrations and the decrease is more marked (in the population-weighted concentrations), indicating that the implementation of policies has been successful in terms of the number of people affected. The opposite effect of population-weighting is observed in areas within Western Asia and Northern Africa where an increasing trend in population-weighted concentrations (from 42.0 to 43.1. μg/m 3 ) contains lower values than for concentrations (from 50.7 to 52.6 μg/m 3 ). In this region, concentrations are inversely correlated with population, reflecting the high concentrations associated with desert dust in areas of lower population density.

Long-term policies to reduce air pollution have been shown to be effective and have been implemented in many countries, notably in Europe and the United States. However, even in countries with the cleanest air there are large numbers of people exposed to harmful levels of air pollution. Although precise quantification of the outcomes of specific policies is difficult, coupling the evidence for effective interventions with global, regional and local trends in air pollution can provide essential information for the evidence base that is key in informing and monitoring future policies. There have been major advances in methods that expand the knowledge base about impacts of air pollution on health, from evidence on the health effects 26 , modelling levels of air pollution 1 , 11 and quantification of health impacts that can be used to monitor and report on progress towards the air pollution-related indicators of the Sustainable Development Goals: SDG 3.9.1 (mortality rate attributed to household and ambient air pollution); SDG 7.1.2 (proportion of population with primary reliance on clean fuels and technology); and SDG 11.6.2 (annual mean levels of fine particulate matter (e.g., PM 2.5 and PM 10 ) in cities (population weighted)) 1 . There is a continuing need for further research, collaboration and sharing of good practice between scientists and international organisations, for example the WHO and the World Meteorological Organization, to improve modelling of global air pollution and the assessment of its impact on health. This will include developing models that address specific questions, including for example the effects of transboundary air pollution and desert dust, and to produce tools that provide policy makers with the ability to assess the effects of interventions and to accurately predict the potential effects of proposed policies.

Globally, the population exposed to PM 2.5 levels above the current WHO AQG (annual average of 10 μg/m 3 ) has fallen from 94.2% in 2010 to 90.0% in 2016, driven largely by decreases in North America and Europe (from 71.0% in 2010 to 48.6% in 2016). However, no such improvements are seen in other regions where the proportion has remained virtually constant and extremely high (e.g., greater than 99% in Central, Southern, Eastern and South-Eastern Asia Sustainable Development Goal (SDG) regions. See Supplementary Information for more details).

The problem, and the need for solutions, is not confined to cities: across much of the world the vast majority of people living in rural areas are also exposed to levels above the guidelines. Although there are differences when considering urban and rural areas in North America and Europe, in the vast majority of the world populations living in both urban and rural areas are exposed to levels that are above the AQGs. However, in other regions the story is very different (see Supplementary Information Fig. 7.1 and Supplementary Information Sections 7 and 8), for example population-weighted concentrations in rural areas in the Central and Southern Asia (55.5 μg/m 3 ), Sub-Saharan Africa (39.1 μg/m 3 ), Western Asia and Northern Africa (42.7 μg/m 3 ) and Eastern Asia and South-Eastern Asia (34.3 μg/m 3 ) regions (in 2016) were all considerably above the AQG. From 2010 to 2016 population-weighted concentrations in rural areas in the Central and Southern Asia region rose by approximately 11% (from 49.8 to 55.5 μg/m 3 ; see Supplementary Information Fig. 7.1 and Supplementary Information Sections 7 and 8). This is largely driven by large rural populations in India where 67.2% of the population live in rural areas 27 . Addressing air pollution in both rural and urban settings should therefore be a key priority in effectively reducing the burden of disease associated with air pollution.

Attempts to mitigate the effects of air pollution have varied according to its source and local conditions, but in all cases cooperation across sectors and at different levels, urban, regional, national and international, is crucial 28 . Policies and investments supporting affordable and sustainable access to clean energy, cleaner transport and power generation, as well as energy-efficient housing and municipal waste management can reduce key sources of outdoor air pollution. Interventions would not only improve health but also reduce climate pollutants and serve as a catalyst for local economic development and the promotion of healthy lifestyles.

Assessment of trends in global air pollution requires comprehensive information on concentrations over time for every country. This information is primarily based on ground monitoring (GM) from 9690 monitoring locations around the world from the WHO cities database for 2010–2016. However, there are regions in this may be limited if not completely unavailable, particularly for earlier years (see Supplementary Information). Even in countries where GM networks are well established, there will still be gaps in spatial coverage and missing data over time. The Data Integration Model for Air Quality (DIMAQ) supplements GM with information from other sources including estimates of PM2.5 from satellite retrievals and chemical transport models, population estimates and topography (e.g., elevation). Specifically, satellite-based estimates that combine aerosol optical depth retrievals with information from the GEOS-Chem chemical transport model 29 were used, together with estimates of sulfate, nitrate, ammonium, organic carbon and mineral dust 30 .

The most recent release of the WHO ambient air quality database, for the first time, contains data from GM for multiple years, where available The version of DIMAQ used here builds on the original version 11 , 30 by allowing data from multiple years to be modelled simultaneously, with the relationship between GMs and satellite-based estimates allowed to vary (smoothly) over time. The result is a comprehensive set of high-resolution (10 km × 10 km) estimates of PM2.5 for each year (2010–2016) for every country.

In order to produce population-weighted concentrations, a comprehensive set of population data on a high-resolution grid (Gridded Population of the World (GPW v4) database 31 ) was combined with estimates from DIMAQ. In addition, the Global Human Settlement Layer 32 was used to define areas as either urban, sub-urban or rural (based on land-use, derived from satellite images, and population estimates). A further dichotomous classification of whether grid-cells within a particular country were urban or rural (allocating sub-urban as either urban or rural) was based on providing the best alignment (at the country-level) to the estimates of urban-rural populations produced by the United Nations 27 .

It is noted that the estimates from DIMAQ used in this article may differ slightly from those used in the WHO estimates of the global burden of disease associated with ambient air pollution 1 , and the associated estimates of air pollution related SDG indicators, due to recent updates in the database and further quality assurance procedures.

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Acknowledgements

The authors would like to thank the WHO Data Integration Task Force, a multi-disciplinary group of experts established as part of the recommendations from the first meeting of the WHO Global Platform for Air Quality, Geneva, January 2014. The Task Force developed the Data Integration Model for Air Quality and consists of the first author, Michael Brauer, Aaron van Donkelaar, Rick Burnett, Howard H. Chang, Aaron Cohen, Rita Van Dingenen, Yang Liu, Randall Martin, Lance A. Waller, Jason West, James V. Zidek and Annette Pruss-Ustun. The authors would like to give particular thanks to Michael Brauer who provided specialist expertise, together with data on ground measurements, and Aaron van Donkelaar and the Atmospheric Composition Analysis Group at Dalhousie University for providing estimates from satellite remote sensing. The authors would also like to thank Dan Simpson for technical expertise on implementing extensions to DIMAQ. Matthew L Thomas is supported by a scholarship from the EPSRC Centre for Doctoral Training in Statistical Applied Mathematics at Bath (SAMBa), under the project EP/L015684/1. The views expressed in this article are those of the authors and they do not necessarily represent the views, decisions or policies to institutions with which they are affiliated.

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GS, PM, and SG conceived the project and led the writing of the manuscript. MLT and GR performed the data analysis. GS and MLT developed the statistical model used to produce the estimates. All authors contributed to the writing of the manuscript.

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Correspondence to G. Shaddick .

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Shaddick, G., Thomas, M.L., Mudu, P. et al. Half the world’s population are exposed to increasing air pollution. npj Clim Atmos Sci 3 , 23 (2020). https://doi.org/10.1038/s41612-020-0124-2

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DOI : https://doi.org/10.1038/s41612-020-0124-2

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Air Pollution: Everything You Need to Know

How smog, soot, greenhouse gases, and other top air pollutants are affecting the planet—and your health.

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What is air pollution?

What causes air pollution, effects of air pollution, air pollution in the united states, air pollution and environmental justice, controlling air pollution, how to help reduce air pollution, how to protect your health.

Air pollution  refers to the release of pollutants into the air—pollutants that are detrimental to human health and the planet as a whole. According to the  World Health Organization (WHO) , each year, indoor and outdoor air pollution is responsible for nearly seven million deaths around the globe. Ninety-nine percent of human beings currently breathe air that exceeds the WHO’s guideline limits for pollutants, with those living in low- and middle-income countries suffering the most. In the United States, the  Clean Air Act , established in 1970, authorizes the U.S. Environmental Protection Agency (EPA) to safeguard public health by regulating the emissions of these harmful air pollutants.

“Most air pollution comes from energy use and production,” says  John Walke , director of the Clean Air team at NRDC. Driving a car on gasoline, heating a home with oil, running a power plant on  fracked gas : In each case, a fossil fuel is burned and harmful chemicals and gases are released into the air.

“We’ve made progress over the last 50 years in improving air quality in the United States, thanks to the Clean Air Act. But climate change will make it harder in the future to meet pollution standards, which are designed to  protect health ,” says Walke.

Air pollution is now the world’s fourth-largest risk factor for early death. According to the 2020  State of Global Air  report —which summarizes the latest scientific understanding of air pollution around the world—4.5 million deaths were linked to outdoor air pollution exposures in 2019, and another 2.2 million deaths were caused by indoor air pollution. The world’s most populous countries, China and India, continue to bear the highest burdens of disease.

“Despite improvements in reducing global average mortality rates from air pollution, this report also serves as a sobering reminder that the climate crisis threatens to worsen air pollution problems significantly,” explains  Vijay Limaye , senior scientist in NRDC’s Science Office. Smog, for instance, is intensified by increased heat, forming when the weather is warmer and there’s more ultraviolet radiation. In addition, climate change increases the production of allergenic air pollutants, including mold (thanks to damp conditions caused by extreme weather and increased flooding) and pollen (due to a longer pollen season). “Climate change–fueled droughts and dry conditions are also setting the stage for dangerous wildfires,” adds Limaye. “ Wildfire smoke can linger for days and pollute the air with particulate matter hundreds of miles downwind.”

The effects of air pollution on the human body vary, depending on the type of pollutant, the length and level of exposure, and other factors, including a person’s individual health risks and the cumulative impacts of multiple pollutants or stressors.

Smog and soot

These are the two most prevalent types of air pollution. Smog (sometimes referred to as ground-level ozone) occurs when emissions from combusting fossil fuels react with sunlight. Soot—a type of  particulate matter —is made up of tiny particles of chemicals, soil, smoke, dust, or allergens that are carried in the air. The sources of smog and soot are similar. “Both come from cars and trucks, factories, power plants, incinerators, engines, generally anything that combusts fossil fuels such as coal, gasoline, or natural gas,” Walke says.

Smog can irritate the eyes and throat and also damage the lungs, especially those of children, senior citizens, and people who work or exercise outdoors. It’s even worse for people who have asthma or allergies; these extra pollutants can intensify their symptoms and trigger asthma attacks. The tiniest airborne particles in soot are especially dangerous because they can penetrate the lungs and bloodstream and worsen bronchitis, lead to heart attacks, and even hasten death. In  2020, a report from Harvard’s T.H. Chan School of Public Health showed that COVID-19 mortality rates were higher in areas with more particulate matter pollution than in areas with even slightly less, showing a correlation between the virus’s deadliness and long-term exposure to air pollution. 

These findings also illuminate an important  environmental justice issue . Because highways and polluting facilities have historically been sited in or next to low-income neighborhoods and communities of color, the negative effects of this pollution have been  disproportionately experienced by the people who live in these communities.

Hazardous air pollutants

A number of air pollutants pose severe health risks and can sometimes be fatal, even in small amounts. Almost 200 of them are regulated by law; some of the most common are mercury,  lead , dioxins, and benzene. “These are also most often emitted during gas or coal combustion, incineration, or—in the case of benzene—found in gasoline,” Walke says. Benzene, classified as a carcinogen by the EPA, can cause eye, skin, and lung irritation in the short term and blood disorders in the long term. Dioxins, more typically found in food but also present in small amounts in the air, is another carcinogen that can affect the liver in the short term and harm the immune, nervous, and endocrine systems, as well as reproductive functions.  Mercury  attacks the central nervous system. In large amounts, lead can damage children’s brains and kidneys, and even minimal exposure can affect children’s IQ and ability to learn.

Another category of toxic compounds, polycyclic aromatic hydrocarbons (PAHs), are by-products of traffic exhaust and wildfire smoke. In large amounts, they have been linked to eye and lung irritation, blood and liver issues, and even cancer.  In one study , the children of mothers exposed to PAHs during pregnancy showed slower brain-processing speeds and more pronounced symptoms of ADHD.

Greenhouse gases

While these climate pollutants don’t have the direct or immediate impacts on the human body associated with other air pollutants, like smog or hazardous chemicals, they are still harmful to our health. By trapping the earth’s heat in the atmosphere, greenhouse gases lead to warmer temperatures, which in turn lead to the hallmarks of climate change: rising sea levels, more extreme weather, heat-related deaths, and the increased transmission of infectious diseases. In 2021, carbon dioxide accounted for roughly 79 percent of the country’s total greenhouse gas emissions, and methane made up more than 11 percent. “Carbon dioxide comes from combusting fossil fuels, and methane comes from natural and industrial sources, including large amounts that are released during oil and gas drilling,” Walke says. “We emit far larger amounts of carbon dioxide, but methane is significantly more potent, so it’s also very destructive.” 

Another class of greenhouse gases,  hydrofluorocarbons (HFCs) , are thousands of times more powerful than carbon dioxide in their ability to trap heat. In October 2016, more than 140 countries signed the Kigali Agreement to reduce the use of these chemicals—which are found in air conditioners and refrigerators—and develop greener alternatives over time. (The United States officially signed onto the  Kigali Agreement in 2022.)

Pollen and mold

Mold and allergens from trees, weeds, and grass are also carried in the air, are exacerbated by climate change, and can be hazardous to health. Though they aren’t regulated, they can be considered a form of air pollution. “When homes, schools, or businesses get water damage, mold can grow and produce allergenic airborne pollutants,” says Kim Knowlton, professor of environmental health sciences at Columbia University and a former NRDC scientist. “ Mold exposure can precipitate asthma attacks  or an allergic response, and some molds can even produce toxins that would be dangerous for anyone to inhale.”

Pollen allergies are worsening  because of climate change . “Lab and field studies are showing that pollen-producing plants—especially ragweed—grow larger and produce more pollen when you increase the amount of carbon dioxide that they grow in,” Knowlton says. “Climate change also extends the pollen production season, and some studies are beginning to suggest that ragweed pollen itself might be becoming a more potent allergen.” If so, more people will suffer runny noses, fevers, itchy eyes, and other symptoms. “And for people with allergies and asthma, pollen peaks can precipitate asthma attacks, which are far more serious and can be life-threatening.”

More than one in three U.S. residents—120 million people—live in counties with unhealthy levels of air pollution, according to the  2023  State of the Air  report by the American Lung Association (ALA). Since the annual report was first published, in 2000, its findings have shown how the Clean Air Act has been able to reduce harmful emissions from transportation, power plants, and manufacturing.

Recent findings, however, reflect how climate change–fueled wildfires and extreme heat are adding to the challenges of protecting public health. The latest report—which focuses on ozone, year-round particle pollution, and short-term particle pollution—also finds that people of color are 61 percent more likely than white people to live in a county with a failing grade in at least one of those categories, and three times more likely to live in a county that fails in all three.

In rankings for each of the three pollution categories covered by the ALA report, California cities occupy the top three slots (i.e., were highest in pollution), despite progress that the Golden State has made in reducing air pollution emissions in the past half century. At the other end of the spectrum, these cities consistently rank among the country’s best for air quality: Burlington, Vermont; Honolulu; and Wilmington, North Carolina. 

No one wants to live next door to an incinerator, oil refinery, port, toxic waste dump, or other polluting site. Yet millions of people around the world do, and this puts them at a much higher risk for respiratory disease, cardiovascular disease, neurological damage, cancer, and death. In the United States, people of color are 1.5 times more likely than whites to live in areas with poor air quality, according to the ALA.

Historically, racist zoning policies and discriminatory lending practices known as  redlining  have combined to keep polluting industries and car-choked highways away from white neighborhoods and have turned communities of color—especially low-income and working-class communities of color—into sacrifice zones, where residents are forced to breathe dirty air and suffer the many health problems associated with it. In addition to the increased health risks that come from living in such places, the polluted air can economically harm residents in the form of missed workdays and higher medical costs.

Environmental racism isn't limited to cities and industrial areas. Outdoor laborers, including the estimated three million migrant and seasonal farmworkers in the United States, are among the most vulnerable to air pollution—and they’re also among the least equipped, politically, to pressure employers and lawmakers to affirm their right to breathe clean air.

Recently,  cumulative impact mapping , which uses data on environmental conditions and demographics, has been able to show how some communities are overburdened with layers of issues, like high levels of poverty, unemployment, and pollution. Tools like the  Environmental Justice Screening Method  and the EPA’s  EJScreen  provide evidence of what many environmental justice communities have been explaining for decades: that we need land use and public health reforms to ensure that vulnerable areas are not overburdened and that the people who need resources the most are receiving them.

In the United States, the  Clean Air Act  has been a crucial tool for reducing air pollution since its passage in 1970, although fossil fuel interests aided by industry-friendly lawmakers have frequently attempted to  weaken its many protections. Ensuring that this bedrock environmental law remains intact and properly enforced will always be key to maintaining and improving our air quality.

But the best, most effective way to control air pollution is to speed up our transition to cleaner fuels and industrial processes. By switching over to renewable energy sources (such as wind and solar power), maximizing fuel efficiency in our vehicles, and replacing more and more of our gasoline-powered cars and trucks with electric versions, we'll be limiting air pollution at its source while also curbing the global warming that heightens so many of its worst health impacts.

And what about the economic costs of controlling air pollution? According to a report on the Clean Air Act commissioned by NRDC, the annual  benefits of cleaner air  are up to 32 times greater than the cost of clean air regulations. Those benefits include up to 370,000 avoided premature deaths, 189,000 fewer hospital admissions for cardiac and respiratory illnesses, and net economic benefits of up to $3.8 trillion for the U.S. economy every year.

“The less gasoline we burn, the better we’re doing to reduce air pollution and the harmful effects of climate change,” Walke explains. “Make good choices about transportation. When you can, ride a bike, walk, or take public transportation. For driving, choose a car that gets better miles per gallon of gas or  buy an electric car .” You can also investigate your power provider options—you may be able to request that your electricity be supplied by wind or solar. Buying your food locally cuts down on the fossil fuels burned in trucking or flying food in from across the world. And most important: “Support leaders who push for clean air and water and responsible steps on climate change,” Walke says.

• “When you see in the news or hear on the weather report that pollution levels are high, it may be useful to limit the time when children go outside or you go for a jog,” Walke says. Generally, ozone levels tend to be lower in the morning.
• If you exercise outside, stay as far as you can from heavily trafficked roads. Then shower and wash your clothes to remove fine particles.
• The air may look clear, but that doesn’t mean it’s pollution free. Utilize tools like the EPA’s air pollution monitor,  AirNow , to get the latest conditions. If the air quality is bad, stay inside with the windows closed.
• If you live or work in an area that’s prone to wildfires,  stay away from the harmful smoke  as much as you’re able. Consider keeping a small stock of masks to wear when conditions are poor. The most ideal masks for smoke particles will be labelled “NIOSH” (which stands for National Institute for Occupational Safety and Health) and have either “N95” or “P100” printed on it.
• If you’re using an air conditioner while outdoor pollution conditions are bad, use the recirculating setting to limit the amount of polluted air that gets inside. 

This story was originally published on November 1, 2016, and has been updated with new information and links.

This NRDC.org story is available for online republication by news media outlets or nonprofits under these conditions: The writer(s) must be credited with a byline; you must note prominently that the story was originally published by NRDC.org and link to the original; the story cannot be edited (beyond simple things such as grammar); you can’t resell the story in any form or grant republishing rights to other outlets; you can’t republish our material wholesale or automatically—you need to select stories individually; you can’t republish the photos or graphics on our site without specific permission; you should drop us a note to let us know when you’ve used one of our stories.

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Environmental and Health Impacts of Air Pollution: A Review

Ioannis manisalidis.

1 Delphis S.A., Kifisia, Greece

2 Laboratory of Hygiene and Environmental Protection, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece

Elisavet Stavropoulou

3 Centre Hospitalier Universitaire Vaudois (CHUV), Service de Médicine Interne, Lausanne, Switzerland

Agathangelos Stavropoulos

4 School of Social and Political Sciences, University of Glasgow, Glasgow, United Kingdom

Eugenia Bezirtzoglou

One of our era's greatest scourges is air pollution, on account not only of its impact on climate change but also its impact on public and individual health due to increasing morbidity and mortality. There are many pollutants that are major factors in disease in humans. Among them, Particulate Matter (PM), particles of variable but very small diameter, penetrate the respiratory system via inhalation, causing respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. Despite the fact that ozone in the stratosphere plays a protective role against ultraviolet irradiation, it is harmful when in high concentration at ground level, also affecting the respiratory and cardiovascular system. Furthermore, nitrogen oxide, sulfur dioxide, Volatile Organic Compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) are all considered air pollutants that are harmful to humans. Carbon monoxide can even provoke direct poisoning when breathed in at high levels. Heavy metals such as lead, when absorbed into the human body, can lead to direct poisoning or chronic intoxication, depending on exposure. Diseases occurring from the aforementioned substances include principally respiratory problems such as Chronic Obstructive Pulmonary Disease (COPD), asthma, bronchiolitis, and also lung cancer, cardiovascular events, central nervous system dysfunctions, and cutaneous diseases. Last but not least, climate change resulting from environmental pollution affects the geographical distribution of many infectious diseases, as do natural disasters. The only way to tackle this problem is through public awareness coupled with a multidisciplinary approach by scientific experts; national and international organizations must address the emergence of this threat and propose sustainable solutions.

Approach to the Problem

The interactions between humans and their physical surroundings have been extensively studied, as multiple human activities influence the environment. The environment is a coupling of the biotic (living organisms and microorganisms) and the abiotic (hydrosphere, lithosphere, and atmosphere).

Pollution is defined as the introduction into the environment of substances harmful to humans and other living organisms. Pollutants are harmful solids, liquids, or gases produced in higher than usual concentrations that reduce the quality of our environment.

Human activities have an adverse effect on the environment by polluting the water we drink, the air we breathe, and the soil in which plants grow. Although the industrial revolution was a great success in terms of technology, society, and the provision of multiple services, it also introduced the production of huge quantities of pollutants emitted into the air that are harmful to human health. Without any doubt, the global environmental pollution is considered an international public health issue with multiple facets. Social, economic, and legislative concerns and lifestyle habits are related to this major problem. Clearly, urbanization and industrialization are reaching unprecedented and upsetting proportions worldwide in our era. Anthropogenic air pollution is one of the biggest public health hazards worldwide, given that it accounts for about 9 million deaths per year ( 1 ).

Without a doubt, all of the aforementioned are closely associated with climate change, and in the event of danger, the consequences can be severe for mankind ( 2 ). Climate changes and the effects of global planetary warming seriously affect multiple ecosystems, causing problems such as food safety issues, ice and iceberg melting, animal extinction, and damage to plants ( 3 , 4 ).

Air pollution has various health effects. The health of susceptible and sensitive individuals can be impacted even on low air pollution days. Short-term exposure to air pollutants is closely related to COPD (Chronic Obstructive Pulmonary Disease), cough, shortness of breath, wheezing, asthma, respiratory disease, and high rates of hospitalization (a measurement of morbidity).

The long-term effects associated with air pollution are chronic asthma, pulmonary insufficiency, cardiovascular diseases, and cardiovascular mortality. According to a Swedish cohort study, diabetes seems to be induced after long-term air pollution exposure ( 5 ). Moreover, air pollution seems to have various malign health effects in early human life, such as respiratory, cardiovascular, mental, and perinatal disorders ( 3 ), leading to infant mortality or chronic disease in adult age ( 6 ).

National reports have mentioned the increased risk of morbidity and mortality ( 1 ). These studies were conducted in many places around the world and show a correlation between daily ranges of particulate matter (PM) concentration and daily mortality. Climate shifts and global planetary warming ( 3 ) could aggravate the situation. Besides, increased hospitalization (an index of morbidity) has been registered among the elderly and susceptible individuals for specific reasons. Fine and ultrafine particulate matter seems to be associated with more serious illnesses ( 6 ), as it can invade the deepest parts of the airways and more easily reach the bloodstream.

Air pollution mainly affects those living in large urban areas, where road emissions contribute the most to the degradation of air quality. There is also a danger of industrial accidents, where the spread of a toxic fog can be fatal to the populations of the surrounding areas. The dispersion of pollutants is determined by many parameters, most notably atmospheric stability and wind ( 6 ).

In developing countries ( 7 ), the problem is more serious due to overpopulation and uncontrolled urbanization along with the development of industrialization. This leads to poor air quality, especially in countries with social disparities and a lack of information on sustainable management of the environment. The use of fuels such as wood fuel or solid fuel for domestic needs due to low incomes exposes people to bad-quality, polluted air at home. It is of note that three billion people around the world are using the above sources of energy for their daily heating and cooking needs ( 8 ). In developing countries, the women of the household seem to carry the highest risk for disease development due to their longer duration exposure to the indoor air pollution ( 8 , 9 ). Due to its fast industrial development and overpopulation, China is one of the Asian countries confronting serious air pollution problems ( 10 , 11 ). The lung cancer mortality observed in China is associated with fine particles ( 12 ). As stated already, long-term exposure is associated with deleterious effects on the cardiovascular system ( 3 , 5 ). However, it is interesting to note that cardiovascular diseases have mostly been observed in developed and high-income countries rather than in the developing low-income countries exposed highly to air pollution ( 13 ). Extreme air pollution is recorded in India, where the air quality reaches hazardous levels. New Delhi is one of the more polluted cities in India. Flights in and out of New Delhi International Airport are often canceled due to the reduced visibility associated with air pollution. Pollution is occurring both in urban and rural areas in India due to the fast industrialization, urbanization, and rise in use of motorcycle transportation. Nevertheless, biomass combustion associated with heating and cooking needs and practices is a major source of household air pollution in India and in Nepal ( 14 , 15 ). There is spatial heterogeneity in India, as areas with diverse climatological conditions and population and education levels generate different indoor air qualities, with higher PM 2.5 observed in North Indian states (557–601 μg/m 3 ) compared to the Southern States (183–214 μg/m 3 ) ( 16 , 17 ). The cold climate of the North Indian areas may be the main reason for this, as longer periods at home and more heating are necessary compared to in the tropical climate of Southern India. Household air pollution in India is associated with major health effects, especially in women and young children, who stay indoors for longer periods. Chronic obstructive respiratory disease (CORD) and lung cancer are mostly observed in women, while acute lower respiratory disease is seen in young children under 5 years of age ( 18 ).

Accumulation of air pollution, especially sulfur dioxide and smoke, reaching 1,500 mg/m3, resulted in an increase in the number of deaths (4,000 deaths) in December 1952 in London and in 1963 in New York City (400 deaths) ( 19 ). An association of pollution with mortality was reported on the basis of monitoring of outdoor pollution in six US metropolitan cities ( 20 ). In every case, it seems that mortality was closely related to the levels of fine, inhalable, and sulfate particles more than with the levels of total particulate pollution, aerosol acidity, sulfur dioxide, or nitrogen dioxide ( 20 ).

Furthermore, extremely high levels of pollution are reported in Mexico City and Rio de Janeiro, followed by Milan, Ankara, Melbourne, Tokyo, and Moscow ( 19 ).

Based on the magnitude of the public health impact, it is certain that different kinds of interventions should be taken into account. Success and effectiveness in controlling air pollution, specifically at the local level, have been reported. Adequate technological means are applied considering the source and the nature of the emission as well as its impact on health and the environment. The importance of point sources and non-point sources of air pollution control is reported by Schwela and Köth-Jahr ( 21 ). Without a doubt, a detailed emission inventory must record all sources in a given area. Beyond considering the above sources and their nature, topography and meteorology should also be considered, as stated previously. Assessment of the control policies and methods is often extrapolated from the local to the regional and then to the global scale. Air pollution may be dispersed and transported from one region to another area located far away. Air pollution management means the reduction to acceptable levels or possible elimination of air pollutants whose presence in the air affects our health or the environmental ecosystem. Private and governmental entities and authorities implement actions to ensure the air quality ( 22 ). Air quality standards and guidelines were adopted for the different pollutants by the WHO and EPA as a tool for the management of air quality ( 1 , 23 ). These standards have to be compared to the emissions inventory standards by causal analysis and dispersion modeling in order to reveal the problematic areas ( 24 ). Inventories are generally based on a combination of direct measurements and emissions modeling ( 24 ).

As an example, we state here the control measures at the source through the use of catalytic converters in cars. These are devices that turn the pollutants and toxic gases produced from combustion engines into less-toxic pollutants by catalysis through redox reactions ( 25 ). In Greece, the use of private cars was restricted by tracking their license plates in order to reduce traffic congestion during rush hour ( 25 ).

Concerning industrial emissions, collectors and closed systems can keep the air pollution to the minimal standards imposed by legislation ( 26 ).

Current strategies to improve air quality require an estimation of the economic value of the benefits gained from proposed programs. These proposed programs by public authorities, and directives are issued with guidelines to be respected.

In Europe, air quality limit values AQLVs (Air Quality Limit Values) are issued for setting off planning claims ( 27 ). In the USA, the NAAQS (National Ambient Air Quality Standards) establish the national air quality limit values ( 27 ). While both standards and directives are based on different mechanisms, significant success has been achieved in the reduction of overall emissions and associated health and environmental effects ( 27 ). The European Directive identifies geographical areas of risk exposure as monitoring/assessment zones to record the emission sources and levels of air pollution ( 27 ), whereas the USA establishes global geographical air quality criteria according to the severity of their air quality problem and records all sources of the pollutants and their precursors ( 27 ).

In this vein, funds have been financing, directly or indirectly, projects related to air quality along with the technical infrastructure to maintain good air quality. These plans focus on an inventory of databases from air quality environmental planning awareness campaigns. Moreover, pollution measures of air emissions may be taken for vehicles, machines, and industries in urban areas.

Technological innovation can only be successful if it is able to meet the needs of society. In this sense, technology must reflect the decision-making practices and procedures of those involved in risk assessment and evaluation and act as a facilitator in providing information and assessments to enable decision makers to make the best decisions possible. Summarizing the aforementioned in order to design an effective air quality control strategy, several aspects must be considered: environmental factors and ambient air quality conditions, engineering factors and air pollutant characteristics, and finally, economic operating costs for technological improvement and administrative and legal costs. Considering the economic factor, competitiveness through neoliberal concepts is offering a solution to environmental problems ( 22 ).

The development of environmental governance, along with technological progress, has initiated the deployment of a dialogue. Environmental politics has created objections and points of opposition between different political parties, scientists, media, and governmental and non-governmental organizations ( 22 ). Radical environmental activism actions and movements have been created ( 22 ). The rise of the new information and communication technologies (ICTs) are many times examined as to whether and in which way they have influenced means of communication and social movements such as activism ( 28 ). Since the 1990s, the term “digital activism” has been used increasingly and in many different disciplines ( 29 ). Nowadays, multiple digital technologies can be used to produce a digital activism outcome on environmental issues. More specifically, devices with online capabilities such as computers or mobile phones are being used as a way to pursue change in political and social affairs ( 30 ).

In the present paper, we focus on the sources of environmental pollution in relation to public health and propose some solutions and interventions that may be of interest to environmental legislators and decision makers.

Sources of Exposure

It is known that the majority of environmental pollutants are emitted through large-scale human activities such as the use of industrial machinery, power-producing stations, combustion engines, and cars. Because these activities are performed at such a large scale, they are by far the major contributors to air pollution, with cars estimated to be responsible for approximately 80% of today's pollution ( 31 ). Some other human activities are also influencing our environment to a lesser extent, such as field cultivation techniques, gas stations, fuel tanks heaters, and cleaning procedures ( 32 ), as well as several natural sources, such as volcanic and soil eruptions and forest fires.

The classification of air pollutants is based mainly on the sources producing pollution. Therefore, it is worth mentioning the four main sources, following the classification system: Major sources, Area sources, Mobile sources, and Natural sources.

Major sources include the emission of pollutants from power stations, refineries, and petrochemicals, the chemical and fertilizer industries, metallurgical and other industrial plants, and, finally, municipal incineration.

Indoor area sources include domestic cleaning activities, dry cleaners, printing shops, and petrol stations.

Mobile sources include automobiles, cars, railways, airways, and other types of vehicles.

Finally, natural sources include, as stated previously, physical disasters ( 33 ) such as forest fire, volcanic erosion, dust storms, and agricultural burning.

However, many classification systems have been proposed. Another type of classification is a grouping according to the recipient of the pollution, as follows:

Air pollution is determined as the presence of pollutants in the air in large quantities for long periods. Air pollutants are dispersed particles, hydrocarbons, CO, CO 2 , NO, NO 2 , SO 3 , etc.

Water pollution is organic and inorganic charge and biological charge ( 10 ) at high levels that affect the water quality ( 34 , 35 ).

Soil pollution occurs through the release of chemicals or the disposal of wastes, such as heavy metals, hydrocarbons, and pesticides.

Air pollution can influence the quality of soil and water bodies by polluting precipitation, falling into water and soil environments ( 34 , 36 ). Notably, the chemistry of the soil can be amended due to acid precipitation by affecting plants, cultures, and water quality ( 37 ). Moreover, movement of heavy metals is favored by soil acidity, and metals are so then moving into the watery environment. It is known that heavy metals such as aluminum are noxious to wildlife and fishes. Soil quality seems to be of importance, as soils with low calcium carbonate levels are at increased jeopardy from acid rain. Over and above rain, snow and particulate matter drip into watery ' bodies ( 36 , 38 ).

Lastly, pollution is classified following type of origin:

Radioactive and nuclear pollution , releasing radioactive and nuclear pollutants into water, air, and soil during nuclear explosions and accidents, from nuclear weapons, and through handling or disposal of radioactive sewage.

Radioactive materials can contaminate surface water bodies and, being noxious to the environment, plants, animals, and humans. It is known that several radioactive substances such as radium and uranium concentrate in the bones and can cause cancers ( 38 , 39 ).

Noise pollution is produced by machines, vehicles, traffic noises, and musical installations that are harmful to our hearing.

The World Health Organization introduced the term DALYs. The DALYs for a disease or health condition is defined as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences ( 39 ). In Europe, air pollution is the main cause of disability-adjusted life years lost (DALYs), followed by noise pollution. The potential relationships of noise and air pollution with health have been studied ( 40 ). The study found that DALYs related to noise were more important than those related to air pollution, as the effects of environmental noise on cardiovascular disease were independent of air pollution ( 40 ). Environmental noise should be counted as an independent public health risk ( 40 ).

Environmental pollution occurs when changes in the physical, chemical, or biological constituents of the environment (air masses, temperature, climate, etc.) are produced.

Pollutants harm our environment either by increasing levels above normal or by introducing harmful toxic substances. Primary pollutants are directly produced from the above sources, and secondary pollutants are emitted as by-products of the primary ones. Pollutants can be biodegradable or non-biodegradable and of natural origin or anthropogenic, as stated previously. Moreover, their origin can be a unique source (point-source) or dispersed sources.

Pollutants have differences in physical and chemical properties, explaining the discrepancy in their capacity for producing toxic effects. As an example, we state here that aerosol compounds ( 41 – 43 ) have a greater toxicity than gaseous compounds due to their tiny size (solid or liquid) in the atmosphere; they have a greater penetration capacity. Gaseous compounds are eliminated more easily by our respiratory system ( 41 ). These particles are able to damage lungs and can even enter the bloodstream ( 41 ), leading to the premature deaths of millions of people yearly. Moreover, the aerosol acidity ([H+]) seems to considerably enhance the production of secondary organic aerosols (SOA), but this last aspect is not supported by other scientific teams ( 38 ).

Climate and Pollution

Air pollution and climate change are closely related. Climate is the other side of the same coin that reduces the quality of our Earth ( 44 ). Pollutants such as black carbon, methane, tropospheric ozone, and aerosols affect the amount of incoming sunlight. As a result, the temperature of the Earth is increasing, resulting in the melting of ice, icebergs, and glaciers.

In this vein, climatic changes will affect the incidence and prevalence of both residual and imported infections in Europe. Climate and weather affect the duration, timing, and intensity of outbreaks strongly and change the map of infectious diseases in the globe ( 45 ). Mosquito-transmitted parasitic or viral diseases are extremely climate-sensitive, as warming firstly shortens the pathogen incubation period and secondly shifts the geographic map of the vector. Similarly, water-warming following climate changes leads to a high incidence of waterborne infections. Recently, in Europe, eradicated diseases seem to be emerging due to the migration of population, for example, cholera, poliomyelitis, tick-borne encephalitis, and malaria ( 46 ).

The spread of epidemics is associated with natural climate disasters and storms, which seem to occur more frequently nowadays ( 47 ). Malnutrition and disequilibration of the immune system are also associated with the emerging infections affecting public health ( 48 ).

The Chikungunya virus “took the airplane” from the Indian Ocean to Europe, as outbreaks of the disease were registered in Italy ( 49 ) as well as autochthonous cases in France ( 50 ).

An increase in cryptosporidiosis in the United Kingdom and in the Czech Republic seems to have occurred following flooding ( 36 , 51 ).

As stated previously, aerosols compounds are tiny in size and considerably affect the climate. They are able to dissipate sunlight (the albedo phenomenon) by dispersing a quarter of the sun's rays back to space and have cooled the global temperature over the last 30 years ( 52 ).

Air Pollutants

The World Health Organization (WHO) reports on six major air pollutants, namely particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. Air pollution can have a disastrous effect on all components of the environment, including groundwater, soil, and air. Additionally, it poses a serious threat to living organisms. In this vein, our interest is mainly to focus on these pollutants, as they are related to more extensive and severe problems in human health and environmental impact. Acid rain, global warming, the greenhouse effect, and climate changes have an important ecological impact on air pollution ( 53 ).

Particulate Matter (PM) and Health

Studies have shown a relationship between particulate matter (PM) and adverse health effects, focusing on either short-term (acute) or long-term (chronic) PM exposure.

Particulate matter (PM) is usually formed in the atmosphere as a result of chemical reactions between the different pollutants. The penetration of particles is closely dependent on their size ( 53 ). Particulate Matter (PM) was defined as a term for particles by the United States Environmental Protection Agency ( 54 ). Particulate matter (PM) pollution includes particles with diameters of 10 micrometers (μm) or smaller, called PM 10 , and extremely fine particles with diameters that are generally 2.5 micrometers (μm) and smaller.

Particulate matter contains tiny liquid or solid droplets that can be inhaled and cause serious health effects ( 55 ). Particles <10 μm in diameter (PM 10 ) after inhalation can invade the lungs and even reach the bloodstream. Fine particles, PM 2.5 , pose a greater risk to health ( 6 , 56 ) ( Table 1 ).

Penetrability according to particle size.

Multiple epidemiological studies have been performed on the health effects of PM. A positive relation was shown between both short-term and long-term exposures of PM 2.5 and acute nasopharyngitis ( 56 ). In addition, long-term exposure to PM for years was found to be related to cardiovascular diseases and infant mortality.

Those studies depend on PM 2.5 monitors and are restricted in terms of study area or city area due to a lack of spatially resolved daily PM 2.5 concentration data and, in this way, are not representative of the entire population. Following a recent epidemiological study by the Department of Environmental Health at Harvard School of Public Health (Boston, MA) ( 57 ), it was reported that, as PM 2.5 concentrations vary spatially, an exposure error (Berkson error) seems to be produced, and the relative magnitudes of the short- and long-term effects are not yet completely elucidated. The team developed a PM 2.5 exposure model based on remote sensing data for assessing short- and long-term human exposures ( 57 ). This model permits spatial resolution in short-term effects plus the assessment of long-term effects in the whole population.

Moreover, respiratory diseases and affection of the immune system are registered as long-term chronic effects ( 58 ). It is worth noting that people with asthma, pneumonia, diabetes, and respiratory and cardiovascular diseases are especially susceptible and vulnerable to the effects of PM. PM 2.5 , followed by PM 10 , are strongly associated with diverse respiratory system diseases ( 59 ), as their size permits them to pierce interior spaces ( 60 ). The particles produce toxic effects according to their chemical and physical properties. The components of PM 10 and PM 2.5 can be organic (polycyclic aromatic hydrocarbons, dioxins, benzene, 1-3 butadiene) or inorganic (carbon, chlorides, nitrates, sulfates, metals) in nature ( 55 ).

Particulate Matter (PM) is divided into four main categories according to type and size ( 61 ) ( Table 2 ).

Types and sizes of particulate Matter (PM).

Gas contaminants include PM in aerial masses.

Particulate contaminants include contaminants such as smog, soot, tobacco smoke, oil smoke, fly ash, and cement dust.

Biological Contaminants are microorganisms (bacteria, viruses, fungi, mold, and bacterial spores), cat allergens, house dust and allergens, and pollen.

Types of Dust include suspended atmospheric dust, settling dust, and heavy dust.

Finally, another fact is that the half-lives of PM 10 and PM 2.5 particles in the atmosphere is extended due to their tiny dimensions; this permits their long-lasting suspension in the atmosphere and even their transfer and spread to distant destinations where people and the environment may be exposed to the same magnitude of pollution ( 53 ). They are able to change the nutrient balance in watery ecosystems, damage forests and crops, and acidify water bodies.

As stated, PM 2.5 , due to their tiny size, are causing more serious health effects. These aforementioned fine particles are the main cause of the “haze” formation in different metropolitan areas ( 12 , 13 , 61 ).

Ozone Impact in the Atmosphere

Ozone (O 3 ) is a gas formed from oxygen under high voltage electric discharge ( 62 ). It is a strong oxidant, 52% stronger than chlorine. It arises in the stratosphere, but it could also arise following chain reactions of photochemical smog in the troposphere ( 63 ).

Ozone can travel to distant areas from its initial source, moving with air masses ( 64 ). It is surprising that ozone levels over cities are low in contrast to the increased amounts occuring in urban areas, which could become harmful for cultures, forests, and vegetation ( 65 ) as it is reducing carbon assimilation ( 66 ). Ozone reduces growth and yield ( 47 , 48 ) and affects the plant microflora due to its antimicrobial capacity ( 67 , 68 ). In this regard, ozone acts upon other natural ecosystems, with microflora ( 69 , 70 ) and animal species changing their species composition ( 71 ). Ozone increases DNA damage in epidermal keratinocytes and leads to impaired cellular function ( 72 ).

Ground-level ozone (GLO) is generated through a chemical reaction between oxides of nitrogen and VOCs emitted from natural sources and/or following anthropogenic activities.

Ozone uptake usually occurs by inhalation. Ozone affects the upper layers of the skin and the tear ducts ( 73 ). A study of short-term exposure of mice to high levels of ozone showed malondialdehyde formation in the upper skin (epidermis) but also depletion in vitamins C and E. It is likely that ozone levels are not interfering with the skin barrier function and integrity to predispose to skin disease ( 74 ).

Due to the low water-solubility of ozone, inhaled ozone has the capacity to penetrate deeply into the lungs ( 75 ).

Toxic effects induced by ozone are registered in urban areas all over the world, causing biochemical, morphologic, functional, and immunological disorders ( 76 ).

The European project (APHEA2) focuses on the acute effects of ambient ozone concentrations on mortality ( 77 ). Daily ozone concentrations compared to the daily number of deaths were reported from different European cities for a 3-year period. During the warm period of the year, an observed increase in ozone concentration was associated with an increase in the daily number of deaths (0.33%), in the number of respiratory deaths (1.13%), and in the number of cardiovascular deaths (0.45%). No effect was observed during wintertime.

Carbon Monoxide (CO)

Carbon monoxide is produced by fossil fuel when combustion is incomplete. The symptoms of poisoning due to inhaling carbon monoxide include headache, dizziness, weakness, nausea, vomiting, and, finally, loss of consciousness.

The affinity of carbon monoxide to hemoglobin is much greater than that of oxygen. In this vein, serious poisoning may occur in people exposed to high levels of carbon monoxide for a long period of time. Due to the loss of oxygen as a result of the competitive binding of carbon monoxide, hypoxia, ischemia, and cardiovascular disease are observed.

Carbon monoxide affects the greenhouses gases that are tightly connected to global warming and climate. This should lead to an increase in soil and water temperatures, and extreme weather conditions or storms may occur ( 68 ).

However, in laboratory and field experiments, it has been seen to produce increased plant growth ( 78 ).

Nitrogen Oxide (NO 2 )

Nitrogen oxide is a traffic-related pollutant, as it is emitted from automobile motor engines ( 79 , 80 ). It is an irritant of the respiratory system as it penetrates deep in the lung, inducing respiratory diseases, coughing, wheezing, dyspnea, bronchospasm, and even pulmonary edema when inhaled at high levels. It seems that concentrations over 0.2 ppm produce these adverse effects in humans, while concentrations higher than 2.0 ppm affect T-lymphocytes, particularly the CD8+ cells and NK cells that produce our immune response ( 81 ).It is reported that long-term exposure to high levels of nitrogen dioxide can be responsible for chronic lung disease. Long-term exposure to NO 2 can impair the sense of smell ( 81 ).

However, systems other than respiratory ones can be involved, as symptoms such as eye, throat, and nose irritation have been registered ( 81 ).

High levels of nitrogen dioxide are deleterious to crops and vegetation, as they have been observed to reduce crop yield and plant growth efficiency. Moreover, NO 2 can reduce visibility and discolor fabrics ( 81 ).

Sulfur Dioxide (SO 2 )

Sulfur dioxide is a harmful gas that is emitted mainly from fossil fuel consumption or industrial activities. The annual standard for SO 2 is 0.03 ppm ( 82 ). It affects human, animal, and plant life. Susceptible people as those with lung disease, old people, and children, who present a higher risk of damage. The major health problems associated with sulfur dioxide emissions in industrialized areas are respiratory irritation, bronchitis, mucus production, and bronchospasm, as it is a sensory irritant and penetrates deep into the lung converted into bisulfite and interacting with sensory receptors, causing bronchoconstriction. Moreover, skin redness, damage to the eyes (lacrimation and corneal opacity) and mucous membranes, and worsening of pre-existing cardiovascular disease have been observed ( 81 ).

Environmental adverse effects, such as acidification of soil and acid rain, seem to be associated with sulfur dioxide emissions ( 83 ).

Lead is a heavy metal used in different industrial plants and emitted from some petrol motor engines, batteries, radiators, waste incinerators, and waste waters ( 84 ).

Moreover, major sources of lead pollution in the air are metals, ore, and piston-engine aircraft. Lead poisoning is a threat to public health due to its deleterious effects upon humans, animals, and the environment, especially in the developing countries.

Exposure to lead can occur through inhalation, ingestion, and dermal absorption. Trans- placental transport of lead was also reported, as lead passes through the placenta unencumbered ( 85 ). The younger the fetus is, the more harmful the toxic effects. Lead toxicity affects the fetal nervous system; edema or swelling of the brain is observed ( 86 ). Lead, when inhaled, accumulates in the blood, soft tissue, liver, lung, bones, and cardiovascular, nervous, and reproductive systems. Moreover, loss of concentration and memory, as well as muscle and joint pain, were observed in adults ( 85 , 86 ).

Children and newborns ( 87 ) are extremely susceptible even to minimal doses of lead, as it is a neurotoxicant and causes learning disabilities, impairment of memory, hyperactivity, and even mental retardation.

Elevated amounts of lead in the environment are harmful to plants and crop growth. Neurological effects are observed in vertebrates and animals in association with high lead levels ( 88 ).

Polycyclic Aromatic Hydrocarbons(PAHs)

The distribution of PAHs is ubiquitous in the environment, as the atmosphere is the most important means of their dispersal. They are found in coal and in tar sediments. Moreover, they are generated through incomplete combustion of organic matter as in the cases of forest fires, incineration, and engines ( 89 ). PAH compounds, such as benzopyrene, acenaphthylene, anthracene, and fluoranthene are recognized as toxic, mutagenic, and carcinogenic substances. They are an important risk factor for lung cancer ( 89 ).

Volatile Organic Compounds(VOCs)

Volatile organic compounds (VOCs), such as toluene, benzene, ethylbenzene, and xylene ( 90 ), have been found to be associated with cancer in humans ( 91 ). The use of new products and materials has actually resulted in increased concentrations of VOCs. VOCs pollute indoor air ( 90 ) and may have adverse effects on human health ( 91 ). Short-term and long-term adverse effects on human health are observed. VOCs are responsible for indoor air smells. Short-term exposure is found to cause irritation of eyes, nose, throat, and mucosal membranes, while those of long duration exposure include toxic reactions ( 92 ). Predictable assessment of the toxic effects of complex VOC mixtures is difficult to estimate, as these pollutants can have synergic, antagonistic, or indifferent effects ( 91 , 93 ).

Dioxins originate from industrial processes but also come from natural processes, such as forest fires and volcanic eruptions. They accumulate in foods such as meat and dairy products, fish and shellfish, and especially in the fatty tissue of animals ( 94 ).

Short-period exhibition to high dioxin concentrations may result in dark spots and lesions on the skin ( 94 ). Long-term exposure to dioxins can cause developmental problems, impairment of the immune, endocrine and nervous systems, reproductive infertility, and cancer ( 94 ).

Without any doubt, fossil fuel consumption is responsible for a sizeable part of air contamination. This contamination may be anthropogenic, as in agricultural and industrial processes or transportation, while contamination from natural sources is also possible. Interestingly, it is of note that the air quality standards established through the European Air Quality Directive are somewhat looser than the WHO guidelines, which are stricter ( 95 ).

Effect of Air Pollution on Health

The most common air pollutants are ground-level ozone and Particulates Matter (PM). Air pollution is distinguished into two main types:

Outdoor pollution is the ambient air pollution.

Indoor pollution is the pollution generated by household combustion of fuels.

People exposed to high concentrations of air pollutants experience disease symptoms and states of greater and lesser seriousness. These effects are grouped into short- and long-term effects affecting health.

Susceptible populations that need to be aware of health protection measures include old people, children, and people with diabetes and predisposing heart or lung disease, especially asthma.

As extensively stated previously, according to a recent epidemiological study from Harvard School of Public Health, the relative magnitudes of the short- and long-term effects have not been completely clarified ( 57 ) due to the different epidemiological methodologies and to the exposure errors. New models are proposed for assessing short- and long-term human exposure data more successfully ( 57 ). Thus, in the present section, we report the more common short- and long-term health effects but also general concerns for both types of effects, as these effects are often dependent on environmental conditions, dose, and individual susceptibility.

Short-term effects are temporary and range from simple discomfort, such as irritation of the eyes, nose, skin, throat, wheezing, coughing and chest tightness, and breathing difficulties, to more serious states, such as asthma, pneumonia, bronchitis, and lung and heart problems. Short-term exposure to air pollution can also cause headaches, nausea, and dizziness.

These problems can be aggravated by extended long-term exposure to the pollutants, which is harmful to the neurological, reproductive, and respiratory systems and causes cancer and even, rarely, deaths.

The long-term effects are chronic, lasting for years or the whole life and can even lead to death. Furthermore, the toxicity of several air pollutants may also induce a variety of cancers in the long term ( 96 ).

As stated already, respiratory disorders are closely associated with the inhalation of air pollutants. These pollutants will invade through the airways and will accumulate at the cells. Damage to target cells should be related to the pollutant component involved and its source and dose. Health effects are also closely dependent on country, area, season, and time. An extended exposure duration to the pollutant should incline to long-term health effects in relation also to the above factors.

Particulate Matter (PMs), dust, benzene, and O 3 cause serious damage to the respiratory system ( 97 ). Moreover, there is a supplementary risk in case of existing respiratory disease such as asthma ( 98 ). Long-term effects are more frequent in people with a predisposing disease state. When the trachea is contaminated by pollutants, voice alterations may be remarked after acute exposure. Chronic obstructive pulmonary disease (COPD) may be induced following air pollution, increasing morbidity and mortality ( 99 ). Long-term effects from traffic, industrial air pollution, and combustion of fuels are the major factors for COPD risk ( 99 ).

Multiple cardiovascular effects have been observed after exposure to air pollutants ( 100 ). Changes occurred in blood cells after long-term exposure may affect cardiac functionality. Coronary arteriosclerosis was reported following long-term exposure to traffic emissions ( 101 ), while short-term exposure is related to hypertension, stroke, myocardial infracts, and heart insufficiency. Ventricle hypertrophy is reported to occur in humans after long-time exposure to nitrogen oxide (NO 2 ) ( 102 , 103 ).

Neurological effects have been observed in adults and children after extended-term exposure to air pollutants.

Psychological complications, autism, retinopathy, fetal growth, and low birth weight seem to be related to long-term air pollution ( 83 ). The etiologic agent of the neurodegenerative diseases (Alzheimer's and Parkinson's) is not yet known, although it is believed that extended exposure to air pollution seems to be a factor. Specifically, pesticides and metals are cited as etiological factors, together with diet. The mechanisms in the development of neurodegenerative disease include oxidative stress, protein aggregation, inflammation, and mitochondrial impairment in neurons ( 104 ) ( Figure 1 ).

Impact of air pollutants on the brain.

Brain inflammation was observed in dogs living in a highly polluted area in Mexico for a long period ( 105 ). In human adults, markers of systemic inflammation (IL-6 and fibrinogen) were found to be increased as an immediate response to PNC on the IL-6 level, possibly leading to the production of acute-phase proteins ( 106 ). The progression of atherosclerosis and oxidative stress seem to be the mechanisms involved in the neurological disturbances caused by long-term air pollution. Inflammation comes secondary to the oxidative stress and seems to be involved in the impairment of developmental maturation, affecting multiple organs ( 105 , 107 ). Similarly, other factors seem to be involved in the developmental maturation, which define the vulnerability to long-term air pollution. These include birthweight, maternal smoking, genetic background and socioeconomic environment, as well as education level.

However, diet, starting from breast-feeding, is another determinant factor. Diet is the main source of antioxidants, which play a key role in our protection against air pollutants ( 108 ). Antioxidants are free radical scavengers and limit the interaction of free radicals in the brain ( 108 ). Similarly, genetic background may result in a differential susceptibility toward the oxidative stress pathway ( 60 ). For example, antioxidant supplementation with vitamins C and E appears to modulate the effect of ozone in asthmatic children homozygous for the GSTM1 null allele ( 61 ). Inflammatory cytokines released in the periphery (e.g., respiratory epithelia) upregulate the innate immune Toll-like receptor 2. Such activation and the subsequent events leading to neurodegeneration have recently been observed in lung lavage in mice exposed to ambient Los Angeles (CA, USA) particulate matter ( 61 ). In children, neurodevelopmental morbidities were observed after lead exposure. These children developed aggressive and delinquent behavior, reduced intelligence, learning difficulties, and hyperactivity ( 109 ). No level of lead exposure seems to be “safe,” and the scientific community has asked the Centers for Disease Control and Prevention (CDC) to reduce the current screening guideline of 10 μg/dl ( 109 ).

It is important to state that impact on the immune system, causing dysfunction and neuroinflammation ( 104 ), is related to poor air quality. Yet, increases in serum levels of immunoglobulins (IgA, IgM) and the complement component C3 are observed ( 106 ). Another issue is that antigen presentation is affected by air pollutants, as there is an upregulation of costimulatory molecules such as CD80 and CD86 on macrophages ( 110 ).

As is known, skin is our shield against ultraviolet radiation (UVR) and other pollutants, as it is the most exterior layer of our body. Traffic-related pollutants, such as PAHs, VOCs, oxides, and PM, may cause pigmented spots on our skin ( 111 ). On the one hand, as already stated, when pollutants penetrate through the skin or are inhaled, damage to the organs is observed, as some of these pollutants are mutagenic and carcinogenic, and, specifically, they affect the liver and lung. On the other hand, air pollutants (and those in the troposphere) reduce the adverse effects of ultraviolet radiation UVR in polluted urban areas ( 111 ). Air pollutants absorbed by the human skin may contribute to skin aging, psoriasis, acne, urticaria, eczema, and atopic dermatitis ( 111 ), usually caused by exposure to oxides and photochemical smoke ( 111 ). Exposure to PM and cigarette smoking act as skin-aging agents, causing spots, dyschromia, and wrinkles. Lastly, pollutants have been associated with skin cancer ( 111 ).

Higher morbidity is reported to fetuses and children when exposed to the above dangers. Impairment in fetal growth, low birth weight, and autism have been reported ( 112 ).

Another exterior organ that may be affected is the eye. Contamination usually comes from suspended pollutants and may result in asymptomatic eye outcomes, irritation ( 112 ), retinopathy, or dry eye syndrome ( 113 , 114 ).

Environmental Impact of Air Pollution

Air pollution is harming not only human health but also the environment ( 115 ) in which we live. The most important environmental effects are as follows.

Acid rain is wet (rain, fog, snow) or dry (particulates and gas) precipitation containing toxic amounts of nitric and sulfuric acids. They are able to acidify the water and soil environments, damage trees and plantations, and even damage buildings and outdoor sculptures, constructions, and statues.

Haze is produced when fine particles are dispersed in the air and reduce the transparency of the atmosphere. It is caused by gas emissions in the air coming from industrial facilities, power plants, automobiles, and trucks.

Ozone , as discussed previously, occurs both at ground level and in the upper level (stratosphere) of the Earth's atmosphere. Stratospheric ozone is protecting us from the Sun's harmful ultraviolet (UV) rays. In contrast, ground-level ozone is harmful to human health and is a pollutant. Unfortunately, stratospheric ozone is gradually damaged by ozone-depleting substances (i.e., chemicals, pesticides, and aerosols). If this protecting stratospheric ozone layer is thinned, then UV radiation can reach our Earth, with harmful effects for human life (skin cancer) ( 116 ) and crops ( 117 ). In plants, ozone penetrates through the stomata, inducing them to close, which blocks CO 2 transfer and induces a reduction in photosynthesis ( 118 ).

Global climate change is an important issue that concerns mankind. As is known, the “greenhouse effect” keeps the Earth's temperature stable. Unhappily, anthropogenic activities have destroyed this protecting temperature effect by producing large amounts of greenhouse gases, and global warming is mounting, with harmful effects on human health, animals, forests, wildlife, agriculture, and the water environment. A report states that global warming is adding to the health risks of poor people ( 119 ).

People living in poorly constructed buildings in warm-climate countries are at high risk for heat-related health problems as temperatures mount ( 119 ).

Wildlife is burdened by toxic pollutants coming from the air, soil, or the water ecosystem and, in this way, animals can develop health problems when exposed to high levels of pollutants. Reproductive failure and birth effects have been reported.

Eutrophication is occurring when elevated concentrations of nutrients (especially nitrogen) stimulate the blooming of aquatic algae, which can cause a disequilibration in the diversity of fish and their deaths.

Without a doubt, there is a critical concentration of pollution that an ecosystem can tolerate without being destroyed, which is associated with the ecosystem's capacity to neutralize acidity. The Canada Acid Rain Program established this load at 20 kg/ha/yr ( 120 ).

Hence, air pollution has deleterious effects on both soil and water ( 121 ). Concerning PM as an air pollutant, its impact on crop yield and food productivity has been reported. Its impact on watery bodies is associated with the survival of living organisms and fishes and their productivity potential ( 121 ).

An impairment in photosynthetic rhythm and metabolism is observed in plants exposed to the effects of ozone ( 121 ).

Sulfur and nitrogen oxides are involved in the formation of acid rain and are harmful to plants and marine organisms.

Last but not least, as mentioned above, the toxicity associated with lead and other metals is the main threat to our ecosystems (air, water, and soil) and living creatures ( 121 ).

In 2018, during the first WHO Global Conference on Air Pollution and Health, the WHO's General Director, Dr. Tedros Adhanom Ghebreyesus, called air pollution a “silent public health emergency” and “the new tobacco” ( 122 ).

Undoubtedly, children are particularly vulnerable to air pollution, especially during their development. Air pollution has adverse effects on our lives in many different respects.

Diseases associated with air pollution have not only an important economic impact but also a societal impact due to absences from productive work and school.

Despite the difficulty of eradicating the problem of anthropogenic environmental pollution, a successful solution could be envisaged as a tight collaboration of authorities, bodies, and doctors to regularize the situation. Governments should spread sufficient information and educate people and should involve professionals in these issues so as to control the emergence of the problem successfully.

Technologies to reduce air pollution at the source must be established and should be used in all industries and power plants. The Kyoto Protocol of 1997 set as a major target the reduction of GHG emissions to below 5% by 2012 ( 123 ). This was followed by the Copenhagen summit, 2009 ( 124 ), and then the Durban summit of 2011 ( 125 ), where it was decided to keep to the same line of action. The Kyoto protocol and the subsequent ones were ratified by many countries. Among the pioneers who adopted this important protocol for the world's environmental and climate “health” was China ( 3 ). As is known, China is a fast-developing economy and its GDP (Gross Domestic Product) is expected to be very high by 2050, which is defined as the year of dissolution of the protocol for the decrease in gas emissions.

A more recent international agreement of crucial importance for climate change is the Paris Agreement of 2015, issued by the UNFCCC (United Nations Climate Change Committee). This latest agreement was ratified by a plethora of UN (United Nations) countries as well as the countries of the European Union ( 126 ). In this vein, parties should promote actions and measures to enhance numerous aspects around the subject. Boosting education, training, public awareness, and public participation are some of the relevant actions for maximizing the opportunities to achieve the targets and goals on the crucial matter of climate change and environmental pollution ( 126 ). Without any doubt, technological improvements makes our world easier and it seems difficult to reduce the harmful impact caused by gas emissions, we could limit its use by seeking reliable approaches.

Synopsizing, a global prevention policy should be designed in order to combat anthropogenic air pollution as a complement to the correct handling of the adverse health effects associated with air pollution. Sustainable development practices should be applied, together with information coming from research in order to handle the problem effectively.

At this point, international cooperation in terms of research, development, administration policy, monitoring, and politics is vital for effective pollution control. Legislation concerning air pollution must be aligned and updated, and policy makers should propose the design of a powerful tool of environmental and health protection. As a result, the main proposal of this essay is that we should focus on fostering local structures to promote experience and practice and extrapolate these to the international level through developing effective policies for sustainable management of ecosystems.

Author Contributions

All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.

Conflict of Interest

IM is employed by the company Delphis S.A. The remaining authors declare that the present review paper was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

REVIEW article

Environmental and health impacts of air pollution: a review.

• 1 Delphis S.A., Kifisia, Greece
• 2 Laboratory of Hygiene and Environmental Protection, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
• 3 Centre Hospitalier Universitaire Vaudois (CHUV), Service de Médicine Interne, Lausanne, Switzerland
• 4 School of Social and Political Sciences, University of Glasgow, Glasgow, United Kingdom

One of our era's greatest scourges is air pollution, on account not only of its impact on climate change but also its impact on public and individual health due to increasing morbidity and mortality. There are many pollutants that are major factors in disease in humans. Among them, Particulate Matter (PM), particles of variable but very small diameter, penetrate the respiratory system via inhalation, causing respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. Despite the fact that ozone in the stratosphere plays a protective role against ultraviolet irradiation, it is harmful when in high concentration at ground level, also affecting the respiratory and cardiovascular system. Furthermore, nitrogen oxide, sulfur dioxide, Volatile Organic Compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) are all considered air pollutants that are harmful to humans. Carbon monoxide can even provoke direct poisoning when breathed in at high levels. Heavy metals such as lead, when absorbed into the human body, can lead to direct poisoning or chronic intoxication, depending on exposure. Diseases occurring from the aforementioned substances include principally respiratory problems such as Chronic Obstructive Pulmonary Disease (COPD), asthma, bronchiolitis, and also lung cancer, cardiovascular events, central nervous system dysfunctions, and cutaneous diseases. Last but not least, climate change resulting from environmental pollution affects the geographical distribution of many infectious diseases, as do natural disasters. The only way to tackle this problem is through public awareness coupled with a multidisciplinary approach by scientific experts; national and international organizations must address the emergence of this threat and propose sustainable solutions.

Approach to the Problem

The interactions between humans and their physical surroundings have been extensively studied, as multiple human activities influence the environment. The environment is a coupling of the biotic (living organisms and microorganisms) and the abiotic (hydrosphere, lithosphere, and atmosphere).

Pollution is defined as the introduction into the environment of substances harmful to humans and other living organisms. Pollutants are harmful solids, liquids, or gases produced in higher than usual concentrations that reduce the quality of our environment.

Human activities have an adverse effect on the environment by polluting the water we drink, the air we breathe, and the soil in which plants grow. Although the industrial revolution was a great success in terms of technology, society, and the provision of multiple services, it also introduced the production of huge quantities of pollutants emitted into the air that are harmful to human health. Without any doubt, the global environmental pollution is considered an international public health issue with multiple facets. Social, economic, and legislative concerns and lifestyle habits are related to this major problem. Clearly, urbanization and industrialization are reaching unprecedented and upsetting proportions worldwide in our era. Anthropogenic air pollution is one of the biggest public health hazards worldwide, given that it accounts for about 9 million deaths per year ( 1 ).

Without a doubt, all of the aforementioned are closely associated with climate change, and in the event of danger, the consequences can be severe for mankind ( 2 ). Climate changes and the effects of global planetary warming seriously affect multiple ecosystems, causing problems such as food safety issues, ice and iceberg melting, animal extinction, and damage to plants ( 3 , 4 ).

Air pollution has various health effects. The health of susceptible and sensitive individuals can be impacted even on low air pollution days. Short-term exposure to air pollutants is closely related to COPD (Chronic Obstructive Pulmonary Disease), cough, shortness of breath, wheezing, asthma, respiratory disease, and high rates of hospitalization (a measurement of morbidity).

The long-term effects associated with air pollution are chronic asthma, pulmonary insufficiency, cardiovascular diseases, and cardiovascular mortality. According to a Swedish cohort study, diabetes seems to be induced after long-term air pollution exposure ( 5 ). Moreover, air pollution seems to have various malign health effects in early human life, such as respiratory, cardiovascular, mental, and perinatal disorders ( 3 ), leading to infant mortality or chronic disease in adult age ( 6 ).

National reports have mentioned the increased risk of morbidity and mortality ( 1 ). These studies were conducted in many places around the world and show a correlation between daily ranges of particulate matter (PM) concentration and daily mortality. Climate shifts and global planetary warming ( 3 ) could aggravate the situation. Besides, increased hospitalization (an index of morbidity) has been registered among the elderly and susceptible individuals for specific reasons. Fine and ultrafine particulate matter seems to be associated with more serious illnesses ( 6 ), as it can invade the deepest parts of the airways and more easily reach the bloodstream.

Air pollution mainly affects those living in large urban areas, where road emissions contribute the most to the degradation of air quality. There is also a danger of industrial accidents, where the spread of a toxic fog can be fatal to the populations of the surrounding areas. The dispersion of pollutants is determined by many parameters, most notably atmospheric stability and wind ( 6 ).

In developing countries ( 7 ), the problem is more serious due to overpopulation and uncontrolled urbanization along with the development of industrialization. This leads to poor air quality, especially in countries with social disparities and a lack of information on sustainable management of the environment. The use of fuels such as wood fuel or solid fuel for domestic needs due to low incomes exposes people to bad-quality, polluted air at home. It is of note that three billion people around the world are using the above sources of energy for their daily heating and cooking needs ( 8 ). In developing countries, the women of the household seem to carry the highest risk for disease development due to their longer duration exposure to the indoor air pollution ( 8 , 9 ). Due to its fast industrial development and overpopulation, China is one of the Asian countries confronting serious air pollution problems ( 10 , 11 ). The lung cancer mortality observed in China is associated with fine particles ( 12 ). As stated already, long-term exposure is associated with deleterious effects on the cardiovascular system ( 3 , 5 ). However, it is interesting to note that cardiovascular diseases have mostly been observed in developed and high-income countries rather than in the developing low-income countries exposed highly to air pollution ( 13 ). Extreme air pollution is recorded in India, where the air quality reaches hazardous levels. New Delhi is one of the more polluted cities in India. Flights in and out of New Delhi International Airport are often canceled due to the reduced visibility associated with air pollution. Pollution is occurring both in urban and rural areas in India due to the fast industrialization, urbanization, and rise in use of motorcycle transportation. Nevertheless, biomass combustion associated with heating and cooking needs and practices is a major source of household air pollution in India and in Nepal ( 14 , 15 ). There is spatial heterogeneity in India, as areas with diverse climatological conditions and population and education levels generate different indoor air qualities, with higher PM 2.5 observed in North Indian states (557–601 μg/m 3 ) compared to the Southern States (183–214 μg/m 3 ) ( 16 , 17 ). The cold climate of the North Indian areas may be the main reason for this, as longer periods at home and more heating are necessary compared to in the tropical climate of Southern India. Household air pollution in India is associated with major health effects, especially in women and young children, who stay indoors for longer periods. Chronic obstructive respiratory disease (CORD) and lung cancer are mostly observed in women, while acute lower respiratory disease is seen in young children under 5 years of age ( 18 ).

Accumulation of air pollution, especially sulfur dioxide and smoke, reaching 1,500 mg/m3, resulted in an increase in the number of deaths (4,000 deaths) in December 1952 in London and in 1963 in New York City (400 deaths) ( 19 ). An association of pollution with mortality was reported on the basis of monitoring of outdoor pollution in six US metropolitan cities ( 20 ). In every case, it seems that mortality was closely related to the levels of fine, inhalable, and sulfate particles more than with the levels of total particulate pollution, aerosol acidity, sulfur dioxide, or nitrogen dioxide ( 20 ).

Furthermore, extremely high levels of pollution are reported in Mexico City and Rio de Janeiro, followed by Milan, Ankara, Melbourne, Tokyo, and Moscow ( 19 ).

Based on the magnitude of the public health impact, it is certain that different kinds of interventions should be taken into account. Success and effectiveness in controlling air pollution, specifically at the local level, have been reported. Adequate technological means are applied considering the source and the nature of the emission as well as its impact on health and the environment. The importance of point sources and non-point sources of air pollution control is reported by Schwela and Köth-Jahr ( 21 ). Without a doubt, a detailed emission inventory must record all sources in a given area. Beyond considering the above sources and their nature, topography and meteorology should also be considered, as stated previously. Assessment of the control policies and methods is often extrapolated from the local to the regional and then to the global scale. Air pollution may be dispersed and transported from one region to another area located far away. Air pollution management means the reduction to acceptable levels or possible elimination of air pollutants whose presence in the air affects our health or the environmental ecosystem. Private and governmental entities and authorities implement actions to ensure the air quality ( 22 ). Air quality standards and guidelines were adopted for the different pollutants by the WHO and EPA as a tool for the management of air quality ( 1 , 23 ). These standards have to be compared to the emissions inventory standards by causal analysis and dispersion modeling in order to reveal the problematic areas ( 24 ). Inventories are generally based on a combination of direct measurements and emissions modeling ( 24 ).

As an example, we state here the control measures at the source through the use of catalytic converters in cars. These are devices that turn the pollutants and toxic gases produced from combustion engines into less-toxic pollutants by catalysis through redox reactions ( 25 ). In Greece, the use of private cars was restricted by tracking their license plates in order to reduce traffic congestion during rush hour ( 25 ).

Concerning industrial emissions, collectors and closed systems can keep the air pollution to the minimal standards imposed by legislation ( 26 ).

Current strategies to improve air quality require an estimation of the economic value of the benefits gained from proposed programs. These proposed programs by public authorities, and directives are issued with guidelines to be respected.

In Europe, air quality limit values AQLVs (Air Quality Limit Values) are issued for setting off planning claims ( 27 ). In the USA, the NAAQS (National Ambient Air Quality Standards) establish the national air quality limit values ( 27 ). While both standards and directives are based on different mechanisms, significant success has been achieved in the reduction of overall emissions and associated health and environmental effects ( 27 ). The European Directive identifies geographical areas of risk exposure as monitoring/assessment zones to record the emission sources and levels of air pollution ( 27 ), whereas the USA establishes global geographical air quality criteria according to the severity of their air quality problem and records all sources of the pollutants and their precursors ( 27 ).

In this vein, funds have been financing, directly or indirectly, projects related to air quality along with the technical infrastructure to maintain good air quality. These plans focus on an inventory of databases from air quality environmental planning awareness campaigns. Moreover, pollution measures of air emissions may be taken for vehicles, machines, and industries in urban areas.

Technological innovation can only be successful if it is able to meet the needs of society. In this sense, technology must reflect the decision-making practices and procedures of those involved in risk assessment and evaluation and act as a facilitator in providing information and assessments to enable decision makers to make the best decisions possible. Summarizing the aforementioned in order to design an effective air quality control strategy, several aspects must be considered: environmental factors and ambient air quality conditions, engineering factors and air pollutant characteristics, and finally, economic operating costs for technological improvement and administrative and legal costs. Considering the economic factor, competitiveness through neoliberal concepts is offering a solution to environmental problems ( 22 ).

The development of environmental governance, along with technological progress, has initiated the deployment of a dialogue. Environmental politics has created objections and points of opposition between different political parties, scientists, media, and governmental and non-governmental organizations ( 22 ). Radical environmental activism actions and movements have been created ( 22 ). The rise of the new information and communication technologies (ICTs) are many times examined as to whether and in which way they have influenced means of communication and social movements such as activism ( 28 ). Since the 1990s, the term “digital activism” has been used increasingly and in many different disciplines ( 29 ). Nowadays, multiple digital technologies can be used to produce a digital activism outcome on environmental issues. More specifically, devices with online capabilities such as computers or mobile phones are being used as a way to pursue change in political and social affairs ( 30 ).

In the present paper, we focus on the sources of environmental pollution in relation to public health and propose some solutions and interventions that may be of interest to environmental legislators and decision makers.

Sources of Exposure

It is known that the majority of environmental pollutants are emitted through large-scale human activities such as the use of industrial machinery, power-producing stations, combustion engines, and cars. Because these activities are performed at such a large scale, they are by far the major contributors to air pollution, with cars estimated to be responsible for approximately 80% of today's pollution ( 31 ). Some other human activities are also influencing our environment to a lesser extent, such as field cultivation techniques, gas stations, fuel tanks heaters, and cleaning procedures ( 32 ), as well as several natural sources, such as volcanic and soil eruptions and forest fires.

The classification of air pollutants is based mainly on the sources producing pollution. Therefore, it is worth mentioning the four main sources, following the classification system: Major sources, Area sources, Mobile sources, and Natural sources.

Major sources include the emission of pollutants from power stations, refineries, and petrochemicals, the chemical and fertilizer industries, metallurgical and other industrial plants, and, finally, municipal incineration.

Indoor area sources include domestic cleaning activities, dry cleaners, printing shops, and petrol stations.

Mobile sources include automobiles, cars, railways, airways, and other types of vehicles.

Finally, natural sources include, as stated previously, physical disasters ( 33 ) such as forest fire, volcanic erosion, dust storms, and agricultural burning.

However, many classification systems have been proposed. Another type of classification is a grouping according to the recipient of the pollution, as follows:

Air pollution is determined as the presence of pollutants in the air in large quantities for long periods. Air pollutants are dispersed particles, hydrocarbons, CO, CO 2 , NO, NO 2 , SO 3 , etc.

Water pollution is organic and inorganic charge and biological charge ( 10 ) at high levels that affect the water quality ( 34 , 35 ).

Soil pollution occurs through the release of chemicals or the disposal of wastes, such as heavy metals, hydrocarbons, and pesticides.

Air pollution can influence the quality of soil and water bodies by polluting precipitation, falling into water and soil environments ( 34 , 36 ). Notably, the chemistry of the soil can be amended due to acid precipitation by affecting plants, cultures, and water quality ( 37 ). Moreover, movement of heavy metals is favored by soil acidity, and metals are so then moving into the watery environment. It is known that heavy metals such as aluminum are noxious to wildlife and fishes. Soil quality seems to be of importance, as soils with low calcium carbonate levels are at increased jeopardy from acid rain. Over and above rain, snow and particulate matter drip into watery ' bodies ( 36 , 38 ).

Lastly, pollution is classified following type of origin:

Radioactive and nuclear pollution , releasing radioactive and nuclear pollutants into water, air, and soil during nuclear explosions and accidents, from nuclear weapons, and through handling or disposal of radioactive sewage.

Radioactive materials can contaminate surface water bodies and, being noxious to the environment, plants, animals, and humans. It is known that several radioactive substances such as radium and uranium concentrate in the bones and can cause cancers ( 38 , 39 ).

Noise pollution is produced by machines, vehicles, traffic noises, and musical installations that are harmful to our hearing.

The World Health Organization introduced the term DALYs. The DALYs for a disease or health condition is defined as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences ( 39 ). In Europe, air pollution is the main cause of disability-adjusted life years lost (DALYs), followed by noise pollution. The potential relationships of noise and air pollution with health have been studied ( 40 ). The study found that DALYs related to noise were more important than those related to air pollution, as the effects of environmental noise on cardiovascular disease were independent of air pollution ( 40 ). Environmental noise should be counted as an independent public health risk ( 40 ).

Environmental pollution occurs when changes in the physical, chemical, or biological constituents of the environment (air masses, temperature, climate, etc.) are produced.

Pollutants harm our environment either by increasing levels above normal or by introducing harmful toxic substances. Primary pollutants are directly produced from the above sources, and secondary pollutants are emitted as by-products of the primary ones. Pollutants can be biodegradable or non-biodegradable and of natural origin or anthropogenic, as stated previously. Moreover, their origin can be a unique source (point-source) or dispersed sources.

Pollutants have differences in physical and chemical properties, explaining the discrepancy in their capacity for producing toxic effects. As an example, we state here that aerosol compounds ( 41 – 43 ) have a greater toxicity than gaseous compounds due to their tiny size (solid or liquid) in the atmosphere; they have a greater penetration capacity. Gaseous compounds are eliminated more easily by our respiratory system ( 41 ). These particles are able to damage lungs and can even enter the bloodstream ( 41 ), leading to the premature deaths of millions of people yearly. Moreover, the aerosol acidity ([H+]) seems to considerably enhance the production of secondary organic aerosols (SOA), but this last aspect is not supported by other scientific teams ( 38 ).

Climate and Pollution

Air pollution and climate change are closely related. Climate is the other side of the same coin that reduces the quality of our Earth ( 44 ). Pollutants such as black carbon, methane, tropospheric ozone, and aerosols affect the amount of incoming sunlight. As a result, the temperature of the Earth is increasing, resulting in the melting of ice, icebergs, and glaciers.

In this vein, climatic changes will affect the incidence and prevalence of both residual and imported infections in Europe. Climate and weather affect the duration, timing, and intensity of outbreaks strongly and change the map of infectious diseases in the globe ( 45 ). Mosquito-transmitted parasitic or viral diseases are extremely climate-sensitive, as warming firstly shortens the pathogen incubation period and secondly shifts the geographic map of the vector. Similarly, water-warming following climate changes leads to a high incidence of waterborne infections. Recently, in Europe, eradicated diseases seem to be emerging due to the migration of population, for example, cholera, poliomyelitis, tick-borne encephalitis, and malaria ( 46 ).

The spread of epidemics is associated with natural climate disasters and storms, which seem to occur more frequently nowadays ( 47 ). Malnutrition and disequilibration of the immune system are also associated with the emerging infections affecting public health ( 48 ).

The Chikungunya virus “took the airplane” from the Indian Ocean to Europe, as outbreaks of the disease were registered in Italy ( 49 ) as well as autochthonous cases in France ( 50 ).

An increase in cryptosporidiosis in the United Kingdom and in the Czech Republic seems to have occurred following flooding ( 36 , 51 ).

As stated previously, aerosols compounds are tiny in size and considerably affect the climate. They are able to dissipate sunlight (the albedo phenomenon) by dispersing a quarter of the sun's rays back to space and have cooled the global temperature over the last 30 years ( 52 ).

Air Pollutants

The World Health Organization (WHO) reports on six major air pollutants, namely particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. Air pollution can have a disastrous effect on all components of the environment, including groundwater, soil, and air. Additionally, it poses a serious threat to living organisms. In this vein, our interest is mainly to focus on these pollutants, as they are related to more extensive and severe problems in human health and environmental impact. Acid rain, global warming, the greenhouse effect, and climate changes have an important ecological impact on air pollution ( 53 ).

Particulate Matter (PM) and Health

Studies have shown a relationship between particulate matter (PM) and adverse health effects, focusing on either short-term (acute) or long-term (chronic) PM exposure.

Particulate matter (PM) is usually formed in the atmosphere as a result of chemical reactions between the different pollutants. The penetration of particles is closely dependent on their size ( 53 ). Particulate Matter (PM) was defined as a term for particles by the United States Environmental Protection Agency ( 54 ). Particulate matter (PM) pollution includes particles with diameters of 10 micrometers (μm) or smaller, called PM 10 , and extremely fine particles with diameters that are generally 2.5 micrometers (μm) and smaller.

Particulate matter contains tiny liquid or solid droplets that can be inhaled and cause serious health effects ( 55 ). Particles <10 μm in diameter (PM 10 ) after inhalation can invade the lungs and even reach the bloodstream. Fine particles, PM 2.5 , pose a greater risk to health ( 6 , 56 ) ( Table 1 ).

Table 1 . Penetrability according to particle size.

Multiple epidemiological studies have been performed on the health effects of PM. A positive relation was shown between both short-term and long-term exposures of PM 2.5 and acute nasopharyngitis ( 56 ). In addition, long-term exposure to PM for years was found to be related to cardiovascular diseases and infant mortality.

Those studies depend on PM 2.5 monitors and are restricted in terms of study area or city area due to a lack of spatially resolved daily PM 2.5 concentration data and, in this way, are not representative of the entire population. Following a recent epidemiological study by the Department of Environmental Health at Harvard School of Public Health (Boston, MA) ( 57 ), it was reported that, as PM 2.5 concentrations vary spatially, an exposure error (Berkson error) seems to be produced, and the relative magnitudes of the short- and long-term effects are not yet completely elucidated. The team developed a PM 2.5 exposure model based on remote sensing data for assessing short- and long-term human exposures ( 57 ). This model permits spatial resolution in short-term effects plus the assessment of long-term effects in the whole population.

Moreover, respiratory diseases and affection of the immune system are registered as long-term chronic effects ( 58 ). It is worth noting that people with asthma, pneumonia, diabetes, and respiratory and cardiovascular diseases are especially susceptible and vulnerable to the effects of PM. PM 2.5 , followed by PM 10 , are strongly associated with diverse respiratory system diseases ( 59 ), as their size permits them to pierce interior spaces ( 60 ). The particles produce toxic effects according to their chemical and physical properties. The components of PM 10 and PM 2.5 can be organic (polycyclic aromatic hydrocarbons, dioxins, benzene, 1-3 butadiene) or inorganic (carbon, chlorides, nitrates, sulfates, metals) in nature ( 55 ).

Particulate Matter (PM) is divided into four main categories according to type and size ( 61 ) ( Table 2 ).

Table 2 . Types and sizes of particulate Matter (PM).

Gas contaminants include PM in aerial masses.

Particulate contaminants include contaminants such as smog, soot, tobacco smoke, oil smoke, fly ash, and cement dust.

Biological Contaminants are microorganisms (bacteria, viruses, fungi, mold, and bacterial spores), cat allergens, house dust and allergens, and pollen.

Types of Dust include suspended atmospheric dust, settling dust, and heavy dust.

Finally, another fact is that the half-lives of PM 10 and PM 2.5 particles in the atmosphere is extended due to their tiny dimensions; this permits their long-lasting suspension in the atmosphere and even their transfer and spread to distant destinations where people and the environment may be exposed to the same magnitude of pollution ( 53 ). They are able to change the nutrient balance in watery ecosystems, damage forests and crops, and acidify water bodies.

As stated, PM 2.5 , due to their tiny size, are causing more serious health effects. These aforementioned fine particles are the main cause of the “haze” formation in different metropolitan areas ( 12 , 13 , 61 ).

Ozone Impact in the Atmosphere

Ozone (O 3 ) is a gas formed from oxygen under high voltage electric discharge ( 62 ). It is a strong oxidant, 52% stronger than chlorine. It arises in the stratosphere, but it could also arise following chain reactions of photochemical smog in the troposphere ( 63 ).

Ozone can travel to distant areas from its initial source, moving with air masses ( 64 ). It is surprising that ozone levels over cities are low in contrast to the increased amounts occuring in urban areas, which could become harmful for cultures, forests, and vegetation ( 65 ) as it is reducing carbon assimilation ( 66 ). Ozone reduces growth and yield ( 47 , 48 ) and affects the plant microflora due to its antimicrobial capacity ( 67 , 68 ). In this regard, ozone acts upon other natural ecosystems, with microflora ( 69 , 70 ) and animal species changing their species composition ( 71 ). Ozone increases DNA damage in epidermal keratinocytes and leads to impaired cellular function ( 72 ).

Ground-level ozone (GLO) is generated through a chemical reaction between oxides of nitrogen and VOCs emitted from natural sources and/or following anthropogenic activities.

Ozone uptake usually occurs by inhalation. Ozone affects the upper layers of the skin and the tear ducts ( 73 ). A study of short-term exposure of mice to high levels of ozone showed malondialdehyde formation in the upper skin (epidermis) but also depletion in vitamins C and E. It is likely that ozone levels are not interfering with the skin barrier function and integrity to predispose to skin disease ( 74 ).

Due to the low water-solubility of ozone, inhaled ozone has the capacity to penetrate deeply into the lungs ( 75 ).

Toxic effects induced by ozone are registered in urban areas all over the world, causing biochemical, morphologic, functional, and immunological disorders ( 76 ).

The European project (APHEA2) focuses on the acute effects of ambient ozone concentrations on mortality ( 77 ). Daily ozone concentrations compared to the daily number of deaths were reported from different European cities for a 3-year period. During the warm period of the year, an observed increase in ozone concentration was associated with an increase in the daily number of deaths (0.33%), in the number of respiratory deaths (1.13%), and in the number of cardiovascular deaths (0.45%). No effect was observed during wintertime.

Carbon Monoxide (CO)

Carbon monoxide is produced by fossil fuel when combustion is incomplete. The symptoms of poisoning due to inhaling carbon monoxide include headache, dizziness, weakness, nausea, vomiting, and, finally, loss of consciousness.

The affinity of carbon monoxide to hemoglobin is much greater than that of oxygen. In this vein, serious poisoning may occur in people exposed to high levels of carbon monoxide for a long period of time. Due to the loss of oxygen as a result of the competitive binding of carbon monoxide, hypoxia, ischemia, and cardiovascular disease are observed.

Carbon monoxide affects the greenhouses gases that are tightly connected to global warming and climate. This should lead to an increase in soil and water temperatures, and extreme weather conditions or storms may occur ( 68 ).

However, in laboratory and field experiments, it has been seen to produce increased plant growth ( 78 ).

Nitrogen Oxide (NO 2 )

Nitrogen oxide is a traffic-related pollutant, as it is emitted from automobile motor engines ( 79 , 80 ). It is an irritant of the respiratory system as it penetrates deep in the lung, inducing respiratory diseases, coughing, wheezing, dyspnea, bronchospasm, and even pulmonary edema when inhaled at high levels. It seems that concentrations over 0.2 ppm produce these adverse effects in humans, while concentrations higher than 2.0 ppm affect T-lymphocytes, particularly the CD8+ cells and NK cells that produce our immune response ( 81 ).It is reported that long-term exposure to high levels of nitrogen dioxide can be responsible for chronic lung disease. Long-term exposure to NO 2 can impair the sense of smell ( 81 ).

However, systems other than respiratory ones can be involved, as symptoms such as eye, throat, and nose irritation have been registered ( 81 ).

High levels of nitrogen dioxide are deleterious to crops and vegetation, as they have been observed to reduce crop yield and plant growth efficiency. Moreover, NO 2 can reduce visibility and discolor fabrics ( 81 ).

Sulfur Dioxide (SO 2 )

Sulfur dioxide is a harmful gas that is emitted mainly from fossil fuel consumption or industrial activities. The annual standard for SO 2 is 0.03 ppm ( 82 ). It affects human, animal, and plant life. Susceptible people as those with lung disease, old people, and children, who present a higher risk of damage. The major health problems associated with sulfur dioxide emissions in industrialized areas are respiratory irritation, bronchitis, mucus production, and bronchospasm, as it is a sensory irritant and penetrates deep into the lung converted into bisulfite and interacting with sensory receptors, causing bronchoconstriction. Moreover, skin redness, damage to the eyes (lacrimation and corneal opacity) and mucous membranes, and worsening of pre-existing cardiovascular disease have been observed ( 81 ).

Environmental adverse effects, such as acidification of soil and acid rain, seem to be associated with sulfur dioxide emissions ( 83 ).

Lead is a heavy metal used in different industrial plants and emitted from some petrol motor engines, batteries, radiators, waste incinerators, and waste waters ( 84 ).

Moreover, major sources of lead pollution in the air are metals, ore, and piston-engine aircraft. Lead poisoning is a threat to public health due to its deleterious effects upon humans, animals, and the environment, especially in the developing countries.

Exposure to lead can occur through inhalation, ingestion, and dermal absorption. Trans- placental transport of lead was also reported, as lead passes through the placenta unencumbered ( 85 ). The younger the fetus is, the more harmful the toxic effects. Lead toxicity affects the fetal nervous system; edema or swelling of the brain is observed ( 86 ). Lead, when inhaled, accumulates in the blood, soft tissue, liver, lung, bones, and cardiovascular, nervous, and reproductive systems. Moreover, loss of concentration and memory, as well as muscle and joint pain, were observed in adults ( 85 , 86 ).

Children and newborns ( 87 ) are extremely susceptible even to minimal doses of lead, as it is a neurotoxicant and causes learning disabilities, impairment of memory, hyperactivity, and even mental retardation.

Elevated amounts of lead in the environment are harmful to plants and crop growth. Neurological effects are observed in vertebrates and animals in association with high lead levels ( 88 ).

Polycyclic Aromatic Hydrocarbons(PAHs)

The distribution of PAHs is ubiquitous in the environment, as the atmosphere is the most important means of their dispersal. They are found in coal and in tar sediments. Moreover, they are generated through incomplete combustion of organic matter as in the cases of forest fires, incineration, and engines ( 89 ). PAH compounds, such as benzopyrene, acenaphthylene, anthracene, and fluoranthene are recognized as toxic, mutagenic, and carcinogenic substances. They are an important risk factor for lung cancer ( 89 ).

Volatile Organic Compounds(VOCs)

Volatile organic compounds (VOCs), such as toluene, benzene, ethylbenzene, and xylene ( 90 ), have been found to be associated with cancer in humans ( 91 ). The use of new products and materials has actually resulted in increased concentrations of VOCs. VOCs pollute indoor air ( 90 ) and may have adverse effects on human health ( 91 ). Short-term and long-term adverse effects on human health are observed. VOCs are responsible for indoor air smells. Short-term exposure is found to cause irritation of eyes, nose, throat, and mucosal membranes, while those of long duration exposure include toxic reactions ( 92 ). Predictable assessment of the toxic effects of complex VOC mixtures is difficult to estimate, as these pollutants can have synergic, antagonistic, or indifferent effects ( 91 , 93 ).

Dioxins originate from industrial processes but also come from natural processes, such as forest fires and volcanic eruptions. They accumulate in foods such as meat and dairy products, fish and shellfish, and especially in the fatty tissue of animals ( 94 ).

Short-period exhibition to high dioxin concentrations may result in dark spots and lesions on the skin ( 94 ). Long-term exposure to dioxins can cause developmental problems, impairment of the immune, endocrine and nervous systems, reproductive infertility, and cancer ( 94 ).

Without any doubt, fossil fuel consumption is responsible for a sizeable part of air contamination. This contamination may be anthropogenic, as in agricultural and industrial processes or transportation, while contamination from natural sources is also possible. Interestingly, it is of note that the air quality standards established through the European Air Quality Directive are somewhat looser than the WHO guidelines, which are stricter ( 95 ).

Effect of Air Pollution on Health

The most common air pollutants are ground-level ozone and Particulates Matter (PM). Air pollution is distinguished into two main types:

Outdoor pollution is the ambient air pollution.

Indoor pollution is the pollution generated by household combustion of fuels.

People exposed to high concentrations of air pollutants experience disease symptoms and states of greater and lesser seriousness. These effects are grouped into short- and long-term effects affecting health.

Susceptible populations that need to be aware of health protection measures include old people, children, and people with diabetes and predisposing heart or lung disease, especially asthma.

As extensively stated previously, according to a recent epidemiological study from Harvard School of Public Health, the relative magnitudes of the short- and long-term effects have not been completely clarified ( 57 ) due to the different epidemiological methodologies and to the exposure errors. New models are proposed for assessing short- and long-term human exposure data more successfully ( 57 ). Thus, in the present section, we report the more common short- and long-term health effects but also general concerns for both types of effects, as these effects are often dependent on environmental conditions, dose, and individual susceptibility.

Short-term effects are temporary and range from simple discomfort, such as irritation of the eyes, nose, skin, throat, wheezing, coughing and chest tightness, and breathing difficulties, to more serious states, such as asthma, pneumonia, bronchitis, and lung and heart problems. Short-term exposure to air pollution can also cause headaches, nausea, and dizziness.

These problems can be aggravated by extended long-term exposure to the pollutants, which is harmful to the neurological, reproductive, and respiratory systems and causes cancer and even, rarely, deaths.

The long-term effects are chronic, lasting for years or the whole life and can even lead to death. Furthermore, the toxicity of several air pollutants may also induce a variety of cancers in the long term ( 96 ).

As stated already, respiratory disorders are closely associated with the inhalation of air pollutants. These pollutants will invade through the airways and will accumulate at the cells. Damage to target cells should be related to the pollutant component involved and its source and dose. Health effects are also closely dependent on country, area, season, and time. An extended exposure duration to the pollutant should incline to long-term health effects in relation also to the above factors.

Particulate Matter (PMs), dust, benzene, and O 3 cause serious damage to the respiratory system ( 97 ). Moreover, there is a supplementary risk in case of existing respiratory disease such as asthma ( 98 ). Long-term effects are more frequent in people with a predisposing disease state. When the trachea is contaminated by pollutants, voice alterations may be remarked after acute exposure. Chronic obstructive pulmonary disease (COPD) may be induced following air pollution, increasing morbidity and mortality ( 99 ). Long-term effects from traffic, industrial air pollution, and combustion of fuels are the major factors for COPD risk ( 99 ).

Multiple cardiovascular effects have been observed after exposure to air pollutants ( 100 ). Changes occurred in blood cells after long-term exposure may affect cardiac functionality. Coronary arteriosclerosis was reported following long-term exposure to traffic emissions ( 101 ), while short-term exposure is related to hypertension, stroke, myocardial infracts, and heart insufficiency. Ventricle hypertrophy is reported to occur in humans after long-time exposure to nitrogen oxide (NO 2 ) ( 102 , 103 ).

Neurological effects have been observed in adults and children after extended-term exposure to air pollutants.

Psychological complications, autism, retinopathy, fetal growth, and low birth weight seem to be related to long-term air pollution ( 83 ). The etiologic agent of the neurodegenerative diseases (Alzheimer's and Parkinson's) is not yet known, although it is believed that extended exposure to air pollution seems to be a factor. Specifically, pesticides and metals are cited as etiological factors, together with diet. The mechanisms in the development of neurodegenerative disease include oxidative stress, protein aggregation, inflammation, and mitochondrial impairment in neurons ( 104 ) ( Figure 1 ).

Figure 1 . Impact of air pollutants on the brain.

Brain inflammation was observed in dogs living in a highly polluted area in Mexico for a long period ( 105 ). In human adults, markers of systemic inflammation (IL-6 and fibrinogen) were found to be increased as an immediate response to PNC on the IL-6 level, possibly leading to the production of acute-phase proteins ( 106 ). The progression of atherosclerosis and oxidative stress seem to be the mechanisms involved in the neurological disturbances caused by long-term air pollution. Inflammation comes secondary to the oxidative stress and seems to be involved in the impairment of developmental maturation, affecting multiple organs ( 105 , 107 ). Similarly, other factors seem to be involved in the developmental maturation, which define the vulnerability to long-term air pollution. These include birthweight, maternal smoking, genetic background and socioeconomic environment, as well as education level.

However, diet, starting from breast-feeding, is another determinant factor. Diet is the main source of antioxidants, which play a key role in our protection against air pollutants ( 108 ). Antioxidants are free radical scavengers and limit the interaction of free radicals in the brain ( 108 ). Similarly, genetic background may result in a differential susceptibility toward the oxidative stress pathway ( 60 ). For example, antioxidant supplementation with vitamins C and E appears to modulate the effect of ozone in asthmatic children homozygous for the GSTM1 null allele ( 61 ). Inflammatory cytokines released in the periphery (e.g., respiratory epithelia) upregulate the innate immune Toll-like receptor 2. Such activation and the subsequent events leading to neurodegeneration have recently been observed in lung lavage in mice exposed to ambient Los Angeles (CA, USA) particulate matter ( 61 ). In children, neurodevelopmental morbidities were observed after lead exposure. These children developed aggressive and delinquent behavior, reduced intelligence, learning difficulties, and hyperactivity ( 109 ). No level of lead exposure seems to be “safe,” and the scientific community has asked the Centers for Disease Control and Prevention (CDC) to reduce the current screening guideline of 10 μg/dl ( 109 ).

It is important to state that impact on the immune system, causing dysfunction and neuroinflammation ( 104 ), is related to poor air quality. Yet, increases in serum levels of immunoglobulins (IgA, IgM) and the complement component C3 are observed ( 106 ). Another issue is that antigen presentation is affected by air pollutants, as there is an upregulation of costimulatory molecules such as CD80 and CD86 on macrophages ( 110 ).

As is known, skin is our shield against ultraviolet radiation (UVR) and other pollutants, as it is the most exterior layer of our body. Traffic-related pollutants, such as PAHs, VOCs, oxides, and PM, may cause pigmented spots on our skin ( 111 ). On the one hand, as already stated, when pollutants penetrate through the skin or are inhaled, damage to the organs is observed, as some of these pollutants are mutagenic and carcinogenic, and, specifically, they affect the liver and lung. On the other hand, air pollutants (and those in the troposphere) reduce the adverse effects of ultraviolet radiation UVR in polluted urban areas ( 111 ). Air pollutants absorbed by the human skin may contribute to skin aging, psoriasis, acne, urticaria, eczema, and atopic dermatitis ( 111 ), usually caused by exposure to oxides and photochemical smoke ( 111 ). Exposure to PM and cigarette smoking act as skin-aging agents, causing spots, dyschromia, and wrinkles. Lastly, pollutants have been associated with skin cancer ( 111 ).

Higher morbidity is reported to fetuses and children when exposed to the above dangers. Impairment in fetal growth, low birth weight, and autism have been reported ( 112 ).

Another exterior organ that may be affected is the eye. Contamination usually comes from suspended pollutants and may result in asymptomatic eye outcomes, irritation ( 112 ), retinopathy, or dry eye syndrome ( 113 , 114 ).

Environmental Impact of Air Pollution

Air pollution is harming not only human health but also the environment ( 115 ) in which we live. The most important environmental effects are as follows.

Acid rain is wet (rain, fog, snow) or dry (particulates and gas) precipitation containing toxic amounts of nitric and sulfuric acids. They are able to acidify the water and soil environments, damage trees and plantations, and even damage buildings and outdoor sculptures, constructions, and statues.

Haze is produced when fine particles are dispersed in the air and reduce the transparency of the atmosphere. It is caused by gas emissions in the air coming from industrial facilities, power plants, automobiles, and trucks.

Ozone , as discussed previously, occurs both at ground level and in the upper level (stratosphere) of the Earth's atmosphere. Stratospheric ozone is protecting us from the Sun's harmful ultraviolet (UV) rays. In contrast, ground-level ozone is harmful to human health and is a pollutant. Unfortunately, stratospheric ozone is gradually damaged by ozone-depleting substances (i.e., chemicals, pesticides, and aerosols). If this protecting stratospheric ozone layer is thinned, then UV radiation can reach our Earth, with harmful effects for human life (skin cancer) ( 116 ) and crops ( 117 ). In plants, ozone penetrates through the stomata, inducing them to close, which blocks CO 2 transfer and induces a reduction in photosynthesis ( 118 ).

Global climate change is an important issue that concerns mankind. As is known, the “greenhouse effect” keeps the Earth's temperature stable. Unhappily, anthropogenic activities have destroyed this protecting temperature effect by producing large amounts of greenhouse gases, and global warming is mounting, with harmful effects on human health, animals, forests, wildlife, agriculture, and the water environment. A report states that global warming is adding to the health risks of poor people ( 119 ).

People living in poorly constructed buildings in warm-climate countries are at high risk for heat-related health problems as temperatures mount ( 119 ).

Wildlife is burdened by toxic pollutants coming from the air, soil, or the water ecosystem and, in this way, animals can develop health problems when exposed to high levels of pollutants. Reproductive failure and birth effects have been reported.

Eutrophication is occurring when elevated concentrations of nutrients (especially nitrogen) stimulate the blooming of aquatic algae, which can cause a disequilibration in the diversity of fish and their deaths.

Without a doubt, there is a critical concentration of pollution that an ecosystem can tolerate without being destroyed, which is associated with the ecosystem's capacity to neutralize acidity. The Canada Acid Rain Program established this load at 20 kg/ha/yr ( 120 ).

Hence, air pollution has deleterious effects on both soil and water ( 121 ). Concerning PM as an air pollutant, its impact on crop yield and food productivity has been reported. Its impact on watery bodies is associated with the survival of living organisms and fishes and their productivity potential ( 121 ).

An impairment in photosynthetic rhythm and metabolism is observed in plants exposed to the effects of ozone ( 121 ).

Sulfur and nitrogen oxides are involved in the formation of acid rain and are harmful to plants and marine organisms.

Last but not least, as mentioned above, the toxicity associated with lead and other metals is the main threat to our ecosystems (air, water, and soil) and living creatures ( 121 ).

In 2018, during the first WHO Global Conference on Air Pollution and Health, the WHO's General Director, Dr. Tedros Adhanom Ghebreyesus, called air pollution a “silent public health emergency” and “the new tobacco” ( 122 ).

Undoubtedly, children are particularly vulnerable to air pollution, especially during their development. Air pollution has adverse effects on our lives in many different respects.

Diseases associated with air pollution have not only an important economic impact but also a societal impact due to absences from productive work and school.

Despite the difficulty of eradicating the problem of anthropogenic environmental pollution, a successful solution could be envisaged as a tight collaboration of authorities, bodies, and doctors to regularize the situation. Governments should spread sufficient information and educate people and should involve professionals in these issues so as to control the emergence of the problem successfully.

Technologies to reduce air pollution at the source must be established and should be used in all industries and power plants. The Kyoto Protocol of 1997 set as a major target the reduction of GHG emissions to below 5% by 2012 ( 123 ). This was followed by the Copenhagen summit, 2009 ( 124 ), and then the Durban summit of 2011 ( 125 ), where it was decided to keep to the same line of action. The Kyoto protocol and the subsequent ones were ratified by many countries. Among the pioneers who adopted this important protocol for the world's environmental and climate “health” was China ( 3 ). As is known, China is a fast-developing economy and its GDP (Gross Domestic Product) is expected to be very high by 2050, which is defined as the year of dissolution of the protocol for the decrease in gas emissions.

A more recent international agreement of crucial importance for climate change is the Paris Agreement of 2015, issued by the UNFCCC (United Nations Climate Change Committee). This latest agreement was ratified by a plethora of UN (United Nations) countries as well as the countries of the European Union ( 126 ). In this vein, parties should promote actions and measures to enhance numerous aspects around the subject. Boosting education, training, public awareness, and public participation are some of the relevant actions for maximizing the opportunities to achieve the targets and goals on the crucial matter of climate change and environmental pollution ( 126 ). Without any doubt, technological improvements makes our world easier and it seems difficult to reduce the harmful impact caused by gas emissions, we could limit its use by seeking reliable approaches.

Synopsizing, a global prevention policy should be designed in order to combat anthropogenic air pollution as a complement to the correct handling of the adverse health effects associated with air pollution. Sustainable development practices should be applied, together with information coming from research in order to handle the problem effectively.

At this point, international cooperation in terms of research, development, administration policy, monitoring, and politics is vital for effective pollution control. Legislation concerning air pollution must be aligned and updated, and policy makers should propose the design of a powerful tool of environmental and health protection. As a result, the main proposal of this essay is that we should focus on fostering local structures to promote experience and practice and extrapolate these to the international level through developing effective policies for sustainable management of ecosystems.

Author Contributions

All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.

Conflict of Interest

IM is employed by the company Delphis S.A.

The remaining authors declare that the present review paper was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Keywords: air pollution, environment, health, public health, gas emission, policy

Citation: Manisalidis I, Stavropoulou E, Stavropoulos A and Bezirtzoglou E (2020) Environmental and Health Impacts of Air Pollution: A Review. Front. Public Health 8:14. doi: 10.3389/fpubh.2020.00014

Received: 17 October 2019; Accepted: 17 January 2020; Published: 20 February 2020.

Reviewed by:

Copyright © 2020 Manisalidis, Stavropoulou, Stavropoulos and Bezirtzoglou. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Ioannis Manisalidis, giannismanisal@gmail.com ; Elisavet Stavropoulou, elisabeth.stavropoulou@gmail.com

† These authors have contributed equally to this work

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

• Biology Article
• Essay On Air Pollution 200 Words 500 Words

Essay on Air Pollution

Essay on air pollution is a crucial topic for students from an academic perspective. Moreover, an essay is one of the most effective ways to educate students about the plight of nature and the repercussions of human activities. Creating awareness for future generations is important if we have to undo decades of ignorance and neglect.

Furthermore, air pollution essay helps students to realize the gravity of the scenario and enable them to take action. Some as simple as using public transport or even carpooling will help reduce a significant amount of air pollution. Read on to discover how to write an engaging essay on air pollution.

Essay on Air Pollution – Important Points to Note

Please consider adopting the following points when writing an essay on air pollution. These tips are also helpful for other essay topics as well:

• Always begin with an introductory paragraph about the topic, preferably detailing its origin.
• Unless the topic is technical, try to avoid jargons.
• Present content in bulleted points wherever possible
• Insert factual data, such as important dates, places or name wherever possible.
• Avoid writing the content in a large monotonous block of text. Remember to break up the content into digestible chunks
• Always conclude the essay with a closing paragraph.

Essay on Air Pollution – Sample 1 (200 Words)

Air pollution is a serious issue and a cause for major concern in today’s world. A report published in 2014  by the World Health Organisation states that 4.21 million individuals died prematurely in 2012 as a result of air pollution. Air pollution existed much before humans, in the form of volcanic eruptions and forest fires. However, it became much more prevalent after the Industrial Revolution.

Rapid industrial growth, unregulated emissions and a host of other issues significantly contributed to the rise in air pollution. In some cases, the severity of air pollution reached an extent where government intervention was necessary. The Great Smog of London, 1952, was an extreme case of air pollution where visibility was severely hampered. It also caused a host of illnesses and the consequent deaths of countless civilians. In November 2017, the levels of air pollution in Delhi were ten times above the safe limits. For reference, the healthy air quality index is between 0 to 50, but during that particular time period, the air quality index hit 500+. This event is now called the Great Smog of Delhi.

An air quality index of 500 and above indicates that the air is heavily polluted and will cause irreversible lung damage and a host of other illnesses to everyone who is exposed to it. Therefore, to avoid such situations in the future, relevant actions must be implemented.

Essay on Air Pollution – Sample 2 (500 Words)

Air pollution may seem like the result of anthropological activities, however, it has been around even before humans evolved. Places which are naturally arid and have minimal vegetation are prone to dust storms. When this particulate matter is added to the air, it can cause health issues in animals exposed to the dust storms.

Furthermore, active volcanoes pump extremely large amounts of toxic plumes and particulate matter into the atmosphere. Wildfires also pump large amounts of carbon monoxide into the atmosphere and hamper photosynthesis for plants. Even animals, especially ruminants such as cows contribute to global warming by producing large quantities of methane, a greenhouse gas.

However, air pollution was never a major concern until the industrial revolution. Industries grew rapidly, untreated emissions were pumped into the atmosphere, and the rise of automobiles significantly contributed to air pollution. Such activities continued without any restrictions until they started to cause a wide range of repercussions.

In humans, air polluted with contaminants can cause a wide array of illnesses ranging from asthma and bronchitis the various forms of cancer. Air pollution is not only present outdoors; interior air pollution is also a great concern. Recent research has actually found credible evidence that room fresheners have the many compounds within them, some of which are classified carcinogens. This means some of those compounds present in the aerosol has the potential to cause some forms of cancer. Other sources of air pollution can include gases such as carbon monoxide and radon.

Radon, in particular, is quite alarming. It is an odourless, colourless gas that occurs naturally. It is found in the soil as Uranium, which breaks down and eventually turns into radon gas. Radon has limited repercussions on health if exposed to low concentrations, however, when this gas gets trapped indoor, the higher levels of concentration can have wreak havoc or ultimately be lethal. Radon is also reported to be released from building materials such as granite. Exposure to radon causes no immediate health effects, but long term exposure has the potential to cause lung cancer.

Air pollution not only affects the lungs but the central nervous system too. It has been linked to a lot of diseases such as schizophrenia and autism. A study also implied that it can cause short-term memory losses or distortion of memory.

Historically, air pollution has caused many crises with the worst ever being the Bhopal Disaster in 1984. Fatalities were estimated at 3,800, with at least 600,000 injured. Next in severity was the Great Smog of 1952 which formed over London, killing an estimated 4,000 civilians over the course of four days.

Though measures have been taken to reduce the effects of air pollution, a lot of irreversible damage has been done. For instance, the effects of global warming have drastically increased; this is very apparent with the rise in sea levels and melting glaciers. If the ice caps continue to melt, then we will have to face drastic repercussions. Scientists have proposed a hypothetical scenario where the greenhouse effect becomes “uncontrolled.” Here, greenhouse gases build up and temperatures continue to rise steeply. Oceans will start to evaporate, adding more water vapour into the earth’s atmosphere. This intensifies the effect, reaching a point where temperatures are sufficiently high for rocks start sublimating. Though this scenario is hypothetical, some speculate that this phenomenon already occurred on Venus. The supporters of this theory back this up by claiming Venus has an atmosphere composed primarily of carbon dioxide. The theory also explains why Venus has an extremely high surface temperature of 462 degrees Celcius; which is in fact, the hottest planet in the solar system.

Hence, we need to reduce our impact on the planet and make a conscious effort to reduce air pollution. Explore more essay topics or other fascinating concepts by registering at BYJU’S

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74 Ocean Pollution Essay Topic Ideas & Examples

🏆 best ocean pollution topic ideas & essay examples, 👍 good essay topics on ocean pollution, 📌 simple & easy ocean pollution essay titles, ❓ research questions about ocean pollution.

• Ocean Pollution and the Fishing Industry In essence, the activities of over six billion people in the world are threatening the survival and quality of water found in the oceans, lakes and other inland water catchment areas.
• The World Oceans Pollution and Overfishing Human beings have taken a lot of time to realize the need for ocean conservation to the extent that the ocean has succumbed to ecological challenges that have affected their lives in a variety of […]
• Concerns of Ocean Ecosystem Pollution The range of adverse outcomes for ocean ecosystems can be discussed in volumes; however, the current discussion will focus on trash in the ocean waters, acidification, and the disruption of the marine life cycles.
• The Problem of Ocean Pollution in Modern World Wastes such as toxic matter, plastics, and human wastes are some of the major sources of pollution in the ocean. Many people consume fish as food; when marine life is affected by toxic substance in […]
• Plastic Ocean Pollution on Ocean Life in U.S. Ocean plastic pollution has had a great impact on a minimum of two hundred and sixty seven species across the world and these include forty three percent of all of the sea mammal species, eighty […]
• How Ocean Pollution Impacts Earth
• Ocean Pollution: Causes, Effects, and Prevention
• Human Impact Upon the Environment: Ocean Pollution and Marine Life
• Ocean Pollution and Other Human Environmental Impacts
• How to Reduce Plastic and Other Ocean Pollution
• Ocean Pollution and Its Effects on the Ocean
• The Causes of Ocean Pollution and the Need for Humans to Save Life
• Ocean Pollution and Its Impact on Coral Reefs
• Plastic Pollution in the Ocean
• Should the Government Regulate Ocean Pollution?
• An Introduction to the Issue of Ocean Pollution in the Third World
• Plastic Pollution in Tho Ocean: Facts and Information
• Ocean Pollution: Marine Pollution Facts and Information
• Ocean Pollution for the Most Wildlife
• The Causes of Ocean Pollution and The Need for Humans to Save Marine Life
• The Historical & Current Characteristics of Western Ireland Coastlines & Galway Bay
• An Overview of the Ocean Waters and Increasing Ocean Pollution
• A Discussion About the Ocean Pollution and Human Wastes
• Ocean Pollution and a “Dead Zone”
• A History of the Ocean Pollution and the Effects of It
• An Overview of the Methods for Cleaning the Ocean Pollution
• A Study of Plastic Ocean Pollution in the Pacific Ocean
• Life Below Water: Conserve and Sustainably Use The Ocean
• The Global Issue of Ocean Pollution and Its Solutions
• Ocean Pollution and the Effects of It
• Plastic Pollution and its Effect on the Thermal Capacity of Seawater
• Causes and Effects of Ocean Pollution
• Environmental Impact on Ocean Pollution
• The Effects of Ocean Pollution on the Environment
• Plastic Pollution and Noise Pollution in Oceans
• Ocean Dumping of Unpurified Wastewater
• Oil Spills Is a Huge Source of Ocean Pollution
• The Effects of Ocean Pollution on the Marine Ecosystem and Animals
• The Problem of The Great Pacific Patch
• Ocean Pollution: Effects on Human Health and Commerce
• Ocean Conservancy and Their Contribution to Whale Protection
• Urban Runoff Is the Primary Source of Ocean Pollution
• Emerging Technologies to Combat Ocean Pollution
• The Harmful Effects of an Ocean Pollution on Human Health
• Sustainability of American Lifestyle With Ocean Pollution
• What Efforts Is Ocean Cleanup Making to Clean up Ocean Plastic and Reduce Pollution?
• How Does Ocean Pollution Affect Coral Reefs?
• What Is the Connection Between Drinking Water Scarcity and Ocean Pollution?
• Is Globalization One of the Causes of Ocean Pollution?
• What Are the Main Causes of Ocean Pollution Around the World?
• How Does Human Overpopulation Affect Ocean Pollution?
• What Is the Government Doing About Ocean Pollution?
• Why Do People in Coastal Fishing Communities and Small Island Nations Suffer the Most from Ocean Pollution?
• Should World Powers Focus on Eradicating Ocean Pollution?
• What Are Some Ways to Help Reduce Ocean Pollution?
• How Can Countries Contribute to Reducing Ocean Pollution in the Economy?
• What Is the Most Dangerous in Ocean Pollution?
• Is There a Connection Between Ocean Pollution and Global Warming?
• What Are the Disadvantages of Ocean Pollution for the National Recreational Fishing Survey (NRFS)?
• How Does Ocean Pollution Affect Humans and Animals?
• What Are Voluntary Incentives to Reduce Ocean Water Pollution?
• Is Human Activity the Main Cause of Ocean Pollution?
• What Is the Link Between Ocean Pollution and Climate Change?
• How Does Ocean Pollution Affect the Economy?
• What Are the Main Causes of Ocean Pollution?
• Are Humans or Animals Most Affected by Ocean Pollution?
• What Are the Effects of Ocean Pollution on Human Health?
• Why Is Microplastic Such a Big Problem in Ocean Pollution?
• How Do Humans Affect the Environment, Ocean Pollution, and Marine Life?
• Is There Any Chance That Ocean Pollution Will Stop?
• What Is the Impact of Pesticide Use on Ocean Pollution and Health Effects?
• How Does Ocean Pollution Affect the Climate?
• What Are the Main Causes and Effects of Ocean Pollution?
• Coral Reef Essay Topics
• Atmosphere Questions
• Greenhouse Gases Research Ideas
• Environment Research Topics
• Environmental Protection Titles
• Hazardous Waste Essay Topics
• Noise Pollution Essay Titles
• Recycling Research Ideas
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Essay on Air Pollution for Students and Children

500+ words essay on air pollution.

Essay on Air Pollution – Earlier the air we breathe in use to be pure and fresh. But, due to increasing industrialization and concentration of poisonous gases in the environment the air is getting more and more toxic day by day. Also, these gases are the cause of many respiratory and other diseases . Moreover, the rapidly increasing human activities like the burning of fossil fuels, deforestation is the major cause of air pollution.

How Air Gets Polluted?

The fossil fuel , firewood, and other things that we burn produce oxides of carbons which got released into the atmosphere. Earlier there happens to be a large number of trees which can easily filter the air we breathe in. But with the increase in demand for land, the people started cutting down of trees which caused deforestation. That ultimately reduced the filtering capacity of the tree.

Moreover, during the last few decades, the numbers of fossil fuel burning vehicle increased rapidly which increased the number of pollutants in the air .

Causes Of Air Pollution

Its causes include burning of fossil fuel and firewood, smoke released from factories , volcanic eruptions, forest fires, bombardment, asteroids, CFCs (Chlorofluorocarbons), carbon oxides and many more.

Besides, there are some other air pollutants like industrial waste, agricultural waste, power plants, thermal nuclear plants, etc.

Greenhouse Effect

The greenhouse effect is also the cause of air pollution because air pollution produces the gases that greenhouse involves. Besides, it increases the temperature of earth surface so much that the polar caps are melting and most of the UV rays are easily penetrating the surface of the earth.

Get the huge list of more than 500 Essay Topics and Ideas

Effects Of Air Pollution On Health

Moreover, it increases the rate of aging of lungs, decreases lungs function, damage cells in the respiratory system.

Ways To Reduce Air Pollution

Although the level of air pollution has reached a critical point. But, there are still ways by which we can reduce the number of air pollutants from the air.

Reforestation- The quality of air can be improved by planting more and more trees as they clean and filter the air.

Policy for industries- Strict policy for industries related to the filter of gases should be introduced in the countries. So, we can minimize the toxins released from factories.

Use of eco-friendly fuel-  We have to adopt the usage of Eco-friendly fuels such as LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), bio-gas, and other eco-friendly fuels. So, we can reduce the amount of harmful toxic gases.

To sum it up, we can say that the air we breathe is getting more and more polluted day by day. The biggest contribution to the increase in air pollution is of fossil fuels which produce nitric and sulphuric oxides. But, humans have taken this problem seriously and are devotedly working to eradicate the problem that they have created.

Above all, many initiatives like plant trees, use of eco-friendly fuel are promoted worldwide.

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• Environmental Pollution Essay

Essay on Environmental Pollution

The environment is the surrounding of an organism. The environment in which an organism lives is made up of various components like air, water, land, etc. These components are found in fixed proportions to create a harmonious balance in the environment for the organism to live in. Any kind of undesirable and unwanted change in the proportions of these components can be termed as pollution. This issue is increasing with every passing year. It is an issue that creates economic, physical, and social troubles. The environmental problem that is worsening with each day needs to be addressed so that its harmful effects on humans as well as the planet can be discarded.

Causes of Environmental Pollution 

With the rise of the industries and the migration of people from villages to cities in search of employment, there has been a regular increase in the problem of proper housing and unhygienic living conditions. These reasons have given rise to factors that cause pollution. 

Environmental pollution is of five basic types namely, Air, Water, Soil, and Noise pollution. 

Air Pollution: Air pollution is a major issue in today’s world. The smoke pouring out of factory chimneys and automobiles pollute the air that we breathe in. Gases like carbon dioxide, carbon monoxide, and sulphur dioxide are emitted with this smoke which mixes with air and causes great harm to the human body, flora, and fauna. The dry-farm waste, dry grass, leaves, and coal used as domestic fuels in our villages also produce harmful gases. Acid rain occurs due to an excess of sulphur dioxide in the air.

The Main Sources of Air Pollution are as Follows:  

Automobile pollution 

Industrial air pollution 

Burning garbage 

Brick kilns 

Indoor air pollution 

Decomposed animals and plants 

Radioactive elements

Water Pollution: Water pollution is one of the most serious environmental issues. The waste products from the growing industries and sewage water are not treated properly before disposing of the wastewater into the rivers and other water bodies, thus leading to water pollution. Agricultural processes with excess fertilizers and pesticides also pollute the water bodies. 

The Main Sources of Water Pollution as Follows:  

Marine commerce. 

Industrial effluents joining seas and oceans. 

Dumping of radioactive substances into seawater. 

Sewage is disposed of into the sea by rivers. 

Offshore oil rigs. 

Recreational activities. 

Agricultural pollutants are disposed of into the water bodies.

Soil or Land Pollution: Soil pollution or land pollution results from the deposition of solid waste, accumulation of biodegradable material, deposition of chemicals with poisonous chemical compositions, etc on the open land. Waste materials such as plastics, polythene, and bottles, cause land pollution and render the soil infertile. Moreover, the dumping of dead bodies of animals adds to this issue. Soil pollution causes several diseases in man and animals like Cholera, Dysentery, Typhoid, etc.

The Main Causes of Soil Pollution are as Follows:  

Industrial waste 

Urban commercial and domestic waste 

Chemical fertilizers 

Biomedical waste 

Noise Pollution: With an increasing population, urbanization, and industrialization, noise pollution is becoming a serious form of pollution affecting human life, health, and comfort in daily life. Horns of vehicles, loudspeakers, music systems, and industrial activities contribute to noise pollution. 

The Main Sources of Noise Pollution as Follows:  

The machines in the factories and industries produce whistling sounds, crushing noise, and thundering sounds. 

Loudspeakers, horns of vehicles. 

Blasting of rocks and earth, drilling tube wells, ventilation fans, and heavy earth-moving machinery at construction sites.

How Pollution Harms Health and Environment

The lives of people and other creatures are affected by environmental pollution, both directly and indirectly. For centuries, these living organisms have coexisted with humans on the planet. 

1. Effect on the Environment

Smog is formed when carbon and dust particles bind together in the air, causing respiratory problems, haze, and smoke. These are created by the combustion of fossil fuels in industrial and manufacturing facilities and vehicle combustion of carbon fumes. 

Furthermore, these factors impact the immune systems of birds, making them carriers of viruses and diseases. It also has an impact on the body's system and organs. 

2.  Land, Soil, and Food Effects 

The degradation of human organic and chemical waste harms the land and soil. It also releases chemicals into the land and water. Pesticides, fertilisers, soil erosion, and crop residues are the main causes of land and soil pollution. 

3. Effects on water 

Water is easily contaminated by any pollutant, whether it be human waste or factory chemical discharge. We also use this water for crop irrigation and drinking. They, too, get polluted as a result of infection. Furthermore, an animal dies as a result of drinking the same tainted water. 

Furthermore, approximately 80% of land-based pollutants such as chemical, industrial, and agricultural waste wind up in water bodies. 

Furthermore, because these water basins eventually link to the sea, they contaminate the sea's biodiversity indirectly. 

4. Food Reaction

Crops and agricultural produce become poisonous as a result of contaminated soil and water. These crops are laced with chemical components from the start of their lives until harvest when they reach a mass level. Due to this, tainted food has an impact on our health and organs. 

5. Climate Change Impact 

Climate change is also a source of pollution in the environment. It also has an impact on the ecosystem's physical and biological components. 

Ozone depletion, greenhouse gas emissions, and global warming are all examples of environmental pollution. Because these water basins eventually link to the sea, they contaminate the sea's biodiversity indirectly. Furthermore, their consequences may be fatal for future generations. The unpredictably cold and hot climate impacts the earth’s natural system. 

Furthermore, earthquakes, starvation, smog, carbon particles, shallow rain or snow, thunderstorms, volcanic eruptions, and avalanches are all caused by climate change, caused entirely by environmental pollution.

How to Minimise Environmental Pollution? 

To minimise this issue, some preventive measures need to be taken. 

Principle of 3R’s: To save the environment, use the principle of 3 R’s; Reuse, Reduce and Recycle. 

Reuse products again and again. Instead of throwing away things after one use, find a way to use them again.  Reduce the generation of waste products.  

Recycle: Paper, plastics, glass, and electronic items can be processed into new products while using fewer natural resources and lesser energy. 

To prevent and control air pollution, better-designed equipment, and smokeless fuels should be used in homes and industries. More and more trees should be planted to balance the ecosystem and control greenhouse effects. 

Noise pollution can be minimised by better design and proper maintenance of vehicles. Industrial noise can be reduced by soundproofing equipment like generators, etc.  

To control soil pollution, we must stop the usage of plastic. Sewage should be treated properly before using it as fertilizers and as landfills. Encourage organic farming as this process involves the use of biological materials and avoiding synthetic substances to maintain soil fertility and ecological balance. 

Several measures can be adopted to control water pollution. Some of them are water consumption and usage that can be minimized by altering the techniques involved. Water should be reused with treatment. 

The melting icebergs in Antarctica resulted in rising sea levels due to the world's environmental pollution, which had become a serious problem due to global warming, which had become a significant concern. Rising carbon pollution poses a risk for causing natural disasters such as earthquakes, cyclones, and other natural disasters. 

The Hiroshima-Nagasaki and Chernobyl disasters in Russia have irreversibly harmed humanity. Different countries around the world are responding to these calamities in the most effective way possible. 

Different countries around the world are responding to these calamities in the most effective way possible. More public awareness campaigns are being established to educate people about the hazards of pollution and the importance of protecting our environment. Greener lifestyles are becoming more popular; for example, energy-efficient lighting, new climate-friendly autos, and the usage of wind and solar power are just a few examples. 

Governments emphasise the need to plant more trees, minimise the use of plastics, improve natural waste recovery, and reduce pesticide use. This ecological way of living has helped humanity save other creatures from extinction while making the Earth a greener and safer ecology. 

 Conclusion

It is the responsibility of every individual to save our planet from these environmental contamination agents. If preventive measures are not taken then our future generation will have to face major repercussions. The government is also taking steps to create public awareness. Every individual should be involved in helping to reduce and control pollution.

FAQs on Environmental Pollution Essay

1. What do you understand by ‘Environmental Pollution’?  

Environmental pollution is the contamination of the environment and surroundings like air, water, soil by the discharge of harmful substances.

2. What preventive measures should be taken to save our environment?

Some of the preventive measures that should be taken to save our environment are discussed below. 

We can save our environment by adopting the concept of carpooling and promoting public transport to save fuel. Smoking bars are public policies, including criminal laws and occupational safety and health regulations that prohibit tobacco smoking in workplaces and other public places.  

The use of Fossil fuels should be restricted because it causes major environmental issues like global warming.  

Encourage organic farming to maintain the fertility of the soil.

3.  What are the main sources of soil pollution?

The main sources of soil pollution as follows:

Industrial waste

Urban commercial and domestic waste

Chemical fertilizers

Biomedical waste

4. What is organic farming?

 It is a farming method that involves growing and nurturing crops without the use of synthetic fertilizers and pesticides.

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May 24, 2024

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Ambitious targets are needed to end ocean plastic pollution by 2100, analysis finds

by Alex Epshtein, Imperial College London

A collaboration between researchers at Imperial College London and GNS Science, suggests that reducing plastic pollution by 5% per year would stabilize the level of microplastics—plastics less than 5 mm in length—in the surface oceans.

However, the modeling shows that even reducing pollution by 20% per year would not significantly reduce existing microplastics levels, meaning they will persist in our oceans beyond 2100.

Microplastics have been found to be circulating in all of the Earth's oceans and some of the greatest concentrations of them are thousands of miles from land. These tiny particles of plastics can be hazardous to marine life and they find their way back from our oceans into human food systems.

The United Nations Environmental Assembly (UNEA) are aiming to adopt a legally binding resolution to completely eradicate the production of plastic pollution from 2040, including ocean microplastics.

The researchers developed a model to predict the impact on ocean microplastics of eight different scenarios of plastic pollution reduction over the next century, starting from 2026 up to 2100.

The results, published in Environmental Research Letters , show that if countries reduce plastic pollution by more than 5% each year, the amount of microplastics in the ocean could stabilize, rather than continue to increase.

First author Zhenna Azimrayat Andrews, who completed the work for her MSc in Environmental Technology at the Center for Environmental Policy, Imperial College London, said, "Plastic is now everywhere in the environment, and the ocean is no exception. While our results show that microplastics will be around in the oceans past the end of the century, stabilizing their levels is the first step towards elimination."

Removing microplastics from the ocean's surface

Microplastics pose the greatest threat when they accumulate in the surface ocean, where they are consumed by ocean life, including fish that we may eat. One way microplastics can be removed from the surface ocean is by clumping together with tiny living organisms or waste material, like organic debris or animal droppings. These clumps can sink down into the deep ocean , taking the microplastics with them.

The team's calculations, combined with real-world observations and testing of the model, suggest that the buoyancy of the microplastics prevents these clumps from sinking, trapping them near the surface. Understanding how these clumps affect the levels of microplastics in the ocean is important for setting goals to reduce plastic pollution.

As marine life holds onto microplastics near the surface, even if the level of pollution produced every year is reduced, there would still be microplastics in the surface ocean for centuries. When they do sink, they will subsequently last in the deeper levels of the ocean for much longer, where their impacts are not well known.

Azimrayat Andrews said, "There can never be a completely successful removal of microplastics from all depths of the ocean, we kind of just need to live with it now. But the current global output of plastic pollution is so great, that even a 1% annual reduction in pollution would make a big difference overall."

Setting ambitious and realistic goals

The researchers' model is the first study that examines the efficacy of plausible treaty reduction targets. The large reductions required to reduce contamination indicate that a more coordinated international policy is necessary, rather than the UN's proposed goal of 0% plastic pollution by 2040.

Azimrayat Andrews said, "If we want to move towards a lower plastic society, change needs to happen at a higher level. These changes should happen on an industrial level, as no single individual should have the weight of the world on their shoulders.

"Therefore, we need a more sustainable lifestyle integration, rather than people having to make individual choices, and so organizations like the NHS don't have this pressure to become zero plastic in 10 years because the UN said so. National organizations will need to reduce their plastic use, but systemic change in industrial and commercial sectors could allow more grace for organizations like the NHS in the meantime."

The researchers hope their analysis will help inform UN negotiations, which are planned throughout the year.

Journal information: Environmental Research Letters

Provided by Imperial College London

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Why cancer-causing pollution from oil refineries is falling

In an environmental success story, refineries have reduced their emissions of benzene due to federal regulations and oversight.

For years, oil refineries across the country have pumped out dangerous levels of benzene, a toxic chemical that can cause leukemia and other blood cancers.

But in a rare example of environmental progress, benzene emissions from nearly all of those refineries have recently plummeted due to strong federal regulations and oversight, according to a new analysis by a watchdog group.

In 2015, the Environmental Protection Agency finalized a rule that requires refineries to continually monitor benzene emissions along their property boundaries, or their fence lines. If refineries exceed the EPA’s “action level” of 9 micrograms per cubic meter on an annual average basis, they must find and fix benzene leaks from storage tanks and other infrastructure.

The regulation appears to be working and protecting hundreds of communities near refineries, with the exception of a few areas along the Gulf Coast, according to the Environmental Integrity Project, a watchdog group that analyzed EPA data.

Only six of the 115 refineries in the country had average annual benzene levels exceeding the EPA’s action level last year, according to the analysis. That figure fell from nine at the end of 2022, 11 in 2021 and 12 in 2020, the group found.

“It’s a big improvement, and benzene is especially nasty,” said Eric Schaeffer, executive director of the Environmental Integrity Project and a former senior EPA enforcement official.

Short-term exposure to high concentrations of benzene, a sweet-smelling chemical found in gasoline and other petroleum products, can cause headaches, dizziness and unconsciousness. Long-term exposure has been linked to a higher risk of cancer, especially leukemia and other cancers that affect the blood and bone marrow.

For Schaeffer, whose group has been largely critical of the EPA’s decisions under both Republican and Democratic presidents, the findings offer a rare opportunity to compliment the agency.

“We complain a lot,” he said, laughing. “It’s our job to point out problems that need attention … but we wanted to recognize a positive trend.”

David Uhlmann, who leads the EPA’s Office of Enforcement and Compliance Assurance, said the federally mandated fence-line monitoring of benzene emissions has been a “game changer.”

“It shines a bright light on facilities that are emitting more benzene than they’re allowed to,” he said in an interview. “And sunshine is the best disinfectant.”

Uhlmann, who became the EPA’s top cop in August, said the Biden administration has prioritized reductions in benzene pollution as part of its commitment to environmental justice .

“In the last administration, there was a reluctance by the political leadership to pursue violations at oil and gas facilities,” he said. “And we’ve corrected for that over the last three years.”

Some refineries have seen consistent year-over-year decreases in benzene levels, the data shows. At HF Sinclair’s Navajo Refinery in Artesia, N.M., the benzene concentration fell from 25.8 micrograms per cubic meter in 2019 to 11.3 in 2020, 8.2 in 2021, 2.3 in 2022, and 2 in 2023.

The decline could curb cancer risks in disadvantaged communities near the refinery. The facility is blocks away from an elementary school and residential neighborhoods, where half of residents live below the poverty line and roughly three-quarters are Latino.

However, the news isn’t all positive along the Gulf Coast, a major hub for oil and gas production. Of the six refineries that surpassed the EPA’s limit last year, four were along the Gulf Coast, with two in Texas and two in Louisiana.

Texas had some of the worst offenders. At TotalEnergies’ Port Arthur Refinery in Port Arthur, Tex., benzene concentrations exceeded the EPA’s action level in every reporting period since monitoring began in January 2019. And at the Pemex Deer Park Refinery east of Houston, benzene pollution has been rising and reached nearly twice the EPA’s limit at the end of last year.

While the overall drop in benzene pollution is encouraging, the data shows that “there is still work to be done, especially in Texas,” said Anthony D’Souza, research and policy coordinator at Air Alliance Houston, a nonprofit advocacy group.

“Some of these polluters are so close to residences, schools, parks and churches,” D’Souza added. “For people who live in these areas, it’s a chronic burden.”

Late last year, The Washington Post reported on people living near Gulf Coast refineries that exceeded safe levels of benzene and other pollutants . Some of those residents and environmental advocates criticized the EPA’s Region 6 office, which covers Texas, Louisiana and three adjoining states, as being far too lenient when ensuring that state regulators enforce environmental laws.

Yet even then, the Region 6 office was starting to act. This past fall, the office notified TotalEnergies that the Port Arthur Refinery had violated the Clean Air Act, according to a notice of violation obtained by The Post.

In the notice, EPA officials wrote that TotalEnergies had failed to promptly alert the Texas Commission on Environmental Quality of a benzene leak at the facility in May 2022. The company did not do so until 113 days after the incident and one day after an EPA inspection of the facility, according to the notice.

The EPA also conducted an inspection of the Deer Park Refinery on April 16, said agency spokesman Jeff Landis. The air monitors appeared to be too far from the facility’s fence line, meaning the benzene concentrations may have been even higher than official records suggest, said an EPA staffer involved in the inspection who spoke on the condition of anonymity because he was not authorized to comment publicly.

TotalEnergies, the French oil giant, and Pemex, the Mexican state-owned petroleum company that acquired full ownership of the Deer Park Refinery in 2022, did not respond to requests for comment.

While the 2015 regulations focused on oil refineries, the EPA recently cracked down on toxic pollution from chemical plants. In April, the agency finalized a rule that will require roughly 200 chemical plants to monitor and reduce emissions of benzene, ethylene oxide and other pollutants linked to increased cancer risk.

In addition, the EPA and the Justice Department announced Tuesday that the petrochemical company TPC Group has agreed to pay more than $30 million in criminal fines and civil penalties related to 2019 explosions at its facility in Port Neches, Tex. The explosions injured at least three workers , prompted evacuation orders for more than 50,000 people and sent a plume of smoke stretching for miles.

“TPC Group sincerely regrets the damage and disruption caused by the November 2019 incident at our Port Neches facility,” spokeswoman Sara Cronin said in an email.

In the more than four years since the explosions, the company has invested millions of dollars in safety initiatives, Cronin said, adding that “we continue to work every day to be a positive part of the communities in which we operate.”

ENCYCLOPEDIC ENTRY

Marine pollution.

Marine pollution is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide.

Biology, Ecology, Earth Science, Oceanography

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• Marine Pollution (Google Doc)

Marine pollution is a growing problem in today’s world. Our ocean is being flooded with two main types of pollution: chemicals and trash.

Chemical contamination, or nutrient pollution, is concerning for health, environmental, and economic reasons. This type of pollution occurs when human activities, notably the use of fertilizer on farms, lead to the runoff of chemicals into waterways that ultimately flow into the ocean. The increased concentration of chemicals, such as nitrogen and phosphorus, in the coastal ocean promotes the growth of algal blooms , which can be toxic to wildlife and harmful to humans. The negative effects on health and the environment caused by algal blooms hurt local fishing and tourism industries.

Marine trash encompasses all manufactured products—most of them plastic —that end up in the ocean. Littering, storm winds, and poor waste management all contribute to the accumulation of this debris , 80 percent of which comes from sources on land. Common types of marine debris include various plastic items like shopping bags and beverage bottles, along with cigarette butts, bottle caps, food wrappers, and fishing gear. Plastic waste is particularly problematic as a pollutant because it is so long-lasting. Plastic items can take hundreds of years to decompose.

This trash poses dangers to both humans and animals. Fish become tangled and injured in the debris , and some animals mistake items like plastic bags for food and eat them. Small organisms feed on tiny bits of broken-down plastic , called micro plastic , and absorb the chemicals from the plastic into their tissues. Micro plastics are less than five millimeters (0.2 inches) in diameter and have been detected in a range of marine species, including plankton and whales. When small organisms that consume micro plastics are eaten by larger animals, the toxic chemicals then become part of their tissues. In this way, the micro plastic pollution migrates up the food chain , eventually becoming part of the food that humans eat.

Solutions for marine pollution include prevention and cleanup. Disposable and single-use plastic is abundantly used in today’s society, from shopping bags to shipping packaging to plastic bottles. Changing society’s approach to plastic use will be a long and economically challenging process. Cleanup, in contrast, may be impossible for some items. Many types of debris (including some plastics ) do not float, so they are lost deep in the ocean. Plastics that do float tend to collect in large “patches” in ocean gyres. The Pacific Garbage Patch is one example of such a collection, with plastics and micro plastics floating on and below the surface of swirling ocean currents between California and Hawaii in an area of about 1.6 million square kilometers (617,763 square miles), although its size is not fixed. These patches are less like islands of trash and, as the National Oceanic and Atmospheric Administration says, more like flecks of micro plastic pepper swirling around an ocean soup. Even some promising solutions are inadequate for combating marine pollution. So-called “ biodegradable ” plastics often break down only at temperatures higher than will ever be reached in the ocean.

Nonetheless, many countries are taking action. According to a 2018 report from the United Nations, more than sixty countries have enacted regulations to limit or ban the use of disposable plastic items. The National Geographic Society is making this content available under a Creative Commons CC-BY-NC-SA license . The License excludes the National Geographic Logo (meaning the words National Geographic + the Yellow Border Logo) and any images that are included as part of each content piece. For clarity the Logo and images may not be removed, altered, or changed in any way.

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The Victims of U.S. Nuclear Testing Deserve More Than This

By W.J. Hennigan

Mr. Hennigan writes about national security issues for Times Opinion.

The men and women came to Capitol Hill last week bearing surgical scars, long medical histories and fading photographs of loved ones long dead. They came from across the country to walk the halls of Congress and show lawmakers the human cost of the U.S. nuclear weapons program.

They call themselves downwinders — a global community of people who lived near nuclear testing sites. In America, more than 100 nuclear devices were exploded in aboveground tests in New Mexico and Nevada from 1945 to 1962. For decades, members of the communities near those sites, as well as others involved in weapons production, have endured rare cancers, autoimmune disorders and other illnesses. But only some have been compensated by the federal government for what they’ve gone through.

The downwinders who visited Washington last week are not currently eligible for federal assistance because they don’t live in the designated areas in Utah, Nevada and Arizona covered under the Radiation Exposure Compensation Act, known as RECA. The 1990 legislation has provided billions of dollars to people exposed to harmful radiation during U.S. nuclear tests or while mining uranium. But many affected communities, including those in southern New Mexico where J. Robert Oppenheimer’s team conducted the first atomic blast in 1945, were left off the list.

They have been fighting to be included under the law. Now RECA is to expire on June 7, bringing an end to the program. A bill stalled in Congress would extend the law and expand compensation to nearly all Americans whose documented health struggles are linked to the nuclear weapons program. The White House supports it. The Senate passed it in a rare bipartisan vote, 69 to 30, in March.

But for the past two months, Speaker Mike Johnson has refused to allow a House vote on the Senate bill. As of Wednesday, there will be just seven working days left in Congress before RECA runs out, cutting off compensation and health screenings to all affected communities.

The federal government is responsible for protecting its citizens. Washington betrayed that obligation when it exposed people to dangerous radiation for decades during the Cold War and then downplayed, denied and ignored the health risks , according to declassified documentation. American downwinders have paid for this neglect; now they’re simply asking their government for restitution.

This article is part of the Opinion series At the Brink , about the threat of nuclear weapons in an unstable world. Read the opening piece here .

Consider the costs borne by people like Bernice Gutierrez , 78, who was 8 days old when the world’s first atomic bomb exploded in July 1945 at the Trinity site, about 35 miles west of her hometown, Carrizozo, N.M.

None of the nearly 500,000 people who resided within a 150-mile radius of the blast were warned. The explosive yield of the Trinity test was 21 kilotons — almost 1.5 times as large as the Hiroshima bomb — sending a mushroom cloud more than 35,000 feet into the sky. Witnesses said ash rained down in New Mexico for days. Like snow, it tumbled into water cisterns, open windows, crop fields and grazing pastures.

In the years since, 29 members of Ms. Gutierrez’s family have been diagnosed with various types of cancer. Several have died, including her son Toby Jr., who died of leukemia when he was 56. Her daughter, Jeanne, is being treated for thyroid cancer. Ms. Gutierrez had her thyroid removed on the advice of her physician because, the doctor told her, a positive cancer diagnosis was all but certain. “We don’t ever ask if we’re going to get it,” she said. “We wonder when.”

Around the world, thyroid disorders are among the most widespread health impacts of nuclear fallout and contamination. The thyroid absorbs a radioactive form of iodine called I-131, a byproduct of nuclear fission used in a nuclear test, which concentrates inside the gland and can lead to increased risk of thyroid disease. While it’s impossible to connect any one person’s cancer diagnosis directly to radiation exposure from the test, the National Cancer Institute estimates that 11,000 to 212,000 cases of thyroid cancer across the country are linked to exposure to radioactive fallout from aboveground nuclear tests in Nevada.

In New Mexico a 2010 Centers for Disease Control and Prevention study noted that radiation levels near some homes in the area of the Trinity test site reached almost 10,000 times what is currently allowed in public areas. It also pointed out that radioactive debris from the test had drifted across a region about 100 miles long and 30 miles wide. More recent studies have shown that the fallout from the test was carried on the wind much farther — to 46 states, Canada and Mexico. “Our government took advantage of the fact that we knew nothing about radiation,” Ms. Gutierrez said. “We knew nothing about the cause and effect of it.”

To qualify for downwinder benefits under RECA, you must prove you lived in one of roughly 20 counties for at least two years from Jan. 21, 1951, to Oct. 31, 1958, when aboveground testing at the Nevada site was most active, or during July 1962, when a 104-kiloton explosion there displaced 12 million tons of sand and rock, hurling much of it into the atmosphere before it returned to earth as dust and in rain.

Additionally, you must have been diagnosed with one of 19 types of cancer that the government has determined are related to the nuclear program. If you check all the boxes, you can receive $50,000. In the three decades since the law took effect, only 41,200 claims have been approved , paying out some $2.6 billion. In comparison, more than 65,000 claimants have received around $20 billion under the 9/11 Victim Compensation Fund .

The new bill would expand eligibility for compensation to certain uranium miners and widen the current list of recognized affected areas, to include Colorado, Idaho, Montana, New Mexico, Missouri, Guam and other communities. It would also increase compensation to up to $100,000 per person, both retroactively and for new claimants.

In the fall, the Congressional Budget Office put the expected cost of RECA’s expansion at more than $140 billion over 10 years, but sponsors have since revised the bill, bringing the cost down, they say, closer to $50 billion. Utah’s senators, Mike Lee and Mitt Romney, both Republicans, objected to that lower price tag and some other aspects of the bill, according to statements from their offices. Last month they introduced competing legislation that would simply extend the existing RECA law for two years — without expanding coverage to include people like Ms. Gutierrez.

Their fiscal objections are surprising, given that both lawmakers are boosters of the U.S. military’s plan to build hundreds of nuclear-tipped intercontinental ballistic missiles, one of the most expensive weapons projects in Air Force history, which also promises some 4,000 new jobs in the senators’ home state. The Air Force recently notified Congress that the missile-building program has exceeded its initial cost projections by at least 37 percent, to more than $130 billion .

Downwinders say it’s duplicitous to fund a nuclear weapon program that’s part of the emerging global arms race while refusing to treat the victims of the first one. We know nuclear weapons work because of the Cold War testing, said Mary Dickson, who was raised in Salt Lake City, about 350 miles from the Nevada test site, where the United States conducted tests until 1992. Those communities played a vital role in building the United States into the world’s sole superpower, only to be neglected later.

Ms. Dickson and her family lived north of the current RECA boundaries during the testing years. But at 29, she was diagnosed with thyroid cancer. Years later, her sister Ann Dickson DeBirk died at age 46 after a long struggle with an autoimmune disease. A second sister was also diagnosed with stomach cancer, and a third has autoimmune disorders.

In Washington last week, a small group met with Mr. Johnson to make a last-ditch effort to persuade him and the rest of Congress to repay their sacrifice. Some went for the first time, selling personal items to pay for the trip. Others, like Ms. Dickson, make regular pilgrimages to Congress to raise awareness about what the U.S. government did — and didn’t do.

For 30 years, she’s been urging voters to pressure their congressional representatives to pay attention to the downwinders’ plight. “I was lucky I got better,” Ms. Dickson told a small crowd gathered outside the Capitol. “My cousin, who lost her husband to colon cancer, always says to me, ‘Your story didn’t end tragically, so you can carry that tragic story forward.’ I have felt an intense obligation to seek justice for all of them.”

It’s time for Congress to correct this mistake. It should not be an option to leave thousands of Americans without lifesaving health screenings and compensation. Mr. Johnson should let the House vote on extending and expanding RECA — and our lawmakers should vote yes. These Americans have waited for too long.

This Times Opinion series is funded through philanthropic grants from the Carnegie Corporation of New York , the Outrider Foundation and the Prospect Hill Foundation . Funders have no control over the selection or focus of articles or the editing process and do not review articles before publication. The Times retains full editorial control.

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips . And here’s our email: [email protected] .

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W.J. Hennigan writes about national security, foreign policy and conflict for the Opinion section.