Air Pollution Causes, Effects, and Solutions

How dirty air costs you money.

Black smoke billows from a brick smokestack, fouling the sky above a stately oak tree.
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Tahreer Photography / Getty Images

Air pollution is the presence of gases and solid particles that result in adverse health effects. They are either natural or human-made. 

The top polluting gases are sulfur dioxide, nitrogen oxides, ammonia, and volatile organic compounds. Other polluting gases include carbon monoxide and ground level ozone. Some areas of the country also suffer from lead air pollution. 

The greatest threats to human health In the United States are ground-level ozone and airborne particles. The first threat, ground level or "bad" ozone, is not emitted directly into the air. It is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight.

The second threat comes from fine solid particles. The Environmental Protection Agency (EPA) categorizes particulate pollution into two types. PM10 are inhalable particles that are 10 micrometers in diameter or less. They include dust and mold. PM 2.5 are particles with diameters 2.5 micrometers or less. These include combustion particles, metals, and organic compounds. 

The EPA measures both gas and particulate air pollution with the Air Quality Index (AQI). It reports on five of the six air pollutants regulated by the Clean Air Act: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. The AQI values range from 0 to 500. They are divided into six levels and the higher the number, the greater the risk. For example, 0 to 50 reflects “good” air quality and 51-100 is “moderate.” On the harmful end of the scale, an AQI of 301 to 500 is “hazardous” and indicates emergency conditions affecting the entire population. 

Health and Economic Effects of Air Pollution

The deadliest type of pollution is air pollution, according to the World Bank. It's the fourth leading risk factor for premature deaths worldwide. In 2013, those deaths cost the global economy $225 billion in lost labor. One reason the costs are so high is that nine out of 10 people in the world breathe highly polluted air. According to the World Health Organization, air pollution kills 7 million people each year. 

Around 40% of Americans live where the air is unhealthy. In 2015, 133.9 million people suffered from unhealthy levels of air pollution. It was more than the 125 million who suffered between 2013 and 2015. They are at greater risk of asthma, lung cancer, and respiratory problems. Research in 2018 found air pollution is also linked to Alzheimer's and dementia. 

In 2011 air pollution from the energy industry cost the U.S economy $131 billion in “social damages” according to one study. Most of this was in the form of health care costs for people who became sick from air pollution. As staggering as it may seem, the cost in 2011 was actually lower than in 2002 when social costs tallied $175 billion. The decline has been attributed to the effectiveness of more stringent emissions regulations and points to the need to continue in this direction.

Air pollution has some indirect costs, too, including unexpected impacts to school and work performance. A study found that the productivity of pear packers in Northern California was measurably lowered by air pollution. Another study found that Chinese call center workers take more breaks on high pollution days. A third study found that there were more absences in Texas school districts as a result of high carbon monoxide levels.

Air pollution knows no borders and can wreak havoc with climate and weather. For example, pollution from Asia’s manufacturing industries has reached the United States. This particularly affects the western part of the United States. It could also lead to more powerful storms over the Pacific Ocean. 

Sources and Causes of Air Pollution

Half of all air pollution is caused by burning fossil fuels for transportation, especially automobiles. Cancer has been linked to volatile organic compounds, such as benzene, acetaldehyde, and 1,3-butadiene found in these fuels. Diesel exhaust is a major contributor to particulate pollution. 

The nation’s 600 coal and oil-fired electric generating plants are the largest emitters of toxic metals. They spew 77% of the acid gases, 50% of the mercury, and 62% of the arsenic in the atmosphere. They also contribute 60% of the sulfur dioxide and 13% of nitrogen oxide.

 A 2014 study found that just 100 power plants emitted a third of the pollution from power plants, factories, and other similar industrial facilities. These "super polluters" included an ExxonMobil Texas refinery and coal plants in West Virginia and Pennsylvania. Four are in southwest Indiana alone. 

Other sources include industrial processes, agriculture, and chemical production. Farms emit ammonia and methane from fertilizer and livestock. They combine with vehicle emissions to create particulates. A 2016 study found that particulate emissions from farms and ranches was greater than from any other man-made source. 

Volcanoes, wildfires, and dust storms are examples of natural sources of air pollution. However, they are only major contributors to air pollution during the event. 

Climate Change and Air Pollution

Climate change is making air pollution worse. Higher temperatures increase the amount of ozone in the lower atmosphere, for example. The American Lung Association (ALA) found that ozone pollution increased between 2014 and 2016. Wildfires also contributed to an increase in air pollution due to high particle counts, according to the ALA. Climate change worsens wildfires by increasing warmer, drier drought conditions. In August 2018, smoke from western wildfires made Seattle and Portland among the most polluted cities in the world.

Regulatory Actions to Reduce Air Pollution

In 1955, the federal government first became concerned about combating air pollution. The Air Pollution Control Act of 1955 funded research to identify causes. The first act to reduce air pollution was the Clean Air Act of 1963. This was followed by the Air Quality Act of 1967. The act regulated interstate transport of pollutants.

The Clean Air Act of 1970 established air quality standards. It required states to meet those standards or face penalties. This Act allowed states to control emissions from stationary sources and from motor vehicles. The U.S. Environmental Protection Agency was established by Congress to implement these requirements. 

The Clean Air Act had a significant impact on the nation’s health. Clean air is important for good mental functioning. A 2017 study compared the earnings of children born each year between 1969 and 1974. It found that those born after the Clean Air Act earned at least $4,300 more by age 30 than those born before.

The 1990 amendments to the Act controlled 189 toxic pollutants. Most important among these were chlorofluorocarbons that were depleting the Earth's ozone layer. Stratospheric ozone absorbs harmful ultraviolet radiation. The radiation causes skin cancer, suppresses immune systems, and damages plant life. In 2018, the National Aeronautics and Space Administration found that the hole in the ozone layer is healing thanks to this act.

In 2009, President Barack Obama used the auto bailout to force automakers to improve fuel efficiency standards. It went into effect in 2012. It required vehicles to average 54.5 miles per gallon by 2025. The goal was to cut 6 billion tons of carbon dioxide emissions from vehicles sold between 2012 and 2025. Those greenhouse gases cause global warming. The standards would also make the U.S. auto industry more competitive in foreign markets that already required stronger emission standards.

California leads the nation with higher standards for automobile emissions. Through the Clean Air Act, Congress allowed California to set its own standards. In 2002, it did so for light duty vehicles. Thirteen other states, representing 40% of new vehicles sold, follow its lead. As a result, auto makers design cars to meet California's standards, improving air quality nationwide. 

The Clean Power Plan was created to cut carbon pollution by 32% from 2005 levels. This plan, launched by the Obama administration in August 2015, would prevent 1,500 to 3,600 early deaths and 90,000 childhood asthma attacks each year.

To cut power plant emissions, the EPA set custom goals for each state. To get there, states could switch from coal to gas, renewables, or nuclear. They could boost energy efficiency or enact carbon taxes.

To pay society’s cost of air pollution, the government should impose Pigouvian taxes. This tax would charge the polluters relative to the harm their pollution imposes on society. If these taxes were added to the cost of gasoline, people would switch to cleaner forms of transportation. This would reduce air pollution and its economic impact. 

How the Trump Administration Is Making Air Pollution Worse

Instead of doing more to fight air pollution, President Donald Trump is doing less. On September 19 , 2019, the Environmental Protection Agency announced it would relax vehicle efficiency rules. It also challenged California's ability to set its own air quality standards. The move would stand in the way of California's 50 mile-per-gallon goal. The Trump Administration has also announced the repeal of the Clean Power Plan. 

The Bottom Line

Air pollution kills 7 million people each year. That’s why the World Bank regards it as the deadliest form of pollution. The worst offenders are emissions from motor vehicles, cattle farms, and coal plants. Climate change only makes the problem worse.

Air pollution costs the global economy billions annually. . Although the U.S. and other governments have passed laws to address air pollution, the problem remains. Pigouvian taxes that require polluters to pay for the damage could pay for the cost of cleanup, but powerful lobbying groups oppose them. 

Individuals can reduce air pollution by making lifestyle changes. Auto use is responsible for half of all pollution, so reducing it would have the biggest effect. Limiting consumption of beef and dairy products would reduce farm emissions. Those who live near coal power plants can insist that utilities install pollution control measures.

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