Air Pollution In The Us: Is The Country Breathing Easy?

Air pollution is a pressing issue in the United States, with nearly half of Americans (approximately 156 million people) residing in areas with unhealthy levels of air pollution. This problem disproportionately affects people of colour, who are more likely to live in areas with higher levels of soot and ozone pollution than white Americans. The sources of air pollution in the US are varied and include transportation, power plants, manufacturing, and wildfires, which are becoming more frequent and intense due to climate change. While the Clean Air Act, first implemented in 1963 and significantly updated in 1970, has helped reduce air pollution by nearly 80% across the country, recent rollbacks and funding challenges faced by the Environmental Protection Agency (EPA) threaten to undermine this progress. The effects of air pollution on human health are significant, ranging from respiratory issues to more rapid onset neurological diseases and various types of cancer.

Air pollution and health: neurological issues, asthma, cardiovascular disease, and cancer

The United States has made significant progress in improving air quality and reducing pollution since the 1970s, but it still faces challenges in ensuring clean and healthy air for its citizens. Air pollution is linked to various health issues, including neurological problems, asthma, cardiovascular disease, and cancer.

Neurological Issues

Air pollution has been linked to several neurological conditions and diseases. Studies have found that exposure to air pollutants can lead to neural inflammation, neurodegeneration, and cerebrovascular barrier disorders. Pollutants such as particulate matter, ozone, sulfur oxides, carbon oxides, nitrogen oxides, and heavy metals can have detrimental effects on the nervous system. Lead pollution, for example, has been associated with behavioural problems, learning deficits, lowered IQ in children, and increased blood pressure and heart disease in adults. While the mechanisms underlying these neurological diseases are not yet fully understood, the evidence suggests that air pollution has significant negative impacts on neurological health.

Asthma

Air pollution is a known trigger and exacerbating factor for asthma. Small airborne particles, such as haze, smoke, soot, and dust, can irritate the airways and lungs, worsening asthma symptoms and leading to increased hospital visits. Ozone, a common air pollutant, is particularly irritating to the lungs and airways, triggering asthma attacks. People with asthma are at greater risk when exposed to air pollution, and high levels of indoor air pollution can also affect them.

Cardiovascular Disease

Air pollution is a contributing factor to cardiovascular disease. Fine particulate matter, with diameters less than 2.5 µm (PM2.5), has been linked to an increased risk of cardiovascular events. Short- and long-term exposure to particle pollution can lead to hospitalizations for coronary syndrome, arrhythmia, heart failure, stroke, and sudden cardiac death, especially in those with pre-existing heart conditions. The evidence is particularly strong for outdoor particle pollution exposure, and high outdoor particle pollution can also elevate indoor pollution levels.

Cancer

Research has suggested a link between air pollution and an increased risk of various cancers, including lung cancer, breast, liver, and pancreatic cancer. A study in Hong Kong found an association between long-term exposure to fine particulate matter (PM2.5) and increased mortality from these cancers. While pollution is just one of several risk factors for cancer, it is a significant public health concern that requires attention and mitigation.

Environmental racism: communities of colour are disproportionately affected by air pollution

The United States has made significant progress in improving air quality over the years, with visible air pollution less frequent and widespread than in the 1970s. However, air pollution remains a pressing issue, with nearly half of the US population residing in areas with unhealthy levels of air pollution. Climate change and extreme weather events, such as heatwaves, droughts, and wildfires, are exacerbating the problem, making it challenging to maintain air quality standards.

Within this context, environmental racism persists in the US, with communities of color disproportionately affected by air pollution. Research has consistently shown that people of color are more likely to live near polluting industries and breathe polluted air. A 2021 EPA-funded study found that, on average, people of color breathe more particulate air pollution, regardless of income level or region. Specifically, Black people are exposed to about 1.5 times more particulate matter than White people, while Hispanic people have about 1.2 times the exposure. Asian Americans and Latinos also face higher levels of air pollution, with exposure to toxic particles from burning gasoline and vehicle emissions.

The systemic nature of this issue is evident, as racial and ethnic exposure disparities continue due to historical housing policies and other systemic factors. Polluting facilities tend to emit higher levels of pollutants in minority neighborhoods, further exacerbating the problem. These findings align with the concept of environmental racism, where environmental risks are disproportionately allocated along racial lines, often without the input of affected communities of color.

The health implications of air pollution exposure are significant, particularly for vulnerable populations. Particulate matter air pollution has been linked to respiratory and cardiovascular issues, including worsening symptoms of asthma, chronic bronchitis, high blood pressure, and an increased risk of lung cancer. Additionally, studies have found associations between air pollution exposure and neurological diseases, including Alzheimer's, as well as adverse birth outcomes for pregnant women living in areas with higher particulate matter exposures.

Addressing environmental racism and reducing air pollution disparities requires a systemic approach. EPA researchers are working to understand the air quality concerns in overburdened communities and provide scientific expertise to assist states, tribes, and communities in improving air quality and protecting the health of their residents. However, efforts to slash staff, funding, and programs at the EPA could hinder progress and leave communities more vulnerable to harmful air pollution.

Climate change: extreme weather events, like wildfires, are worsening air quality

The United States has made significant progress in improving air quality and reducing air pollution over the years. The Clean Air Act, implemented by the US Environmental Protection Agency (EPA), has played a crucial role in achieving national air quality standards and reducing emissions from transportation, power plants, and manufacturing. However, climate change-induced extreme weather events, such as wildfires, are now posing a serious threat to these hard-fought gains in air quality.

The "State of the Air" 2025 report by the American Lung Association revealed that nearly half of the US population (approximately 156.1 million people) lived in areas with unhealthy levels of air pollution between 2021 and 2023. This issue is particularly prominent in western states, where extreme heat, drought, and wildfires have exacerbated the problem. Wildfires produce immense amounts of particulate matter (PM) and release toxic combustion products, including hazardous air pollutants such as PM2.5, NO2, ozone, aromatic hydrocarbons, and lead. These pollutants have severe health impacts, affecting the lungs, heart, brain, nervous system, skin, gut, kidney, eyes, nose, and liver. They have also been linked to cognitive impairment, memory loss, and an increased risk of neurological diseases, including Alzheimer's.

The changing climate is making it increasingly challenging to maintain healthy air quality. Warmer temperatures and drier conditions, coupled with the urbanization of rural areas, are extending the fire season and intensifying wildfire events. As a result, more people are being exposed to harmful levels of air pollution, and the frequency of high ozone days and spikes in particle pollution is on the rise. The geographic distribution of air pollution is also shifting, with the 2025 report showing a return to higher pollution levels in eastern states.

To address these issues, the EPA has taken initial steps to limit greenhouse gas emissions from large sources, such as issuing national greenhouse gas emission standards for cars and trucks. However, recent rollbacks, restructuring, and funding challenges faced by the EPA could hinder the nation's ability to monitor and protect air quality effectively. It is crucial to prioritize reducing greenhouse gas emissions without delay, as emphasized by the National Research Council (NRC) and other scientific bodies, to mitigate the risks posed by climate change and extreme weather events on air quality.

To protect public health during wildfire events, organizations like the California Air Resources Board offer guidance through programs such as "Smoke Ready California." This program provides recommendations such as using N95 or KN95 masks, staying indoors with windows and doors closed, and creating a "Cleaner Air Space" within the home to reduce smoke exposure. Early warning systems, evacuation orders, and preparedness measures are also essential to minimizing the impact of wildfires on human health and the environment.

Clean Air Act: the US EPA's efforts to reduce air pollution since 1970

The Clean Air Act, enacted in 1970, has been instrumental in reducing air pollution in the United States. The Act, signed into law by President Richard Nixon, was a response to the toxic pollution that plagued American cities, with smog so heavy that it was visible and tangible. Since its implementation, the US Environmental Protection Agency (EPA) has made significant strides in improving air quality and protecting public health.

One of the primary goals of the Clean Air Act was to establish National Ambient Air Quality Standards (NAAQS) that set safe levels of pollution over different time periods. The EPA was tasked with reviewing, updating, and enforcing these standards, while the responsibility for ensuring compliance was largely left to the states. The Act also directed states to develop State Implementation Plans (SIPs) to address industrial sources of pollution and achieve the NAAQS goals.

Amendments to the Clean Air Act in 1977 and 1990 further strengthened its impact. The 1977 amendments introduced provisions to protect areas with clean air and tightened rules around automobile emissions. In 1990, the Clean Air Act Amendments underwent a major shift, aiming for a cost-effective approach to reducing air pollution. These amendments established a national permits program, addressed the phase-out of ozone-depleting chemicals, and implemented a market-based cap-and-trade program to control acid rain.

The EPA's efforts under the Clean Air Act have achieved dramatic reductions in air pollution, preventing hundreds of thousands of serious health issues annually. Since 1990, emissions of key air pollutants have declined by approximately 50%. The EPA has successfully phased out lead in motor vehicle gasoline, meeting national air quality standards, and has issued standards for greenhouse gas emissions and fuel economy for vehicles.

Despite this progress, air pollution remains a challenge in the United States. Climate change, including extreme heat, drought, and wildfires, is exacerbating air quality issues. The "State of the Air" 2025 report found that 46% of Americans live in areas with failing grades for unhealthy levels of ozone or particle pollution. The EPA faces ongoing obstacles such as funding challenges and restructuring, threatening its ability to monitor and protect air quality. However, the Clean Air Act continues to provide a framework for addressing air pollution and protecting public health.

The future: transitioning to renewable energy sources and cleaner industrial processes

The United States has made significant strides in addressing air pollution, with emissions from transportation, power plants, and manufacturing decreasing over time. However, due to climate change, maintaining air quality has become more challenging. As of 2025, 46% of Americans live in areas with failing grades for unhealthy levels of ozone or particle pollution.

Looking forward, transitioning to renewable energy sources and implementing cleaner industrial processes are crucial steps for the US to improve air quality and combat climate change. The Renewable Electricity Futures Study (RE Futures), funded by the US Department of Energy, suggests that renewable generation could play a more significant role in the US electricity system than previously thought. This study explores scenarios where renewable electricity generation meets up to 90% of US electricity demand by 2050. While challenges related to geographical distribution and output variability exist, a combination of commercially available renewable technologies and a more flexible electric grid can help achieve these goals.

The US has already made notable progress in renewable energy adoption. In 2024, renewables (including wind, solar, geothermal, and hydropower) and battery storage made up 30% of the country's large-scale power-generating capacity. Carbon-free energy sources like nuclear power have also gained attention, with companies like Amazon and Google investing in small modular nuclear reactors (SMRs). The growth of renewable energy sources and battery storage technologies will enhance the stability and security of the US power system.

To further accelerate the transition to renewable energy, the US government and businesses must continue to promote and invest in clean energy technologies. Policies and incentives that support the development and adoption of renewable energy sources, such as wind, solar, and hydropower, are essential. Additionally, the US can encourage the manufacturing and automotive industries to adopt cleaner industrial processes, reducing greenhouse gas emissions and improving air quality.

Cleaner industrial processes will also play a crucial role in the future. Businesses in the cleaning industry, for example, are increasingly adopting sustainable practices and products to meet customer demands and contribute to environmental sustainability. This includes the utilization of advanced technology, such as robotic vacuums and biodegradable cleaning solutions, to enhance cleaning effectiveness and reduce environmental impact. By embracing sustainability across the value chain, from manufacturing to packaging and shipping, companies can make a significant difference.

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