The Air We Breathe: A Looming Deadline For Change

The Clean Air Act, first introduced in 1970, has helped cut pollution as the US economy has grown. The EPA has issued emissions standards to control toxic emissions from major sources, and states have elected to enforce these standards. The EPA has also implemented regulations for the management of ozone-depleting substances, and actions to protect the ozone layer are estimated to save millions of people from skin cancer and cataracts. Despite these achievements, six out of ten Americans still live in areas where air pollution reaches unhealthy levels. In some places, people were losing up to six years of life expectancy to fine-particle pollution. While there is no definitive answer to how many more years of polluted air we can expect, continued efforts to improve air quality through policy, technology, and interventions are crucial to ensuring a healthier future for all.

Air pollution is the single greatest threat to human health globally

Air pollution is a major threat to global health and prosperity. It is responsible for over 6.5 million deaths each year, a number that has increased over the past two decades. Air pollution is a complex mix of hazardous substances from human-made and natural sources. Human-made air pollution includes vehicle emissions, fuel oils, natural gases, and by-products of manufacturing and power generation. Natural sources include smoke from wildfires, ash and gases from volcanic eruptions, and gases like methane released from decomposing organic matter.

The harmful effects of air pollution are evident in the form of respiratory issues, oxidative stress, inflammation, and an increased risk of chronic diseases and cancer. Fine particulate matter, such as PM2.5, can be inhaled deeply into the lungs, causing serious health problems. Exposure to air pollution is linked to lung cancer, colorectal and prostate cancers, and an increased risk of strokes, especially in post-menopausal women.

In 2019, the World Health Organization (WHO) identified air pollution as the largest environmental risk to health, impacting approximately 2.4 billion people exposed to dangerous levels of household air pollution. WHO has developed strategies to raise awareness about the risks of air pollution and promote interventions to address this issue. The organization provides technical support to member states and offers guidance, tools, and advice on mitigating health risks associated with air pollution.

Despite efforts to address air pollution, it continues to pose a significant threat. Climate change, conventional air pollution, and ozone layer depletion are key challenges. Extreme heat, droughts, and wildfires contribute to worsening air quality, and communities of color are disproportionately affected by these issues. The Clean Air Act and initiatives like the Clean Power Plan aim to reduce air pollution, but more urgent action is needed to reduce greenhouse gas emissions and protect public health.

Climate change, conventional pollution, and ozone layer depletion are key obstacles

Ozone depletion and climate change are interconnected issues that impact air quality. Ozone depletion involves the destruction of the Earth's protective stratospheric ozone layer by industrially produced chemicals containing chlorine or bromine. These chemicals are also greenhouse gases, which contribute to climate change by absorbing infrared radiation from the Earth's surface, leading to a warming effect. While ozone depletion does not directly cause climate change, the two issues are linked through the impact of certain gases on atmospheric processes.

Climate change refers to the alteration of the global climate system due to greenhouse gases like carbon dioxide and methane. The changing climate has made it more challenging to address air pollution. For example, the “State of the Air” 2025 report noted a shift in the geographic distribution of air pollution, with improved conditions on the west coast but increased ozone and particle pollution in central and eastern states due to wildfires in Canada.

Addressing ozone depletion and climate change requires careful consideration of the complex interactions between these issues. While reducing ozone-depleting substances can have positive effects on mitigating global warming, it is important to choose alternatives that do not exacerbate climate change. For instance, hydrofluorocarbons (HFCs) are commonly used as substitutes for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) but are powerful greenhouse gases themselves. Therefore, addressing these issues effectively requires a comprehensive understanding of their linkages and potential solutions that benefit both areas.

Air pollution disproportionately affects communities of colour

Despite efforts to improve air quality, air pollution continues to threaten the health and welfare of Americans. According to the "State of the Air" 2025 report, 46% of Americans (approximately 156.1 million people) live in areas with unhealthy levels of ozone or particle pollution. This issue disproportionately affects communities of colour, who are more likely to be exposed to unhealthy air and suffer adverse health effects as a result.

Research has consistently shown that racial and ethnic minority groups in the United States and the United Kingdom experience higher levels of air pollution than their white counterparts. A 2025 study by the EPA found that people of colour in the United States breathe more particulate air pollution on average, regardless of income level or region. This is due in part to historical discriminatory practices such as "redlining", where Black communities were denied mortgage loans and investment, leading to economic disadvantage. As a result, communities of colour are more likely to be located near industrial facilities, hazardous waste sites, and polluting industries, increasing their exposure to harmful pollutants.

The health impacts of air pollution are more severe for communities of colour. Studies have found that African Americans, Hispanics, and Asians have a higher risk of premature death from particle pollution than whites, and are more likely to suffer from lung and heart problems due to exposure to fine particulate matter (PM2.5). Additionally, low socioeconomic status, which is more prevalent among racial and ethnic minorities, is associated with an increased risk of premature death from fine particle pollution. This is partly due to the fact that pollution sources are often located near disadvantaged communities, exacerbating the exposure to harmful pollutants.

Systemic racism has played a significant role in the disproportionate impact of air pollution on communities of colour. Julian Marshall, a co-author of the 2025 EPA study and a professor of civil and environmental engineering at the University of Washington, stated that "over time, people of colour and pollution have been pushed together... for nearly all types of emissions." This has resulted in environmental injustice, with people of colour experiencing higher exposure to multiple types of emissions and facing greater health risks as a result.

Addressing this issue requires a multifaceted approach. The EPA has set goals to reduce carbon pollution and maintain energy reliability and affordability through initiatives such as the Clean Power Plan and the Clean Air Act. However, it is crucial to acknowledge and address the systemic racism that has contributed to the disproportionate impact of air pollution on communities of colour. By working towards environmental justice and ensuring equal access to clean air, we can mitigate the health risks faced by these vulnerable communities.

Wildfires, industrial activity, and vehicle emissions are major contributors

According to the "State of the Air 2025" report, despite decades of successful efforts to reduce sources of air pollution, the problem persists. Wildfires, industrial activity, and vehicle emissions are major contributors to air pollution.

Wildfires have been identified as a significant source of air pollution, with smoke from these fires drifting for thousands of miles, carrying particulate matter that can cause serious health issues. The impact of wildfires on air quality is expected to increase in the coming years, as climate change contributes to more frequent and severe fire seasons. Wildfire smoke can contain polycyclic aromatic hydrocarbons (PAHs), which have been linked to eye and lung irritation, blood and liver issues, and even cancer. The smoke can also have economic impacts, reducing earnings in sectors such as manufacturing, utilities, healthcare, and transportation.

Industrial activity, including power plants, oil refineries, and factories, contributes to air pollution through the emission of pollutants such as ozone and particulate matter. These emissions can lead to elevated ozone concentrations and reduced air quality, even in areas far from the sources. The Clean Power Plan aims to address this issue by setting standards for power plants to reduce carbon pollution and address climate change.

Vehicle emissions from cars, trucks, buses, planes, and other sources are a significant contributor to air pollution. Mobile sources, including vehicles, account for more than half of all air pollution in the United States. Efforts to reduce greenhouse gas emissions from vehicles have been implemented, such as the national greenhouse gas emission standards for cars and light trucks for model years 2012-2025.

Addressing these major contributors to air pollution is crucial for improving air quality and protecting public health. While progress has been made in reducing emissions, the changing climate and increasing frequency of wildfires present ongoing challenges.

Regulations and standards can help reduce pollution and improve air quality

Despite improvements in air quality over the years, air pollution remains a pressing issue that threatens public health and welfare. The Clean Air Act, implemented by the US Environmental Protection Agency (EPA), plays a pivotal role in addressing this challenge by establishing regulations and standards to reduce air pollution and improve air quality.

One of the key strategies employed by the EPA is the issuance of emissions standards for various sources of air pollution. These standards target major industrial sources, such as chemical plants, oil refineries, and manufacturing facilities, as well as small "area" sources that contribute significantly to urban toxic pollutants. The EPA has also set standards for vehicles, including cars, trucks, and locomotives, leading to significant reductions in emissions and improvements in fuel efficiency. For instance, new heavy-duty trucks and buses emit 99% less pollution than 1970 models.

The Clean Air Act also addresses air pollution from power plants, which are the nation's largest source of carbon pollution. The Clean Power Plan aims to reduce carbon emissions from existing power plants while maintaining energy reliability and affordability. Additionally, the Act requires new industrial facilities to incorporate good pollution control measures into their design, ensuring that the country's industrial base becomes cleaner over time.

Furthermore, the EPA has taken steps to reduce greenhouse gas emissions, recognizing the urgency of addressing climate change. In collaboration with the National Highway and Traffic Safety Administration, the EPA established the first national greenhouse gas emission standards for cars and trucks for model years 2012-2025. These standards not only aim to reduce emissions but also promote fuel economy and energy security.

The impact of these regulations and standards is evident in the overall reduction of air pollutant emissions. Between 1970 and 2023, total emissions of the six principal air pollutants in the United States dropped by 78%, even as economic growth and energy consumption increased. However, it is important to acknowledge that air pollution remains a pervasive issue, with nearly half of Americans living in areas with unhealthy levels of ozone or particle pollution.

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