Air Pollution: Where Does The Us Stand Globally?

Air pollution is a pressing issue in the United States, with the American Lung Association's State of the Air 2025 report revealing that nearly half of the US population resides in areas with poor air quality, earning an F grade. The report, which assesses air pollution across metropolitan areas, found that Bakersfield, California, topped the list for the worst short-term and year-round particle pollution. Los Angeles was ranked as the city with the worst ozone pollution. The geographic distribution of air pollution has shifted back east, with central and eastern states experiencing higher levels of ozone and particle pollution due to factors such as heat waves and wildfires. While the Clean Air Act has driven pollution reduction for over 50 years, disparities persist, with communities of color disproportionately exposed to unhealthy air and facing higher vulnerabilities due to underlying health conditions.

The US ranked 84th out of 106 countries for air pollution in 2020

The United States of America (USA) ranked 84th out of 106 countries for air pollution in 2020. This ranking was based on the country's average annual Air Quality Index (AQI) figure, which was 40. In comparison, Bangladesh, the most polluted country, had an AQI of 162. Within the US itself, there is variation in air quality. For instance, Waimea, Hawaii is the cleanest city with an AQI of 9, while Yosemite Lakes, California is the most polluted with an AQI of 107.

Air pollution is a serious health threat, causing and exacerbating various health issues. Particle pollution, for example, can cause early death, heart attacks, strokes, and respiratory issues. It is also linked to an increased risk of premature birth and lower birth weight in newborns. Ozone pollution can irritate the lungs, causing inflammation, and is especially harmful to children, older adults, and those with lung diseases such as asthma.

Certain activities and sources contribute significantly to air pollution in the US. Vehicular emissions, for instance, release nitrogen dioxide (NO2) and sulfur dioxide (SO2) into the air. NO2 is particularly prevalent in areas with high traffic volumes. Mining, construction, and the extraction of materials also release particulate matter and pollutants into the air. Additionally, black carbon, a component of soot, has carcinogenic properties and can be visually unappealing when coating roadsides.

To address air pollution, the Clean Air Act has been instrumental in driving pollution reduction for over 50 years. The US Environmental Protection Agency plays a critical role in cleaning up air pollution, and efforts to monitor and grade air quality help identify areas for improvement. However, despite these efforts, air pollution remains a significant concern, with nearly half of Americans living in places with failing grades for unhealthy air quality as of 2025.

Air pollution can cause asthma attacks, harm children's lung development, and even be deadly

Air pollution is a serious health threat, and it can be especially harmful to children. In 2025, nearly half of the people in the US lived in areas where the air quality was rated F in the "State of the Air" report. More than 42 million people lived in counties that received an F for all three air pollution measures.

The US obtained an overall ranking of 84 out of 106 world cities in 2020, with an average annual figure of US AQI 40. The cleanest city was Waimea, Hawaii, while the most polluted was Yosemite Lakes, California.

Children exposed to outdoor coarse particulate matter (PM10-2.5) are more likely to develop asthma and require emergency medical treatment. This is because their respiratory systems are still developing, and they traditionally spend more time outdoors. Air pollution can also trigger asthma attacks in children who already have the condition. It can irritate their airways, causing swelling and tightness, and make them more susceptible to upper respiratory infections.

Additionally, air pollution has been linked to increased risk of premature birth and lower birth weight in newborns. Particle pollution, which includes tiny bits of dust, dirt, smoke, and soot, can cause breathing problems for people of all ages, especially those with pre-existing lung diseases. It is important for people with asthma to pay attention to pollution levels and limit their time outdoors when necessary.

Black carbon, a component of soot, has carcinogenic properties and is released by vehicles

The United States emitted about 6.1% of the world's soot in 2020, ranking 84th out of 106 countries. Yosemite Lakes, California, was the most polluted city in the US, while Waimea, Hawaii, was the cleanest.

Black carbon, a component of soot, is produced by the incomplete combustion of carbon-containing materials, such as fossil fuels, biomass, diesel, gasoline, and other petroleum-based fuels. It is a potent carcinogen, causing various types of cancer, respiratory diseases, and cardiovascular dysfunctions. Black carbon is released by vehicles, and its presence is typically indicated by high levels of nitrogen dioxide in areas with heavy traffic.

The transport sector contributes about 23% of black carbon emissions, with diesel engines being a significant source in North America. The combustion of diesel, gasoline, and other petroleum-based fuels releases black carbon particles coated with volatile and semi-volatile components, such as H2SO4 and organics. These particles are small enough to penetrate the body's natural defenses when inhaled, causing harm to human health.

In addition to its carcinogenic effects, black carbon has climate-altering properties due to its ability to absorb solar radiation and release it as heat, contributing to short-term global warming. It warms the atmosphere by absorbing light, altering weather patterns and ecosystem cycles. Black carbon's warming impact is up to 1,500 times stronger than that of CO2 per unit of mass.

Reducing black carbon emissions from vehicles and improving fuel standards can help mitigate the health and environmental impacts associated with this pollutant.

People of colour are disproportionately affected by air pollution and are more vulnerable to its health effects

The United States obtained an overall ranking of 84th out of 106 world cities in terms of air pollution in 2020. Yosemite Lakes, California, was the most polluted city, while Waimea, Hawaii, was the cleanest.

People of color are disproportionately affected by air pollution and are more vulnerable to its health effects. A study by researchers at the EPA-funded Center for Air, Climate, and Energy Solutions found that people of color in the United States breathe more particulate air pollution on average, regardless of income level or region. This includes African Americans, Hispanics, Asians, and other people of color who are exposed to a regulated air pollutant called fine particulate matter (PM2.5). PM2.5 is responsible for 85,000 to 200,000 excess deaths annually in the United States and can cause lung and heart problems, especially for those with chronic diseases, younger people, older people, and other vulnerable populations.

The disparities in exposure to air pollution for people of color are driven by factors such as systemic racism, housing policies, and other socio-economic factors. Pollution sources tend to be located near disadvantaged communities, and people of color are more likely to live in counties with higher levels of pollution. This is due in part to decades of residential segregation, which has resulted in higher exposure to air pollution for African Americans. Additionally, people of color may have limited access to healthcare, face poorer job opportunities, and have dirtier workplaces, further increasing their risk of health harm from air pollution.

Furthermore, race appears to be a significant factor in nearly all regions, with people of color experiencing greater than average exposures from source types that contribute to a large proportion of overall exposure. This indicates that the disparities in exposure to air pollution for people of color are not solely driven by income levels but are influenced by racial and ethnic factors as well. The authors of the study suggest that regulations need to be designed to effectively address the environmental injustice faced by people of color due to their increased exposure to air pollution.

The Clean Air Act has successfully reduced air pollution over the last 50 years

Air pollution is a serious health threat, causing asthma attacks, harming lung development in children, and even leading to early death. It is also linked to premature births and lower birth weight in newborns. In the United States, the Clean Air Act has been instrumental in reducing air pollution and improving air quality over the last 50 years.

The Clean Air Act, passed by Congress in 1970, was designed to tackle a variety of air pollution problems and address emerging threats. It has resulted in improved air quality across the country, controlling common pollutants such as sulfur dioxide (SO2) and nitrogen oxides (NOx) and placing restrictions on dangerous air toxics. Since 1990, there has been an approximate 50% decline in emissions of key air pollutants. Carbon monoxide, for example, has decreased by 74%, ground-level ozone by 21%, and lead by 82% from 2010.

The Clean Air Act has also had a positive impact on the environment. It has helped to reduce the risk of acid rain, protect the ozone layer, and improve the quality of soil, freshwater bodies, and vegetation. In addition, the Act has contributed to the nation's economy, with the Environmental Protection Agency estimating benefits of almost US$2 trillion, outweighing the costs of implementing the Act's measures.

Despite the success of the Clean Air Act, air pollution remains a significant issue in the United States. Recent data shows an increase in harmful pollutants, and the country continues to lead in premature pollution-related deaths. However, the Clean Air Act provides a framework for continued efforts to address air pollution and protect the health and environment of its citizens.

The Clean Air Act has been a landmark piece of legislation, driving pollution reduction and improving air quality in the United States for the past 50 years. While challenges remain, the Act has been instrumental in mitigating the health and environmental risks associated with air pollution.

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