Air Quality Trends: Is The Sky Really Clearing?

Air pollution is a serious health threat, causing millions of premature deaths worldwide every year. While the US has made progress in improving air quality in recent decades, the trend changed about five years ago, and air pollution is now getting worse. This is due to a combination of factors, including pollution from wildfires, heat, and drought, which are worsened by climate change. Despite the efforts of the Environmental Protection Agency (EPA) to regulate pollutant sources such as diesel car tailpipes and coal power plants, nearly half of the US population lives with unhealthy levels of air pollution.

Air pollution is a serious health threat, causing respiratory issues, cancer, and other health problems

Air pollution is a serious health threat, affecting almost every organ in the body. The main exposure pathway is through the respiratory tract, which can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs.

One of the most significant dangers of air pollution is its impact on respiratory health. Short-term exposure to high levels of particulate matter can lead to reduced lung function, respiratory infections, and aggravated asthma. Wildfires, heat, and drought are significant contributors to air pollution, and the trend of worsening air quality due to these factors has made it challenging to improve overall air quality. In addition, people who live or work near busy highways or exercise outdoors are at an increased risk of experiencing the harmful effects of air pollution, which can trigger asthma attacks and cause shortness of breath, coughing, wheezing, and chest pain.

Long-term or chronic exposure to fine particulate matter increases the risk of developing serious diseases such as stroke, heart disease, chronic obstructive pulmonary disease (COPD), lung cancer, and other types of cancer. Even healthy young adults may experience respiratory symptoms and decreased lung function due to air pollution. The elderly, pregnant women, and people with pre-existing conditions like asthma, COPD, diabetes, heart disease, or lung cancer are at an even higher risk of adverse health effects from air pollution.

Air pollution has also been linked to adverse pregnancy outcomes, including low birth weight and small gestational age. It can impact the developing fetus, leading to impaired cognitive functioning and an increased risk of Parkinson's disease, Alzheimer's disease, and other dementias later in life. Additionally, air pollution has been associated with an increased risk of clinical depression and anxiety.

While there have been efforts to reduce air pollution, such as the Clean Air Act, and improvements in vehicle emissions and air quality, air pollution remains a serious environmental and health issue. It continues to pose a significant threat to human health, with approximately one in every three Americans still breathing unhealthy air.

Climate change is worsening air quality, making it harder to predict pollution levels

The quality of the air we breathe has improved over the years, thanks to various regulations and policies aimed at reducing air pollution. However, the complex interplay between air pollution and climate change presents new challenges. Climate change is worsening air quality and making it harder to predict pollution levels, creating a dynamic and uncertain future for air quality management.

The Impact of Climate Change on Air Quality

Climate change is causing air quality to deteriorate in several ways. Firstly, warmer temperatures are leading to an increase in ground-level ozone, a harmful pollutant that affects the lungs, hearts, and brains. The chemical reactions that create ozone occur more frequently at higher temperatures, and ozone itself is a greenhouse gas that further contributes to climate change by trapping heat. As a result, some regions are experiencing accelerated warming, such as the Arctic, which has significant ecological implications.

Secondly, climate change is exacerbating extreme weather events, including heat waves, droughts, and wildfires, which negatively impact air quality. Heat waves, for example, can create stagnant air that concentrates air pollutants in one area, increasing exposure to harmful substances. Similarly, droughts and wildfires release particulate matter, such as dust and smoke, which reduce air quality and pose risks to human health.

Thirdly, climate change is affecting pollen production and prolonging pollen seasons. Warmer temperatures and higher carbon dioxide concentrations promote plant growth, leading to increased pollen concentrations in the air. These airborne allergens degrade both outdoor and indoor air quality and are associated with respiratory issues such as asthma and allergies.

The Challenges of Predicting Pollution Levels

The dynamic nature of climate change makes it increasingly difficult to predict pollution levels accurately. While certain trends, such as the impact of wildfires, heat, and drought on air quality, are evident, the specific outcomes vary by region. For example, the Lung Association's data shows that the number of people living in places with failing grades in particulate matter has almost doubled in the past five years, with most of them residing in the West.

Additionally, the complex interactions between various pollutants and climate change components add uncertainty to predictions. For instance, while black carbon, a particulate pollutant from combustion, contributes to atmospheric warming, particulate sulfates have a cooling effect on the atmosphere. Disentangling these relationships and their regional variations is a complex task that requires ongoing research.

Climate change is worsening air quality and making it more challenging to predict pollution levels. The intricate connections between climate change and air pollution create a dynamic and uncertain future. As climate change continues to impact weather patterns, pollen production, and the distribution of pollutants, managing air quality becomes a more complex endeavor. To effectively address these challenges, a comprehensive understanding of the relationships between climate change and air pollution is essential, along with the implementation of adaptive strategies to mitigate their detrimental effects on human health and the environment.

The Clean Air Act has helped reduce pollution, but recent trends show an increase

The Clean Air Act has been instrumental in reducing air pollution in the United States over the past few decades. The Act, which was enacted in 1963, authorizes the Environmental Protection Agency (EPA) to regulate air pollutants and polluting industries, and has achieved dramatic reductions in pollution levels.

Since 1970, the Clean Air Act has lowered levels of six common pollutants: particles, ozone, lead, carbon monoxide, nitrogen dioxide, and sulfur dioxide, as well as numerous toxic pollutants. Between 1970 and 2020, emissions of these six common pollutants dropped by 78%. This has led to significant improvements in air quality, with national concentrations of air pollutants improving between 1990 and 2020: carbon monoxide by 73%, lead by 86%, annual nitrogen dioxide by 61%, ozone by 25%, 24-hour coarse particle concentrations by 26%, annual fine particles by 41%, and sulfur dioxide by 91%.

The Clean Air Act has also played a critical role in protecting public health and the environment. By reducing air pollution, the Act has prevented hundreds of thousands of cases of serious health issues each year, including respiratory and cardiovascular diseases, and has reduced the risk of premature death. The economic benefits of the Clean Air Act are also significant, with improved economic welfare and growth rates due to reduced medical costs and lower absenteeism among American workers.

However, recent trends indicate an increase in air pollution levels. Despite the progress made by the Clean Air Act, the "State of the Air" 2025 report found that 46% of Americans (approximately 156.1 million people) live in areas with unhealthy levels of ozone or particle pollution. This is an increase of nearly 25 million people compared to the previous year's report. Climate change, extreme heat, drought, and wildfires have been identified as contributing factors to the worsening air quality, and people of color are disproportionately impacted by these issues.

While the Clean Air Act has made significant strides in reducing air pollution, the current trends highlight the ongoing challenges in maintaining and improving air quality. The EPA faces threats to its funding and staffing, which could hinder its ability to continue making progress in combating air pollution and protecting public health.

Wildfires, heat, and drought are major contributors to declining air quality

While air pollution in the United States has improved over the past few decades, wildfires, heat, and drought are threatening to reverse this progress. These factors, influenced by climate change, are major contributors to declining air quality.

Wildfires release carbon and particulate matter into the atmosphere, causing air quality to deteriorate. The particulate matter released by wildfires is extremely harmful to human health, as it can infiltrate the lungs and bloodstream due to its minuscule size. According to the World Meteorological Organization (WMO), the vicious cycle of climate change, wildfires, and air pollution is having a spiralling negative impact on human health, ecosystems, and agriculture. The WMO's Air Quality and Climate Bulletin recorded increased levels of all air pollutants, including ozone, carbon monoxide, nitrogen oxides, and PM2.5, during the 2023 wildfires in Chile, demonstrating the severe detriment to air quality caused by these events.

Heat plays a significant role in worsening air quality. Ozone, one of the most dangerous air pollutants, is more likely to form in hot weather. Ozone causes smoggy air, which poses a threat to lungs, hearts, and brains. Extreme heat, along with drought, also fuels the risk of wildfires, creating a cycle that further degrades air quality.

Drought conditions, exacerbated by climate change, make forests more vulnerable to fires, increasing the likelihood of wildfires. The impact of drought is evident in the case of the 2023 wildfires in Chile, which occurred in a region affected by a pervasive drought. The combination of high temperatures, winds, and drought created the ideal conditions for the rapid spread of fires, leading to devastating consequences for the environment and human health.

The complex interplay between wildfires, heat, and drought creates a challenging situation for improving air quality. As climate change intensifies, the frequency and severity of these events are likely to increase, making it increasingly difficult to achieve consistent progress in reducing air pollution.

People of colour are disproportionately affected by air pollution and its health risks

While there have been efforts to reduce air pollution, the air quality in the US is worsening due to pollution from wildfires, heat, and drought, which are trends worsened by climate change. A report by the American Lung Association (ALA) found that 46% of Americans (156.1 million people) live in areas with unhealthy levels of ozone or particle pollution. This is a notable increase of 25 million people compared to the previous year's report.

People of color are disproportionately affected by air pollution and its health risks. A 2021 study by researchers at the EPA-funded Center for Air, Climate, and Energy Solutions found that people of color in the US breathe more particulate air pollution on average, regardless of income level or region. This is due to the systemic racism that has pushed people of color and pollution together. As a result, they are at a higher risk of health issues caused by air pollution.

The EPA-funded study also found that people of color are more likely to be exposed to a regulated air pollutant called fine particulate matter (PM2.5). Exposure to PM2.5 can cause serious health issues, especially for those with pre-existing health conditions, younger people, older people, and other vulnerable populations. The health issues caused or exacerbated by air pollution include lung and heart problems, increased risk during pregnancy, respiratory disease, cardiovascular disease, and worse cognition.

Furthermore, a 2016 study of New Jersey residents found that African Americans had a higher risk of premature death from long-term exposure to particle pollution, especially in communities with lower home values and lower median incomes. Similarly, studies of Atlanta, Georgia, found that particle pollution increased the risk of asthma attacks in zip codes with high poverty rates and among people eligible for Medicaid.

The American Lung Association recognizes these disparities and has held workshops focused on urban air pollution and health inequities. The EPA is also working towards providing all people with equal protection from environmental and health hazards. They are providing scientific expertise and tools to assist states, tribes, and communities in addressing air quality concerns and improving the quality of life for all.

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