Updated at 11:37 a.m. on April 9, 2025

Inhalation of tiny particles known as particulate matteroften derived from burning fossil fuelshas far-reaching consequences for human health. The journey of these microscopic specks begins when they are inhaled through the nose, traveling down into the lungs where they can infiltrate even the smallest air sacs responsible for gas exchange. From there, they may breach the bloodstream, potentially affecting vital organs such as the heart, or even crossing the blood-brain barrier. Its a disturbing reality that many of us inhale these harmful particles daily, yet the implications can be dire. A significant enough exposure has the potential to transform the basic act of breathing into a serious health risk, exacerbating conditions like asthma, chronic obstructive pulmonary disease (COPD), respiratory infections, and even leading to irreversible lung damage.

Research has also linked air pollution to various cardiovascular diseases, including heart attacks and a multitude of other heart-related disorders. Additionally, studies have found correlations between air pollution and mental health issues, including increased rates of depression, anxiety, and even suicide. Beyond these alarming links, air pollutants can trigger strokes and are associated with neurodegenerative diseases, such as dementia and Parkinson's disease, even when exposure levels are considered average. The impact is particularly troubling for expectant mothers; studies indicate that these harmful particles can traverse the placenta, impairing fetal lung development and increasing risks of premature births and low birth weights. Moreover, prenatal exposure has been associated with a heightened risk of autism, and subsequent exposure during childhood has been correlated with cognitive deficits, including lower IQ.

The lungs continue to develop until approximately age 25. As emphasized by Dr. Alison Lee, a pulmonologist from the Icahn School of Medicine at Mount Sinai, once youve lost lung function, you cant get it back. This reality makes persistent exposure to air pollution even more alarming, as it can inflict permanent health damage on children, setting the stage for a lifetime of health challenges.

While it may be difficult to imagine a person succumbing directly to air pollution, this grim reality occurs with alarming frequency. In the United States, it is estimated that particulate matter contributes to the deaths of more individuals annuallybetween 100,000 and 200,000than vehicular accidents do. This staggering figure stems from the role of air pollution as a major underlying factor in chronic diseases or as a trigger for acute events like heart attacks and asthma attacks. Despite marked improvements in air quality over the years, researchers warn that even relatively low levels of particulate matter pose significant health risks.

The source of this invisible danger lies in the burning of fossil fuels, which releases harmful by-products into our atmosphere, ultimately infiltrating our bodies unless stringent regulations are enforced. However, the current administration under former President Trump has displayed a troubling lack of commitment to addressing this issue. Through a series of new policies and aggressive rollbacks of existing regulations, the administration appears to be paving the way for increased pollution while suppressing scientific evidence that highlights these health risks. As a result, the quality of air that Americans breathe is at risk of deterioration.

In recent developments, the Environmental Protection Agency (EPA) has signaled intentions to reverse numerous environmental protections. One of these rollbacks includes the rescinding of updated particulate matter standards established during the Biden administration, which were projected to avert up to 4,500 premature deaths and 800,000 asthma cases by 2032a benefit valued at an impressive $46 billion. A reassessment of regulations limiting the release of airborne mercury and arsenic from power plants is also on the table. In a statement regarding these changes, the EPA asserted that the U.S. had already made significant gains in air quality, implying that these advancements were sufficient.

It's crucial to note that while air quality in the U.S. has indeed improved since the days of unchecked industrial pollution, a stark reality remains: at least one in three Americans lives in areas where the air quality still poses health risks. The particulate matter standard being reconsidered is still nearly double the limit recommended by the World Health Organization, which aims to safeguard public health.

The process of rolling back regulations is not instantaneous and may allow for deterioration of air quality in the interim. Last month, the EPA informed businesses that they could request exemptions from certain pollution regulations via email, indicating that the president will make a decision on such requests. This opens a potential loophole for regulatory evasion. Compounding matters, recent staffing cuts at the EPA are expected to hinder enforcement of existing air quality standards. Moreover, the increasing frequency and intensity of wildfires, exacerbated by climate change, are threatening to reverse decades of progress in air quality. Joan Casey, an environmental epidemiologist at the University of Washington, warned that neglecting climate change will only contribute to worse wildfire seasons, propelling the nation back toward a more polluted past.

Additionally, the administration's cuts to scientific research raise concerns regarding the potential impacts of its deregulation efforts. In recent months, the government has shuttered access to critical air quality data and canceled essential research grants, even planning to dissolve an entire EPA division dedicated to studying the environmental impacts on public health. Such actions create an environment of intentional ignorance: if the government cannot prove harm, they may feel less compelled to regulate it. This poses a significant challenge for understanding the real implications of air pollution, especially as new studies continue to emerge, linking air pollution to worsening mental health and increasing incidence of neurodegenerative diseases. As Casey remarked, I think often were underestimating the true impact.

During a recent conversation with Marianthi-Anna Kioumourtzoglou, an epidemiologist at Columbia University, she expressed dismay at the cancellation of her grant aimed at investigating how climate change and air pollution affect cognitive function in aging populations. Earlier this year, she was also dismissed from her position on the EPAs Clean Air Scientific Advisory Committee. Regardless, she is all too aware of the detrimental effects of the current rollbacks, stating definitively, There will be more heart attacks, more respiratory adverse health outcomes for sure. She pointed out that our cognitive functions are likely to decline further, exacerbating the progression of diseases like Alzheimers and Parkinsons. Moreover, the incidence of pollution-related mental health issues, including depression and anxiety, could also rise. Even a slight uptick in the risk or prevalence of these health issues at the population level can severely impact quality of life and economic productivity.

Kioumourtzoglou rightfully draws a comparison between the risks posed by smoking and those posed by air pollution. While individual exposure to harmful air pollutants may seem less significant compared to smokingan activity fewer people engage inthe reality is that virtually everyone breathes. Therefore, even minor reductions in cognitive function across a population can lead to substantial collective consequences.

The potential for the Trump administration to further downplay the significance of air pollution has also raised alarms. In December, the Heritage Foundation released a report asserting that no definitive link exists between air pollution and adverse health outcomes. While Kioumourtzoglou dismissed this notion, the precedent it sets is troubling, particularly given the administration's track record of prioritizing such narratives. The report aimed to undermine decades of scientific research, contending that studies linking air pollution to health effects fail to establish causation due to their observational nature.

This challenges not only air pollution research but the scientific methodology as a whole. Most public health research relies on observational studies, as conducting controlled experiments on humans exposed to harmful pollutants is inherently unethical. Researchers gather data from populations already exposed to pollutants and work to identify how various factors influence health outcomes. Over time, robust biostatistical methods have been developed to infer causal relationships across multiple studies.

According to Corwin Zigler, a biostatistician at Brown University, when EPA scientists and regulators establish a connection between a pollutant and a health outcome, they do so based on extensive evidence, not just a handful of studies. Thats the scientific consensus, Zigler affirmed, emphasizing that the EPAs assessment process is backed by decades of rigorous scientific research. He remains confident that particulate matter causes harm even at current exposure levels in the U.S.

While studies documenting the health impacts of air pollution may present probabilities and percentages, they reflect the reality of countless individuals suffering as a result. For Dr. Lee, the pulmonologist, the issue became personal when her 5-year-old son began suffering from alarming asthma attacks that necessitated emergency care. Although asthma attacks might seem routine, anyone who has experienced a severe episode understands the potential for trauma. Over years of reporting on air pollution, I have heard such attacks described as feeling like a heavy weight pressing down on the ribcage or the sensation of being a fish out of water, gasping for breath. Its a harrowing experience.

Recognizing the risk posed by air pollution, Dr. Lee made the difficult decision to relocate her family from New York City to the suburbs a year and a half ago, a move that has since spared them from emergency room visits. Clearly, we know that where you live determines your health, Lee stated. Yet, many individuals lack the ability to make such life-altering choices to secure cleaner air. The Trump administration has concurrently initiated cuts to programs designed to address geographic disparities in air quality while simultaneously implementing policies that may exacerbate pollution for all. EPA Administrator Zeldin has characterized these rollbacks as a pathway to unleash the Golden Age of American prosperity. Yet, true prosperity cannot be achieved if individuals are forced to endure environments that compromise their health and well-being.