A recent study has found that lower exposure to PM2.5, a type of air pollution, is associated with lower mortality rates among the general population. However, the study also discovered that marginalized communities may benefit more from decreased PM2.5 levels. The research examined the impact of PM2.5 exposure on different subpopulations, such as White higher-income individuals, Black higher-income individuals, White low-income individuals, and Black low-income individuals.
The results showed that as PM2.5 levels decreased from 12 μg per cubic meter to 8 μg per cubic meter, the hazard ratio for mortality decreased for all subpopulations. However, the hazard ratios were lower for marginalized communities compared to the White higher-income subpopulation. For example, the hazard ratio for decreasing PM2.5 levels from 12 μg per cubic meter to 8 μg per cubic meter was 0.963 for White higher-income individuals, 0.931 for Black higher-income individuals, 0.940 for White low-income individuals, and 0.939 for Black low-income individuals.
This study adds to a growing body of research that has found that PM2.5 disproportionately affects minority and low-income populations in the United States, despite overall reductions in PM2.5 levels in recent years. The research highlights the need for stronger air pollution regulations to protect the health of all Americans, particularly those who are most vulnerable.
The current annual average level of PM2.5 that complies with the EPA's National Ambient Air Quality Standards (NAAQS) is 12 μg/m3. The study found that if this standard was lowered to 8 μg/m3, there would be an estimated 4% reduction in mortality rates for higher-income White individuals. However, marginalized communities would experience even greater benefits, with estimated reductions of 7% for Black higher-income individuals and 6% for both White low-income and Black low-income individuals.
The study also examined the reasons behind the disparities in PM2.5 exposure among different subpopulations. It found that exposure inequities are caused by factors such as “disparate siting,” where roadways and pollution-emitting facilities are disproportionately located in Black or low-income communities. This disparity in exposure is observed in both urban and rural areas. Additionally, the study found that although Black Americans produce less air pollution than White Americans, they breathe in more of it.
These findings highlight the role of structural racism and social exclusion in creating inequities in PM2.5 exposure. Black Americans, who already have less access to healthcare and higher rates of health problems, also face higher levels of pollution. Decades of segregation have resulted in Black individuals living in areas with greater exposure to air pollution, regardless of income or region.
The study utilized Medicare data from over 73 million Americans aged 65 and older between 2000 and 2016. The data was analyzed based on racial identity, income level, and PM2.5 exposure. The researchers estimated the associations between annual PM2.5 exposure and mortality in different subpopulations.
The findings of this study have important implications for the EPA's decision-making regarding air pollution regulations. The EPA is currently considering stronger rules for PM2.5 air pollution, and the study suggests that these stronger rules would benefit marginalized communities the most. The research calls for a substantially stronger NAAQS for annual PM2.5 levels, potentially lowering the standard to ≤8 μg per cubic meter.
The study was supported by the National Institutes of Health and the Alfred P. Sloan Foundation. The researchers emphasize the need for bold action from the EPA to establish stronger air pollution regulations to protect the health of all Americans, particularly those who are most affected by air pollution. They argue that stronger rules will not only reduce the impact of climate change on human health but also drive innovative climate change solutions.
Overall, this study highlights the importance of addressing air pollution inequities and the need for stronger regulations to protect the health of marginalized communities. By reducing PM2.5 exposure, we can significantly reduce the risk of premature death and improve the health outcomes for all Americans.
0. “Air Pollution and Mortality at the Intersection of Race and Social Class | NEJM” nejm.org, 24 Mar. 2023, https://www.nejm.org/doi/full/10.1056/NEJMsa2300523
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