A new study led by Harvard T.H. Chan School of Public Health suggests that implementing stronger regulations to lower levels of fine particulate air pollutants (PM2.5) would benefit the health of all Americans, with Black Americans and low-income Americans likely to reap the most benefits, including a lower risk of premature death.
The study, which will be published on March 24, 2023, in the New England Journal of Medicine, is the first to examine how groups defined simultaneously by both racial identity and socioeconomic position differ in their exposure and susceptibility to PM2.5 air pollution.
To arrive at their findings, the researchers analyzed Medicare data from more than 73 million Americans aged 65 and older between 2000 and 2016, categorized by racial identity (Black or White), income level (Medicaid eligible or ineligible), and annual average PM2.5 exposure by zip code. They found that while all aging Americans’ risk of premature death would decrease with stronger air pollution rules, Black higher-income, Black low-income, and White low-income adults may benefit more than White higher-income adults. The study found that reducing the National Ambient Air Quality Standards (NAAQS) for annual average PM2.5 levels from the current standard of 12 μg/m3 to 8 μg/m3 could result in an estimated 4% reduction of mortality rate for higher-income White adults, while the benefit would be considerably higher for marginalized communities, with a 7% reduction for Black higher-income and 6% for both White low-income and Black low-income adults.
The researchers attribute these differences to social forces, including structural racism, social exclusion, and poverty, which combine in unique ways to alter the impact of PM2.5 on marginalized populations. They suggest that structural racism seems to matter more than poverty when determining the health effects of air pollution.
The study’s senior author, Francesca Dominici, Clarence James Gamble Professor of Biostatistics, Population, and Data Science and co-director of the Harvard Data Science Initiative, believes that the EPA has a huge opportunity to establish substantially stronger NAAQS for PM2.5 air pollution. Dominici argues that implementing these regulations is a pragmatic, proven way to clean up the air, reduce the impact of climate change on human health, and drive innovative climate change solutions. On January 6, 2023, the EPA announced a proposal to lower the NAAQS, and public comment closes on March 28, with the agency expected to finalize its decision later this year.
One idea that can be borrowed from this is the use of Medicare data to analyze the impact of air pollution on vulnerable populations. The researchers in the study analyzed Medicare data from over 73 million Americans aged 65 and older to determine how exposure to PM2.5 air pollution impacted different racial and socioeconomic groups. This approach could be useful to other countries in understanding the impact of air pollution on their own aging populations.
For example, a study conducted in Japan used similar methods to analyze the impact of PM2.5 air pollution on the mortality rate of older adults. The researchers used data from the National Health Insurance Claims Database and found that higher levels of PM2.5 air pollution were associated with an increased risk of mortality among older adults, particularly those with preexisting health conditions (Oshiro et al., 2020). This approach could be replicated in other countries to better understand the impact of air pollution on their aging populations and inform policy decisions.
Another idea that can be borrowed is the focus on addressing structural racism and social exclusion in order to reduce health disparities related to air pollution. The researchers in the study found that social forces, including structural racism and poverty, contribute to the disproportionate impact of air pollution on marginalized populations. Addressing these underlying issues could help to reduce health disparities related to air pollution.
This approach has been highlighted in other studies as well. For example, a study conducted in the UK found that addressing socioeconomic inequalities was key to reducing health disparities related to air pollution (Kelly et al., 2018). Similarly, a study conducted in the US found that policies aimed at reducing racial and socioeconomic disparities in exposure to air pollution could lead to significant health benefits (Miranda et al., 2011). Emphasizing the need to address underlying social and economic factors could be helpful to other countries in developing policies to reduce health disparities related to air pollution.
In summary, borrowing the ideas of using Medicare data to analyze the impact of air pollution on vulnerable populations and addressing structural racism and social exclusion could be helpful to other countries in understanding the impact of air pollution on their own populations and developing policies to reduce health disparities. These approaches have been used successfully in studies conducted in other countries and could be replicated in other contexts.