Cardiovascular deaths related to fine particulate matter (PM2.5) have declined significantly throughout the twenty-first century; however, that decline has been uneven across racial groups, according to a new study led by the Yale School of Public Health.
“Air quality regulations have worked, but they’ve worked unevenly,” said senior author Kai Chen, associate professor of environmental health sciences at the Yale School of Public Health. “Our study shows that even at relatively low levels of overall PM2.5, specific components continue to drive cardiovascular mortality.”
For their study, the authors examined two decades of nationwide mortality and pollution data, finding PM2.5 contributed to roughly 42,000 cardiovascular deaths in 2001, declining to some 23,500 deaths by 2020. The authors found this improvement was largely due to reductions in sulfate and ammonium, which are particles closely linked to coal-fired power plants and agricultural emissions. By 2020, black carbon, a component of soot produced by traffic, diesel engines, and burning, emerged as the largest contributor to PM2.5-related cardiovascular mortality,
Although cardiovascular deaths associated with air pollution decreased for all groups, Black and Hispanic populations experienced slower improvements than non-Hispanic White populations. Compared with White populations, Black populations were disproportionately affected by black carbon and sulfate.
“These disparities reflect decades of structural and environmental inequities,” said Dr. Chen. “Communities of color are more likely to live near highways, industrial facilities, and other pollution sources, resulting in disproportionately higher exposure to air pollution. What’s more, they also experience systemic disparities in health care access and endure higher baseline cardiovascular risk factors, contributing to the higher burden of PM2.5-related cardiovascular deaths.”
To mitigate these racial disparities, the research team advocates for future air pollution control policies to target individual particles, such as black carbon, rather than lowering the overall average PM2.5 concentration.
