MONDAY, March 27, 2023 (HealthDay News) -- While all Americans could benefit from proposed new limits on what’s called PM2.5 air pollution, new research indicates the change has the potential to benefit Black and low-income Americans the most.

The limits being considered by the U.S. Environmental Protection Agency (EPA) could cut death rates in those more vulnerable groups by up to 7%, according to researchers from Harvard T.H. Chan School of Public Health, in Boston.

“The EPA is currently considering stronger rules for PM2.5 air pollution and the decision will have profound effects on ensuring all Americans have an equal opportunity to breathe clean air,” said co-lead author Scott Delaney, a research associate in the department of environmental health at Harvard.

“Our research shows that, while stronger rules will protect all aging Americans from air pollution, those harmed the most by air pollution will benefit the most — and that these benefits may be larger than prior research suggests,” Delaney said in a Harvard news release.

These stronger air quality policies could also drive innovative ways to reduce the emission of heat-trapping gases, the study authors said. This might save even more lives through its impact on climate change.

To study this, the researchers used Medicare data from more than 73 million Americans aged 65 and older between 2000 and 2016 according to race, income level and annual average PM2.5 exposure by ZIP code.

All aging Americans’ risk of premature death would decrease with stronger air pollution rules, the study found.

But Black higher-income, Black low-income and white low-income adults may benefit more than white higher-income adults, the researchers reported.

Current National Ambient Air Quality Standards (NAAQS) for annual average PM2.5 levels is 12 μg/m3.

If that standard was lowered to 8 μg/m3, the result would be an estimated 4% reduction in death rates for higher-income white adults. But it would lead to a 7% reduction for Black higher-income and 6% reduction for both white low-income and Black low-income adults.

The findings were published March 24 in the New England Journal of Medicine. Funding for the study came from the U.S. National Institutes of Health and the Alfred P. Sloan Foundation.

“These differences result from social forces — structural racism, social exclusion, poverty — that combine in unique ways to alter the impact of PM2.5 on marginalized populations,” said co-lead author Kevin Josey, postdoctoral research fellow in the department of biostatistics. “However, structural racism seems to matter more than poverty when determining the health effects of air pollution.”

The EPA, on Jan. 6, announced a proposal to lower the NAAQS. The reduction could be to a level between 9 and 10 μg/m3, although the EPA is also considering levels as low as 8 μg/m3.

Public comment on the issue will close on March 28. The EPA will finalize the decision later this year.

“The EPA has a huge opportunity,” said senior study author Francesca Dominici, co-director of the Harvard Data Science Initiative. “We have a shared responsibility to safeguard the air we breathe and to protect our more vulnerable community members from the effects of climate change."

More information

The World Health Organization has more on air quality.

SOURCE: Harvard T.H. Chan School of Public Health, news release, March 24, 2023