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Minor soot levels linked to older American deaths, study finds

As more findings come out reporting the fatal consequences of pollution, the Biden administration has made stronger industry regulation of emissions central to its environmental justice platform.Charlie Riedel/Associated Press

WASHINGTON — Older Americans who regularly breathe even low levels of pollution from smokestacks, automobile exhaust, wildfires, and other sources face a greater chance of dying early, according to a major study made public Wednesday.

Researchers at the Health Effects Institute, a group that is funded by the Environmental Protection Agency as well as automakers and fossil fuel companies, examined health data from 68.5 million Medicare recipients across the United States. They found that if the federal rules for allowable levels of fine soot had been slightly lower, as many as 143,000 deaths could have been prevented over the course of a decade.


Exposure to fine particulate matter has long been linked to respiratory illness and impaired cognitive development in children. The tiny particles can enter the lungs and bloodstream to affect lung function, exacerbate asthma, and trigger heart attacks and other serious illness. Earlier research has found that exposure to particulate matter contributed to about 20,000 deaths a year.

The new study is the first in the United States to document deadly effects of the particulate matter known as PM 2.5 (because its width is 2.5 microns or less) on people who live in rural areas and towns with little industry.

“We found a risk of dying early from exposure to air pollution, even at very low levels of air pollution across the United States,” said Daniel S. Greenbaum, president of the Health Effects Institute.

The findings come as the Biden administration is considering whether to strengthen the national standard for PM 2.5, which is currently set at a yearly average of 12 micrograms per cubic meter, a level higher than that recommended by World Health Organization.

Researchers concluded that 143,257 deaths could have been prevented between 2006 and 2016 if the standard had been tightened to 10 micrograms per cubic meter.


“If we were to reduce PM 2.5, we would be saving a substantial amount of lives,” said Francesca Dominici, a professor of biostatistics at Harvard who led the study, which took four years to complete. “It’s highly significant.”

“This is important evidence for EPA to consider,” Dominici added.

Other studies have linked fine soot pollution to higher rates of death from COVID-19, with Black and other communities of color particularly at risk because they are more likely to be located near highways, power plants and other industrial facilities.

The Biden administration has made tighter regulation of emissions from power plants, factories, and other industrial sites central to its strategy to address environmental justice.

By law, the EPA is required to review the latest science and update the soot standard every five years. The Trump administration opted not to strengthen the standard when it conducted the most recent review, despite growing scientific evidence of the harm to public health caused by particulate matter.

Using the public data of the 68.5 million Medicare recipients — nearly every American older than 65 — researchers focused on people living in rural areas and other places that are not well monitored by the EPA, either because they are sparsely populated or because pollution levels are not considered as high as in cities or along the congested East Coast.

A spokesman for the EPA said the agency was expected to propose a draft rule by summer and to issue a final rule by the spring of 2023.


Polluting industries are expected to lobby heavily against a stricter new soot pollution rule.

The American Petroleum Institute, which represents oil and gas companies, did not review the Health Effects Institute research but questioned the need for tighter pollution rules. In a statement, the trade group said “the current scientific evidence indicates the existing standards are effectively designed to protect public health and meet statutory requirements.”

The institute noted that emissions of traditional pollutants like PM 2.5 have dropped significantly since the 1970s because of the use of cleaner automobile fuels and the rise of natural gas in power generation instead of coal.

Some experts said companies were resigned to the likelihood the Biden administration will tighten the rule, but were concerned about how far it might go.

“It’s a question of how much,” said Jeffrey Holmstead, a lawyer who served in the EPA in both Bush administrations.

A significant reduction in allowable limits would be “very costly” for companies, Holmstead said. He also noted that in communities that do not have major industrial centers, much of the fine soot pollution comes from automobiles, making it difficult for state governments to regulate.

“At what point do you say we’re going to prohibit any kind of combustion engines because everything contributes to PM 2.5?” Holmstead said. “And if you set a level that is overly-stringent, you basically prohibit any new economic development in certain parts of the country.”