More than 100,000 Americans each year die of heart attacks, strokes and other illnesses caused by air pollution spewed from factories, motor vehicles and even bucolic-seeming farmland, according to a new report that contradicts an EPA panel whose members downplayed the risks during a public meeting last month.

The findings, in a new study published Monday in the Proceedings of the National Academy of Sciences, put a human toll and a price tag – some $886 billion a year – on the health impacts caused by air pollution, especially from fine particulate matter known as PM 2.5.

"The link between fine particulate matter pollution and decreased health impacts is well-established in the literature from epidemiological studies, and our work builds on that," says study co-author Jason Hill, an associate professor of engineering at the University of Minnesota. "This is a substantial cost to human health, both in terms of lives lost and economic impact."

Members of a powerful EPA committee, however, all but dismissed such connections during a meeting March 28, with some stating they did not even agree inhaling air pollution – including soot – could lead to an early death.

There are "varying opinions on the adequacy of the evidence supporting the EPA's conclusion that there is a causal relationship between [particulate matter] exposure and mortality," Tony Cox, chairman of the agency's Clean Air Scientific Advisory Committee, said in prepared remarks, adding that he was "actually appalled" by what he claimed was a lack of evidence connecting air pollution to health consequences.

According to the study in the Proceedings of the National Academy of Sciences, the estimated annual toll – about 107,000 fatalities a year – is roughly equal to the number of people in the U.S. killed in car crashes every year. Such consequences are not evenly distributed: Emissions of PM 2.5, no surprise, are densest in cities and especially along the East Coast. However, agriculture accounts for about 15 percent of premature deaths caused by particulate matter, which is emitted by fertilizer and manure. Corn production alone generates about a quarter of such emissions.

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"We always think of coal and dirty diesel as the big contributors to PM 2.5, but agriculture is responsible for 15 percent of deaths from reduced air quality," Hill says. "There's no one sector, no one major source of emissions that's responsible for high PM 2.5 levels and damages. It's really a number of different sectors and a number of different pollutants."

Such emissions can also travel as far as 160 miles, the study found.

The findings, based on emissions data gathered by the EPA, add to the broad scientific consensus that air pollution is detrimental to human health. Another report last week, for example, concluded that air pollution in smog-choked cities in Asia and Africa can shorten children's lives by as much as 20 months. In the U.S., meanwhile, African American, Latino and low-income communities bear the overwhelming brunt of air pollution and its health impacts.

Officials at the EPA under the Trump administration, though, have pushed back on such conclusions, an effort that one former EPA official likened to the "tobacco denial of health effects or denial of climate change health effects."

"I just want to emphasize the fringe nature of these proposals," H. Christopher Frey, who led the Clean Air Scientific Advisory Committee and served on a particulate matter review board at the agency that was disbanded, told NPR. "There's a very small community that have scientific credentials but are moving outside their area of expertise to try to raise doubt after doubt after doubt on issues where they really don't have the strongest competence."

Cox's remarks, however, reflect an effort within the EPA to weaken limits on emissions of fine particulate matter. The move would, in turn, slash the projected health benefits of other pollution measures that also help reduce emissions of particulate matter, including climate measures like the Clean Power Plan, which President Donald Trump has sought to eliminate.

Regardless whether EPA implements such changes, "the connection between PM 2.5 and health impacts, premature mortality, all the things associated with it, is drawn from very strong epidemiological evidence," Hill says.