Scott Tiller, a coal miner of 31 years, takes a break while operating a machine in a mine in West Virginia. (David Goldman/Associated Press)

Exposure to emissions from coal-fired power plants over a long period of time is significantly more harmful to the heart than other forms of carbon pollution, a new study says.

The risk of death from heart disease, including heart attacks, was five times as high for people who breathed pollution from coal emissions over 20 years than for those who were exposed to other types of air pollution, according to the study’s findings. The burning of coal releases fine particles with a potent mix of toxins, including arsenic and selenium.

“Our results indicate that, pound for pound, coal-burning particles contribute roughly five times as much to heart disease mortality risk as the average air pollution particle in the United States,” said George D. Thurston, a professor of population health and environmental medicine at New York University and lead author of the study.

Thurston and the study’s 10 other authors said that their findings should end assumptions in previous studies that carbon “particles have the same toxicity, irrespective of their source.”

A coal-fired power plant in Colstrip, Mont. Exposure to emissions from these types of plants is significantly more harmful to the heart than other forms of carbon pollution, a new study says. (James Woodcock/Billings Gazette via Associated Press)

And they said the findings show the Environmental Protection Agency’s effort to strengthen regulation of power plant emissions standards — as part of the White House’s Clean Power Plan — does not go far enough.

The EPA’s calculations for lowering air pollution with stricter coal emissions standards nationwide are wrong, the research shows, because the estimates are based on the assumption that particles from all sources of carbon pollution are equally toxic and carry the same risks.

Windblown particles from dust in Phoenix are far less toxic than emissions from coal-burning power plants in Pittsburgh. And urban motor traffic in Los Angeles produces emissions that are about half as toxic as coal, Thurston said.

“You have to look at the various sources,” he said. “If we want to clean particles, where should we start? We should start with the particles that are most toxic.”

Thurston said governments across the world have taken clean-air models from the United States and applied them without considering that the level of danger is higher or lower depending on the pollution source.

“In the Arab world, there are high levels of particle pollution, but they’re from windblown soil,” Thurston said. “You think those are the same as coal? They’re not.”

The study, published in the journal Environmental Health Perspectives, was released Wednesday to coincide with the world climate talks in Paris.

The EPA said in August that its plan would lower power plant carbon pollution that causes “the soot and smog that harm health, while advancing clean energy innovation,” according to its Web site. The agency estimated that it would help Americans avoid 1,700 heart attacks and 3,600 premature deaths.

Nearly half of the nation’s state attorneys general filed lawsuits seeking to block the new regulations when they were finalized in September. Patrick Morrisey, West Virginia’s attorney general, called the plan “one of the most far-reaching energy regulations in this nation’s history.”

Air pollution has been identified by the World Health Organization as a major health threat linked to heart disease across the globe. In the United States, it causes 1 in every 5 heart-disease-related deaths, according to the American Heart Association.

The study relied on a trove of data collected between 1982 and 2004 by the American Cancer Society, which sent hundreds of volunteers to ask approximately 1 million people about their health. The coal study examined information collected from about 450,000 people who lived in areas where pollution exposure data was available.

To reduce the number of people dying from air pollution worldwide, Thurston and his colleagues said there must be a stronger emphasis on reducing coal emissions.

Aruni Bhatnagar, a University of Louisville professor of cardiovascular medicine and a volunteer with the American Heart Association, called the study’s findings surprising because of the long-held assumption in previous studies.

Before now, there had been only talk, based on expert guesses, that coal emissions could be “more toxic than other particles,” Bhatnagar said.