Study reveals sources of deadly air pollution in the U.S. 

Researchers at the University of Minnesota are providing new insight into the causes and health impacts of poor air quality. The study reveals that each year, approximately 100,000 deaths are tied to various sources of air pollution in the United States.

While about half of these deaths can be linked to fossil fuel emissions, the researchers also identified sources of deadly pollution that are much less obvious.

“People usually think of power plants and cars, but nowadays, livestock and wood stoves are as big of a problem,” said study co-author Sumil Thakrar. “It’s also our farms and our homes.” 

The study showed that government regulations have succeeded in reducing pollution from some sectors of the economy, such as electricity and transportation. Meanwhile, other polluting sectors like agriculture and residential buildings have received much less attention.

The investigation was focused on data from the EPA on all sources of pollution in the United States, including their locations and total emissions. Using newly-developed computer models, the team analyzed the data to determine where pollution travels and how it affects human health.

Previous studies have linked one particularly harmful pollutant, PM2.5, to heart attacks, strokes, lung cancer, and other diseases. 

The current investigation revealed that about half of all deaths from PM2.5 are a result of burning fossil fuels. The remaining PM2.5 pollution-related deaths were largely tied to animal farming, dust from construction and roads, and wood burning for heating and cooking.

“Essentially we’re asking, ‘what’s killing people and how do we stop it?'” said Thakrar. “The first step in reducing deaths is learning the impact of each and every emission source.”

Air quality in the U.S. is primarily regulated by the federal government, which sets maximum pollution limits. The study authors suggest regulators can improve this approach by focusing instead on reducing emissions from specific sources.

“Targeting particularly damaging pollution sources is a more efficient, and likely more effective, way of regulating air quality,” said study co-author Professor Jason Hill. “Think of springing a leak in your boat while out fishing. Why fret too much about how much water is coming in when what you really should be doing is plugging the hole?”

The study also revealed that PM2.5 is harmful to human health in other forms beyond vehicle exhaust. 

Ammonia, which is released from animal manure and the fertilization of crops, was found to be responsible for about 20,000 deaths caused by man-made PM2.5 pollution. However, ammonia is not regulated to any large extent, noted the researchers.

“Our work provides key insights into the sources of damage caused by air pollution and suggests ways to reduce impacts,” said Thakrar. “We hope policymakers and the public will use this to improve the lives of Americans.”

The study is published in the journal Environmental Science & Technology Letters.

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By Chrissy Sexton, Earth.com Staff Writer