Air quality in the US
New MIT study finds more than half of all air-quality-related early deaths in the United States are a result of cross-state pollution, or emissions originating outside of the state in which those deaths occur. Image: Chelsea Turner, MIT.

Half of U.S. deaths related to air pollution are linked to out-of-state emissions

Study tracks pollution from state to state in the 48 contiguous United States.

More than half of all air-quality-related early deaths in the United States are a result of emissions originating outside of the state in which those deaths occur, MIT researchers report today in the journal Nature.

The study focuses on the years between 2005 and 2018 and tracks combustion emissions of various polluting compounds from various sectors, looking at every state in the contiguous United States, from season to season and year to year.

Electric power generation is the greatest contributor to out-of-state pollution-related deaths, the findings suggest. In 2005, for example, deaths caused by sulfur dioxide emitted by power plant smokestacks occurred in another state in more than 75 percent of cases.

The researchers caution, however, that today, emissions from other sectors are increasingly contributing to harmful cross-state pollution.

“Regulators in the U.S. have done a pretty good job of hitting the most important thing first, which is power generation, by reducing sulfur dioxide emissions drastically, and there’s been a huge improvement, as we see in the results,” says study leader Steven Barrett, an associate professor of aeronautics and astronautics at MIT. “Now it’s looking like other emissions sectors are becoming important. To make further progress, we should start focusing on road transportation and commercial and residential emissions.”

Barrett’s coauthors on the paper are Sebastian Eastham, a research scientist at MIT; Irene Dedoussi, formerly an MIT graduate student and now an assistant professor at Delft University of Technology; and Erwan Monier, formerly an MIT research scientist and now an assistant professor at the University of California at Davis. The research was a collaboration between MIT’s Laboratory for Aviation and the Environment and the MIT Joint Program on the Science and Policy of Global Change.


In general, the researchers found that out-of-state air pollution was associated with more than half of all pollution-related early deaths in the U.S. from 2005 to 2018.

In terms of the impact on individual states, the team found that many of the northern Midwest states such as Wyoming and North Dakota are “net exporters” of pollution-related health impacts, partly because the populations there are relatively low and the emissions these states generate are carried away by winds to other states. Those states that “import” health impacts tend to lie along the East Coast, in the path of the U.S. winds that sweep eastward.

New York in particular is what the researchers call “the biggest importer of air pollution deaths”; 60 percent of air pollution-related early deaths are from out-of-state emissions.

“There’s a big archive of data we’ve created from this project,” Barrett says. “We think there are a lot of things that policymakers can dig into, to chart a path to saving the most lives.”

This research was supported, in part, by the U.S. Environmental Protection Agency, the MIT Martin Family Fellowship for Sustainability, the George and Marie Vergottis Fellowship at MIT, and the VoLo Foundation.

Source: MIT News

Also covered by: CNN, "Air pollution can cross state lines, and with deadly consequences, study says"; The New York Times, "Calculating Air Pollution’s Death Toll, Across State Lines"Reuters, "Air pollution crossing U.S. state lines, causing premature deaths"; Scientific American, "Deadly Air Pollution Doesn’t Respect State Borders"; Science Magazine, "Deadly air pollution is blowing into your state from a surprisingly large source"; U.S. News & World Report, "Air Pollution Made in One State Can Cause Deaths in Others"; Bloomberg, "New Yorkers Are Dying from Air Pollution Caused by Other States"; Boston Globe, "Massachusetts has 3rd highest number of deaths from out-of-state air pollution, study finds"; Forbes, "Trouble Breathing? The Culprit Could Be From Out Of State"

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