WEDNESDAY, Feb. 12, 2020 (HealthDay News) -- Deadly air pollution doesn't stop at state borders, researchers warn.

Their analysis of 2005-2018 data on different types of air pollution from a variety of sources showed that half of pollutants generated in one state are carried by winds to affect the health and life span of people in other states.

More than half of early deaths related to air pollution in the United States are the result of emissions that originated in other states, according to the study from the Massachusetts Institute of Technology.

Electric power generation is the greatest contributor. For example, more than three-fourths of deaths caused by sulfur dioxide emissions occurred in another state.

One positive finding: Early deaths associated with air pollution fell 30% between 2005 and 2018. That's about 30,000 early deaths avoided.

"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," said study leader Steven Barrett, an associate professor of aeronautics and astronautics at MIT.

The study also found that the proportion of early deaths that occur due to emissions from other states decreased from 53% in 2005 to 41% in 2018.

Researchers attributed the change to tighter air quality laws that significantly reduced power plant emissions.

But emissions from other sources are increasingly contributing to cross-state air pollution, they noted.

"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 said in an MIT news release.

The findings were published Feb. 12 in the journal Nature.

More information

The American Lung Association has more on air pollution.