(CNN)Air pollution is known to have negative -- even deadly -- effects on our health, and studies have shown that breathing pollution can kill, even at levels below air quality guidelines.
Air pollution can cross state lines, and with deadly consequences, study says
Now, a new study shows that air pollution produced in one state often blows across state lines, and can contribute to health issues and even premature deaths hundreds of miles away.
The study, published Wednesday in the journal Nature, found that, on average, around half of the early deaths in the US linked to pollution actually occur outside the borders of the state where the toxic air originated.
"This situation is a bit like secondhand smoke, but on a national scale," said Steven Barrett, director of the Laboratory for Aviation and the Environment at the Massachusetts Institute of Technology and a co-author of the study.
The study found that the northern Midwest states are the largest net "exporters" of pollution-related early deaths outside state lines, due to their to low local populations, high emissions and the large populations that are located downwind.
On the other hand, a group of states in the Northeast are significant "importers" of air pollution premature deaths, meaning many of the deaths that occur there are from toxic particles that originated elsewhere.
Of the 48 contiguous states studied, New York had the largest percentage of premature deaths from out-of-state pollution in all three of the years examined.