(Ivanhoe Newswire) -- Americans can thank fresh air for increasing their life spans.

Over recent decades, the average life expectancy in 51 cities across the United States increased by almost three years. Five months of that time is thanks to cleaner air.

"Such a significant increase in life expectancy attributable to reducing air pollution is remarkable," C. Arden Pope III, Ph.D., an epidemiologist at Brigham Young University in Provo, Utah, and lead author of the study, was quoted as saying.

Researchers compared two sets of data -- from 1998 and 2000 -- on air pollution and life expectancy in the cities. Cities that had been the most polluted and cleaned up the most added on average roughly 10 months to their residents' lives. Other studies suggest the reduction in air pollution is reducing cardiovascular and cardiopulmonary disease.

"Not only are we getting cleaner air that improves our environment, but it is improving our public health," Dr. Pope said.

SOURCE: New England Journal of Medicine, 2009;360:376-386