Americans Owe Five Months of Their Lives to Cleaner Air

Are you a city dweller? The cleaner air of this "going green" era may actually be increasing your lifespan. A new study by researchers at Brigham Young University and Harvard School of Public Health shows that average life expectancy in 51 U.S. cities increased nearly three years over recent decades, and approximately five months of that increase came thanks to cleaner air.

"Such a significant increase in life expectancy attributable to reducing air pollution is remarkable," said C. Arden Pope III, a BYU epidemiologist and lead author on the study in the Jan. 22 issue of the New England Journal of Medicine.

"We find that we're getting a substantial return on our investments in improving our air quality. Not only are we getting cleaner air that improves our environment, but it is improving our public health."

The research matched two sets of data from 51 cities across the nation: changes in air pollution between about 1980 and about 2000; and residents' life expectancies during those years. The scientists applied advanced statistical models to account for other factors that could affect average life spans, such as changes in population, income, education, migration, demographics and cigarette smoking.

In cities that had previously been the most polluted and cleaned up the most, the cleaner air added approximately 10 months to the average resident's life. On average, Americans were living 2.72 years longer at the end of the two-decade study period; up to five months, or 15 percent, of that increase came because of reduced air pollution.

Other studies show that these gains are likely coming from reductions in the cardiovascular and cardiopulmonary disease that typically accompany air pollution.

"There is an important positive message here that the efforts to reduce particulate air pollution concentrations in the United States over the past 20 years have led to substantial and measurable improvements in life expectancy," said study co-author Douglas Dockery, chair of the Department of Environmental Health at Harvard School of Public Health.