Clean Air Means Longer Life, Study Says

Jan. 22, 2009— -- If the air in your city is clean, you can tack on about five months to your life. So suggests a new study by researchers at Brigham Young University and Harvard School of Public Health.

This study found that the average life expectancy in 51 cities in the United States increased by nearly three years in recent decades and that approximately five months of that increase came as a result of cleaner air.

"Life expectancy is a well-understood indicator for public health," said C. Arden Pope III, a Brigham Young University epidemiologist and lead author on the study in the Jan. 22 issue of the New England Journal of Medicine. "We find that we are getting a substantial return on our investments in improving our air quality."

Pope is no stranger to this issue. He and co-author Douglas Dockery, chair of the Department of Environmental Health at Harvard School of Public Health, teamed up with other researchers on important studies in the 1990s that revealed the negative health effects of infinitesimally small particles of pollution.

So small are these particles, known as "PM2.5," that you would have to line up 25 of them end to end to span the width of a human hair. The danger of these tiny particles is that they can find their way deep into the respiratory system when inhaled.

Dr. Joel Schwartz, an environmental epidemiologist at the Harvard School of Public Health, agreed that the research "suggests that there is a phenomenon in the United States regarding increase in air pollution and shortened life span that is greater than the six locations studied in [previous research]."