Science Wednesday: OnAir: Breathe Cleaner, Live Longer

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On my second day of work, I was asked to find a Stephen Colbert video.

I found it on the Comedy Central web site

The subject of Colbert’s mockery is actually one of the most significant air studies recently published. It presents evidence, for the first time, that breathing cleaner air actually makes people live longer.

A 2009 study by Arden Pope, Majid Ezzati, and Doug Dockery published in the New England Journal of Medicine shows that cleaner air in the U.S. has increased life expectancy by an average of 5 months.

Over the past few decades, EPA has regulated air pollution because various scientific studies have determined that it is harmful to human health. As particles emitted into the air have been gradually reduced, pollutant levels in air have significantly decreased.

But despite the obviously cleaner air, it has been extremely difficult to confirm the resulting health improvements. Couldn’t better health also be attributed to decreased cigarette smoking, better eating habits and health care, or a variety of other changes?

Pope, Ezzati, and Dockery—an EPA PM Research Center grantee—matched air monitoring data with life expectancy data spanning three decades and 51 cities across the US. Using advanced statistical models, they accounted for any other factors that might also affect life span (like cigarette smoking) in order to see the effects of air quality alone.

Their results showed that an increase in life expectancy of 5 months was directly attributable to an average reduction of 6 micrograms per cubic meter of fine particle air pollution between 1980 and 2000.

The implication of the study—that EPA air regulations have directly and substantially lengthened human lives—is a triumph for both regulatory agencies and researchers world wide because it shows that air research and policy really do work.

Stephen Colbert isn’t the only one to recognize the importance of this finding. News of the study was reported in the Washington PostNew York Times, and in an entire segment on NBC Nightly News.

I spoke to Doug Dockery, investigator of the study and scientist at the Harvard School of Public Health, to get his take on the impact of this finding.

“There is an important positive message here,” he said.

“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.”

About the Author: Becky Fried is a student contractor with EPA’s National Center for Environmental Research, part of the Office of Research and Development.

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