Clean Air Extends Life Expectancy

Douglas W. Dockery, Sc.D.
Harvard School of Public Health
NIEHS Grant P30ES00002

New NIEHS-supported research findings published in the New England Journal of Medicine claim that improvements in air quality over the last 20 years have increased average life expectancy in the U.S. by approximately five months. Researchers at Brigham Young University and the Harvard School of Public Health tracked particulate matter air pollution in 51 major metropolitan areas from 1978 through 2001 and compared those data to death records and census data. On average, life expectancy increased by 2.72 years with about 15 percent of that increase due to improved air quality. Cities that had the greatest air quality improvements saw the greatest gains in life expectancy. Overall, a reduction of 10 micrograms per cubic meter in the ambient air concentration of particulate matter was associated with an estimated increase in average life expectancy of 0.61 years.

The study signals that efforts to curtail the small, toxic particles known as PM2.5 produced by power plants, factories, cars, and trucks and inhaled by city-dwellers had significant health benefits over those two decades. Clean-air advocates and public health specialists have touted the findings and have said that even stronger standards for air pollutants are needed and justified.

Research over the past few decades has investigated particulate matter air pollution. The foreign matter inflames lung tissue, which leads to an increase in plaque build-up in arteries contributing to heart and lung disease.

Citation: Pope CA 3rd, Ezzati M, Dockery DW. Fine-particulate air pollution and life expectancy in the United States. N Engl J Med. 2009 Jan 22;360(4):376-86.