For those wondering just how much impact cleaning up the air can have, researchers now have a much fuller picture.
Reductions in particulate air pollution during the 1980s and 1990s led to an average five-month increase in life expectancy in 51 U.S. metropolitan areas, including Denver.
Some of the more initially polluted cities such as Pittsburgh and Buffalo, N.Y., showed a 10-month increase, researchers will report today.
The reductions in pollution accounted for about 15 percent of the nearly three-year increase in life expectancy during the period, said epidemiologist C. Arden Pope III of Brigham Young University, lead author of the study appearing in the New England Journal of Medicine.
It is well-known that particulate air pollution reduces life expectancy, said environmental epidemiologist Joel Schwartz of the Harvard School of Public Health, who was not involved in the study.
But public-policy makers “are interested in the question of, ‘If I spend the money to reduce pollution, what really happens?’ ” he said.
The particulates in question are called fine particulates because they are smaller than 2.5 microns in diameter, allowing them to burrow deep into the small air passages of the lung. They have repeatedly been shown to produce cardiovascular and pulmonary disease.
Larger particulates, which cause visibility problems, have a much smaller effect on health.
