They concluded in their paper that, “A decrease of 10 µg per cubic meter in the concentration of fine particulate matter was associated with an estimated increase in mean (±SE) life expectancy of 0.61±0.20 year (P=0.004).”
And, “A reduction in exposure to ambient fine-particulate air pollution contributed to significant and measurable improvements in life expectancy in the United States.”
U.S. environmental health scientist Douglas Dockery (Harvard School of Public Health), another author of the study, stated, "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.”
A third author of the study, U.S. international health researcher Maiid Ezzati (Harvard School of Public Health), stated, "Life expectancy is the single most comprehensive summary of how people's longevity is affected by factors like air pollution that cause early death."
He concluded, "We were able to use routine mortality statistics to track longevity in all cities over a long period of time and analyze how it has been influenced by changes in air pollution."
For more information on air quality (anti-air pollution) in U.S. cities, please go to the American Lung Association's website "State of the Air," a 2004 ranking of the top cities in the United States by quality of their air.