Between 1980 and 2000, average life expectancy increased by 2.72 years in 51 US cities, and 15 per cent, or approximately five months, of that gain owed to cleaner air, according to a new study.
The average levels of fine particulate matter (PM2.5) in the cities studied dropped from 21 to 14 micrograms per cubic metre (µg/m3) during the 1980s and 1990s. A decrease of 10 µg/m3 was associated with an estimated increase in mean life expectancy of 7.3 months.
Cities that had previously been the most polluted and saw the most extensive clean-ups added an average 10 months to residents’ lives. Health gains were also found in cities that initially had relatively clean air but then made further improvements in reducing air pollution.
“Such a significant increase in life expectancy attributable to reducing air pollution is remark-able,” said Arden Pope, an epidemiologist and lead author on the study.
Source: Fine-Particulate Air Pollution and Life Expectancy in the United States, The New England Journal of Medicine, Volume 360:376-386, 22 January 2009.