Cleaner air equals longer lives
2009-01-22 08:40
Boston - Dramatic improvements in US
air quality over the last two decades have added 21 weeks to
the life of the average American, researchers reported on
Wednesday.
Reducing fine particles given off by automobiles, diesel
engines, steel mills and coal-fired power plants have added as
much as 15% of the 2.72 years of extra longevity seen in
the United States since the early 1980s, they wrote in the New
England Journal of Medicine.
Changes in smoking habits are the biggest reason why
Americans are living longer, said Arden Pope, an epidemiologist
at Brigham Young University in Utah who led the study.
Improved socioeconomic conditions, judged partly by the
proportion of high school graduates living in an area, rank
next. But cleaner air was a big factor.
"It's stunning that the air pollution effect seems to be as
robust as it is after controlling for these other things," Pope
said in a telephone interview.
Using life expectancy, economic, demographic and pollution
data from 51 metropolitan areas, Pope and his colleagues found
when fine-particle air pollution dropped by 10 micrograms per
cubic meter, life expectancy rose by 31 weeks.
Fine-particle counts
Areas such as Akron, Ohio, and Philadelphia showed that kind
of drop in air pollution.
The bigger the decline, the longer people began living.
In some areas where fine-particle counts dropped by 13 to
14 micrograms - such as Buffalo, New York and Pittsburgh -
people typically started living about 43 weeks longer.
The findings show there has been a real dividend from the
efforts since the 1970s to improve air quality, said Pope.
In a commentary, Daniel Krewski of the University of Ottawa
said the study "provides direct confirmation of the population
health benefits of mitigating air pollution and greatly
strengthens the foundation of the argument for air-quality
management."
Based on earlier research, the World Health Organisation
has estimated that 1.4% of all deaths around the world
are caused by air pollution particles.