National Analysis
http://www.ehponline.org/docs/2009/0800108/abstract.pdf
Antonella Zanobetti and Joel Schwartz
doi: 10.1289/ehp.0800108 (available at http://dx.doi.org/)
Online 13 February 2009
ehponline.org
Abstract
Background: While many studies have examined the effects of air pollution on
mortality,
data limitations have resulted in fewer studies of PM2.5 and of coarse
particles.
We conducted a national, multi-city time series study of the acute effect of
PM2.5 and PM
coarse on the increased risk of death for all causes, cardiovascular
disease, myocardial
infarction, stroke, and respiratory mortality for the years 1999-2005.
Method: We applied a city and season specific Poisson regression in 112 US
cities to
examine the association of mean (day of death and previous day) PM2.5 and PM
coarse
with daily deaths. We combined the city-specific estimates using a random
effect
approach, in total, by season and by region.
Results: We found a 0.89 % increase (95% CI: 0.75- 1.22) in total mortality,
a 0.85 %
increase (95% CI: 0.46- 1.24) in CVD, a 1.18 % increase (95% CI: 0.48- 1.89)
in MI, a
1.78 % increase (95% CI: 0.96- 2.62) in stroke, and a 1.68 % increase (95%
CI: 1. 04-
2.33) in respiratory deaths for 10 ?g/m3 increase in 2-day averaged PM2.5.
The effects
were higher in spring. For PM coarse we found significant but smaller
increases for all
causes analyzed.
Conclusions: We conclude that our analysis showed an increased risk of
mortality for all
and specific causes associated with PM2.5, and the risks are higher than
what previously
observed for PM10. In addition, coarse particles are also associated with
more deaths.
