标题：Cardiopulmonary Effects of Fine Particulate Matter Exposure among Older Adults, during Wildfire and Non-Wildfire Periods, in the United States 2008–2010
摘要：Background: The effects of exposure to fine particulate matter ( PM 2.5 ) during wildland fires are not well understood in comparison with PM 2.5 exposures from other sources. Objectives: We examined the cardiopulmonary effects of short-term exposure to PM 2.5 on smoke days in the United States to evaluate whether health effects are consistent with those during non-smoke days. Methods: We examined cardiopulmonary hospitalizations among adults ≥ 65 y of age, in U.S. counties ( n = 692 ) within 200 km of 123 large wildfires during 2008–2010. We evaluated associations during smoke and non-smoke days and examined variability with respect to modeled and observed exposure metrics. Poisson regression was used to estimate county-specific effects at lag days 0–6 (L0–6), adjusted for day of week, temperature, humidity, and seasonal trend. We used meta-analyses to combine county-specific effects and estimate overall percentage differences in hospitalizations expressed per 10 - μ g / m 3 increase in PM 2.5 . Results: Exposure to PM 2.5 , on all days and locations, was associated with increased hospitalizations on smoke and non-smoke days using modeled exposure metrics. The estimated effects persisted across multiple lags, with a percentage increase of 1.08% [95% confidence interval (CI): 0.28, 1.89] on smoke days and 0.67% (95% CI: − 0.09 , 1.44) on non-smoke days for respiratory and 0.61% (95% CI: 0.09, 1.14) on smoke days and 0.69% (95% CI: 0.19, 1.2) on non-smoke days for cardiovascular outcomes on L1. For asthma-related hospitalizations, the percentage increase was greater on smoke days [6.9% (95% CI: 3.71, 10.11)] than non-smoke days [1.34% (95% CI: − 1.10 , 3.77)] on L1. Conclusions: The increased risk of PM 2.5 -related cardiopulmonary hospitalizations was similar on smoke and non-smoke days across multiple lags and exposure metrics, whereas risk for asthma-related hospitalizations was higher during smoke days.
