Vedal Sverre, Dutton Steven J
Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health and Community Medicine, Seattle, WA 98105, USA.
Environ Res. 2006 Sep;102(1):29-35. doi: 10.1016/j.envres.2006.03.008. Epub 2006 May 22.
Unusual air pollution episodes, such as when smoke from wildfires covers a large urban area, can be used to attempt to detect associations between short-term increases in particulate matter (PM) concentrations and subsequent mortality without relying on the sophisticated statistical models that are typically required in the absence of such episodes. The objective of this study was to explore whether acute increases in PM concentrations from wildfire smoke cause acute increases in daily mortality. The temporal patterns of daily nonaccidental deaths and daily cardiorespiratory deaths for June of 2002 in the Denver metropolitan area were examined and compared to those in two nearby counties in Colorado that were not affected by the wildfire smoke and to daily deaths in Denver in June of 2001. Abrupt increases in PM concentrations in Denver occurred on 2 days in June of 2002 as a result of wildfire smoke drifting over the Denver area. Small peaks in mortality corresponded to both of the PM peaks, but the first mortality peak also corresponded to a peak of mortality in the control counties, and cardiorespiratory deaths began to increase on the day before the second peak. Further, there was no detectable increase in cardiorespiratory deaths in the hours immediately following the PM peaks. Although the findings from this study do not rule out the possibility of small increases in mortality due to abrupt and dramatic increases in PM concentrations from wildfire smoke, in a population of over 2 million people no perceptible increases in daily mortality could be attributed to such events.
异常的空气污染事件，比如野火产生的烟雾覆盖大片城区时，可以用来尝试检测颗粒物（PM）浓度短期升高与随后死亡率之间的关联，而无需依赖在没有此类事件时通常所需的复杂统计模型。本研究的目的是探讨野火烟雾导致的PM浓度急性升高是否会引起每日死亡率的急性升高。对丹佛市区2002年6月的每日非意外死亡和每日心肺死亡的时间模式进行了检查，并与科罗拉多州附近两个未受野火烟雾影响的县的时间模式以及丹佛2001年6月的每日死亡情况进行了比较。由于野火烟雾飘过丹佛地区，20002002年6月丹佛的PM浓度出现了突然升高。死亡率的小高峰与两个PM高峰相对应，但第一个死亡率高峰也与对照县的死亡率高峰相对应，并且心肺死亡在第二个高峰的前一天就开始增加。此外，在PM高峰后的数小时内，心肺死亡没有可检测到的增加。尽管本研究的结果并未排除野火烟雾导致的PM浓度突然大幅升高可能使死亡率略有增加的可能性，但在超过200万人口中，此类事件并未导致每日死亡率出现明显增加。
