Ostro B D, Hurley S, Lipsett M J
California Office of Environmental Health Hazard Assessment, Oakland 94612, USA.
Environ Res. 1999 Oct;81(3):231-8. doi: 10.1006/enrs.1999.3978.
Many epidemiological studies provide evidence of an association between airborne particles, measured as PM10 (particulate matter less than 10 microm in diameter), and daily morbidity and mortality. Most of these studies have been conducted in urban areas where PM10 consists primarily of fine particles (<2.5 microm in diameter). Few studies have investigated impacts associated with coarse mode particles (>2.5 microm in diameter). We investigated associations between PM10 and daily mortality in the Coachella Valley, a desert resort and retirement area east of Los Angeles, where coarse particles of geologic origin typically comprise approximately 50-60% of PM10 and can exceed 90% during wind events. Our analysis utilized daily data on mortality from 1989 through 1992 as well as several pollutant and meteorological variables, including PM10, nitrates, sulfates, ozone, nitrogen dioxide, carbon monoxide, temperature, and relative humidity. Outcome variables included several measures of daily mortality, including all-cause, cardiovascular and respiratory mortality, and counts of deaths for those above age 50. Multivariate Poisson regression models were used to explain these health endpoints, controlling for temperature, humidity, day of the week, season, and time, using locally weighted smoothing techniques. The analysis indicated statistically significant associations between PM10 (2- or 3-day lags) and each measure of mortality. The results were robust to various model specifications, correction for autocorrelation and overdispersion, and analysis of influential observations. A 10 microg/m3 change in daily PM10 was associated with an approximately 1% increase in mortality, which is of similar magnitude to particle-associated impacts identified in urban areas. Thus, our findings provide evidence for a mortality effect of PM10 in an area where the particulate mass is dominated by coarse particles.
许多流行病学研究提供了证据，表明以PM10（直径小于10微米的颗粒物）衡量的空气中颗粒物与每日发病率和死亡率之间存在关联。这些研究大多在城市地区进行，在这些地区，PM10主要由细颗粒物（直径小于2.5微米）组成。很少有研究调查与粗模式颗粒物（直径大于2.5微米）相关的影响。我们调查了洛杉矶以东的沙漠度假和退休地区科切拉山谷中PM10与每日死亡率之间的关联，在该地区，地质来源的粗颗粒物通常占PM10的约50 - 60%，在风力事件期间可能超过90%。我们的分析利用了1989年至1992年的每日死亡率数据以及几个污染物和气象变量，包括PM10、硝酸盐、硫酸盐、臭氧、二氧化氮、一氧化碳、温度和相对湿度。结果变量包括几种每日死亡率的衡量指标，包括全因死亡率、心血管和呼吸系统死亡率，以及50岁以上人群的死亡人数。使用多元泊松回归模型来解释这些健康终点，并通过局部加权平滑技术控制温度、湿度、星期几、季节和时间。分析表明，PM10（滞后2天或3天）与每种死亡率衡量指标之间存在统计学上的显著关联。结果对于各种模型设定、自相关和过度离散校正以及有影响观测值的分析都是稳健的。每日PM10每变化10微克/立方米，死亡率大约增加1%，这与在城市地区确定的与颗粒物相关的影响幅度相似。因此，我们的研究结果为在颗粒物质量以粗颗粒物为主的地区PM10对死亡率的影响提供了证据。
