Schwartz J, Dockery D W, Neas L M
Harvard School of Public Health, Boston, Massachusetts, USA.
J Air Waste Manag Assoc. 1996 Oct;46(10):927-39.
Recent epidemiologic studies have consistently reported increased daily mortality associated with exposures to particulate air pollution. Currently, particulate mass is measured as particles smaller than 10 microns (PM10). Fine (PM2.5) and coarse (PM10-PM2.5) mass and sulfate particle concentrations were measured in six eastern U.S. cities for eight years, and aerosol acidity concentrations were measured for approximately one year. Daily mortality for these metropolitan areas was combined with particulate air pollution and weather measurements. City-specific associations with each measure of particle pollution were estimated by Poisson regression, adjusting for time trends and weather by nonparametric methods. Combined effect estimates were calculated as the inverse variance weighted mean of the city-specific estimates. PM10, PM2.5, and SO4= were each significantly associated with increased daily mortality, while no associations were found with coarse mass nor with aerosol acidity (H+) concentrations. The strongest association was found with PM2.5. A 10 micrograms/m3 increase in two-day mean PM2.5 was associated with a 1.5% (95% CI 1.1% to 1.9%) increase in total daily mortality. Somewhat larger increases were found for deaths caused by chronic obstructive pulmonary disease (+3.3%) and by ischemic heart disease (+2.1%). These data suggest that increased daily mortality is specifically associated with particle mass constituents found in the aerodynamic diameter size range under 2.5 microns, that is, with combustion-related particles.
近期的流行病学研究一致报告称，接触空气中的颗粒物污染会导致每日死亡率上升。目前，颗粒物质量是以直径小于10微米的颗粒（PM10）来衡量的。在美国东部六个城市对细颗粒物（PM2.5）、粗颗粒物（PM10 - PM2.5）质量以及硫酸盐颗粒浓度进行了为期八年的测量，并对气溶胶酸度浓度进行了约一年的测量。将这些大都市地区的每日死亡率与颗粒物空气污染及气象测量数据相结合。通过泊松回归估计每个城市与每种颗粒物污染指标之间的关联，并采用非参数方法对时间趋势和天气进行校正。综合效应估计值通过各城市估计值的逆方差加权均值计算得出。PM10、PM2.5和SO4=均与每日死亡率上升显著相关，而粗颗粒物质量和气溶胶酸度（H+）浓度与死亡率无关联。与PM2.5的关联最为强烈。两日平均PM2.5每增加10微克/立方米，总每日死亡率就会增加1.5%（95%置信区间为1.1%至1.9%）。慢性阻塞性肺疾病导致的死亡（+3.3%）和缺血性心脏病导致的死亡（+2.1%）的增加幅度略大。这些数据表明，每日死亡率上升与空气动力学直径小于2.5微米范围内的颗粒物质量成分具体相关，即与燃烧相关的颗粒有关。
