Dockery D W, Pope C A, Xu X, Spengler J D, Ware J H, Fay M E, Ferris B G, Speizer F E
Environmental Epidemiology Program, Harvard School of Public Health, Boston, MA 02115.
N Engl J Med. 1993 Dec 9;329(24):1753-9. doi: 10.1056/NEJM199312093292401.
Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks.
In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities.
Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most polluted of the cities as compared with the least polluted was 1.26 (95 percent confidence interval, 1.08 to 1.47). Air pollution was positively associated with death from lung cancer and cardiopulmonary disease but not with death from other causes considered together. Mortality was most strongly associated with air pollution with fine particulates, including sulfates.
Although the effects of other, unmeasured risk factors cannot be excluded with certainty, these results suggest that fine-particulate air pollution, or a more complex pollution mixture associated with fine particulate matter, contributes to excess mortality in certain U.S. cities.
近期研究报告了空气中颗粒物污染与每日死亡率之间的关联。基于人群的美国大都市地区横断面研究也发现了空气中颗粒物污染与年度死亡率之间的关联，但这些研究受到了批评，部分原因是它们没有直接控制吸烟及其他健康风险因素。
在这项前瞻性队列研究中，我们在控制个体风险因素的同时，估算了空气污染对死亡率的影响。利用美国六个城市8111名成年人14至16年死亡率随访数据进行生存分析，包括Cox比例风险回归模型分析。
死亡率与吸烟的关联最为密切。在对吸烟及其他风险因素进行校正后，我们观察到空气污染与死亡率之间存在具有统计学意义的显著关联。污染最严重城市与污染最轻城市相比，校正后的死亡率比值为1.26（95%置信区间为1.08至1.47）。空气污染与肺癌和心肺疾病导致的死亡呈正相关，但与其他原因导致的死亡合计情况无关。死亡率与包括硫酸盐在内的细颗粒物空气污染关联最为密切。
尽管不能确定地排除其他未测量风险因素的影响，但这些结果表明，细颗粒物空气污染或与细颗粒物相关的更复杂污染混合物，导致了美国某些城市的超额死亡率。
