我国四个典型城市空气污染所致超额死亡评估

Evaluation of excess mortality caused by PM2.5 in four typical Chinese big cities

目的探讨环境空气中粒径≤2．5μm的颗粒物（PM2.5）对我国北京、上海、广州、西安4个典型城市造成的超额死亡人数。方法收集目标城市北京、上海、广州、西安2004--2009年可得的每日健康和气象数据（包括温度和湿度数据），在控制时间趋势、星期几效应、气象影响因素的基础上，利用广义相加模型建立细颗粒物与非意外死亡之间的暴露-反应关系模型，获得PM2.5对于非意外死亡的相对危险度，然后在各城市统计年鉴的基础上，根据各自的细颗粒物暴露水平和健康数据分别计算各城市由PM2.5导致的超额死亡人数。结果北京、西安、广州、上海4个城市PM2.5对非意外死亡的相对危险度（95％CI）分别为1．0027（1．0010～1．0044），1．0020（1．0007～1．0033），1．0056（1．0022—1．0091），1．0036（1．0011～1．0061）。与北方2个城市北京和西安相比，南方2个城市广州和上海单位PM2.5浓度升高所对应的相对危险度较高。2010年北京、上海、广州、西安因PM2.5污染分别造成早死人数为2349、2980、1715、726人，共计7770人，分别占当年总死亡人数的1．9％，1．6％，2．2％和1．6％。结论虽然PM2.5污染对城市居民非意外死亡的相对危险度存在一定的地域差异，但其已经给公共健康造成一定的损失，亟需加强PM：，污染的治理。

Objective To evaluate the adverse effects of particulate matter ≤2.5 p.m in aerodynamic diameter （PM2.5 ） on public health in four typical cities： Beijing, Shanghai, Guangzhou and Xi＇an. Methods Daily health and meteorological data （including ambient temperature and relative humidity） were collected in the past several years. For the relative risk of PM2.5 effects on mortalities, generalized additive model （GAM） was used to obtain the exposure-response coefficients between PM2.5 and non-accidental mortalities after controlling time trend, week effects and meteorological factors. Then excess mortalities were calculated according to coefficients, health data and air pollution level. Results The relative risks of PM2.5 effects on mortalities were 1. 0027 （ 1. 0010 - 1. 0044 ）, 1. 0020 （ 1. 0007 - 1. 0033 ）, 1. 0056 （ 1. 0022 - 1. 0091 ）, 1. 0036 （ 1. 0011 - 1. 0061 ） for Beijing, Xi＇ an, Shanghai, Guangzhou respectively. Compared with relative risks in northern cities （Beijing and Xi＇an） , relative risks in southern cities （Shanghai and Guangzhou ） were higher. The numbers of excess mortalities caused by PM2.5 in Beijing, Shanghai, Guangzhou, Xi＇an were 2349, 2980, 1715, 726 and accounted for 1.9%, 1.6%, 2. 2% and 1.6% of the total death number in 2010 respectively. Conclusions Although relative health risks caused by PM2.5 vary geographically for urban residents, public health is endangered. More efforts should be devoted to reducing PM2.5 pollution.