中文摘要：

目的 了解银川市2013—2014年大气污染物浓度与人群暴露水平,定量分析和评价该市大气污染物与出生缺陷的暴露-反应关系及其关键窗口期。方法 收集银川市2013年10月1日—2014年12月31日出生缺陷个案资料,以及该市2013年1月1日—2014年12月31日空气质量数据、气象资料。采用病例交叉设计分析大气污染物浓度与出生缺陷的暴露-反应关系。结果 研究期间银川市大气PM2.5年均浓度为51μg/m-3,PM10年均浓度为114μg/m-3,SO_2年平均浓度为73μg/m-3,NO_2年平均浓度为43μg/m-3,均高于GB 3095—2012《环境空气质量标准》国家二级标准限值。在控制气象因素的影响下,妊娠后前3个月大气PM2.5、PM10、SO_2浓度每升高10μg/m-3,可能会增加出生缺陷的发生风险,OR（95%CI）分别为1.017（1.013-1.022）,1.011（1.009-1.014）,1.002（1.001-1.003）;分娩前第1个月NO_2、CO浓度每升高10μg/m-3可能会增加出生缺陷的风险,OR（95%CI）分别为1.003（1.001-1.006）,1.106（1.018-1.202）;分娩前第2个月NO_2每升高10μg/m-3可能会增加出生缺陷的风险,OR（95%CI）为1.008（1.005-1.011）;分娩前3个月大气PM2.5、PM10、NO_2、CO浓度每升高10μg/m-3可能会增加出生缺陷的风险,OR（95%CI）分别为1.008（1.005-1.011）,1.013（1.010-1.015）,1.012（1.009-1.015）,1.208（1.106-1.320）,均有统计学意义（P〈0.05）。结论 银川市大气污染较重,妊娠早期是PM2.5、PM10、SO_2对出生缺陷影响的关键窗口期,妊娠晚期是NO_2、CO对出生缺陷影响的关键窗口期。

英文摘要：

Objective To understand the exposure level of air pollution and evaluate the exposure-response relationship between air pollution and birth defects and related critical window period quantitatively in Yinchuan. Methods The data of air pollution and birth defects from January 1st 2013 to December 31st 2014 was collected. The case-crossover design was employed to analyze the exposure-response relationship between air pollution and birth defects. Results During the study period, the annual concentration of ambient PM2.5, PM10, SO2, NO2 was 51, 114, 73 and 43 μg/m3, respectively, larger than secondary standard National Ambient Air Quality Standard. After adjustment for the influence of meteorological factors, it was found that a 10 μg/m3 increase in the ambient PM2.5, PM10 and SO2 may increase the risk of birth defects during the first trimester, ORs（95%C1） were 1.017（1.013-1.022）, 1.011（1.009-1.014） and 1.002（1.001-1.003）, respectively. A 10 p,g/m3 increase in the ambient NO2 may increase the risk of birth defects during the second month before delivery, 0R（95%C1） was 1.008 （1.005-1.011）. A 10μg/m3 increase in the ambient PM2.5, PM10, NO2 and CO may increase the risk of birth defects during the last trimester, ORs（95%CI） were 1.008（1.005-1.011）, 1.013（1.010-1.015）, 1.012（1.009-1.015）and 1.208（1.106- 1.320）, respectively. Conclusion Air pollution in Yinchuan is serious. The exposure-response relationship between air pollution and birth defects is obvious. The critical window period is first trimester and the last trimester.