中文摘要：

目的比较三元催化器催化前后汽油机中苯系物排放的健康风险的改变情况，探讨健康环境风险评估方法在汽油机排放物健康效应评价中的可行性。方法采集分析100％负荷下三元催化器进气口和出气口中苯系物（苯、甲苯、二甲苯）的浓度，利用健康环境风险评估方法比较催化前后苯系物健康风险的变化。结果在100％负荷下经三元催化器催化后，甲苯、二甲苯的危害指数降低，苯的危害指数和致癌风险升高；苯系物的慢性长期健康危害指数降低。结论三元催化器改变了汽油机排放物的健康风险，催化后苯系物的非致癌风险降低，致癌风险增加。健康环境风险评估可以用于汽油机排放物的健康效应。

英文摘要：

Objective To assess the effects of three way catalytic converter on the health risk of benzene series. Methods After collecting the benzene series （benzene, toluene, xylene） in the air inlet and air outlet of the three way catalytic converser in 100% working loads, their health risk was assessed with the methods of health risk assessment. Results After catalysis, the hazard index of toluene and xylene decreased in all loads, the hazard index and carcinogenesis risk of benzene increased in 100% loads, the chronic long-term hazard index of benzene deceased in 100% loads. Conclusion The three way catalytic converter can change the health risk of benzene series emission by gasoline engine, the carcinogenesis risk of benzene series emission will be increased when the gasoline is treated with the three way catalytic converter.