成都市大气环境VOCs污染特征及其健康风险评价

Pollution Characteristics and Health Risk Assessment of Atmospheric VOCs in Chengdu

于2012年9月,在成都市分别选取代表城市大气环境和路边大气环境的两个采样点对大气中挥发性有机物(VOCs)进行采样,对不同大气环境中VOCs的浓度水平与变化特征、组成和反应活性进行分析,并对其中的芳香烃化合物进行健康风险评价.结果表明,成都市城市大气环境和路边大气环境中TVOCs的平均质量浓度分别为(108.57±52.43)μg·m^(-3)和(132.61±49.31)μg·m^(-3),不同大气环境中各烃类物质浓度均呈现出烷烃>芳香烃>烯烃>炔烃的趋势;城市和路边大气环境中芳香烃和烯烃对臭氧生成潜势(OFP)贡献较大,关键物种均为间/对二甲苯、甲苯、乙烯、邻二甲苯和丙烯;不同大气环境中的苯、甲苯、乙苯和二甲苯(BTEX)对人体的非致癌风险和危害指数均小于1,对暴露人群不存在非致癌风险;致癌物质苯对人体的致癌风险高于安全阈值1.00E-06,对暴露人群可能存在致癌风险.

Volatile organic compounds（ VOCs） were measured in atmospheric samples collected from urban and roadside atmospheric environments in Chengdu in September 2012. The composition, chemical reactivity, and concentration level and its variation characteristics of VOCs were studied,and the health risk of aromatic compounds was assessed. Results showed that the mean mass concentrations of total VOCs（ TVOCs） were（ 108. 57 ± 52. 43） μg·m^（-3） and（ 132. 61 ± 49. 31） μg·m^（-3） for the urban and roadside atmospheric environments,respectively. The highest mass concentrations were observed for alkanes,followed by aromatics,alkenes,and alkynes. Aromatics and alkenes contributed more to ozone formation potential（ OFP） of the urban and roadside atmospheric environments,and m/p-xylene,toluene,ethene,o-xylene,and propene were the key reactive species. The values of hazard quotient and hazard index were less than 1 for benzene,toluene,ethylbenzene,and o-xylene（ BTEX）,showing that they had no appreciable risk of non-cancer health effects on the exposed population. However,the value of cancer risk was above the safety threshold for benzene,showing that it was a potential cancer risk to the exposed population.