【作者】 姚青； 蔡子颖； 马志强； 韩根友； 刘敬乐； 韩素芹；

【Author】 YAO Qing;CAI Zi-ying;MA Zhi-qiang;HAN Gen-you;LIU Jin-le;HAN Su-qin;Tianjin Institute of Meteorological Science;Tianjin Environmental Meteorology Center;Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei;Beijing Saak-Mar Environmental Instrument Ltd.;

【机构】 天津市气象科学研究所； 天津市环境气象中心； 京津冀环境气象预报预警中心； 北京赛克玛环保仪器有限公司；

【摘要】 采用AMA GC5000BTX在线色谱仪监测天津城区2012年10月-2013年2月大气中苯、甲苯、乙苯、邻二甲苯和间-对二甲苯（苯系物,BTEX）的浓度,采用气溶胶生成系数（FAC）计算各组分的SOA生成潜势,采用US EPA的健康风险评价模型对BTEX的人体健康风险进行评估.结果表明,观测期间BTEX浓度均值为40.02±23.66μg/m³,其中甲苯浓度最高,苯和间-对二甲苯次之,邻二甲苯最低,雾-霾日BTEX平均值为49.78±25.03μg/m³,远高于非雾-霾日（28.57±15.18μg/m³）.BTEX浓度日变化差异明显,非雾-霾日B/T均值为0.70,雾-霾日增至0.77,表明观测期间以机动车排放污染为主,雾-霾污染期间BTEX来源复杂,生物质燃烧和燃煤等的贡献增大.甲苯对SOA的贡献最大,间、对-二甲苯次之,雾-霾日BTEX对SOA的贡献值高于非雾-霾日.观测期间BTEX的HI为0.455,其中雾-霾日HI为0.578,非雾-霾日HI为0.309,均低于EPA认定安全范围,表明苯系物非致癌风险在安全阈值范围内,但苯的致癌风险值为7.64×10^-5,高于EPA规定的安全阈值,需要引起高度关注.更多还原

【Abstract】 BTEX were measured by AMA GC5000 in Tianjin City from October 2012 to February 2013. The average concentration of BTEX was 40.02±23.66μg/m³ during the observation period. Toluene showed highest level among the BTEX, while o-xylene was the minimum. There was bimodal diurnal variation of BTEX, with peaks at early morning and late afternoon. The daily average of BTEX was 49.78±25.03μg/m³ during fog/haze period, compared to 28.57±15.18μg/m³ in non-fog/haze period. The ratio of B/T was 0.7 during non-fog/haze period, indicated BTEX mainly came from vehicle emissions. However, the ratio increased to 0.77 in fog/haze period, indicated industrial coal combustion could accelerate the air pollution. Toluene was the most important precursor for SOA among BTEX, while m,p-xylene took the second place. The averaged HI value was 0.455 during the observation period, with 0.578 in fog/haze day and 0.309 in non-fog/haze day, which was under the up limit of safety range recommended by US EPA. Nevertheless, the risk of cancer caused by benzene was 7.64×10^-5, beyond the safety threshold of EPA, which should be concern.更多还原