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 with 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.
姚青, 蔡子颖, 马志强, 韩根友, 刘敬乐, 韩素芹. 天津大气中BTEX的变化特征与健康风险评估[J]. 中国环境科学, 2017, 37(9): 3276-3284.
YAO Qing, CAI Zi-ying, MA Zhi-qiang, HAN Gen-you, LIU Jing-le, HAN Su-qin. Variation characteristics and health risk assessment of BTEX in Tianjin. CHINA ENVIRONMENTAL SCIENCECE, 2017, 37(9): 3276-3284.
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