上海城郊大气挥发性有机物污染特征、活性组分及风险评估

Volatile organic compounds in suburban atmosphere in Shanghai:pollution characterization,activity and health risk

为了解上海城郊大气中挥发性有机物(VOCs)的时空污染特征及其对人体潜在健康风险,选取上海某城郊10个点位进行连续6年(2012-2017年)的采样分析。结果表明,上海该城郊大气VOCs平均质量浓度为(243.80±151.52)μg/m3,其中烷烃、卤代烃、芳香烃、含氧VOCs和不饱和脂肪烃依次占VOCs总浓度的45.72%、20.04%、18.84%、11.19%、4.21%。上海郊区不同功能区VOCs总浓度年际变化趋势较为一致,总体呈下降趋势;在空间上,化工区主干道路附近的两采样点VOCs质量浓度最高,分别为307.81、340.97μg/m3。O3生成潜势和等效丙烯浓度计算结果显示,芳香烃为上海城郊大气中最主要的活性物种,且关键活性组分为甲苯、间/对-二甲苯和异丁烷等。上海城郊大气中27种风险VOCs的总致癌风险值为3.02×10-4,高于可接受限值(1.00×10-4),长期暴露可能有致癌风险。

In order to understand the temporal-spatial distributions and health risk of volatile organic compounds(VOCs)in suburban area in Shanghai,10 sites were selected for consecutive 6 years(from 2012 to 2017)of VOCs monitoring.Results showed that the average concentration of VOCs was(243.80±151.52)μg/m3,in which alkanes,halogenated hydrocarbons,aromatic hydrocarbons,oxygenated VOCs and unsaturated fatty hydrocarbon accounted for45.72%,20.04%,18.84%,11.19% and 4.21%,respectively.The concentration of VOCs showed similar annual variation trends with a steady decrease in different functional zones.For spatial analysis,the VOCs concentration of two sampling sites near the main road in the chemical industrial zone was the highest,which were 307.81,340.97μg/m3.Ozone formation potential and equivalent propylene concentration of VOCs indicated that aromatic hydrocarbons were the most active species,and the key active components were toluene,m/p-xylene and isobutane.The human health risks caused by 27 risky VOCs species were calculated,and the total cancer risk was 3.02×10-4,which was higher than the acceptable limit(1.00×10-4),suggesting long-term exposural possible potential carcer risk.