摘要:
对上海市城区和郊区采集的64个总悬浮颗粒物(TSP)样品进行GC/MS分析,结果表明:全年PAHs浓度范围为2.25-221.6ng·m-3,并呈现明显的秋、冬季节高而夏季低的变化特征,且PAHs年平均值郊区稍微高于城区.多环芳烃中苯并(b+k)荧蒽、茚并(1,2,3-cd)芘、晕苯等化合物相对含量较高,四环以上的组分全年平均含量在90%以上.采用苯并(a)芘和苯并(a)芘等效质量浓度(BaPE)对上海市大气颗粒物中的PAHs进行致癌风险评价,BaP年均值在城区和郊区分别为2.57ng·m-3和2.86ng·m-3,秋季BaP年均值超过了居民区标准限值(5.0ng·m-3).BaPE在城区和郊区的年均浓度分别为5.82ng·m-3和7.24ng·m-3,秋季污染最为严重.
关键词:
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多环芳烃
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颗粒物
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等效浓度
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上海市
Abstract:
Total suspended particle(TSP)samples were collected at two sites(urban versus suburban area)in Shanghai between October 2005 and August 2006.17 PAHs compounds including 15 EPA priority PAHs were extracted by ultrasonic extraction method and were quantified using GC/MS.The results indicated that the total amount of PAHs at two sampling sites ranged from 2.25 to 221.6ng·m-3.Clear seasonal variation of PAHs concentration was observed at two sites with higher level in fall and winter but lower in summer and the value in suburban area was greater than that in urban area.PAHs profile was predominated by benzo(b+k)fluoran-thene,indeno(1,2,3-cd)pyrene and coronene and the average contribution of high rings components(4-ring)was more than 90% at both sites.Adopting benzo(a)pyrene(BaP)and benzo(a)pyrene-equivalent car-cinogenic concentration(BaPE)to evaluate carcinogenic power of atmospheric aerosol PAHs,annual average concentration of BaP was 2.57ng·m-3at Zhabei and 2.86ng·m-3at Jiading,respectively;the BaP concen-tration at two site was in excess of the regional standard(5.0ng·m-3).The annual BaPE was 5.82ng·m-3 and 7.24ng·m-3at urban and suburban area,respectively,and the highest level occurred in fall season.