北京城区PM2.5中致癌重金属季节变化特征及其来源分析 |
摘要点击 6005 全文点击 2452 投稿时间:2013-05-08 修订日期:2013-07-17 |
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中文关键词 PM2.5 砷 健康风险 富集 来源 |
英文关键词 PM2.5 arsenic health risk enrichment source |
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中文摘要 |
于2009年4、7、10月和2010年1月在北京城区采集了PM2.5样品,采用电感耦合等离子体质谱仪分析得到29种金属元素,对7种致癌重金属浓度、富集程度及其可能的来源进行了分析.结果表明,7种致癌重金属As、Cd、Co、Cr、Ni、Pb和Se年均值浓度分别为(11.6±14.0)、(2.6±2.4)、(1.0±0.7)、(11.3±9.4)、(4.0±2.4)、(142.5±98.9)、(3.3±2.2)ng·m-3,其中仅As年均值浓度超过WHO参考限值的0.8倍.7种致癌重金属仅As、Cd、Pb和Se等4种重金属有明显富集现象,富集因子均超过500,其中夏季富集因子明显高于其它季节.春、秋和冬季4种高富集致癌重金属主要来源于北京周边的燃煤和城区机动车排放,夏季则主要来源于区域性污染源的输送. |
英文摘要 |
During April, July, October 2009 and January 2010, daily (24-h average) PM2.5 samples were collected at urban sites in Beijing and 29 metal elements were analyzed by the ICP-MS. The characteristics of 7 carcinogenic heavy metal mass concentrations, enrichment, and possible sources were discussed. The annual average concentrations of As, Cd, Co, Cr, Ni, Pb and Se were (11.6±14.0), (2.6±2.4), (1.0±0.7), (11.3±9.4), (4.0±2.4), (142.5±98.9) and (3.3±2.2) ng·m-3, respectively. Only annual average concentration of As exceeded WHO standard by a factor of 0.8. Higher enrichment factors of As, Cd, Pb and Se were found and their enrichment factors exceeded 500. Their enrichment factors in summer were much higher than those in other seasons. The local coal combustion and vehicle exhaust should be the dominant sources for the above four carcinogenic heavy metals in spring, autumn and winter, while regional transportation contributed more in summer. |
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