南昌市秋季大气PM_(2.5)中金属元素污染及生态风险评价

The Pollution Characteristics and Potential Ecological Risk of Heavy Metals in PM_(2.5) in Autumn in Nanchang

2013年秋季采集了南昌市6个不同功能区的大气PM_(2.5)样品,分析了PM_(2.5)含量及其中18种金属元素的含量。结果表明:采样期间南昌市大气PM_(2.5)平均质量浓度均在《环境空气质量标准》(GB 3095—2012)日平均浓度限值二级标准规定(75μg/m3)的范围内。PM_(2.5)中多数金属元素的含量水平低于中国内地城市,而与香港和国外城市相比则偏高。分别采用富集因子法和潜在生态风险指数法对重金属污染风险进行了评价。富集因子法表明Zn、Pb、Hg、Cu等元素富集程度较高,Cd富集程度极高,人为源显著;潜在生态风险指数法表明Pb、Hg、Cd潜在生态风险程度为极强,南昌市总体潜在生态风险表现为极强,2种方法的评价结果较为一致。

During Autumn in 2013,PM2.5samples were collected in six different functional zones in Nanchang. The PM2.5content and eighteen kinds of metal elements content in PM2.5were studied. It is shown that the average content of PM2.5during autumn in Nanchang was under the Ambient Air Quality Standards（ GB 3095—2012）,which daily average limit of secondary standard was 75 μg / m3. Compared with the domestic and international cities,most elements in atmospheric levels of PM2.5were lower than other domestic mainland cities,and higher than Hong Kong and foreign cities. And the pollution status was evaluated with enrichment factors and Hakanson potential ecological risk index,respectively. The results showed that the enrichment factor values of Zn,Pb,Hg and Cu was high,Cd was extremely high,suggesting that these elements were closely related primarily to anhropogenic emissions. The potential ecological risk of Pb,Hg and Cd was extremely strong,the whole potential ecological risk of Nanchang city was very strong. The evaluation results of the two methods is consistent.