珠海市郊区大气PM2.5中元素特征及重金属健康风险评价

为探讨珠海市郊区大气环境PM_2.5中主要元素尤其是重金属的污染特征及其健康风险，于2014~2015年选取春、夏、秋、冬季4个典型月采集了PM_2.5样品.利用X射线荧光光谱法分析得到15种元素的含量，进一步利用富集因子和主成分分析方法分析其来源，并采用US EPA环境健康风险评价模型评估痕量重金属的健康风险.结果表明：大气PM_2.5中地壳元素（Al、Si、Ca、Fe、Ti）总质量浓度在春、夏、秋、冬季典型月分别为（708±213）、（645±269）、（1155±503）和（1466±492）ng·m^-3，痕量重金属元素（Ba、Co、Cr、Cu、Mn、Ni、Pb、Sb、V、Zn）总质量浓度在春、夏、秋、冬典型月分别为（271±124）、（163±87.6）、（424±192）和（546±183）ng·m^-3.富集因子分析显示Sb、Zn、Pb、Cu、Ni、Ba、Ca、Co等元素富集显著，其富集因子均值范围为172~2426.主成分分析显示，区域性输送污染源、船舶源、燃煤和电子工业是PM_2.5中重金属的主要来源，其贡献率分别为53.4%、13.0%、7.6%和6.8%.健康风险评价结果表明，Mn元素对儿童存在一定的非致癌风险，Cr、Pb和Co存在一定的致癌风险.

Elemental Characteristics and Health Risk Assessment of Heavy Metals in Atmospheric PM2.5 in a Suburb of Zhuhai City

To investigate the characteristics, sources, and health risks of trace heavy metals in fine particles, PM_2.5 samples were collected at a suburban site of Zhuhai in the Pearl River Delta Region. Fifteen elements in the PM_2.5 were analyzed by an X-ray fluorescence method. The results showed that the total mass concentrations of crustal elements (Al, Si, Ca, Fe, and Ti) in a typical month during spring, summer, autumn, and winter were (708±213), (645±269), (1155±503), and (1466±492) ng·m^-3, respectively, while the total mass concentrations of the rest of the trace elements (Ba, Co, Cr, Cu, Mn, Ni, Pb, Sb, V, and Zn) were (271±124), (163±87.6), (424±192), and (546±183) ng·m^-3, respectively. The element concentrations decreased in the following order:Si > Al > Fe > Zn > Ca > Pb > Ba > Mn > Sb > Cu > Ti > V > Ni > Cr > Co. Enrichment factors (EFs) analysis showed that Sb, Zn, Pb, Cu, Ni, Ba, Ca, and Co were heavily enriched, with EFs values ranging from 172 to 2426. Principal component analysis further showed that regional transport, ship emissions, coal combustion, and the electronics industry were the major sources of heavy metals, contributing 53.4%, 13%, 7.6%, and 6.8% of the total, respectively. Health risk assessment results indicated that Mn may pose a non-carcinogenic risk to children, and Cr, Pb, and Co may pose cancer risks to humans.