上海市虹口区PM_(2.5)中重金属和类重金属污染特征及健康风险评价

Pollution characteristics and health risk assessment of heavy metals and metalloids in atmospheric PM_(2.5) in Hongkou District of Shanghai

目的了解上海市虹口区大气细颗粒物(PM_(2.5))中重金属污染特征、来源及对人群健康影响。方法 2019年1—12月采集该区大气PM_(2.5)共87个样品,采用电感耦合等离子体质谱法测定Sb、Al、As、Be、Cd、Cr、Hg、Pb、Mn、Ni、Se、Tl 12种元素的含量,运用富集因子法识别重金属来源,采用美国环保署(environmental protection agency,EPA)推荐的健康风险评价模型进行重金属呼吸途径的人群健康风险评价。结果上海市虹口区大气PM_(2.5)中12种元素的中位数浓度范围为0.006~76.200 ng/m^(3),中位数浓度由高到低依次为Mn>Pb>Ni>As>Se>Cr>Sb>Cd>Tl>Hg>Be,其中Be、Hg、Pb、Ni、Tl浓度变化有季节性差异(P<0.05),Pb、Cd、Hg和As年平均浓度均未超过GB 3095—2012《环境空气质量标准》中标准限值。PM_(2.5)金属元素的相关性分析,Sb、Al、As、Cd、Cr、Pb、Mn、Se、Tl两两相关(r=0.237~0.941,均P<0.05),Be与所有元素都不相关,重金属富集因子值除了Be外,其余均>10。各重金属通过呼吸途径暴露的非致癌风险均<1;4种致癌元素中,Cd和Ni经呼吸途径进入不同人群的体内致癌风险<10-6,Cr和As致癌风险为10-6~10-4,不同人群非致癌和致癌风险由高到低依次为儿童>成年男性>成年女性。结论上海市虹口区大气PM_(2.5)中重金属污染季节特征明显,表现为春冬污染水平较高。重金属来源主要来自人为污染,Pb、Cd和Tl可能高度同源,Cr和As对人群健康的潜在危害风险较高,应引起重视。

Objective To investigate the characteristics,sources and health effects on different populations of heavy metals in atmospheric PM_(2.5) in Hongkou District of Shanghai. Methods A total of 87 PM_(2.5) samples were collected in the area from January to December in 2019. The contents of Sb,Al,As,Be,Cd,Cr,Hg,Pb,Mn,Ni,Se and Tl were determined by inductively coupled plasma mass spectrometry(ICP-MS). The sources of heavy metals were identified by enrichment factor method,and the health risk by heavy metal respiratory pathway was assessed by the assessment model recommended by the U.S. Environmental Protection Agency(EPA). Results The median concentrations of 12 elements in atmospheric PM_(2.5) in Hongkou District of Shanghai ranged from 0.006 to 76.200 ng/m^(3),and the order of median concentrations from high to low were Mn>Pb>Ni>As>Se>Cr>Sb>Cd>Tl>Hg>Be. There were seasonal differences in the concentrations of Be,Hg,Pb,Ni and Tl(P<0.05). The annual average concentrations of Pb,Cd,Hg and As did not exceed the standard limits in GB 3095-2012 Ambient Air Quality Standard. By correlation analysis for the PM2.5 metal elements,Sb,Al,As,Cd,Cr,Pb,Mn,Se and Tl were correlated(r =0.237-0.941,all P <0.05),while Be was not related to all elements. Except Be,the enrichment factors of all heavy metals were greater than 10. The non-carcinogenic risk of heavy metal exposure through respiratory pathway was less than 1. In the 4 carcinogenic elements,the carcinogenic risk of Cd and Ni entering different population through respiratory pathway was less than 10-6,the carcinogenic risk of Cr and As was between10-6-10-4. The non-carcinogenic and carcinogenic risk order of different groups from high to low was children >adult male >adult female. Conclusion The seasonal characteristics of heavy metal pollution in atmospheric PM_(2.5) in Hongkou District of Shanghai is obvious,which shows that the pollution level is higher in spring and winter. The sources of heavy metals mainly come from man-made pollution,and Pb,Cd and Tl maybe highly homologous. The potential risk of Cr and As on human health is high,which should be paid attention to.