南京市PM2.5中金属元素污染特征及健康风险

监测分析了南京市浦口区典型工业区(2016年12月—2017年10月)PM 2.5中金属元素的浓度,分析了季节差异及来源,评价了健康风险。结果表明,PM 2.5年均值为61.24μg/m 3,全年有33.33%的天数超过《环境空气质量标准》(GB 3095—2012)的日均限值。绝大多数金属元素的平均值为:冬季>春季>秋季>夏季。As的全年平均值为(2.01±1.09)ng/m 3,较为接近我国环境标准限值。PM 2.5中金属元素主要来自工业排放、自然过程、金属冶炼及交通活动,Cr、Ni、As、Cd、Cu、Zn和Pb的富集性较高。健康风险评价结果显示,Mn的非致癌风险最高,所有金属对儿童和成人的总非致癌风险值为0.0884,低于安全阈值1;Cr(Ⅵ)的致癌风险最高,所有金属对儿童和成人的总致癌风险分别为6.23×10-7和2.49×10-6,均在可接受水平内。

Pollution Characteristics and Health Risks of Metal Elements in PM2.5 from Nanjing

The concentrations of metal elements in PM 2.5 in Pukou District,a typical industrial zone of Nanjing were monitored and analyzed from December 2016 to October 2017.The seasonal differences and sources of metal elements were analyzed,and their health risks were evaluated.The results showed that the average annual concentration of PM 2.5 was 61.24μg/m 3,and 33.33%of the days in the whole year exceeded the daily average limit of national ambient air quality standard(GB 3095—2012).The average concentrations of most metal elements decreased as:winter>spring>autumn>summer.The annual average value of As(2.01±1.09)ng/m 3 was close to the limit value of China s environmental standards.Metal elements in PM 2.5 mainly came from industrial emissions,natural processes,metal smelting and transportation activities.The enrichment degrees of Cr,Ni,As,Cd,Cu,Zn and Pb were relatively high.Results of health risk assessment showed that the non-carcinogenic risk of Mn was the highest.The total non-carcinogenic risk value of children and adults was 0.0884,which was lower than the safety threshold of 1.The carcinogenic risk of Cr(Ⅵ)was the highest.The total carcinogenic risks of children and adults were 6.23×10-7 and 2.49×10-6,respectively,which were both within the acceptable level.