我国城市土壤重金属的污染格局分析

Contamination pattern of heavy metals in Chinese urban soils

收集了国内43个大中城市的3688个城区土壤重金属数据,通过描述性分析、评价分析、聚类分析等,初步确定了我国城市土壤重金属的污染格局.结果表明,我国城市土壤As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的平均赋存量分别为13.39、0.68、63.04、38.17、0.31、26.18、47.34、137.72 mg·kg-1.Nemerrow指数、地质累积指数和潜在生态危害指数评价表明,污染最严重的城市是太原、南京、开封,主要污染重金属是Hg、Cd、Pb.43个城市中,上海、武汉、淄博、昆明、抚顺、昌吉、郑州、贵阳、成都、攀枝花、天津、珠海、大庆、北京、南宁、广州、香港、长春、太原等19个城市属于Cd强度污染;徐州、长沙、开封、重庆、乌鲁木齐、沈阳、西安、杭州、南京、兰州、洛阳等11个城市属于Hg-Cd强度污染、Pb中度污染;其余13个城市属一般轻度污染.长江以南城市土壤重金属污染比长江以北城市严重,中小城市土壤重金属污染低于特大城市.

The description analysis, assessment analysis and clustering analysis were conducted to determine the contamination pattern of heavy metals in Chinese urban soils based on 3688 samples from 43 cities. The results showed that the average contents of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in urban soil were 13.39, 0.68, 63.04, 38.17, 0.31, 26.18, 47.34 and 137.72 mg.kg-1. According to Nemerrow index, Geoaccumulation index and Potential ecological risk index,the most polluted heavy metals were Hg, Cd and Pb, and the most polluted cities were Taiyuan, Nanjing, Kaifeng. 43 cities involved could be classified into three types, i. e Cd severity （including Shanghai , Wuhan, Nanjing, Zibo, Kunming, Changji, Zhengzhou, Guiyang, Chengdu, Panzhihua, Tianjing, Zhuhai, Daqing, Beijing, Nanning, Guangzhou, HongKong, Chan.gchun, Taiyuan）, Hg-Cd severity, Pb medium （ including Xuzhou, Changsha , Kaifeng, Chongqing, Urumqi Shenyang, Xi＇an, Hangzhou, Nanjing, Lanzhou, Luoyang）, and other mild contamination of 13 cities. The contamination of heavy metals in the cities to the south of the Yangtze River was more serious than that of the cities to the north of the Yangtze River, while the metal contamination in metropolis soils was more serious than that of towns.