中国城市土壤重金属空间分布与污染研究

研究对比分析了中国城市土壤重金属的空间变异、时间差异、污染水平以及环境风险,研究结果表明,中国城市土壤重金属含量均超过了中国土壤背景值,尤其是Cd和Pb的污染严重,其含量分别是中国土壤背景值的91.37倍和41.91倍,Ni的污染较轻,其含量是中国土壤背景值的1.59倍。中国城市土壤重金属的含量存在明显地区差异,东部、中部和西部地区的城市土壤重金属含量差异较大,省会城市和地级城市的污染程度不一,城市不同功能区之间也存在明显区别。同时,城市土壤中金属含量也因城市发展时间的长短而又一定差异。中国城市土壤重金属总体内梅罗综合污染指数是45.404,属于重度污染,中国城市土壤重金属综合潜在生态风险指数为71.56,潜在生态风险程度为高级。不同等级的城市污染程度不一,造成的环境风险也不同。

Study on the Spatial Distribution and Pollution Evaluation of Heavy Metal in Urban Soil of China

The study about spatial variability,time differences,pollution levels and environmental risks of heavy metals from China's urban soil show that the heavy metal contents in Chinese cities are over the soil background value in China,especially the contents of Cd and Pb,which were 91.37 times and 41.91 times to the Chinese soil background value.And the content of Ni l is only 1.59 times to the Chinese soil background value.There are significant regional differences of the heavy metals contents in urban soils in China.The heavy metals contents in urban soils of the eastern,central and western regions are quite different,and the pollution of capital cities and prefecture-level cities are different.There are also obvious differences among different functional areas the city.Meanwhile,the metal content of urban soils change with the length of time of urban development.Nemero comprehensive pollution index of China's urban soil heavy metal was 45.404,which is heavily polluted.The potential ecological risk index of China's urban soil heavy metal is 71.56,which is high potential ecological risk.Different levels of urban pollution with development degrees cause the different environmental risks.