Ecological Risk Assessment of Heavy Metal in Urban Area Soil

The Yangtse delta area is one of the most rapidly developing areas in China. There are mega-cities like Nanjing and the surrounding urban areas of different sizes. As a traditional historical and industrial city, Nanjing city was investigated for heavy metals in its soil. Based on spatial characteristic of Nanjing City, 12 samples were regarded as descriptions of different function zone in urban area. The concentration of Cu, Cr, Pb, and Zn were analyzed. By index of geo-accumulation and potential ecological risk index, urban soil pollution was assessed, which indicated that urban soil in Nanjing have been slightly polluted except for particular areas where soil contamination is severe. Results of the values by order is Pb>Cu>Cr>Zn through the potential ecology risk index. It was presented that urbanization and industrialization were interrelated with urban soil pollution by heavy metals.