Distribution and Assessment of Cr, Pb, Ni and Cd in Topsoil of the Modern Yellow River Delta, China

Abstract

Modern Yellow River Delta (MYRD) is a typical petrochemical and agricultural industrial area of China. To effectively assess the current status of the four heavy metals (Cr, Pb, Ni and Cd) of topsoil residues, soil samples (0 ~ 20 cm) (n = 104) in the MYRD were collected and analyzed. The results showed that the contents of the four heavy metals were all below or equal to the level 1 background content as specified in the National Environmental Quality Standard for Soils, while the content of Cd and Pb were 1.68 and 1.41 times higher than the background value of soil in Shandong province, respectively. The difference of four heavy metal contents between different kinds of land types existed. Geoaccumulation index and potential ecological risk index methods were used to evaluate the risk of the four heavy metal pollution in the MYRD. The results showed that there was a light or moderate pollution of heavy metals Cd and Pb, which were a strong ecological hazard. Therefore, it is necessary to enhance the monitoring and controlling of heavy metal Cd and Pb pollution in the MYRD.