Distribution of heavy metals in soils and surface sediments along Rizhao coast and environmental assessment

Contents of Cu, Pb, Zn, Cr, Ni, Cd, As and Hg in soils and surface sediments of Rizhao coast have been analyzed in order to detect the distribution and contamination of these elements. Results show that the high values of heavy metals in soils are mainly distributed in the urban residential land, industrial and mining land, which are obviously from industrial pollutants. The high values of Cu, Zn, Cr, Ni and Hg in the nearshore area are mainly distributed in the areas close to Shijiu Port and Lanshan Port, obviously controlled by particle sizes of bottom sediments. However, the enrichment of Cd, Pb and As in the southeastern area might be related to the adsorption of iron and manganese oxides. In addition, As owes its high content to its high background. Ecological risk assessment suggests that the total degree of pollution and ecological risk of heavy metals contamination in urban areas are high and very high, but medium or low in suburban farmland and nearshore areas.