DISTRIBUTION PATTERN OF HEAVY METALS IN THE SURFACE SEDIMENTS OF THE AREA OF CIRCUM-BOHAI BAY AND ECOLOGICAL ENVIRONMENT ASSESSMENT

The distribution pattern of heavy metals in the surface sediments around the Circum-Bohai Bay and its influencing factors were studied in the paper.The Nemerow comprehensive index method is adopted for ecological assessment.Results show that the Liaodong Bay is the most seriously polluted area from among the three studied areas.Cd and Hg are highly beyond the standard.Spatially,high values occur in the west of the northern Liaodong Bay and the Xiaoling River estuary off the Huludao.Cu,Pb and Zn show similar distribution pattern due to similar provenance and granularity.The assessment of ecological risk indicates that the area near Huludao is the most vulnerable area in heavy metal pollution.