Distribution and environment assessment of heavy metals in sediments of Qingdao offshore

Through analyzing the testing results of 157 surface sediment samples and 46 river samples collected from Qingdao offshore and surrounding rivers,systematic study was conducted to examine the heavy metal elements (As、Cd、Cr、Cu、Hg、Pb、Zn)distribution characteristics and influencing factors and to assess the environmental quality with Nemerow Index.Results show that the distribution characteristics of heavy metals in Qingdao offshore can be divided into three types:(1) Cr,Cu,Zn are as a class whose high value areas banded extending from northeast to southwest; (2) As,Cd,Pb are as a class and its high value areas concentrated in the southeast of Laoshan waters; (3) the high value of Hg are concentrated in the northern part of Jiaozhou Bay.Through Nemerow index consolidated results,partial stations have been contaminated and were concentrated in the southeast of Laoshan seas and Jiaozhou Bay area.By the river surface samples for comparative study,river sediments is one of the possible sources of heavy metals.