Pollution status and assessment of seven heavy metals in the seawater and sediments of Hangzhou Bay, China

Hangzhou Bay, one of the fastest economy and population growth region in China, was heavily polluted by a large amounts of industrial waste water and domestic sewage containing harmful heavy metal pollutants. To investigate the status of heavy metals pollution and assess the ecological risks in Hangzhou Bay, seven heavy metals (Cu, Zn, Pb, Cd, Cr, Hg and As) concentrations of water and sediments were analyzed. Heavy metals concentrations in sediments close to the estuarine coast and nearshore area were higher than that in other areas. Cu, Zn, Pb, Cd, Cr and As in sediments might have extensive homologies and originate from the petroleum industry. The pollutions of Cu, Zn, Pb, Cd, Cr and As in seawater and sediment were very light or no pollution. Both in seawater and sediments, the Hg contamination was the most serious among the measured seven heavy metals and should be paid more attention.