THE ENVIRONMENT BACKGROUND VALUES OF HEAVY METAL AND POLLUTION HISTORY IN BOHAI BAY AND ITS ADJACENT ESTUARY AREAS
渤海湾及其邻近河口区重金属环境背景值和污染历史

Eleven sediment drilling cores were obtained with the long-box and static pressure sampler in Bohai Bay and its adjacent estuary areas during the year of 1983-1985. Based on 210Pb age dating and the analysis of heavy metals in sediments, the sedimentation rate, the environment background values and the artificial increment of Cu, Zn,Pb, Cd in 4 periods in Bohai Bay are determined. The range of sedimentation rate is 1.8-44.2 mm/a. The high sedimentation rate is in Jiyunhe River mouth, Haihe River mouth and the old Yellow River mouth; the low sedimentation rate is in the middle part of the bay. According to the calculation of sedimentation flux of heavy metals, the greatest discharge of Cu into the bay was in 1964 and the load was 73.751; the most discharge of Pb reached the highest in 1974 and the load was 64.57t; the discharge of Zn, Cd appeared in 1983 and the loads were 249.32, 5.77t separately.