ENVIRONMENT QUALITY OF LIAODONG BAY AND POLLUTION EVOLUTION OF HEAVY METALS

The concentration of heavy metals in the surface sediment and core samples in the northern part of the Liaodong Bay were systematically analyzed with X-ray fluorescence spectrometer(XRF), and the distribution pattern, environment quality and pollution history of heavy metals in surface sediments were studied in combination with ¹³⁷Cs and ²¹⁰Pb dating. Results show that the high values of As,Cd,Cu,Pb,Cr and Zn are distributed near the Huludao,and decrease off shore. Some stations in the Liaodong Bay were polluted by heavy metals, the sum of mild and severe pollution rate is 34.5%, with 65.5% remaining clean. Severely polluted stations are distributed around the Huludao water. The pollution of heavy metal in the Liaodong Bay appeared approximately in 1975, and reached a peak in 1997. Since then, it has been significantly decreasing. The pollution of heavy metals in the Liaodong Bay is obviously related to the coastal socio-economic development and a national environmental protection policy is required to ensure a safe and clean environment.