DISTRIBTION OF HEAVY METALS AT THE JUNCTION OF LIANSHAN, WULI AND CISHAN ESTUARIES, JINZHOU BAY AND THEIR CONTAMINATION EVALUATION

Heavy metal distribution patterns were studied in this paper based on 24 seawater samples and 12 surface sediment samples collected from the junction of three estuaries, i.e. the Lianshan estuary, Wuli estuary and Cishan estuary, of Jinzhou Bay. The methods of single factor evaluation and geoaccumulation index were adopted to evaluate the contamination level of the area. The results show that the element contents of the surface sediment are in an order of Zn>Cu>Cr>Pb>Hg>Cd, and their contents decrease with the distance increase from the coast. According to the geoaccumulation index, it is heavily polluted by Zn in three stations, moderately polluted in two stations, and mild moderately polluted in the rest stations. Cu, Pb, and Cr elements are all ranked between the light pollution and mild moderate pollution. The pollutants in the seawater in the study area are dominated by Pb and Zn. According to the records, the Pb content exceeds the standard at eight stations. There is only one station where Pb contents exceeds the standard. The other stations are qualified to meet the requirements for marine management and protection of corresponding functional areas.