Pollution Levels And Behavior Of Persistent Organic Pollutants In Marine Sediments And Organisms

Polycyclic Aromatic Hydrocarbon is a kind of typical Persistent Toxic Substance, which wide-spread in all kinds of media, with bioaccumulation, long distance migration, toxicity and durability. It also has terrible damage to human health and environment security because of its mutagenesis, carcinogenesis and teratoeenesis.The concentration level, spatial distribution and source of Polycyclic Aromatic Hydrocarbon(PAHs) in the surficial sediments, fishes from four costal cities, Qinhuangdao, Tianjin, Weifang, Dalian, and organisms of the Bohai Sea were investigated. And assess the risk of biological samples for human health. The results indicated that the concentrations of total PAHs(∑PAHs) ranged from 21.9 to 586.4 ng/g(dry weight, dw) with the mean value of 175.1 ng/g(dw). The concentration in sediments of the Bohai Bay with the mean value of 430.9 ng/g(dw) was significantly higher than those of the other areas. Significantly positive correlation between ∑PAHs and TOCs(p < 0.05) implied that the organic content was one important factor affecting the distribution of PAHs in surficial sediments. The characteristic distribution of different rings indicated that PAHs in the Bohai sea was mainly from the process of high temperature combustion, and the transportation way was mainly from the dry atmospheric deposition and river input. The biplots of characteristic PAH congener ratios further indicated that the sources of PAHs in the surficial sediment of the Bohai sea was from the combustion of petroleum and related products, coal and biomass. The concentration of cylindrical samples decreased gradually, when the samples depth increase. The trend is more obvious in gulf than in central sea area.In all biological samples, the PAHs concentration range of fish is 118.2 ~ 516.7 ng/g, dw,and the average value is 225.5 ng/g, dw. The PAHs concentration range of shellfish is 128.8 ~ 548.1 ng/g, dw,and the average value is 276.5 ng/g, dw. According to the concentration of fish from large to small, in order, are Weifang, Tianjin, Qinhuangdao, Dalian; according to the concentrations of shellfish from large to small, in order, are Tianjin, Weifang, Qinhuangdao, Dalian. PAHs in fish samples are based on 2 ~ 3 rings, and in shellfish samples are based on low molecular weight PAHs. The upper limit values of PAHs mass fraction of organic pollutants in edible fish and shellfish for high consumption group and low consumption group are 27.5 ng/g、2.5 ng/g.