The Research Of PCBs Distribution In Multi-medium Of The Yangtze River And Its Possible Source Apportionment

Polychlorinated biphenyls(PCBs) is a kind of typical persistent organic pollutants (POPs). The ecological behavior and toxicological effects of PCBs are of global concern due to their detrimental properties:toxicity, persistence, and bio-accumulation are harmful to ecological integrity and humans.In this research,98 polychlorinated biphenyls (PCBs) samples of surface water, surface sediment and surface soil that collected from the Yangtze River were pretreated by Liquid-liquid or Soxhlet Extraction and detected by GC/MS. The kinds, concentrations, profiles, spatial distribution, possible sources and risk assessment of these pollutants were analyzed and discussed.The results showed that:(1) The samples of surface water, sediment and soil taken from sites around the Yangtze River basin showed total PCBs levels were in the range of 0.69-678.9ng/L, 7.46- 39.61 ng/g dry weight(dw) and 8.81-199.40 ng/g dw, respectively. The concentration of PCBs of surface water and sediment are relatively lower than other rivers in China, while it was a more serious situation in surface soil for PCBs pollution in the Yangtze River basin. In terms of the correlation of total PCBs concentration in the melti-medium of the Yangtze River basin, there wasrelatively obvious correlationbetween the surface water and surface soil.(2) Cities around the Yangtze River basin made long-term effects on the PCBs concentration and tributaries accepted by main stream were likely major factor to affect the total PCBs levels of water as well.(3) The profile of PCB congeners reflected the active use of PCBs in China, which suggested that a larger amount of these residues are domestic sources. Principal Component Analysisby SPSS indicated thatit was the possible source of higher PCBs in surface soilthatemerging sources in basin of the Yangtze River orcross-border atmospheric transmission. Cities located alongside the stem stream were primary PCBs pollution sources of whole basin possibly and PCBs was transported to tributary zone by long-range atmospheric transmission.(4) The mean dioxins PCBs concentrations of surface water, surface sediment and surface soil samples were 0.09 ng/L,0.79 ng/g and 1.49 ng/g, respectively. Overall, dioxins PCBs pollution level of the Yangtze River was relatively higher than other domestic reported, especially that in surface sediment and soil.