Polychlorinated organic compounds (PCOCs) in waters, suspended solids and sediments of the Yangtse River

The contamination levels of polychlorinated organic compounds (PCOCs) in wa ters, suspended solids and sediments of the Yangtse River (Nanjing part) we re analyzed in this paper. Their concentrations determined by GC/MS were ve ry tow in comparison with those in European River. The average concentratio n of total HCH (alpha-HCH, beta-HCH, gamma-HCH) was much higher than that o f other PCOCs in all waters, which made up 65% of total amount of PCOCs. Du e to the complete dilution and mixture of pollutants in the mighty Yangtse River, the content of PCOCs at each sampling station demonstrated very simi lar spatial pattern for waters and suspended solids. Since the small suspen ded solid (<0.7 mu m) passed through the filter was also considered as diss olved part, the dominant parts of HCHs, PCA and PCBs were found in dissolve d phase with percentage proportion of 85-94%, 72-85% and 61-78%, respective ly. For DDTs, HCB and PeCB, their contents in dissolved phase were slightly higher than in particulate phase. The contents of PCOCs in sediments were also very low and varied with high fluctuation at different sampling points , indicating the heterogeneous deposition. HCB and its metabolite (PeCB) pr esented the highest contamination levels among PCOCs in sediments. (C) 2000 Elsevier Science Ltd. All rights reserved.