Organo-chlorine pesticide (DDT and HCH) residues in the Taihu Lake Region and its movement in soil-water system I. Field survey of DDT and HCH residues in ecosystem of the region.
The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years. A field survey was carried out during 1999-2000 in the Taihu Lake Region. Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated. DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 microg/kg in the surface (0-15 cm) layer, 6 out of 10 with 0.5 to 4.0 microg/kg in the subsoil layer (16-30 cm), and 4 of 10 with 0 to 2.7 microg/ kg in the deep soil layer (31-50 cm). Results for HCH residues in soil samples were similar to those of DDT. These results indicate that OCP residues in 0-50 cm profile had been leached out or degraded to safe level. In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 microg/l, with an average of 1.0 microg/l. While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 microg/l, with an average 5.6 microg/l. DDT residues in sediment ranged from 0.1 to 8.8 microg/kg, while HCH ranged from 0.3 to 66.5 microg/kg. DDT residues in fish body ranged from 3.7 to 23.5 microg/kg and HCH ranged from 3.7 to 132 microg/kg. These results demonstrate an accumulation through food chain (from soil-water-sediment-microbes-crop-fish-... etc.), also that HCH residues are generally more persistent than DDT residues. However, all these data are well below than the state warning standard limit.
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Agronomy College, Yangzhou University, Yangzhou 225009, China. fengke55@yahoo.com
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D000818:Animals; D002681:China; D003634:DDT / Q000378:metabolism; D017753:Ecosystem; D005399:Fishes / Q000378:metabolism; D019015:Geologic Sediments / Q000032:analysis; D001556:Hexachlorocyclohexane / Q000378:metabolism; D007306:Insecticides / Q000378:metabolism*; D010573:Pesticide Residues / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D007306:Insecticides; D010573:Pesticide Residues; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D001556:Hexachlorocyclohexane; D003634:DDT