| Organochlorine Pesticides will be stable in the environment for a long time and bioaccumulate in the food chain.it will threat environment and human health. Dichloro Diphenyl Trichloroethane(DDT) and Hexachlorocyclohexane(HCHs) are typical compounds of OCPs. After they were banned, there were less reports about residual concentration in the environment in the rencent 30 years.We collect more then 200 samples in Raoyang County Hebei Province between 1983 and 2010. Then we detected DDT and HCHs in muscle and heavy metals Cu, Zn, Pb, As, Cd in bone. The conclusion is as followed:(1)The concentration of HCHs decreased to 1/89.7 and half life is 4.9 years. It’s 937.82 ng/g dw( dry weight) in 1983 and 1984, but 10.57 ng/g dw in 2009 and 2010.The half lives of α-HCH, β-HCH, γ-HCH are about 5.9 years, 3.8years, 6.4 years, respectively. As time went on, the ratios of β-HCH and α-HCH show decreased trend. We explain the inconsistency between previous researches and this study using the volatility and migration of HCHs.(2) The half life of DDT is 6.4 years and it was 1331.85 ng/g dw in 1983 and 1984, but 35.42 ng/g dw in 2009 and 2010. The half lives of o,p’-DDE, p,p’-DDE, o,p’-DDD, p,p’-DDD, o,p’-DDT and p,p’-DDT are 12.0years, 6.8years, 6.4years, 6.8years, 6.0years, 4.6years, respectively.(3) The EF of o,p’-DDD, o,p’-DDT are below 0.5, which proves CYP in Cricetulus Barabensis tend to degrand dextral o,p’-DDD and o,p’-DDT.But we consider the microorganism in Raoyang will metabolite levorotatory α-HCH because the EF is above 0.5.(4) Pb and As decreased 31.6% and 15% between 1983 and 2010, but Cd decreased unconspicuously. Cu decreased 24.7% between 1983 and 2002, then increased 6.59 times after 2006. Zn maintained a stable concentration but decreased after 2006. Therefore, we make a conclusion that industry has not polluted the land seriously. Maybe the rivers were polluted and the soil was influenced by irrigation. |
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