DDE Remediation and Degradation

DDE (2,2-bis(p-chlorophenyl)-1,1-dichloroethylene) is not a natural product; it is found only as a recalcitrant degradation product of 2,2-bis(p-chlorophenyl)- 1,1,1-trichloroethane (DDT) or as a contaminant in technical-grade DDT (Metcalf 1995). DDT was produced and used starting in 1939, finally gaining widespread use by 1943 (Turusov et al. 2002). By the 1960s, evidence indicated that DDT and its metabolites, DDE and DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)-ethane), were highly persistent in the environment and accumulated in higher mammals. DDT derivatives have been reported to be responsible for the thinning of bird eggshells (Heberer and Dunnbier 1999). Other studies suggested that the derivatives and isomers of DDT are endocrine disrupters causing impaired reproduction in wildlife by emasculation and abnormal sexual development (Sharpe 1995). The U.S. Environment Protection Agency (USEPA) has determined that DDT, DDD, and DDE are probable human carcinogens (ATSDR 2002). DDT was banned in the United States during the early 1970s, except for the emergency control of vectorborne diseases (Heberer and Dunnbier 1999; Spencer et al. 1996).