Waterborne toxicity of several dichlorodiphenyltrichloroethane congeners to Hyalella azteca and its implications for contaminated sediment assessment.

Although banned long ago in many countries and jurisdictions, the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and compounds related to it remain in the aquatic environment, particularly in sediments, and can pose risks to aquatic life. To inform ecological risk assessment of these compounds, we tested the toxicity of six DDT congeners, specifically the p, p' (4,4') forms of DDT, dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenylchloroethylene (DDMU), as well as the o, p' (2,4') isomers of DDT and DDD. The epibenthic amphipod, Hyalella azteca, was exposed for 7 days to waterborne chemical and assessed for changes in survival and growth.