THE USE OF NONTRADITIONAL ASSAYS IN AN INTEGRATED ENVIRONMENTAL ASSESSMENT OF CONTAMINATED GROUND-WATER

The toxic potential of ground water contaminated with several probable carcinogenic heavy metals and halogenated solvents was evaluated usin g an integrated environmental assessment approach. A number of assays, which included acute toxicity, short-term chronic toxicity, genotoxic ity, developmental toxicity and carcinogenicity, were used to assist i n a hazard assessment. Comprehensive analytical chemistry was performe d throughout the 9-month exposure to document the chemical characteris tics of the ground water. hn initiation-promotion protocol using a non -neoplastic concentration of diethylnitrosamine as an initiator in a 9 -month chronic exposure of Japanese medaka (Oryzias latipes) was used to evaluate potential carcinogenicity of the ground water The fish wer e exposed to groundwater concentrations of 1%, and 10% ground water by volume. No significant lesions were found in tile Japanese medaka exp osed to groundwater concentrations at 1% or 10% ground water by volume , Likewise, no genotoxicity, developmental toxicity, acute toxicity or short term chronic toxicity, were found at concentrations of less tha n or equal to 10% ground water by volume. The negative results obtaine d in this study show that the potential hazard posed by low concentrat ions of a complex mixture containing suspect carcinogens may not be ma nifested at environmentally relevant concentrations.