USE OF IN-VITRO MICROBIAL ASSAYS OF SEDIMENT EXTRACTS TO DETECT AND QUANTIFY CONTAMINANTS WITH SIMILAR MODES OF ACTION

Mutagenicity of organic solvent extracts of contaminated sediments from a Great Lakes Area of Concern (AOC) was evaluated with Ames and Mutatox(R) assays. Extract mutagenicity was evaluated with and without S9 metabolic activation in both assays. H4IIE rat cell hepatoma assays also were conducted on the organic solvent extracts of the sediments. Little direct mutagenicity was observed in either the Ames or Mutatox(R) assays, however, a greater number of extracts were observed to be mutagenic after S9 metabolic activation. Although numerous potentially mutagenic compounds exist in sediments from this AOC, polycyclic aromatic hydrocarbons (PAHs) appear to be the likely cause of a major fraction of the observed mutagenicity in the Ames and Mutatox(R) assays. PAHs, as opposed to compounds with a mode of action similar to 2,3,7,8-TCDD, also appear responsible for the majority of the enzyme induction observed in the H4IIE assay.