ACUTE AND GENETIC TOXICITY OF EXTRACTS OF MUNITIONS WASTE-WATER CONTAMINATED SOILS

Aqueous and solvent extracts were prepared from 15 soil samples obtained from four lagoons containing munitions production wastewaters. The toxicity of the extracts was evaluated using bioassays to measure acute toxicity (Microtox) and mutagenicity (Salmonella and Aspergillus). Selected extracts were also subjected to a chemical analysis. The results from the Microtox assay indicated that contaminated soils induced acute toxic responses that ranged from 1.4 to more than 11,000 times greater than the toxicity of the background soil. In the Salmonella mutagenicity assay, responses induced by contaminated soils collected during the second sampling visit ranged from 1.2 to 29 times greater than the mutagenic response induced by the background soil. The weighted activity of the background soil in Salmonella ranged from 16 to 21 revertants per gram, while contaminated soils induced weighted activities that ranged from 1,893 revertants per gram to 354,152 revertants per gram. Using the Aspergillus diploid system, contaminated soils induced responses that were 0.7 to 4.1 times greater than the response induced by the background soil. Although there was some correlation between the response in Aspergillus and the chemical based risk estimate, samples which induced an estimated risk of less than 1E-6 induced a positive response in at least one bioassay. Aqueous extracts of contaminated soils also induced a positive response in the Salmonella assay, while the aqueous extract of the background soil failed to induce a doubling of revertant colonies. These data suggest that different chemicals are responsible for the mutagenic and acute toxic response. The results also indicate that the bioassays used in this study are capable of detecting low levels of TNT in the soil.