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

Aqueous and solvent extracts were prepared from 15 soil samples obtain ed from four lagoons containing munitions production wastewaters. The toxicity of the extracts was evaluated using bioassays to measure acut e toxicity (Microtox) and mutagenicity (Salmonella and Aspergillus). S elected extracts were also subjected to a chemical analysis. The resul ts from the Microtox assay indicated that contaminated soils induced a cute toxic responses that ranged from 1.4 to more than 11,000 times gr eater than the toxicity of the background soil. In the Salmonella muta genicity assay, responses induced by contaminated soils collected duri ng the second sampling visit ranged from 1.2 to 29 times greater than the mutagenic response induced by the background soil. The weighted ac tivity of the background soil in Salmonella ranged from 16 to 21 rever tants per gram, while contaminated soils induced weighted activities t hat ranged from 1,893 revertants per gram to 354,152 revertants per gr am. Using the Aspergillus diploid system, contaminated soils induced r esponses that were 0.7 to 4.1 times greater than the response induced by the background soil. Although there was some correlation between th e response in Aspergillus and the chemical based risk estimate, sample s which induced an estimated risk of less than 1E-6 induced a positive response in at least one bioassay. Aqueous extracts of contaminated s oils also induced a positive response in the Salmonella assay, while t he 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 a lso indicate that the bioassays used in this study are capable of dete cting low levels of TNT in the soil.