Mutagenic characterization of soil and water samples from a superfund site

This study was conducted to evaluate the utility of short-term microbial bioassays to assess the mutagenic hazard of an uncontrolled hazardous waste site, and to compare the results from chemical and biological analysis of split soil and water samples. The results from chemical analysis indicated that the greatest concentration of contaminants was present in samples from an oil-stained area, and from the vicinity of a PCB disposal area. The results from the analyses of mutagenicity of these samples indicates that these samples also had the greatest specific activity, inducing 155 and 140 net revertants when the methylene chloride and methanol fractions were assayed, respectively. However, when the samples are compared on the basis of weighted activity, the sample from the vicinity of the PCB disposal area had the maximum activity (2410 revertants per gram of soil). While a second sample from the vicinity of the PCB disposal area had a weighted activity of 757 revertants per gram of soil, it contained no organic constituents which could be identified using standard analytical procedures. These results indicate that a combined testing protocol using both chemical and biological analysis will provide a more accurate data base from which to make a risk assessment than the use of either method alone.