Mutagenic potential of plants grown on municipal sewage sludge-amended soil

Abstract

TheSalmonella/microsome assay was used to monitor the mutagenic potential of the organic extract of plants grown on municipal sewage sludge amended soils. The solvent-extractabie organic chemicals from sewage sludge, unamended Padina fine sand (Grossarenic Paleustalf), sludge amended Padina fine sand, and two forage crops; alfalfa (Medicago sativa) and coastal bermudagrass (Cynodon dactylon) were tested withSalmonella strain TA98 with and without metabolic activation. The mutagenic potential of the sludge-amended soil was greater than that of the unamended soil. Fractions extracted from the sludge amended soil over a 154 day period displayed an increase in mutagenicity. None of the plant extracts, whether collected from plants grown on sludge amended or unamended soils, induced a positive response (doubling of revertants at two consecutive dose levels) in the bioassay. Thus, for the evaluated conditions, plants are not likely to translocate significant quantities of organic mutagens from municipal sludge amended soil.