title: Evaluating the effects of bioremediation on genotoxicity of polycyclic aromatic hydrocarbon-contaminated soil using genetically engineered, higher eukaryotic cell lines.
abstract: Bioremediation is one of the commonly applied remediation strategies at sites contaminated with polycyclic aromatic hydrocarbons (PAHs). However, remediation goals are typically based on removal of the target contaminants rather than on broader measures related to health risks. We investigated changes in the toxicity and genotoxicity of PAH-contaminated soil from a former manufactured-gas plant site before and after two simulated bioremediation processes: a sequencing batch bioreactor system and a continuous-flow column system. Toxicity and genotoxicity of the residues from solvent extracts of the soil were determined by the chicken DT40 B-lymphocyte isogenic cell line and its DNA-repair-deficient mutants. Although both bioremediation processes significantly removed PAHs from the contaminated soil (bioreactor 69% removal, column 84% removal), bioreactor treatment resulted in an increase in toxicity and genotoxicity over the course of a treatment cycle, whereas long-term column treatment resulted in a decrease in toxicity and genotoxicity. However, when screening with a battery of DT40 mutants for genotoxicity profiling, we found that column treatment induced DNA damage types that were not observed in untreated soil. Toxicity and genotoxicity bioassays can supplement chemical analysis-based risk assessment for contaminated soil when evaluating the efficacy of bioremediation.
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599-7431, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Nakamura
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Richardson
authors.forename: Michael D
authors.initials: MD
authors.lastname: Aitken
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D002460:Cell Line; D002645:Chickens; D004249:DNA Damage; D006256:Hazardous Waste; D009153:Mutagens / Q000633:toxicity*; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D006256:Hazardous Waste; D009153:Mutagens; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants