Detection of direct-acting mutagens in ambient air: A comparison of two highly sensitive mutagenicity assays

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Environmental and Molecular Mutagenesis; (United States)

DOI:https://doi.org/10.1002/em.2850200105· OSTI ID:7261053

Houk, V S; Goto, S; Endo, O; Claxton, L D; Lewtas, J; Matsushita, H ^[1]

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1. U.S. Environmental Protection Agency, Health Effects Research Laboratory, Research Triangle Park, NC (United States)

Ambient air has been shown to contain numerous hazardous pollutants, many of which are known or suspected carcinogens and mutagens. Bioassays play a prominent role in the characterization of these genotoxic pollutants, and as new test methods are developed, it is incumbent upon researchers to evaluate assay performance and report relative merits. In this study, two Salmonella test methods (the spiral and preincubation assays) were assessed to determine their usefulness as screening methods for monitoring direct-acting mutagens in ambient air. The spiral assay automates the conventional plate-incorporation assay and has been shown to reduce the labor, materials, and sample mass required to perform mutagenicity testing. The preincubation assay has been shown to enhance test sensitivity for certain classes of compound, thereby reducing the amount of sample required for dose-response analysis. Both assays were used to test organic extracts of airborne particulate matter collected in Tokyo during the winters of 1988 and 1990. In addition to the conventional tester strains TA98 and TA100, two newly developed YG strains were evaluated. Strains YG1024 and YG1029-derived from TA98 and TA100, respectively-contain an acetyltransferase plasmid that confers upon the strains greater sensitivity towards nitroarenes. Results from this study indicated that both assays were able to detect direct-acting mutagens in the Tokyo air samples. The mutagenic activity associated with the samples was directly related to the particle mass present in a given volume of air. Mutagenic response was greater in the spiral assay relative to the preincubation assay, especially when YG tester strains were used. The YG strains were significantly more sensitive to mutation than the TA strains in both assays, which suggests that nitroaromatics are an important class of genotoxic contaminant present in Tokyo air.

• OSTI ID: 7261053
• Journal Information: Environmental and Molecular Mutagenesis; (United States), Vol. 20:1; ISSN 0893-6692
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
JAPAN
AIR POLLUTION
NITRO COMPOUNDS
MUTAGEN SCREENING
DOSE-RESPONSE RELATIONSHIPS
GENETIC VARIABILITY
PARTICULATES
SALMONELLA TYPHIMURIUM
SOLUBILITY
TRANSFERASES
ASIA
BACTERIA
BIOLOGICAL VARIABILITY
DEVELOPED COUNTRIES
ENZYMES
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLES
POLLUTION
PROTEINS
SALMONELLA
SCREENING
550200* - Biochemistry
560300 - Chemicals Metabolism & Toxicology