Characterization of organic extracts from standard reference materials 1649, 'urban dust/organics,' and 1650, 'diesel particulate matter', using a microsuspension assay. A WHO/IPCS/CSCM study.
Mutagenicity associated with replicate organic extracts from standard reference materials 1649 'urban dust/organics' (air particles), and 1650, 'diesel particulate matter' (diesel particles), was determined using a Salmonella microsuspension assay. The results indicate that the mutagenicity of samples such as these can readily be determined using the microsuspension assay with only 5% of the mass required for the standard plate incorporation assay. In general, 80% of the variation in mutagenic activity was due to the bioassay procedure and 20% to the extraction process. Extracts from both samples had primarily direct-acting mutagenicity as there were no significant differences in responses with and without metabolic activation (S9). The TA98-S9 mean air particles mutagenic activities (C.V., %) based on mass of extractable organics or particles were 4.4 (4.7%) and 0.29 (3.6%) revertants/micrograms, respectively, and for the diesel particles were 66 (44%) and 12 (29%) revertants/microgram, respectively. More of the observed direct-acting mutagenicity in the diesel particles extracts was due to nitro-substituted compounds because there were significant reductions in activity with TA98NR (45% of TA98 -S9) and TA98-1,8-DNP6 (21% of TA98 -S9). In the air particles extracts, the TA98NR activities were not significantly different from TA98 -S9 but the TA98-1,8-DNP6 levels were.
Bagley
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ST
Department of Biological Sciences, Michigan Technological University, Houghton 49931.
Stoltz
S L
SL
Becker
D M
DM
Keen
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RE
D000393:Air Pollutants / Q000633:toxicity*; D000704:Analysis of Variance; D004391:Dust; D005742:Gasoline / Q000633:toxicity*; D007391:International Cooperation; D009152:Mutagenicity Tests / Q000592:standards; D009153:Mutagens / Q000633:toxicity*; D012016:Reference Values; D012486:Salmonella typhimurium / Q000187:drug effects; D014944:World Health Organization
D000393:Air Pollutants; D004391:Dust; D005742:Gasoline; D009153:Mutagens