Genotoxicity of diesel-exhaust particles dispersed in simulated pulmonary surfactant.
Keane-MJ; Xing-G; Harrison-JC; Ong-T; Wallace-WE
Mutat Res 1991 Jul; 260(3):233-238
The effect of the major phospholipid component of pulmonary surfactant, dipalmitoyl-lecithin, on the uptake and expression of genotoxicity in in-vitro bioassays was examined and the results were compared with solvent extracted sampling from the same sources. Both eukaryotic and prokaryotic cells were used in this study. A diesel sample was obtained by scraping the exhaust pipe and cap of a large diesel truck that had been allowed to idle for 30 minutes. Another sample was obtained from glass fiber filters from an engine operating on an urban driving cycle. Diesel samples were extracted with dichloromethane and transferred into dimethyl-sulfoxide and subjected to assay. Both types of extractions yielded similar results in both the Salmonella mutagenicity assay and the sister chromatid exchange assay using V79 cells. After separation of the samples into supernatant and sediment fractions, the activity of both diesel samples was shown to reside exclusively in the supernatant fraction for the solvent extracted samples, and exclusively in the sedimented fraction for surfactant dispersed samples. These results confirmed and extended to eukaryotic cells the earlier finding that genotoxicity can be expressed by diesel particles dispersed in phospholipid surfactant, and the genotoxicity is exclusively associated with the particles in surfactant solubilized diesel samples. The exclusive association of genotoxicity with the supernatant fraction of solvent extracted diesel particles was also demonstrated in eukaryotes.
NIOSH-Author; Mutagenicity; Lung-cells; Genotoxic-effects; Diesel-exhausts; Automotive-emissions; Environmental-pollution; Combustion-products; Microbial-test-systems; Mammalian-cells