Mutagenicity of Diesel Exhaust Soot Dispersed in Phospholipid Surfactants.
Wallace-W; Keane-M; Xing-S; Harrison-J; Gautam-M; Ong-T
Environmental Hygiene II 1990:7-10
The mutagenicity of diesel exhaust extracts dispersed in phospholipid surfactants was examined. Two particulate fractions from a diesel truck engine were extracted with dichloromethane and dimethyl-sulfoxide (DCM/DMSO). After evaporation of the solvent, the samples were dispersed in lecithin, dipalmitoyl- glycerophosphorylethanolamine, or dipalmitoyl-phosphatidic-acid. The preparations and the DCM/DMSO extracts were tested for mutagenicity in the Ames/Salmonella assay using strain (TA-98) with or without liver S9 activation. Mutagenicity was also determined after filtering the extracts and dispersions through a 0.2 micron teflon filter. A diesel particulate extract in DMSO or dispersed in lecithin was tested for mutagenicity in Chinese-hamster-V79 cells using induction of sister chromatid exchanges (SCEs) as the endpoint. Concentrations ranged from 0 to 75 micrograms per milliliter. The phospholipid dispersed samples and DCM/DMSO extracts showed comparable mutagenic activity in the Ames/Salmonella assay when the S9 activation system was absent. When the S9 system was present, the mutagenicity of the phospholipid preparations was lower relative to that of the DCM/DMSO extracts. After filtration, most of the mutagenic activity of the DCM/DMSO extracts was in the filtrate. No activity was found in the phospholipid filtrates. The DMSO extract caused a significant induction of SCEs in V79 cells. The lecithin preparation of the diesel particulates did not increase the SCE frequency above the background level. The authors conclude that the mutagenic activity of diesel particulates is carried in a form that can be solubilized.
Diesel-exhausts; Mutagenesis; Phospholipids; Mammalian-cells; Microbial-test-systems; Sample-preparation; Solvent-extraction;
Book or book chapter;
Environmental Hygiene II