Cytotoxicity of diesel exhaust particle extract — A comparison among five diesel passenger cars of different manufacturers

The cytotoxicity of the dichloromethane extracts of diesel exhaust particles from passenger cars of different manufactures was studied in cultured Chinese hamster ovary cells. While exhaust particles from diesel cars of the same make and model yielded extracts of similar cytotoxicity, those from cars of different manufacturers yielded extracts with a 3-fold difference in cytotoxicity. Using data on the percentages of extractable organic chemicals and total exhaust particulate emission rates, the emission rates of cytotoxin into the environment from the different cars were calculated. Of the 3 factors that could affect the emission rate of cytotoxins (cytotoxicity of the extractable chemicals, amount of cytotoxins per particle, and particulate emission rate), the differences in particulate emission rates were found to be the predominant factors leading to the differences in the emission rate of cytotoxins. Our findings indicate the need to consider other chemical and physical data, not just the activities of the extracts, when the potential health risk due to the exhaust emissions of different automobiles are compared.