Study on the mutagenicity of diesel exhaust particles.

The mutagenicity of diesel exhaust particles (DEP) was studied by using Salmonella typhimurium strains TA98 and TA100 in vitro and mice micronucleus in vivo test. DEP from six kinds of medium and heavy-duty diesel vehicles, which were made in China and imported, were tested. The vehicles were operated under free accelerating condition. The results showed that the DEP contained mutagenic activity. An increase in the number of the Salmonella TA98 was observed in the presence and especially in the absence of S9 mix. Positive results were also obtained from mice micronucleus assay. The frequency of mice bone marrow micronucleated polychromatic erythrocytes (M PCE) was increased and it showed a definite dose-response relationship. Comparing the different types of the vehicles, we found that the mutagenicity of DEP from domestic made vehicles was stronger than that from the imported ones.