Assessing the influence of methanol-containing additive on biological characteristics of diesel exhaust emissions using microtox and mutatox assays

Ta-Chang Lin, Mu-Rong Chao
2002 Science of the Total Environment  
Ž . Here we investigate the effect of the methanol-containing additive MCA on the biological characteristics of diesel exhaust emissions. Microtox and Mutatox assays, respectively, were used to evaluate the acute toxicity and genotoxicity of crude extracts from diesel engine exhaust. The engine was tested on a series of diesel fuels blended Ž . with five additive levels 0, 5, 8, 10 and 15% of MCA by volume . Emission tests were performed over the hot start Ž . portion of the transient
more » ... -Federal Test Procedure HD-FTP and two selected steady-state modes. Ž . Microtox results show that MCA additive moderately lowers the toxicity levels of particle-associated SOF samples, Ž . but generally increase the vapor-phase XOC associated toxicity. A strong correlation was found between XOC-Ž . associated toxicity and total hydrocarbon THC concentrations, while only a slight link was found between Ž . SOF-associated toxicity and particulate matter PM concentrations. For Mutatox test results, when either 5 or 8% MCA used, XOC and SOF-associated genotoxicity in both steady-state and hot-start transient cycle tests were relatively lower compared to those of the base diesel. The genotoxic potential of XOC samples was significantly Ž . increased after treatment with an exogenous metabolic activation system S9 . On the contrary, the genotoxic potential of SOF samples without S9 metabolic activation was generally higher than those with S9. It is noteworthy Ž . that the total particle-associated SOF PAHs emissions showed trends quite similar to that of the genotoxic Ž . potential. As expected, the total particle-associated SOF PAHs correlated moderately with direct mutagenicity, and fairly well with indirect mutagenicity. Finally, the genotoxicity data did not parallel the Microtox results in this study, indicating that potentially long-term genotoxic agents may not be revealed by short-term toxicity assays. ᮊ
doi:10.1016/s0048-9697(01)00866-x pmid:11846175 fatcat:iox3tq4xhbaefnbirkmw76wvtm