Mutagenicity and dioxin-like activity of biodiesel emissions

Abstract

Diesel emissions have been shown to elicit a variety of toxicological effects, and alternative fuels (i.e., biodiesel) are currently being assessed to determine their ability to reduce the risks of adverse health effects. Exhaust emissions were generated using ULSD and biodiesel blended fuels and extracts of diesel PM (i.e., filters and PUFs) were separated into polar aromatic and non-polar neutral compounds. Mutagenic activity was assessed using the Salmonella mutagenicity assay, and Ah-receptor agonism was assessed using the DRCALUX assay. Results indicate that organic extracts of diesel/biodiesel particles contain direct- and indirect-acting polar aromatic mutagens as well as polar and non-polar Ah-receptor agonists. The mutagenicity of direct-acting compounds decreases with increasing concentrations of biodiesel in the fuel; however, there is no change in the indirect-acting mutagenicity. Furthermore, the ability of polar and non-polar compounds to induce the Ah-receptor increases with increasing concentrations of biodiesel in the fuel. These results provide an initial framework for evaluating the toxicological hazards of biodiesel emissions.