Mutagenic potential of biodiesel exhaust particles and effect of engine operating conditions.
Kisin EK; Shi XC; Keane MJ; Bugarski AD; Shvedova AA
Toxicologist 2014 Mar; 138(1):331
Approximately 28,000 underground miners are potentially exposed to relatively high concentrations of diesel particulate matter (PM) in the mining industry. Changing fuel supply from diesel (ULSD) to biodiesel and its blends is considered to be a viable option for controlling exposures to PM but the potential for adverse health effect has yet to be addressed. This study was conducted to investigate the mutagenic potential of diesel engine emissions from neat (B100) and blended (B50) soy-based fatty acid methyl ester (FAME) biodiesel in comparison with ULSD PM using different engine operating conditions and exhaust aftertreatment configurations. The exhaust samples were collected for engine equipped with either a standard muffler or a combination of the muffler and diesel oxidation catalytic converter (DOC) that was operated at four different steady-state modes. Bacterial gene mutation activity of exhaust PM was tested on the organic solvent extracts using the Ames Salmonella assay. The mutagenic activity was strongly affected by fuels, engine operating conditions, and exhaust aftertreatment systems. The mutagenicity was increased with the fraction of biodiesel in the fuel. While the mutagenic activity was observed in B50 and B100 samples collected from both lightand heavy-load operating conditions, the ULSD samples were only mutagenic at light-load conditions. The presence of DOC in the exhaust system resulted in decreased mutagenicity when engine was fueled with B100 and B50 and operated at light-load conditions. This was not the case with ULSD. Heavy-load operating condition in the presence of DOC resulted in a decrease of mutagenicity only when engine was fueled with B50, but not B100 or ULSD. Therefore, the results indicate that PM from neat or blended biodiesel has a higher mutagenic potency than ULSD. Further research is needed to investigate the health effects of biodiesel as well as efficiency of DOC or other exhaust aftertreatment systems.
Toxicology; Air-quality; Pollutants; Pollution; Environmental-pollution; Respiration; Respiratory-irritants; Respiratory-system-disorders; Pulmonary-system; Pulmonary-system-disorders; Pulmonary-function; Exposure-levels; Lung; Fumes; Aerosols; Laboratory-animals; Animals; Chemical-composition; Dust-particles; Dust-exposure; Dusts; Particulates; Workers; Work-environment; Diesel-exhausts; Diesel-emissions; Fuels; Mining-industry; Underground-mining; Underground-miners; Miners; Risk-factors
The Toxicologist. Society of Toxicology 53rd Annual Meeting and ToxExpo, March 23-27, 2014, Phonex, Arizona