AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Genotoxic Potential of Organic Extracts from Particle Emissions of Diesel and Rapeseed Oil Powered Engines
JAN TOPINKA, Alena Milcova, Jana Schmuczerova, Martin Mazac, Martin Pechout, Michal Vojtisek-Lom, Institute of Experimental Medicine AS CR, Prague, Czech Repu
Abstract Number: 301 Working Group: Health Related Aerosols
Abstract The study was performed to identify genotoxicity induced by organic extracts from particulate matter in the exhaust of two typical diesel engines run on diesel fuel and neat heated fuel-grade rapeseed oil: A Cummins ISBe4 engine tested using the World Harmonized Steady Cycle (WHSC) and modified Engine Steady Cycle (ESC) and a Zetor 1505 engine tested using the Non-Road Steady Cycle (NRSC). In addition, biodiesel B-100 (neat methylester of rapeseed oil) was tested in the Cummins engine run on the modified ESC cycle. Diluted exhaust was sampled with high-volume samplers on Teflon coated filters. Filters were extracted with dichlormethane and DNA adduct levels induced by extractable organic matter (EOM) in an acellular assay of calf thymus DNA coupled with 32P-postlabeling in the presence and absence of rat liver microsomal S9 fraction were employed. The results suggest that diesel emissions contain substantially more total PAHs than rapeseed oil emissions (for the ESC cycle) or that these concentrations were comparable (for the WHSC and NRSC cycles), while c-PAHs levels were comparable (for the ESC cycle) or significantly higher (for the WHSC and NRSC cycles) for rapeseed oil emissions. DNA adduct levels induced by diesel and rapeseed oil derived EOM were comparable, but consistently slightly higher for diesel than for rapeseed oil. Highly significant correlations were found between 12 priority PAHs concentrations and DNA adduct levels (0.980; p<0.001). Metabolic activation by the microsomal S9 fraction resulted in several fold higher genotoxicity, suggesting a major contribution of PAHs to genotoxicity. Generally, DNA adduct levels were more dependent on the type of engine and the test cycle than on the fuel. Our findings suggest that the genotoxicity of particulate emissions from the combustion of rapeseed oil is significant and is comparable to that from the combustion of diesel fuel. Support: LIFE10 ENV/CZ/651 (MEDETOX).