Comparison of Emissions and Mutagenicity from Biodiesel, Vegetable Oil, GTL and Diesel Fuel

Diesel engine emissions (DEE) are classified as probably carcinogenic to humans. Since 1995 we observed an appreciable reduction of mutagenicity of DEE driven by reformulated or newly designed fuels in several studies. We compared the mutagenic effects of DEE from two different batches of rapeseed oil (RSO) with rapeseed methyl ester (RME, biodiesel), natural gas derived synthetic fuel (gas-to-liquid, GTL), and a reference diesel fuel (DF). Additionally, we determined the regulated emissions of total hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NO_X), and particulate matter (PM). Compared with the reference DF the two RSO qualities significantly increased the mutagenic effects of the particle extracts by factors of 9.7 up to 59. RME extracts had a moderate but significant higher mutagenic response. GTL samples did not differ significantly from DF. Concerning the regulated emissions, the results remained below the margins except a up to 15% increase of NO_X for the tested bio fuels.