R. Crebelli et al., THE EFFECT OF FUEL COMPOSITION ON THE MUTAGENICITY OF DIESEL-ENGINE EXHAUST, Mutation research. Mutation research letters, 346(3), 1995, pp. 167-172
The effect of fuel composition on the mutagenicity of diesel engine em
ission was investigated. To this end, a fuel matrix comprising fuels w
ith different contents of aromatic and naphthenic compounds was used.
Extracts of the organic phase of raw exhausts obtained with different
fuels were tested for mutagenicity in bacterial reversion assays. The
results obtained demonstrate that the mutagenicity of diesel exhaust i
s largely dependent on the aromatic content of the fuel. In fact, muta
genicity was greatly reduced when the aromatic content of the fuel was
lowered by hydrogen treatment. Conversely, mutagenicity was enhanced
when the fuel was enriched with fractions of di- or triaromatic compou
nds. The addition of di- and trinaphthenic compounds only produced bor
derline mutagenicity. No clear relationship was observed between sulfu
r content of the fuel and mutagenicity of the exhaust. Assays in bacte
rial strains with different sensitivity to nitroaromatic compounds sug
gest a low contribution of the highly mutagenic dinitropyrenes to the
responses observed, and a relatively greater contribution of l-nitropy
rene or other nitroaromatics processed by the same bacterial nitroredu
ctase.