title: The effect of fuel composition on the mutagenicity of diesel engine exhaust.
abstract: The effect of fuel composition on the mutagenicity of diesel engine emission was investigated. To this end, a fuel matrix comprising fuels with 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 is largely dependent on the aromatic content of the fuel. In fact, mutagenicity 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 compounds. The addition of di- and trinaphthenic compounds only produced borderline mutagenicity. No clear relationship was observed between sulfur content of the fuel and mutagenicity of the exhaust. Assays in bacterial strains with different sensitivity to nitroaromatic compounds suggest a low contribution of the highly mutagenic dinitropyrenes to the responses observed, and a relatively greater contribution of 1-nitropyrene or other nitroaromatics processed by the same bacterial nitroreductase.
authors.affiliation: Istituto Superiore di Sanità, Laboratory of Comparative Toxicology and Ecotoxicology, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Crebelli
authors.forename: L
authors.initials: L
authors.lastname: Conti
authors.forename: B
authors.initials: B
authors.lastname: Crochi
authors.forename: A
authors.initials: A
authors.lastname: Carere
authors.forename: C
authors.initials: C
authors.lastname: Bertoli
authors.forename: N
authors.initials: N
authors.lastname: Del Giacomo
mesh_terms: D009152:Mutagenicity Tests; D009153:Mutagens; D010578:Petroleum; D011083:Polycyclic Compounds / Q000633:toxicity; D011721:Pyrenes / Q000633:toxicity; D012485:Salmonella typhi / Q000187:drug effects; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D009153:Mutagens; D010578:Petroleum; D011083:Polycyclic Compounds; D011721:Pyrenes; D001335:Vehicle Emissions; C033310:1,8-dinitropyrene; C033309:1,6-dinitropyrene; C037413:1,3-dinitropyrene; C032668:1-nitropyrene