Nitroarenes: Their Detection, Mutagenicity and Occurrence in the Environment

Nitroarenes and hydroxylated nitroarenes have been identified in diesel and other combustion source emissions and ambient air using bioassay-directed chemical analysis. Studies of the extractable organic matter associated with airborne particles show that substantial mutagenicity is associated with fractions which are more polar than the polycyclic aromatic hydrocarbons (PAH). These mutagenic polar neutral and acidic fractions contain nitroarenes. Hydroxylated nitroarenes, where the aromatic portion consists of one- and two-rings (e.g., hydroxylated nitrobenzene, -toluene, -naphthalene, and -biphenyl), have been found in relatively high concentrations in the organic acids in ambient air. The distribution of nitroarenes and hydroxylated nitroarenes and the specific isomers present in the air appear to be related to their mechanism of formation and source whether they are emitted directly from combustion sources or formed through atmospheric transformation.