Polycyclic aromatic hydrocarbons and mutagens in ambient air particles

Abstract

The presence of mutagenic compounds in ambient air particles has led to a reassessment of the role of polycyclic aromatic hydrocarbons (PAH) in air pollution research. Besides PAH, other air pollutants were associated with carcinogenicity, although by means of an effect which indirectly and preliminarily indicates carcinogenicity. While PAH themselves are mutagens, they only marginally contribute to the mutagenicity of the particles. However, a close relation exists between PAH and the other mutagenic compounds. Both are emitted in the flue gases of combustion processes and they show a clear structural relationship, i.e. the mutagens most probably are oxygenated and nitrated PAH‐derivates. Furthermore PAH might give rise to mutagens via atmospheric reactions. The present paper deals with several aspects of the relation between PAH and mutagenicity. The contribution of PAH, nitrated PAH and more polar compounds to the mutagenicity was studied by mutagenicity testing and chemical analysis of Chromatographic fractions prepared with TLC and HPLC. The contribution of PAH and mono‐nitro PAH could be clearly established. The marginal contribution of the former was confirmed, the contribution of the latter is small compared to that of more polar nitro‐compounds. The atmospheric conversion of PAH was studied by analysing the variations of PAH‐profiles, i.e. the proportion among PAH‐concentrations. Clear indications for conversions were found but the influence of sampling artifacts could not be excluded. PAH‐concentrations showed moderate to reasonable correlations with mutagenicity, no relation between variations of PAH‐profile and mutagenicity could be demonstrated, possibly due to methodological factors.