Polycyclic aromatics-derived benzene carboxylic acids (BPCAs) as a fast predictor of the genotoxicity of combustion particles.

Polycyclic aromatic compounds (PAC) are common toxics in combustion particles. Numerous studies on health effects of PAC mixtures focused on limited compounds. It's still challenging to quantify complex PAC mixtures in combustion particles. Recently, benzene polycarboxylic acids (BPCAs) method, which involves conversion of PAC mixtures into a few BPCAs, has been used to quantify complex PAC mixtures in particles. In this study, in vitro biossays were used to evaluate the toxicity of extractable organic matter (EOM) in combustion particles. Analysis with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) identified ~1000 molecules, mostly aromatics (84.47 ± 5.32 %), that positively associate with the EOM toxicity (p < 0.05). We further employed BPCAs method to quantify PAC mixtures in the EOM of combustion particles, and observed the toxicity (especially genotoxicity) of EOM linearly increases with the abundance of PAC mixtures (r²: 0.68-0.89, p < 0.05), as it is shown by a data set referring to all source types including biomass burning, coal combustion and vehicle exhaust. The genotoxicity of PAC mixtures in EOM of combustion particles was estimated to be 10-13 times that of benzo[a]pyrene at the same mass concentration. Target analysis of 48 PAC was carried out, but a weaker relationship is found for the toxicity of EOM and the abundance of 48 PAC. Taken together, we suggest PAC-derived BPCAs as a fast predictor of the genotoxicity of combustion particles, which could be promising in routine monitoring of PAC pollution in the air.