Genotoxic effects of polycyclic aromatic hydrocarbon derivatives released from recycled asphalt aggregates in BEAS-2B cells and Hydra vulgaris

The present study aimed to evaluate the genotoxic potential of four secondary polycyclic aromatic hydrocarbons (PAHs+) emitted by recycled asphalt fumes (1-nitropyrene, quinoline, 2-naphthol and 6H-benzo[c,d]pyrene-6-one) using complementary human and aquatic models. Genotoxic effects were assessed in the human bronchial epithelial BEAS-2B cell lines using the cytokinesis-block micronucleus assay, while DNA damage in the freshwater invertebrate Hydra vulgaris was evaluated using the alkaline comet assay. All tested PAHs + induced significant increases in centromere negative micronucleus frequency in BEAS-2B cell lines, with a significant concentration-related effect relationship observed for all compounds except 1-nitropyrene. These findings demonstrate the clastogenic potential of the selected PAHs+ in human pulmonary cells. In Hydra vulgaris, significantly higher levels of DNA fragmentation compared to controls were observed; however, no concentration-related effect relationship nor consistent trend were observed for any of the tested compounds. Notably, apoptosis was observed at the two highest concentrations of 2-naphthol. The value of this study was also to explore new mutagenic and potential carcinogenic tracers beyond B[a]P that could be more relevant in complex mixtures such as recycled asphalt fumes, in which their concentrations are higher than B[a]P. Finally, further studies focusing on the mixture effects of PAHs+ are required to better evaluate the environmental and human health risks associated with asphalt recycling practices.