A look beyond the priority: A systematic review of the genotoxic, mutagenic, and carcinogenic endpoints of non-priority PAHs*

Knowledge of the toxic potential of polycyclic aromatic hydrocarbons (PAHs) has increased over time. Much of this knowledge is about the 16 United States Environmental Protection Agency (US EPA) priority PAHs; however, there are other US EPA non-priority PAHs in the environment, whose toxic potential is underestimated. We conducted a systematic review of in vitro, in vivo, and in silico studies to assess the genotoxicity, mutagenicity, and carcinogenicity of 13 US EPA non-priority parental PAHs present in the environment. Electronic databases, such as Science Direct, PubMed, Scopus, Google Scholar, and Web of Science, were used to search for research with selected terms without time restrictions. After analysis, following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) protocol, 249 articles, published between 1946 and 2020, were selected and the quality assessment of these studies was performed. The results showed that 5-methylchrysene (5-MC), 7,12-dimethylbenz[a]anthracene (7,12-DMBA), cyclopenta[cd]pyrene (CPP), and dibenzo[al]pyrene (Db [al]P) were the most studied PAHs. Moreover, 5-MC, 7,12-DMBA, benz[j]aceanthrylene (B[j]A), CPP, anthanthrene (ANT), dibenzo[ae]pyrene (Db[ae]P), and Db[al]P have been reported to cause mutagenic effects and have been being associated with a risk of carcinogenicity. Retene (RET) and benzo[c]fluorene (B[c]F), the least studied compounds, showed evidence of a strong influence on the mutagenicity and carcinogenicity endpoints. Overall, this systematic review provided evidence of the genotoxic, mutagenic, and carcinogenic endpoints of US EPA non-priority PAHs. However, further studies are needed to improve the future protocols of environmental analysis and risk assessment in severely exposed populations . (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The systematic review found evidence of genotoxic, mutagenic, and carcinogenic endpoints in 13 US EPA non-priority PAHs. Some of the PAHs, such as 5-MC, 7,12-DMBA, CPP, and Db [al]P, have been extensively studied and shown to have mutagenic effects and potential carcinogenicity. More research is needed to improve future protocols for environmental analysis and risk assessment in populations with high exposure to these PAHs.