Studying the mixture effects of brominated flame retardants and metal ions by comet assay

This study was designed to evaluate the sensitivities of diverse cell lines on DNA damage effects and genotoxic effects of three brominated flame retardants (BFRs) and three metal ions (Cu2+, Cd2+, Hg2+) by comet assay. First, THP-1 was identified as the most sensitive cell line in terms of DNA damage among 11 kinds of cells screened. Accordingly, the THP-1 cell line was used as a model in subsequent single/ combined genotoxicity tests. Single exposure tests to BFRs or metal ions revealed that the DNA damage effects increased with increasing exposure concentration. In combined exposure tests, BFRs (at concentrations of 1/2 EC50) were deployed in combination with different concentrations of Cu2+, Cd2+, or Hg2+. The results showed that the % tail DNA values were significantly increased by most mixtures. Our findings on combined toxic effects by comet assay provide valuable information for setting valid environmental safety evaluation standards. (C) 2020 Elsevier Ltd. All rights reserved.