Brominated flame retardants induce intragenic recombination in mammalian cells

In the present study we have examined the effects of brominated flame retardants (BFR) and several other environmental contaminants in two in vitro assays for intragenic recombination at an endogenous locus in mammalian cells. A total ten compounds were investigated, i. e., two technical PCB mixtures (Aroclor 1221 and Aroclor 1254), DDT, PCP, tetrabromobisphenol A (TBBPA), 4,4'-bischlorophenyl sulfone (BCPS), hexabromocyclododecane (HBCD) and the three different polybrominated diphenylethers (PBDEs): 2-bromodiphenylether (MBDE), 3,4-dibromodiphenylether (DBDE) and 2,4,2', 4'-tetrabromodiphenylether (TBDE). In the SPD8 assay system statistically significant increases in recombination frequency were observed with Aroclor 1221, BCPS, DBDE, DDT, HBCD, MBDE and TBDE. In the Sp5 assay system, only DBDE, HBCD and MBDE caused statistically significant increases in recombination frequency. In conclusion, our findings indicate that the modern additives to plastic, i.e., HBCD and PBDEs, as well as the plastic monomer BCPS may have the same effect to human health as DDT and PCBs, in terms of inducing genetic recombination, which is known to provoke a number of diseases, including cancer.