Identification of Emerging Brominated Chemicals as the Transformation Products of Tetrabromobisphenol A (TBBPA) Derivatives in Soil

In contrast to the extensive investigation already conducted on tetrabromobisphenol A (TBBPA), the metabolism of TBBPA derivatives is still largely unknown. In this paper, we characterized unknown brominated compounds detected in 84 soil samples collected from sites around three brominated flame retardant production plants to determine possible transformation products of TBBPA derivatives. In addition to tribromobisphenol A (TriBBPA), dibromobisphenol A (DBBPA), and TBBPA, six novel transformation products, TriBBPA mono(allyl ether) (Tr1BBPA-MAE), DBBPA-MAE, hydroxyl TriBBPA-MAE, TBBPA mono(2-bromo-3-hydroxypropyl ether) (TBBPA-MBHPE), TBBPA mono(2,3-dihydroxypropyl ether) (TBBPA-MDHPE), and TBBPA mono(3-hydroxypropyl ether) (TBBPA-MHPE) were identified. The detection frequencies of these identified chemicals in soil samples ranged from 17% to 89%, indicating the widespread presence of the transformation products. To uncover the possible TBBPA derivative transformation pathways involved, super-reduced vitamin B12 (cyanocobalamin, (CCAs)) was used to treat TBBPA derivative and transformation products in this process were characterized. To our knowledge, this is the first study examining the transformation of TBBPA derivatives and the first to report several novel associated TBBPA and bisphenol A derivatives as transformation products. Our research suggests that ether bond breakage and debromination contribute to the transformation of TBBPA derivatives and the existence of the novel transformation products. These data provide new insights into the fate of TBBPA derivatives in environmental compartments.