A review on environmental occurrence, toxic effects and transformation of man-made bromophenols

Brominated phenols (BPs) of anthropogenic origin are aromatic substances widely used in the industry as flame retardants (FRs) and pesticides as well as the components of FRs and polymers. In this review, we have focused on describing 2,4-dibromophenol (2,4-DBP), 2,4,6-tribromophenol (2,4,6-TBP) and pentabromophenol (PBP), which are the most commonly used in the industry and are the most often detected in the air, aquatic and terrestrial ecosystems and the human body. This review describes human-related sources of these BPs that influence their occurrence in the environment (atmosphere, surface water, sediment, soil, biota), indoor air and dust, food, drinking water and the human organism. Data from in vitro and in vivo studies showing 2,4-DBP, 2,4,6-TBP and PBP toxicity, including their estrogenic activity, effects on development and reproduction, perturbations of cellular redox balance and cytotoxic action have been described. Moreover, the processes of BPs transformation that occur in human and other mammals, plants and bacteria have been discussed. Finally, the effect of abiotic factors (e.g. UV irradiation and temperature) on BPs conversion to highly toxic brominated dioxins and brominated furans as well as polybrominated biphenyls and polybrominated diphenyl ethers has been presented.