Human exposure and thyroid toxicity of polybrominated diphenyl ethers

Abstract

Polybrominated diphenyl ethers (PBDEs), a kind of important Brominated Flame Retardant (BFR), are widely used in electronic products, construction materials and textiles. PBDEs have been detected in many environmental media (including air, water, dust, sediment and food), many animal and human tissues. For their environmental persistence, high bioaccumulative and multiple biotoxicitiies, PBDEs have been viewed as one of the most concerned environmental Endocrine Disrupting Chemicals (EDCs) at present. Although detailed mechanisms are not clear, studies have found that PBDEs can induce toxicity to liver, endocrine system, nervous system, reproduction and immune system. What's more, lots of experiments indicate that PBDEs exposure can alter the levels of thyroid hormones. Recently, studies on the impact of PBDEs exposure on thyroid hormones have been quite a few and have not reached an agreement, especially on the alternation of thyroid hormones caused by PBDEs exposure, which has also been a hot issue. This paper reviews from the basic properties, usage, exposure and biotoxicity of PBDEs. We mainly introduce the impact PBDEs have on the thyroid and thyroid hormones in terms of biotoxicity, and attach importance to the endocrine disruption and neurodeveloptoxicity. We also give a preliminary introduction to hydroxylated and methoxylated polybrominated diphenyl ethers, structural analogs of PBDEs, which researchers start late to study. This paper can be a reference for the further research on PBDEs exposure and biotoxicity.