Measurement of endocrine disruptors (environmental hormones) - Endocrine-disrupting effects and chemical analysis of hydroxylated PCBs metabolites

The persistent organic pollutants and some other chemical compounds in the environment which exhibit endocrine modulating effects has attracted much attention recently. These chemicals are referred to as endocrine disruptors or environmental hormones, and a variety of chemicals including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins, pesticides such as DDT, plastic additives such as bisphenol A, detergent additives such as alkylphenols are listed as the endocrine disruptors. It has also been shown that specific hydroxylated PCBs interact with the estrogen hormone and thyroid hormone systems. Several hydroxylated PCBs metabolites, which structure is resemble to that of thyroid hormone, thyroxine (T4), are determined in human blood. These observations indicate the significance of hydroxylated PCBs metabolites as potential endocrine disruptors in human. This paper reviews the metabolism of PCBs, endocrine-disrupting effects of hydroxylated PCBs based on interactions with estrogen hormone metabolism, thyroid hormone metabolism and the chemical analysis of phenolic organohalogen compounds such as hydroxylated PCBs. Measurement of estrogenic activities of hydroxylated PCBs by bioassay (yeast two-hybrid assay) is also presented.