Oxidative Degradation of BPA Using TiO sub(2) in Water, and Transition of Estrogenic Activity in the Degradation Pathways

Oxidative degradation of bisphenol A (BPA) using titanium dioxide (TiO sub(2)), and transition of estrogenic activity in the degradation pathways was studied. The objectives were to clarify the relationship with estrogenic activity from the degradation pathways demonstrated by oxidation of BPA in water. Approximately 99% of the BPA was decomposed with 300 min, and gas chromatography (GC) mass spectrometry (MS) and liquid chromatography (LC). MS analysis revealed many intermediates during the degradation process. Estrogenic activities of the degradation pathways of the BPA in water were assessed by a constructed yeast two-hybrid assay system for human estrogen receptor alpha (hER alpha ) and Japanese medaka fish estrogen receptor alpha . Estrogenic activity for hER alpha and medER alpha was reduced to less than 20% of the initial activity for BPA after 240 min of ultraviolet (UV) irradiation.