Formation of chlorinated derivatives of bisphenol A in waste paper recycling plants and their estrogenic activities

High concentrations of bisphenol A were detected in the effluent from several pulping processes for waste paper containing thermal paper and/or other printed paper. Chlorinated derivatives of bisphenol A were found to be formed by its reaction with a low concentration of chlorine in the effluent from the bleaching process using sodium hypochlorite. Poly-chlorinated derivatives were mainly detected in the final effluents from two plants because they were not biodegraded in the water recycling process by treatment with activated sludge. The estrogenic activities of bisphenol A and its chlorinated derivatives were evaluated by an agonist assay using the yeast two-hybrid system with and without a metabolic activation test using rat liver S9. All of the chlorinated derivatives tested showed more potent activity than bisphenol A without S9. The activity of 3,3'-dichlorinated BPA was 38-fold stronger than that of bisphenol A. The activities of these compounds were almost eliminated upon treatment with S9.