Exposure to environmental endocrine-disrupting chemicals (EDCs) can cause extensive health issues. However, specific EDCs remain elusive. This work aimed at performing nontargeted identification of estrogen receptor α (ERα)-active compounds using an ERα protein affinity assay combined with high-resolution mass spectrometry in the source and drinking water sampled from major rivers in China. Fifty-one potential ERα-active compounds across 13 categories were identified. For the first time, diisodecyl phenyl phosphate was found to have antiestrogenic activity, and three chemicals (galaxolidone, bensulfuron methyl, and UV234) were plausible ERα ligands. Among the 51 identified compounds, 12 were detected in the aquatic environment for the first time, and the concentration of N-phenyl-2-naphthylamine, a widely used antioxidant in rubber products, was up to 1469 and 1190 ng/L in source and drinking water, respectively. This study demonstrated the widespread presence of known and unknown ERα estrogenic and antiestrogenic pollutants in the major rivers that serve as key sources of drinking water in China and the low removal efficiency of these chemicals in drinking water treatment plants.
Keywords: ERα active compounds; ERα protein affinity assay; N-phenyl-2-naphthylamine; antioxidants; nontargeted analysis.