In vitro agonistic and antagonistic endocrine disrupting effects of organic extracts from waste water of different treatment processes

Effluents from wastewater treatment plant (WWTP) have been reported to have a broad spectrum of endocrine disrupting compounds (EDCs). The majority of studies have focused on the occurrence of estrogenic activity, while ignoring nuclear hormone receptors (NRs) pathways. In the present study, a battery of in vitro yeast bioassays and a cell bioassay, including antagonistic and agonistic effects on estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR), estrogen-related receptor (ERR) and aryl hydrocarbon receptor (AHR), were conducted to evaluate the removal efficiencies of EDCs by different treatment processes of a WWTP located in Beijing. Estrogenic, anti-estrogenic, anti- androgenic, anti-progesteronic, anti-ERR and the activation of AHR activities were detected in samples from all treatment processes and the receiving water. The concentration of estrogenic contaminants with estradiol (E₂) equivalent concentrations ranged from 0.82 × 10^-9 to 3.54 × 10^-9 g E₂-EQ·L^-1. The concentration of anti-estrogenic contaminants with 4-hydroxytamoxifen (4-OHT) equivalent concentrations ranged from 1.24 × 10^-6 to 2.36 × 10^-6 g 4-OHT-EQ·L^-1. The concentration of anti-androgenic contaminants ranged from 2.21 × 10^-8 to 3.52 × 10^-6 g flutamide-EQ·L^-1. The concentration of anti-progesteronic contaminants ranged from 3.15 × 10^-5 to 2.71 × 10^-4 g RU486-EQ·L^-1. The concentration of anti-ERR contaminants ranged from 7.09 × 10^-5 to 6.50 × 10^-4 g 4-OHT-EQ·L^-1. The concentration of AHR activators ranged from 1.7 × 10^-10 to 3.4 × 10^-10 g TCDD-EQ·L^-1. These processes including secondary clarifier, coagulation, as well as coal and sand filtration could eliminated 67.2% of estrogenic contaminants, 47.0% of anti-estrogenic contaminants, 98.3% of anti-androgenic contaminants, 88.4% of anti-progesteronic contaminants, 65.4% of anti-ERR contaminants and 46.9% of AHR activators. WWTP effluents contain multiple receptor disruptors may have very complex adverse effects on exposed organisms.