Molecular Characterization of Estrogen Receptor Agonists during Sewage Treatment Processes Using Effect-Directed...

Area of Science:

• Environmental Chemistry
• Toxicology
• Analytical Chemistry

Background:

• Endocrine-disrupting compounds (EDCs) pose risks to aquatic ecosystems.
• Sewage treatment processes are expected to remove EDCs, but their effectiveness varies.
• Pharmaceuticals are a significant source of EDCs in wastewater.

Purpose of the Study:

• To evaluate the endocrine-disrupting potential of chemicals during sewage treatment.
• To identify specific compounds responsible for persistent estrogen receptor (ER) activity.
• To assess the removal efficiency of EDCs, including pharmaceuticals, in wastewater.

Main Methods:

• In vitro bioassays were used to assess aryl hydrocarbon receptor (AhR), androgen receptor (AR), glucocorticoid receptor (GR), and ER-mediated activities.
• Organic extracts and fractions from different treatment stages were analyzed.
• Reverse-phase high-performance liquid chromatography (RP-HPLC) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) were employed for compound identification.

Main Results:

• AhR, AR, and GR potencies decreased during treatment, but ER potencies remained significant.
• RP-HPLC fraction F5 showed high ER potencies, containing novel ER agonists arenobufagin and loratadine.
• Pharmaceuticals like loratadine contributed to ER potencies in the final effluent, indicating incomplete removal.

Conclusions:

• Sewage treatment does not fully eliminate endocrine-disrupting potential, particularly ER activity.
• Widely used pharmaceuticals are released into aquatic environments due to incomplete removal during wastewater treatment.
• Further strategies are needed to mitigate the environmental impact of pharmaceuticals in sewage effluent.