(Anti)estrogenic activity impacted by complex environmental matrices: A DOM and multiphase distribution approach

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Estrogenic endocrine disruptors in aquatic environments pose risks.
• Bioassays like the Yeast Estrogen Screen (YES) are vital for monitoring.
• Environmental matrix properties can affect bioassay responses.

Purpose of the Study:

• To assess the influence of physicochemical properties and environmental matrices on the YES assay.
• To investigate interactions between 17β-estradiol (E2) and humic acid (HA) using the Schild approach.
• To screen environmental samples (landfill leachate, WWTP influents/effluents) for estrogenic activity.

Main Methods:

• Evaluation of E2 and HA mixtures via Schild analysis.
• Screening of dissolved and particulate phases of environmental samples for (anti)estrogenic activity.
• Statistical analysis (Principal Component Analysis - PCA) correlating results with physicochemical parameters.

Main Results:

• Humic acid significantly reduced E2 response, potentially via bioavailability reduction or enzymatic inhibition.
• Landfill leachate showed high estrogenicity (1282-2591 ng L⁻¹ E2-Eq), while WWTPs showed lower levels (12.1-41.4 ng L⁻¹ and <2.3 ng L⁻¹).
• The particulate phase contributed significantly (33-100%) to E2-Eq; antiestrogenic activity was also detected, potentially masking estrogenicity.

Conclusions:

• In vitro YES assay results are influenced by intrinsic environmental sample factors.
• Interpretation requires consideration of organic matter, cytotoxicity, and antiestrogenic activity.
• Multiphase distribution of estrogenic compounds was suggested, supported by organic matter characteristics.