Modeling the exposure of wild fish to endocrine active chemicals: Potential linkages of total estrogenicity to field-observed intersex

• Published in: Water research (Oxford) 2018-08, Vol.139, p.187-197
• Main Authors: Arlos, Maricor J., Parker, Wayne J., Bicudo, José R., Law, Pam, Hicks, Keegan A., Fuzzen, Meghan L.M., Andrews, Susan A., Servos, Mark R.
• Format: Article
• Language: English
• Subjects: Estrogen; Exposure assessment; Intersex; Rainbow darter; Wastewater; Water quality model
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2018.04.005

Decades of studies on endocrine disruption have suggested the need to manage the release of key estrogens from municipal wastewater treatment plants (WWTP). However, the proposed thresholds are below the detection limits of most routine chemical analysis, thereby restricting the ability of watershed managers to assess the environmental exposure appropriately. In this study, we demonstrated the utility of a mechanistic model to address the data gaps on estrogen exposure. Concentrations of the prominent estrogenic contaminants in wastewaters (estrone, estradiol, and ethinylestradiol) were simulated in the Grand River in southern Ontario (Canada) for nine years, including a period when major WWTP upgrades occurred. The predicted concentrations expressed as total estrogenicity (E2 equivalent concentrations) were contrasted to a key estrogenic response (i.e., intersex) in rainbow darter (Etheostoma caeruleum), a wild sentinel fish species. A predicted total estrogenicity in the river of ≥10 ng/L E2 equivalents was associated with high intersex incidence and severity, whereas concentrations