Sunlight and Microbes Remove Potent Estrogens from the Willamette River

Associate Professor of Chemistry David Griffith gives a lecture for nonspecialists on the research that he and his students have done over the past few years on estrogens in the Willamette River.

Halogenated estrogens are thought to be moderately potent endocrine-disrupting compounds that are formed during chlorine-based wastewater disinfection. These halogenated forms can represent up to half of the total mass flow of estrogens delivered from wastewater treatment plants to receiving waters. Yet, little is known about the processes that influence the environmental fate of halogenated estrogens. 

This seminar will describe our recent efforts to characterize the rates, mechanisms, and transformation products of halogenated estrogen photolysis and biodegradation in the Willamette River. We show that aerobic biodegradation and abiotic oxidation of 17β-estradiol and its halogenated forms take place on timescales of days and primarily yield less potent estrone derivatives. In contrast, the photolysis of halogenated estrogens in river water occurs on sub-hour timescales. 

Ultimately, the fate of estrogens and other phenolic contaminants in sewage-impacted waters will be strongly dependent on the relative abundance of halogenated forms in wastewater effluent and the extent to which these forms are exposed to natural sunlight or UV light during wastewater treatment.