title: Changes in hormone and stress-inducing activities of municipal wastewater in a conventional activated sludge wastewater treatment plant.
abstract: Conventional municipal wastewater treatment plants do not efficiently remove contaminants of emerging concern, and so are primary sources for contaminant release into the aquatic environment. Although these contaminants are present in effluents at ng-μg/L concentrations (i.e. microcontaminants), many compounds can act as endocrine disrupting compounds or stress-inducing agents at these levels. Chemical fate analyses indicate that additional levels of wastewater treatment reduce but do not always completely remove all microcontaminants. The removal of microcontaminants from wastewater does not necessarily correspond to a reduction in biological activity, as contaminant metabolites or byproducts may still be biologically active. To evaluate the efficacy of conventional municipal wastewater treatment plants to remove biological activity, we examined the performance of a full scale conventional activated sludge municipal wastewater treatment plant located in Guelph, Ontario, Canada. We assessed reductions in levels of conventional wastewater parameters and thyroid hormone disrupting and stress-inducing activities in wastewater at three phases along the treatment train using a C-fin assay. Wastewater treatment was effective at reducing total suspended solids, chemical and biochemical oxygen demand, and stress-inducing bioactivity. However, only minimal reduction was observed in thyroid hormone disrupting activities. The present study underscores the importance of examining multiple chemical and biological endpoints in evaluating and monitoring the effectiveness of wastewater treatment for removal of microcontaminants.
authors.affiliation: Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada.
authors.forename: Pola
authors.initials: P
authors.lastname: Wojnarowicz
authors.affiliation: School of Engineering, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Yang
authors.affiliation: School of Engineering, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Hongde
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Parker
authors.affiliation: Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada. Electronic address: chelbing@uvic.ca.
authors.forename: Caren C
authors.initials: CC
authors.lastname: Helbing
mesh_terms: D000818:Animals; D001681:Biological Assay; D057919:Biological Oxygen Demand Analysis; D002947:Cities; D052244:Endocrine Disruptors / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D006728:Hormones / Q000737:chemistry*; D007814:Larva / Q000187:drug effects; D009584:Nitrogen / Q000737:chemistry; D009864:Ontario; D011892:Rana catesbeiana; D012722:Sewage / Q000737:chemistry; D013312:Stress, Physiological; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply
chemical_list: D052244:Endocrine Disruptors; D006728:Hormones; D009584:Nitrogen; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Amphibian; C-fin; Endocrine disruption; Microcontaminant; Thyroid hormone