Wastewater release and its impacts on Canadian waters

Abstract

Discharge of sewage to the environment in the form of treated or untreated wastewater can have serious impacts on human health and quality of life and on ecosystem condition. Since a previous review in 1997, upgrades to wastewater treatment facilities, along with improved source control, have produced successes in reducing loadings of certain pollutants (e.g., mercury, polychlorinated biphenyls) to Canadian waters. However, nationally, loads of phosphorus discharged from wastewater treatment facilities have not changed in recent years (2003–2008), and releases of nitrogen have increased slightly. In some locations, wastewater discharges are contributors to bacterial contamination, toxicity from heavy metals and ammonia, and eutrophication, all of which continue to threaten public and environmental health. An increasing number of studies are also demonstrating developmental, reproductive, and behavioural changes in fish and other aquatic organisms from exposure to pharmaceuticals, personal-care products, or other pollutants in domestic wastewater, even after treatment. Minimizing wastewater discharge and mitigating its effects on the environment and human health will be a challenge. It is critical that gains achieved by improved wastewater treatment and other control measures not be reversed by relaxation of efforts or by failure to keep pace with population growth.

Multi-biomarker responses as indication of contaminant effects in Gambusia affinis from impacted rivers by municipal effluents

“…e l s e v i e r . c o m / l o c a t e / s c i t o t e n v (Lavado et al, 2006), which are known to contain pharmaceuticals, personal care products, hormones, metals and persistent organic chemicals (Holeton et al, 2011;Houde et al, 2013). Contaminants from municipal wastewater discharges may be taken up by aquatic animals, leading to the impairment of organism health conditions (Gagnon et al, 2006).…”

“…Municipal wastewater effluents represent a major source of loading for chemical contaminants in the aquatic environment (Holeton et al, 2011). These effluents are derived from a range of complex discharges such as domestic and industrial wastewaters, as well as runoffs …”

Aquatic ecotoxicology: what has been accomplished and what lies ahead? An Eastern Canada historical perspective

“…These key features thus enable ecotoxicological investigations to quantify their exposure to contaminants and to measure their effects over space and time. In this section, we briefly discuss selected biomarker results obtained with bivalves impacted by urban effluents, an important point source of mixed (domestic and industrial) pollution impacting receiving waters in Canada 43 and elsewhere. 44 The focus is on the immunosuppressive and reproductive consequences of urban effluents on molluscan shellfish, due to the fact that these biomarkers are linked to population effects as indicated previously.…”

Urban Pollution Increases Sensitivity to Temperature Changes in Elliptio complanata Mussels Exposed to Municipal Wastewaters

“…This results in an increase in urban pollution (untreated wastewater diluted by rain), which can lead to increased contamination of watercourses and deleterious effects on aquatic biota. Municipal wastewaters are recognized as a source of pollutants such as polyaromatic hydrocarbons, heavy metals, cyclic aliphatic hydrocarbons (steroids), antibiotics and many other pharmaceutical products [2,3]. Municipal effluents are well known to contain endocrine disrupters which can cause reproductive, developmental and behavioral changes in fish and other organisms.…”