Biological responses in fish exposed to municipal wastewater treatment plant effluent in situ

Effluents from municipal wastewater treatment plants (MWTPs) are complex mixtures of chemicals including endocrine-disrupting compounds (EDCs) and 17α-ethynylestradiol (EE2). The objective of this study was to evaluate selected responses of two fish species, in two different years, exposed in situ to MWTP effluent. Biological markers of exposure (plasma vitellogenin (VTG) and antioxidant enzymes) were measured in two species of male fish, rainbow trout (Oncorhynchus mykiss) and fathead minnow (Pimephales promelas), caged at sites associated with wastewater outfall. The estrogenicity of the final effluent in 2010 was determined to be 17.0 + 0.4 ng/L estrogen equivalents (EEQ) and reduced to 7.5 + 2.9 ng/L EEQ after infrastructure upgrades. Pharmaceuticals and personal care products in the effluent and surface water in both years confirmed the exposures at each downstream site. Despite the presence of estrogenic compounds in the MWTP effluent, no effluent-caged male fish demonstrated plasma VTG induction. Minnows and trout that received an intraperitoneal injection of 5 mg/g EE2 showed VTG induction at both field sites. In 2012, the liver somatic index (LSI) of both species increased with exposure, as did changes in antioxidant enzymes, and reactive oxygen species (ROS) activity. Multiple biological mechanisms are modified by effluent exposure, and multiple endpoints are needed to assess risk.Standards Development Branch|| Ontario Ministry of the Environment and Climate Change (OMECC)||the Canadian Water Network||Natural Sciences and Engineering Research Council|| Canada Research Chairsto MRS|| OMECC Laboratory Services Branch||Trent University||University of Ottawa ||Environment and Climate Change Canad

Emergence and Spread of the SARS-CoV-2 Omicron Variant in Alberta Communities Revealed by Wastewater Monitoring

Wastewater monitoring of SARS-CoV-2 allows for early detection and monitoring of COVID-19 burden in communities and can track specific variants of concern. Targeted assays enabled relative proportions of SARS-CoV-2 Omicron and Delta variants to be determined across 30 municipalities covering >75% of the province of Alberta (pop. 4.5M) in Canada, from November 2021 to January 2022. Larger cities like Calgary and Edmonton exhibited a more rapid emergence of Omicron relative to smaller and more remote municipalities. Notable exceptions were Banff, a small international resort town, and Fort McMurray, a more remote northern city with a large fly-in worker population. The integrated wastewater signal revealed that the Omicron variant represented close to 100% of SARS-CoV-2 burden prior to the observed increase in newly diagnosed clinical cases throughout Alberta, which peaked two weeks later. These findings demonstrate that wastewater monitoring offers early and reliable population-level results for establishing the extent and spread of emerging pathogens including SARS-CoV-2 variants.Alberta Healt

An Assessment of the Spatial and Temporal Variability of Biological Responses to Municipal Wastewater Effluent in Rainbow Darter (<i>Etheostoma caeruleum</i>) Collected along an Urban Gradient

<div><p>Municipal wastewater effluent (MWWE) and its constituents, such as chemicals of emerging concern, pose a potential threat to the sustainability of fish populations by disrupting key endocrine functions in aquatic organisms. While studies have demonstrated changes in biological markers of exposure of aquatic organisms to groups of chemicals of emerging concern, the variability of these markers over time has not been sufficiently described in wild fish species. The aim of this study was to assess the spatial and temporal variability of biological markers in response to MWWE exposure and to test the consistency of these responses between seasons and among years. Rainbow darter (<i>Etheostoma caeruleum</i>) were collected in spring and fall seasons over a 5-year period in the Grand River, Ontario, Canada. In addition to surface water chemistry (nutrients and selected pharmaceuticals), measures were taken across levels of biological organization in rainbow darter. The measurements of hormone production, gonad development, and intersex severity were temporally consistent and suggested impaired reproduction in male fish collected downstream of MWWE outfalls. In contrast, ovarian development and hormone production in females appeared to be influenced more by urbanization than MWWE. Measures of gene expression and somatic indices were highly variable between sites and years, respectively, and were inconclusive in terms of the impacts of MWWE overall. Robust biomonitoring programs must consider these factors in both the design and interpretation of results, especially when spatial and temporal sampling of biological endpoints is limited. Assessing the effects of contaminants and other stressors on fish in watersheds would be greatly enhanced by an approach that considers natural variability in the endpoints being measured.</p></div

Variability of biological measures decreases with increasing biological complexity.

<p>A comparison of variability in measures of male rainbow darter reproduction across levels of biological organization at a (A) reference site and a (B) MWWE-exposed site from collections in the fall of 2007 (red triangles), 2010 (green squares), 2011 (yellow diamonds), and 2012 (blue down-facing triangles). Measures compared include gene expression of <i>vtg</i> (VTG), <i>in vitro</i> production of testosterone (T), gonad development and relative proportion of spermatozoa (SPZ), and gonad somatic index (GSI).</p

Comparison of significant changes observed in male rainbow darter downstream of the Waterloo (DSW) and Kitchener (DSK) MWWTPs in relation to either the rural reference site (R) or the immediate upstream (USW, USK respectively) reference site.

<p>Comparisons are made for fall and spring field collections.</p

Canonical analysis of principal coordinates (CAP) ordination with biological variables as vectors.

<p>(A) Female and (B) male biological measures collected from a reference site (green squares), sites upstream of municipal wastewater treatment plant (MWWTP) outfalls (red downward triangles), or downstream of MWWTP outfalls (blue triangles).</p

Condition factor increases downstream of MWWTP outfalls in fall, but not spring.

<p>Condition factor of (A, C) female and (B, D) male rainbow darter collected through an urban gradient in the (A, B) fall of 2007 (red triangles), 2009 (grey circles), 2010 (green squares), 2011 (yellow diamonds), and 2012 (blue down-facing triangles) and in the (C, D) spring of 2009 (grey circles), 2010 (green squares), 2011 (yellow diamonds), and 2012 (blue down-facing triangles). The dashed line indicates the 10% critical effect size calculated from the mean of the data from the rural reference site (R), and the solid line indicates the 95% confidence interval from the pooled R.</p

Liver somatic index is variable through the urban watershed.

<p>Liver somatic index of (A, C) female and (B, D) male rainbow darter collected through an urban gradient in the (A, B) fall of 2007 (red triangles), 2009 (grey circles), 2010 (green squares), 2011 (yellow diamonds), and 2012 (blue down-facing triangles) and in the (C, D) spring of 2009 (grey circles), 2010 (green squares), 2011 (yellow diamonds), and 2012 (blue down-facing triangles). The dashed line indicates the 25% critical effect size calculated from the mean of the data from the rural reference site (R), and the solid line indicates the 95% confidence interval from the pooled R.</p

Principal coordinates (PCO) analysis of biological measures.

<p>(A) Female and (B) male biological measures collected from a reference site (green squares), sites upstream of municipal wastewater treatment plant (MWWTP) outfalls (red downward triangles), or downstream of MWWTP outfalls (blue triangles). Each sampling site is labeled with the season (spring or fall) that data were collected. PCO is based on a Euclidean distance resemblance matrix.</p

Concentration of nutrients and pharmaceuticals increases downstream of MWWTPs.

<p>(A) Mean concentration of ammonia (mg/L) and (B) the sum of dominant chemicals of emerging concern (naproxen, ibuprofen, venlafaxine, carbamazepine, and triclosan) in river surface water. Samples were collected in the fall (dark symbols) and in the spring (open symbols) of 2010 (squares), 2011 (diamonds), and 2012 (down-facing triangles). Sites that share a common letter are not significantly different (<i>p</i> > 0.05) as determined by a 2-way ANOVA with a Tukey’s post-hoc test (no interactions were found for season and site).</p