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Induction of vitellogenin (VTG) is widely used as a biomarker of exposure of male or immature fish to chemicals that are agonists of the estrogen receptor (i.e., xenoestrogens). Analysis of VTG in samples of epidermal mucosa collected from fish is a non-invasive method for evaluating whether wild fish are exposed to xenoestrogens. In this study, the mean levels of VTG in the mucus of immature brook trout (Salvelinus fontinalis) collected from the Credit River in Ontario, Canada downstream of aging residential septic systems and in an agricultural watershed were 0.67 ng per mg protein, which was significantly elevated relative to the mean VTG levels of 0.22 ng per mg protein in the mucus of immature brook trout collected from a less impacted site. To validate the mucus assay, immature brook trout were exposed in the laboratory to 17α-ethinylestradiol (EE2) at nominal concentrations of 10, 50 and 100 ng/L and VTG levels in mucus from these fish showed a concentration-dependent increase relative to fish from the control treatment. This study illustrates the utility of this non-lethal method for assessing whether wild fish have been exposed in situ to xenoestrogens. Exposures to xenoestrogens from non-point sources may be impacting brook trout populations in urban watersheds in southern Ontario.

Innovative and robust methods are needed to evaluate the risks to native aquatic organisms exposed to organic compounds released from contaminated sediments. In the present study, we deployed semi-permeable membrane devices (SPMDs) above sediments in a contaminated harbor at a location in the Laurentian Great Lakes (i.e. Owen Sound Bay) and prepared extracts from these passive samplers for analysis of organic contaminants and for toxicity testing using early life stages of Japanese medaka (Oryzias latipes) and lake whitefish (Coregonus clupeaformis). The concentrations of several classes of organic contaminants estimated from analysis of the SPMD extracts indicated that several polynuclear aromatic hydrocarbon (PAHs) were present in the water column in the inner harbor of Owen Sound Bay at concentrations higher than water quality standards for the protection of aquatic life. Several medaka exposed to the SPMD extract from the inner harbor as well as a positive control compound, benzo[a]pyrene, developed yolk sac edema. However, whitefish did not show the same response. Overall, these data indicate this contamination could contribute to toxicity in sensitive species. The coupling of passive sampling and in vivo bioassays with early life stages of fish shows promise as a method to assess the potential for risks from biologically available fractions of organic contaminants in water. A novel aspect of the present study is the development of a bioassay procedure with early life stages of lake whitefish involving exposures at low temperatures over durations of time that are longer than the bioassays with more conventional model fish species.

Prompted by a recent report that 6PPD-quinone (6PPD-q), a by-product of a common tire manufacturing additive that is present in road runoff, is toxic to coho salmon (Oncorhynchus kisutch), extracts of water samples collected from an urban river were re-analyzed to determine if this compound was present in stormwater-influenced flows. In addition, extracts were analyzed for 1,3-diphenylguanidine (DPG), which is also used in tire manufacturing. Samples were originally collected in the fall of 2019 and winter of 2020 in the Greater Toronto Area of Canada from the Don River, a highly urbanized watershed in close proximity to several major multi-lane highways. These target compounds were analyzed using ultra-high pressure liquid chromatography with high resolution mass spectrometric detection with parallel reaction monitoring. Both 6PPD-q and DPG were detected above limits of quantification (i.e., 0.0098 µg/L) in all extracts. Maximum concentrations for 6PPD-quinone of 2.30 ± 0.05 µg/L observed in the river during storm events exceeded the LC50 for this compound for coho salmon (i.e., > 0.8 µg/L). In composite samples collected at intervals throughout one rain event, both compounds reached peak concentrations a few hours after initiation of the event (i.e., 0.52 µg/L for DPG and 2.85 µg/L for 6PPD-q), but the concentrations of 6PPD-q remained elevated above 2 µg/L for over 10-h in the middle of the event. Estimates of cumulative loads of these compounds in composite samples indicated that kg amounts of these compounds entered the Don River during each hydrological event, and the loads were proportional to the amounts of precipitation. This study contributes to the growing literature indicating that potentially toxic tire-wear compounds are present at elevated levels and are transported via road runoff into urban surface waters during rain events. Supplementary Information The online version contains supplementary material available at 10.1007/s00244-021-00878-4.

It is well established that persistent organic pollutants are transported long distances in the atmosphere and deposited into aquatic and terrestrial ecosystems in remote areas, including high altitude lakes. The objective of this research was to evaluate whether compounds of wastewater origin were present in four remote upland headwater lakes in Ireland that primarily receive loadings from atmospheric deposition. Using Polar Organic Chemical Integrative Samplers (POCIS) deployed in the lakes for 60 to 68 days, seven compounds were detected at levels that could be quantified but 25 of the target compounds were not detected. The detected compounds included the cannabinoid metabolite, tetrahydrocannabinol carboxylate (THC-COOH), codeine, acetaminophen (paracetamol), ibuprofen, and the artificial sweeteners, sucralose, and saccharin, which were all present at concentrations estimated to be 125 ng/L. Caffeine was also present in the lakes at estimated concentrations between 213 and 1320 ng/L. Cocaine and tramadol were detected in POCIS deployed in some of the lakes, but at levels below the limits of quantitation. The highest concentrations of the target analytes were detected in two lakes located in the eastern part of Ireland. These data are consistent with regional atmospheric transport of these compounds originating from wastewater treatment plants in Ireland. However, contaminants from wastewater treatment plants in the United Kingdom may also be a source in these upland lakes that are located far from emissions of urban pollution.

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. HIGHLIGHTS Effluent exposure resulted in induction of antioxidant enzymes and ROS activity in caged fish.; Despite measurable estrogen equivalents in the effluent, downstream caged male fathead minnow did not demonstrate VTG induction.; EE2 injected, control male fish exposed to wastewater or upstream reference conditions responded with elevated VTG concentrations.; Several factors may have reduced the VTG response in caged fish.

Hexamethoxymethyl-melamine (HMMM) is used as a crosslinking agent in resins and plastics and in the manufacture of tires. In the present study, surface water samples were collected from two rivers adjacent to high traffic highways in the Greater Toronto Area in Ontario, Canada. Composite samples collected from the Don River and Highland Creek during rain events and a period of rapid snowmelt were preconcentrated using solid phase extraction and analyzed using liquid chromatography with high-resolution mass spectrometry. Elevated concentrations (> 1 µg/L) of HMMM were detected in surface waters during rain events in October of 2019 and during snow melt in early March of 2020. There were lower average concentrations of HMMM detected during rain events in the winter and spring of 2020. Temporal profiles of changes in the concentrations of HMMM in composite samples collected every 3 h during a rain event in October 2019 closely corresponded to the hydrograph profiles at the sampling sites, with the HMMM concentrations peaking > 6 h after the peak in water levels. This work contributes to the literature showing that HMMM is a ubiquitous contaminant of urban watersheds and that runoff from roads is a vector for the transport of this compound into urban surface waters. Supplementary Information The online version of this article (10.1007/s00244-021-00815-5) contains supplementary material, which is available to authorized users.

Nanosilver (AgNP) is an anti-microbial agent widely used in consumer products, with significant potential for these nanoparticles to be released into aquatic environments. Laboratory studies involving short-term exposures of fish to AgNP show a range of toxicological effects, but these studies do not address potential responses in long-lived organisms resulting from chronic exposures. A collaborative study involving additions of AgNP to environmentally relevant concentrations over two field seasons took place at the IISD-Experimental Lakes Area, providing an opportunity to study the impacts of chronic exposures to long-lived fish species. In the present study, we evaluated the abundance and growth of an apex predator, Northern Pike (Esox lucius), collected from Lake 222 before, during and after the AgNP dosing period and compared results to those from a nearby unmanipulated lake (Lake 239). While the abundance of Northern Pike from Lake 222 during the study period was essentially stable, per capita availability of their primary prey species, Yellow Perch (Perca flavescens) declined by over 30%. Northern Pike fork length- and weight-at-age (indices of growth rate) declined following AgNP additions, most notably in age 4 and 5 fish. No similar changes in prey availability or growth were observed in Northern Pike from the reference lake. Body condition did not change in Northern Pike collected from either Lake 222 or Lake 239. Our results indicate that declines in the growth of Northern Pike chronically exposed to AgNP likely resulted from reduced prey availability but direct sublethal effects from AgNP exposure could also have been a factor. The persistence of reduced growth in Northern Pike two years after the cessation of AgNP additions highlight the potential legacy impacts of this contaminant once released into aquatic ecosystems.

Polar organic chemical integrative samplers (POCIS) are widely used to track contaminants in surface waters. However, POCIS have not been used previously to monitor for artificial sweeteners as an indicator of wastewater pollution. In this study, we report for the first time the POCIS sampling rates (Rs

The Sustainable Development Goal 6 calls for global progress by 2030 in treating domestic wastewater and providing access to adequate sanitation facilities. However, meeting these goals will be a challenge for most Small Island Developing States, including Caribbean island nations. In the nearshore zone of the Soufriere region on the Caribbean island of St. Lucia, there is a history of high levels of bacteria of fecal origin. Possible land-based sources of microbial contamination in the Soufriere Bay include discharges from the Soufriere River and transport of wastewater, including fecal material from the town of Soufriere. This area is an important tourist destination and supports a local fishery. To identify the sources of microbial contamination in Soufriere Bay, a range of monitoring methods were employed in this study. In grab samples of surface water collected from the Soufriere River, counts of total coliforms and Escherichia coli were elevated above water quality guidelines. However, the spikes in concentrations of these indicator organisms in the river did not necessarily coincide with the spikes in the levels of total coliforms and E. coli detected in samples collected on the same dates in Soufriere Bay, indicating that there are other sources of pollution in the Bay besides discharges from the river. Monitoring for chemical indicators of wastewater (i.e., caffeine, sucralose, fluconazole) in the Soufriere River indicated that there are inputs of sewage or human fecal material throughout the watershed. However, analysis of Bacteroidales 16S rRNA genetic markers for fecal bacteria originating from humans, bovine ruminants, or other warm-blooded animals indicated that the majority of microbial contamination in the river was not from humans. Monitoring for chemical indicators of wastewater using passive samplers deployed in Soufriere Bay indicated that there are two "hot spots" of contamination located offshore of economically depressed areas of the town of Soufriere. This study indicates that efforts to control contamination of Soufriere Bay by fecal microorganisms must include management of pollution originating from both sewage and domestic animals in the watershed.

Polar Organic Chemical Integrative Samplers (POCIS) were deployed in two watersheds in Córdoba province and one watershed in Buenos Aires province in Argentina. The fungicides, tebuconazole, carbendazim and azoxystrobin, and the herbicides, atrazine, dicamba and 2,4-D were detected in POCIS deployed in each of the three watersheds. Estimated time weighted average concentrations of atrazine were greater than 2 µg/L at the outflow of Brava Lake in Buenos Aires province, and this concentration exceeds the Canadian water quality guideline for protection of aquatic life. The concentrations of all other pesticides were less than 400 ng/L. The distribution of pesticides detected in surface waters indicated that the sources were runoff from agricultural and urban lands and discharges from wastewater treatment plants.

Several micropollutants, including caffeine, artificial sweeteners, pharmaceuticals, steroid hormones and a current-use pesticide were analyzed in water samples collected from five groundwater pumping stations in Barbados. The presence of caffeine and three artificial sweeteners (i.e. acesulfame, sucralose, saccharin) in groundwater samples indicated that groundwater was being contaminated by infiltration of wastewater into the karst aquifer. An estrogen (i.e. estrone), three pharmaceuticals (i.e. carbamazepine, trimethoprim, ibuprofen) and a transformation product of the fungicide, chlorothalonil (i.e. 4-hydroxychlorothalonil) were also detected at ng/L concentrations in groundwater collected from two or more pumping sites. The concentrations of carbamazepine and trimethoprim were correlated with the concentrations of caffeine (R2 values of 0.70 to 0.80), indicating pharmaceutical contamination of groundwater by infiltration from domestic wastewater. The concentrations of caffeine were generally higher in groundwater samples collected in June during the wet season relative to the concentrations in samples collected in February during the dry season, indicating that infiltration of contaminants is higher during periods of heavy rainfall. Rapid rates of degradation and relatively slow rates of infiltration may explain why several target analytes were not detected in groundwater. Elevated concentrations of 4-hydroxychlorothalonil > 0.1 μg/L in samples collected at two of the monitoring sites warrant further studies on the sources and the distribution of this compound and other pesticides used in agriculture and for turf-treatment (e.g. golf courses). Overall, more data are needed in order to implement mitigation strategies that are effective in reducing chemical contamination in groundwater in Barbados.

Antidepressant drugs have been detected in municipal wastewater effluents (MWWEs) at ng/L to low μg/L concentrations. We exposed fathead minnow (Pimephales promelas) over a full lifecycle to a mixture of five antidepressants at concentrations similar to a MWWE (1× AntiD Mix); venlafaxine at 2400 ng/L, citalopram at 240 ng/L, fluoxetine at 90 ng/L, sertraline at 20 ng/L, and bupropion at 90 ng/L, and 10× these concentrations (i.e. 10× AntiD Mix). Mean measured concentrations of venlafaxine, citalopram, fluoxetine, sertraline, and bupropion were 2300, 160, 110, 7 ng/L, and below detection limits, respectively, for the 1× AntiD Mix, and 33,000, 2900, 1000, 210, and 100 ng/L, respectively for the 10× AntiD Mix. During the life-cycle exposure, no significant changes were observed in survival of fathead minnows. When male fish from the exposed treatments reached maturity, their weights were increased compared to control males. There were no significant differences in condition factor, gonadosomatic index, or liver-somatic index in the exposed fish. Exposed fathead minnows produced similar numbers of eggs as control fish, and there were no changes in nest-defense behaviours of male minnows. Egg quality, % fertilization, and % hatching in F1 fry were unaffected by exposure to the antidepressants. Eggs hatched 0.5 d earlier, deformities in fry were 50% lower, and there were transient decreases in length of F1 larvae at 8 days post-hatch in offspring from the treatment with the 10× AntiD Mix. Overall, exposure to the antidepressant mixture at environmentally relevant concentrations (i.e. 1× AntiD Mix) caused no adverse effects in fathead minnows. Exposure to the 10× AntiD Mix increased the weight of adult male minnows and caused subtle effects in F1 offspring. This study is the first to assess sublethal effects in fish exposed to mixtures of antidepressants over a full lifecycle. Capsule No effects were observed in fathead minnow exposed for a lifecycle to antidepressant mixtures at environmentally-relevant concentrations.

Little is known about the dissipation rate of microcontaminants in biosolids during storage and stabilization in stockpiles (unsaturated) or storage lagoons/tanks (saturated). The objective of this study was to characterize the dissipation in biosolids of two antibiotics, sulfamethoxazole (SMX) and trimethoprim (TMP), in microcosms under saturated and unsaturated conditions that simulate biosolids that are stockpiled on land or deposited in lagoons/tanks, respectively. The laboratory experiment was conducted at 22 °C using biosolids spiked at an initial nominal concentration of 10 mg kg−1 for both antibiotics. Biosolids were sampled in triplicate at seven sampling times over a 42-d period. Concentrations of SMX and TMP in extracts prepared from biosolids were quantified using liquid chromatography with tandem mass spectrometry. Dissipation data fitted to a first-order kinetic model indicated that the time to 50% dissipation (DT50) for SMX was significantly shorter in the unsaturated microcosms (2.8 d) than the saturated microcosms (4.4 d), while the DT50 for TMP was significantly shorter in microcosms under saturated conditions (10 d) relative to unsaturated conditions (116 d). These results indicate that the reducing conditions that develop in biosolids deposited in lagoons or placed in storage tanks might be effective for enhancing the microbial degradation of antibiotics that are otherwise persistent under aerobic conditions (i.e., TMP), while also being effective for removing other antibiotics including those that dissipate relatively readily under aerobic conditions (i.e., SMX).

This book provides insight into the hydrology, ecosystem services and management of water resources in the Parana River basin, including the importance of water to the socio-economic development of the countries within the watershed. Running through Brazil. Paraguay and Argentina, the Parana River and its watershed is home to some of South America's major population centers as well as important ecosystems threatened by development. At the same time, the river is a major resource driving the economies of the nations within its boundaries. This volume examines the impacts of environmental degradation, and the tradeoffs between the energy sector and the maintenance of ecosystem services. In particular, it focuses on the threats from development to sensitive ecosystems within the basin and the challenges of transboundary management of water resources. In addition to presenting wider perspectives on water management, the volume specifically covers water infrastructure, aquatic ecosystems, water quality, geomorphological influences and the impact of climate change. Finally, by assessing each country's current status in meeting the Sustainable Development Goals this volume provides a timely analysis as national governments within the basin are becoming increasingly concerned about the sustainability of the freshwater ecosystems within the Parana River basin. This book will be of great interest to students and scholars of water and natural resource management, environmental policy, sustainable development and Latin American studies. It will also be relevant to water management professionals.

As a result of historical industrial activity, the sediments in the inner harbor of Owen Sound Bay in the northeastern part of Lake Huron in Ontario, Canada are contaminated with organic compounds. The present study showed that the concentrations of Ʃ PAH16-EPA in all sediments in the inner harbor were above the sediment quality guidelines for the province of Ontario, Canada, with mean Ʃ PAH16-EPA concentrations at the most contaminated site of 46,000 μg/kg dry weight. The concentrations of polychlorinated biphenyls, brominated diphenyl ethers, and organochlorine compounds were all below sediment quality guidelines. The patterns of PAH and alkyl-PAH compounds in sediment cores indicated that contamination is from mixed sources, with a strong indication of pyrogenic contamination from industries that used to operate in the area, including a coal gasification plant. Other areas of the bay are impacted by petrogenic contamination, potentially from spills of fuel. The even distribution of PAH and alkyl-PAH compounds throughout core profiles at depths up to 25 cm indicates that this is a dynamic system and contaminated sediments are not being covered by deposition of less contaminated sediments. This study illustrates the value of determining the patterns of both PAH and alkyl-PAH compounds in sediments for regulatory purposes and also for forensic source tracking.

Indigenous rights, knowledge, and value systems are linked inextricably to the lands, waters, and non-human beings that form the environments of Indigenous Peoples. Across the globe, the rights of Indigenous peoples are being formally recognized and as a result, efforts are being made to include Indigenous Knowledge and value systems in environmental policy and decision making. Scientists and decision makers must not only recognize this reality, but also operationalize these efforts through meaningful changes to create space for the inclusion of Indigenous Knowledge, Indigenous values, and sovereignty within the current methods for scientific enquiry and the development of environmental policies. Professionals in the environmental field have a responsibility to ensure that their work has a positive impact on Indigenous Peoples and their environments. In this study, we explore the concept of consultation and informed consent through the lens of the development of environmental policy and decision making. We will discuss these concepts in the context of ecological risk assessment related to a case study focused on contaminated sediment in a harbor within the Great Lakes. We will demonstrate a process that deconstructs the current protocols for risk assessments at sites with localized pollutants in sediment and rebuilds them with elements that recognize both Western and Indigenous knowledge systems. This process includes collaborative fieldwork, relationship building, and informal and formal interviews with participants and community members. By utilizing such approaches, we were able to develop a risk assessment framework that recognizes the sovereignty of Indigenous peoples and promotes effective Nation-to-Nation decision making.

Two separate pilot-scale studies were performed at two wastewater treatment plants comparing conventional ozonation and catalytic ozonation with an alumina-based catalyst supplied by BASF. The results of the first pilot study showed that catalytic ozonation achieved the same degree of disinfection as conventional ozonation with 30% lower applied ozone dose and enhanced the removal of several contaminants of emerging concern (CECs). The second pilot study conducted over 6 months of operation with the same batch of catalyst showed sustained enhanced removal of CECs relative to ozonation alone. The removals of CECs by catalytic ozonation was particularly effective for compounds with low reaction rates with ozone, indicating reactions with hydroxyl radicals formed in the presence of the catalyst. Analysis of plasma vitellogenin and total glutathione in liver tissues of juvenile rainbow trout (Oncorhynchus mykiss) injected with wastewater extracts indicated that catalytic ozonation removed the estrogenic activity and modulated oxidative stress caused by exposure to the organic compounds in wastewater extracts. Analysis of other biomarker responses indicated that no transformation products were formed that can cause lipid damage in the liver or affect levels of a brain neurotransmitter (i.e. serotonin). Catalytic ozonation is a promising technology to increase the efficiency of ozone treatment of municipal wastewater and to meet increasingly more stringent regulations for effluent quality.

Silver nanoparticles (AgNP) are widely used as antibacterial agents in both commercial products and for industrial applications. As such, AgNP has a high potential for release into freshwater environments. As part of a whole-lake ecosystem experiment to examine the impacts of AgNP exposure at low µg/L concentrations over multiple years, we evaluated biological responses in Yellow Perch (Perca flavescens) before, during, and after AgNP additions to a freshwater lake. Yellow Perch were monitored for responses to in situ AgNP additions at the cellular (suite of biomarkers), individual (growth, prey consumption, and metabolism), and population (abundance and gross prey consumption) scales. At the cellular level, several biomarkers of oxidative stress in liver tissues revealed down-regulation, including decreased mRNA levels of catalase and glutathione peroxidase in Yellow Perch collected during AgNP exposure, and elevated ratios of reduced to oxidized glutathione. At the individual level, Yellow Perch bioenergetic models revealed that prey consumption and total metabolism significantly declined during AgNP additions and remained depressed one year after AgNP addition. At the population level, Yellow Perch densities and gross prey consumption declined after AgNP was added to the lake. Together, these results reveal a holistic assessment of the negative impacts of chronic exposure to environmentally relevant AgNP concentrations (i.e., µg/L) on Yellow Perch at cellular, individual, and population levels.

Over the past century, evidence has emerged that endocrine disrupting chemicals (EDCs) have an impact on reproductive health. An increased frequency of reproductive disorders has been observed worldwide in both wildlife and humans that is correlated with accidental exposures to EDCs and their increased production. Epidemiological and experimental studies have highlighted the consequences of early exposures and the existence of key windows of sensitivity during development. Such early in life exposures can have an immediate impact on gonadal and reproductive tract development, as well as on long-term reproductive health in both males and females. Traditionally, EDCs were thought to exert their effects by modifying the endocrine pathways controlling reproduction. Advances in knowledge of the mechanisms regulating sex determination, differentiation and gonadal development in fish and rodents have led to a better understanding of the molecular mechanisms underlying the effects of early exposure to EDCs on reproduction. In this manuscript, we review the key developmental stages sensitive to EDCs and the state of knowledge on the mechanisms by which model EDCs affect these processes, based on the roadmap of gonad development specific to fish and mammals., The authors are grateful to the Intersectoral Centre for Endocrine Disruptor Analysis (ICEDA)'s researcher network that facilitated this Special Issue. LNM was supported by a H2020-Marie Skłodowska-Curie Action MSCA-IF-RI- 2017 awarded by the European Commission (ref. 797725-EpiSTOX)., With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Venlafaxine is an antidepressant and anti-anxiety drug that has been detected in municipal wastewater at low μg/L concentrations. In this study, the nest-defense behavior of adult male fathead minnows (Pimephales promelas) was observed in fish exposed for a full lifecycle to venlafaxine nominal concentrations of 0.88, 8.8, and 88 μg/L (i.e. 1, 9.3, 75 μg/L mean measured concentrations). Nest-defense behaviors quantified were the time taken to contact a dummy intruder fish (on a flexible stick, held near each nest) and the number of contacts made during a 1 min period. In male fathead minnows exposed to venlafaxine over a full lifecycle at environmentally relevant nominal concentrations (i.e. 0.88 and 8.8 μg/L) no significant effects were observed in behavior. However, in males exposed over a full lifecycle to the highest concentration of venlafaxine (i.e. 88 μg/L), nest-defense behaviors were increased in males with empty nests, as shown by the significantly elevated percentage of empty-nest males that made contact with the dummy intruder fish (89%) relative to the lower percentage of contacts (65%) among the Control males (p = 0.046). Lifecycle exposure to high venlafaxine (88 μg/L) caused males to over-protect their empty nests. Environmental venlafaxine concentrations are approximately 70 x lower than this, so it is unlikely that behavioral changes from venlafaxine exposure would occur in the environment. Normal nest defense behaviours in control males varied, depending on whether they were protecting empty nests or nests with eggs. Compared to Control males with empty nests, more Control males with eggs in their nests made contact with the dummy intruder fish (p = 0.014), contact was faster (i.e.

Road runoff is an important vector for the transport of chemicals originating from tire wear into receiving waters. In this study, samples of surface water were collected in the summer of 2020 from two rivers near high-traffic corridors in the Greater Toronto Area (GTA) in Canada. These samples were analyzed for two additives used in tire production, 1,3-diphenyl guanidine (DPG) and hexamethoxymethylmelamine (HMMM), as well 26 of the transformation compounds of HMMM. In addition, samples were analyzed for 6PPD-quinone (6PPD-q), an oxidation by-product of a tire additive that was recently identified as a candidate compound responsible for mass mortalities of Coho salmon (Oncorhynchus kisutch) in spawning streams in the USA. Grab and composite samples were collected during rain events (i.e., wet events) at both locations. Grab samples were collected from the Don River upstream, downstream and at the point of discharge from a municipal wastewater treatment plant (WWTP) during a period of dry weather. Of the target analytes, 6PPD-q, DPG and HMMM, as well as 15 of the transformation compounds of HMMM, were detected at concentrations above limits of quantitation. The concentrations of 6PPD-q in the receiving waters during wet events were within the range of the LC50 for adult Coho salmon. One of the transformation products (TPs) of HMMM, dimethoxymethylmelamine was detected in a composite sample from Highland Creek at an estimated concentration greater than 10 μg/L, indicating that more research is needed to evaluate the potential hazards to the aquatic environment from this compound. Sampling in the Don River during a dry period showed that discharges of wastewater from WWTPs are also continuous sources of the TPs of HMMM. This study contributes to the growing literature showing that chemicals derived from tire wear are ubiquitous in urban watersheds and may be a significant hazard to aquatic organisms.

To study the effects of exposure of fish to opioid drugs, we exposed Japanese medaka (Oryzias latipes) over a full life cycle to codeine spiked into river water at nominal concentrations of 100, 1,000 and 25,000 ng/L and to fentanyl spiked into river water at nominal concentrations of 5, 25 and 1,000 ng/L. The measured concentrations during medaka exposures were consistent with the nominal concentrations. Treatments with codeine at all test concentrations reduced the number of eggs produced by female medaka, as well as the number of mature oocytes observed histologically in the ovaries. Exposures to codeine also resulted in altered concentrations of hormones within the hypothalamic-pituitary-gonadal axis, including reduced levels of 17β-estradiol in female medaka. Fentanyl did not affect reproduction or the levels of hormones in medaka at the concentrations tested. Monitoring of surface waters in southern Ontario, Canada downstream of wastewater treatment plants showed that the test concentrations of fentanyl and codeine were environmentally relevant. The results of this work contribute to the literature on the impacts of opioids and other drugs of abuse released into surface waters.

To determine whether discharges of contaminants from municipal wastewater treatment plants (WWTPs) may be contributing to the decline in populations of brook trout (Salvelinus fontinalis) in the watershed of the Credit River in ON, Canada, we caged juvenile brook trout upstream and downstream of the WWTPs of the small communities of Acton and Orangeville. Levels of vitellogenin were significantly elevated in liver tissue of trout caged downstream of both WWTPs, indicating exposure to estrogenic substances. Levels of thiobarbituric acid reactive substances indicative of oxidation of lipids were elevated in the gill tissue of brook trout caged downstream of the Orangeville WWTP, and levels of total glutathione were significantly lower in the gills of brook trout caged downstream of the Acton WWTP. Both biomarkers are indicative of oxidative stress, although many constituents of wastewater could be responsible for these responses. More work is needed to determine whether discharges of wastewater are contributing to the decline of brook trout in the Credit River and other cold-water streams in the Lake Ontario catchment basin.

Venlafaxine is an antidepressant drug that has been detected in municipal wastewater effluents at low μg/L concentrations. To assess the potential of this compound to affect the survival, development and reproductive capacity of fish, we exposed fathead minnow ( Pimephales promelas ) over a full lifecycle in a flow-through system to nominal venlafaxine concentrations of 0.88, 8.8, and 88 μg/L. Mean measured venlafaxine concentrations in these treatments were 1.0, 9.3 and 75 μg/L. During the 167–168 d exposure, no significant changes were observed in survival, or the weights and lengths of fathead minnows. At maturity, there were no significant differences relative to controls in condition factor, liver-somatic index, or secondary sex characteristics in the venlafaxine exposed male or female fish. Fathead minnows from the highest venlafaxine treatment (i.e. 88 μg/L) produced 46% more eggs per female than control fish (p = 0.031). Egg quality, % fertilization, % hatching, and % deformities in F1 fry were unaffected by exposure of the parent fish to venlafaxine at any of the test concentrations. Venlafaxine exposure at environmentally relevant concentrations (i.e. 0.88 and 8.8 μg/L) caused no adverse effects in fathead minnows. This study is the first to assess the potential for effects in fish exposed to the antidepressant venlafaxine over a full lifecycle.

One of the categories of environmental contaminants possibly contributing to declining sockeye salmon (Oncorhynchus nerka) in the Fraser River, British Columbia, Canada is pesticides. In this 4-month study, the effects of environmentally relevant concentrations of a waterborne neonicotinoid, clothianidin (0.15, 1.5, 15 and 150 μg/L), on embryonic, alevin and early swim-up fry sockeye salmon derived from four unique genetic crosses of the Pitt River, BC stock were investigated. There were no significant effects of clothianidin on survival, hatching, growth or deformities, although genetic variation significantly affected these endpoints. Clothianidin caused a significant 4.7-fold increase in whole body 17β-estradiol levels in swim-up fry after exposure to 0.15 μg/L, but no effects were observed on testosterone levels. In addition, hepatic expression of the gene encoding glucocorticoid receptor 2 was also impacted at the highest concentration of clothianidin tested, and was found to be ∼4-fold lower compared to the sockeye reared in control water. These results indicate additional examination of clothianidin and its effects on salmonid gonad development and the reproductive and stress endocrine axes in general, is warranted.

International audience; The chemical composition and properties of environmental media determine nanomaterial (NM) transport, fate, biouptake, and organism response. To compare and interpret experimental data, it is essential that sufficient context be provided for describing the physical and chemical characteristics of the setting in which a nanomaterial may be present. While the nanomaterial environmental, health and safety (NanoEHS) field has begun harmonization to allow data comparison and re-use (e.g. using standardized materials, defining a minimum set of required material characterizations), there is limited guidance for standardizing test media. Since most of the NM properties driving environmental behaviour and toxicity are medium-dependent, harmonization of media is critical. A workshop in March 2016 at Duke University identified five categories of test media: aquatic testing media, soil and sediment testing media, biological testing media, engineered systems testing media and product matrix testing media. For each category of test media, a minimum set of medium characteristics to report in all NM tests is recommended. Definitions and detail level of the recommendations for specific standardized media vary across these media categories. This reflects the variation in the maturity of their use as a test medium and associated measurement techniques, variation in utility and relevance of standardizing medium properties, ability to simplify standardizing reporting requirements, and in the availability of established standard reference media. Adoption of these media harmonization recommendations will facilitate the generation of integrated comparable datasets on NM fate and effects. This will in turn allow testing of the predictive utility of functional assay measurements on NMs in relevant media, support investigation of first principles approaches to understand behavioral mechanisms, and support categorization strategies to guide research, commercial development, and policy.

Surface water contamination with current-use pesticides (CUPs) is usually associated with inputs from agriculture. However, there are several urban sources of these compounds, including pesticides used in public spaces, golf courses, and lawns and gardens; discharges of municipal wastewater containing fungicides from pharmaceuticals and personal care products (PPCPs); and runoff of biocides that are used in construction materials. Polar organic chemical integrative samplers (POCIS) were used to monitor the occurrence of fungicides and selected herbicides in surface waters in the densely populated urban area near Toronto, Canada. Samplers were deployed in five urban streams, one agriculturally dominated stream, and at five locations in the nearshore zone of western Lake Ontario adjacent to urban areas. Sampling rates for target compounds in POCIS determined in laboratory calibration experiments ranged between 0.03 and 0.65 L/day. For herbicides, atrazine was detected at all sites, and diuron, 2,4-D, and mecoprop were frequently detected. The fungicides carbendazim and thiophanate-methyl were detected at all sites, and a hydroxy-metabolite of the fungicide chlorothalonil was also widely detected. Fungicides used in PPCPs (e.g. fluconazole, climbazole) were primarily detected in POCIS deployed in locations impacted by municipal wastewater. Estimated time-weighted average (TWA) concentrations of iprodione and carbendazim in urban streams were consistent with the number of golf courses in the watershed. However, runoff of biocides from building materials may also be a source of these fungicides. Overall, these data indicate that urban environments, as indicated by the Toronto area, have several point and non-point sources of fungicides and other CUPs.

There is a risk of exposure of aquatic organisms to nanosilver (AgNP) from discharges of municipal and industrial wastewater. In the present study, yellow perch (Perca flavescens) were exposed in static-renewal experiments conducted over 96 h and 10 d to environmentally relevant concentrations (i.e. 1 and 100 µg/L) of AgNP and Ag+. The greatest accumulation of total silver (tAg) occurred in the liver of P. flavescens and there was >10-fold more accumulation in the treatments with Ag+ relative to the AgNP treatments. Residues of tAg increased with concentration and duration of exposure in liver, gill and muscle. Both exposures caused a 2-fold induction of gene expression for metallothionein (mt) in liver tissue after 96 h of exposure, and reductions in levels of oxidized glutathione (GSSG) in liver after 10 d of exposure. Both AgNP and Ag+ decreased the expression of heat-shock proteins (hsp70). Exposure to the high concentration of AgNP for 10 d significantly increased lipid peroxidation in gill tissue, as indicated by the thiobarbituric acid reactive substances (TBARS) assay. There was a negative correlation between mean levels of GSSG and TBARS for both gill and liver tissue when data for all treatments were combined. It is significant that these biological responses were observed in P. flavescens exposed to AgNP, even though accumulation of tAg was at least 10-fold lower relative to the treatments with Ag+. This article is protected by copyright. All rights reserved

Single particle ICP-MS (spICP-MS) is a useful tool for characterizing and quantifying suspensions of metallic nanoparticles, but there are currently limitations on the minimum size of nanoparticles that can be detected using this technique. In this study, we demonstrated the spICP-MS capabilities of a double focusing magnetic sector ICP-MS instrument for analysis of commercially available Ag NP suspensions and samples of Ag NPs suspended in natural lake water, including data on particle event integration and sizing, particle counting and measurement of dissolved Ag background. Analysis of commercially available AgNP suspensions using a dwell time of 30 us determined that the ionic background dependent size detection limit is ∼10 nm at 2.7 ng Ag L−1. In samples collected from a lake in which AgNPs were added experimentally (PVP-capped, 30–50 nm size distribution), the Ag NPs were shown to have a modal diameter of ∼20 nm, with a dissolved Ag background of 6–13 ng L−1. The minimum particle size detectable in the lake water samples was approximately 15–18 nm, depending on the dissolved Ag concentration. There was no evidence of matrix effects in lake water that would adversely affect the accuracy of the particle sizing. The determination of particle number concentrations by spICP-MS was shown to be limited by particle size dependent transport efficiencies and losses through adsorption on sample vials. Overall, while further development of the sample preparation protocols is needed, the spICP-MS technique described in this study demonstrates improved discrimination of AgNPs from dissolved Ag and a lower particle size range relative to previously described instrumental methods.

A total of 15 kg of silver nanoparticles (AgNPs) was added continuously over two ice-free field seasons to a boreal lake (i.e., Lake 222) at the IISD Experimental Lakes Area in Canada. We monitored the accumulation of silver (Ag) in the tissues of yellow perch ( Perca flavescens) and northern pike ( Esox lucius) exposed to the AgNPs under environmentally relevant conditions. The greatest accumulation was observed in the liver tissues of pike, and a single pike sampled in the second year of additions had the highest concentration observed in liver of 5.1 micrograms per gram of wet weight. However, the Ag concentrations in gill and muscle tissue of both pike and perch did not exceed 0.35 micrograms per gram of wet weight. Following additions of AgNP, the Ag residues in fish tissues declined, with a half-life of Ag in pike liver of 119 days. Monitoring using passive sampling devices and single-particle inductively coupled plasma mass spectrometry during the AgNP addition phase confirmed that Ag nanoparticles were present in the water column and that estimated mean concentrations of Ag increased over time to a maximum of 11.5 μg/L. These data indicate that both a forage fish and a piscivorous fish accumulated Ag in a natural lake ecosystem dosed with AgNPs, leading to Ag concentrations in some tissues of the piscivorous species that were 3 orders of magnitude greater than the concentrations in the water.

Because of the widespread use of silver nanoparticles in commercial products, discharges of municipal wastewater may be a point source of silver in the aquatic environment. We monitored two sites in western Lake Ontario impacted by discharges from wastewater treatment plants serving the City of Toronto. Concentrations of silver were elevated in bottom sediments and suspended sediments collected at the two sites. We also deployed two types of passive samplers in the water column at the two sites, the newly developed Carbon Nanotube Integrative Samplers for monitoring “CNIS-labile” silver and Diffusive Gradient in Thin Film samplers for monitoring “DGT-labile” silver. Results from these passive samplers indicated that the concentrations of silver at the two sites were either below detection limits or were in the ng/L range. In laboratory experiments where the sediments were re-suspended in Milli-Q water, a small proportion of the silver (i.e.

In this study, we evaluated the distribution and concentrations of a range of neonicotinoid insecticides (NNIs) and other insecticides, fungicides, biocides and selected herbicides in watersheds that drain into the lower Great Lakes in Ontario, Canada. Polar Organic Chemical Integrative Samplers (POCIS) were deployed in 18 watersheds during late May to late June of 2016. Grab samples were also collected in 7 of these watersheds. There was generally good agreement between the time-weighted average concentrations of pesticides estimated from the POCIS and the concentrations detected in grab samples. The NNIs, thiamethoxam, clothianidin and imidacloprid, were present in several watersheds at concentrations that exceeded the Canadian Water Quality Guideline for imidacloprid of 0.23 μg/L. The new generation insecticides, flonicamid and flupyradifurone were also detected in some watersheds, which is the first report of these pesticides in the peer-reviewed literature. Atrazine, 2,4-D, dicamba, carbendazim, thiophanate methyl and several azole-based fungicides were also widely detected. Discriminant Function Analysis (DFA) indicated that a high proportion (i.e. >80%) of the watersheds could be discriminated from each other on the basis of the pattern of pesticides detected in surface waters, and the proportion of field crops in the watershed.

There have been few reports in the peer-reviewed literature on the levels of contaminants of emerging concern (CECs) in municipal wastewater from the Caribbean region. In this study of wastewater collected from two wastewater treatment plants in Barbados, caffeine and ibuprofen were detected at µg/L concentrations, whereas two steroid hormones (i.e. androstenedione, estrone) and several prescription pharmaceuticals were detected at ng/L concentrations. Among drugs of abuse, benzoylecgonine (i.e. metabolite of cocaine), MDMA (i.e. Ecstasy) and MDA (i.e. 3,4-methylenedioxyamphetamine) were present at the highest concentrations in untreated wastewater. Overall, these data show that there is potential impact in the marine environment in Barbados from CECs discharged into the coastal zone.

Pharmaceuticals and personal care products (PPCPs), and endocrine disrupting compounds (EDCs) are micropollutants of emerging concern that have been detected in the aquatic environment and in some cases, in drinking water at nanogram per liter levels. The goal of this study was to evaluate the removal of 15 model PPCPs and EDCs from water by direct UV photolysis, using either low (LP)-or medium (MP) -pressure mercury vapor arc lamps. Some of the model compounds are either weak bases or weak acids, and therefore, the pKa values were determined or confirmed for those compounds using spectrophotometric titrations. The molar absorption coefficients of ionized and non-ionized forms were also determined. The quantum yields at 253.7 nm in phosphate buffer solutions of pH 7.2 were determined to be 0.033 ± 0.004 for sulfamethoxazole, 0.0035 ± 0.0008 for sulfachloropyridazine, 0.006 ± 0.002 for acetaminophen, 0.34 ± 0.07 for triclosan, 0.35 ± 0.14 for estrone, 0.08 ± 0.05 for 17α-ethinylestradiol, 0.086 ± 0.012 for ibuprofen. The quantum yield for 4-n-nonylphenol photolysis at 253.7 nm varied with the initial concentration from 0.32 ± 0.08 at 23 μg/L to 0.092 ± 0.006 at 230 μg/L. The pseudo-first order rate constants determined for direct photolysis at 253.7 nm of the studied micropollutants followed the order: triclosan ≈ sulfamethoxazole >> 4-n-nonylphenol ≈ sulfachloropyridazine ≈ estrone > acetaminophen ≈ 17α-ethinylestradiol ≈ ibuprofen. In contrast to the results observed for the monochromatic radiation (LP lamp), all 15 model compounds photolyzed under exposure to the broadband radiation emitted by the MP lamp.

The concentrations of 17 drugs of abuse, including cocaine, several amphetamines, opioid drugs, and 2 metabolites--benzoylecgonine, a metabolite of cocaine, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrolidine, a metabolite of methadone--were investigated in an urban watershed that is heavily impacted by discharges of municipal wastewater. The artificial sweetener sucralose was also monitored as a persistent tracer of contamination from municipal wastewater. Monitoring was conducted in a municipal wastewater treatment plant (WWTP) and at sites upstream and downstream of the WWTP discharge, as well as in a drinking water treatment plant (DWTP) located 19 km downstream of the WWTP discharge that withdraws raw water from the river. Drug concentrations were monitored with polar organic chemical integrative samplers deployed for 2 wk in the river and in the WWTP and DWTP. Several of the investigated compounds exhibited a decrease in concentration with distance downstream from the wastewater discharge into the river, but there was little attenuation of sucralose, cocaine, benzoylecgonine, morphine, acetylmorphine, acetylcodeine, and oxycodone. Heroin and methadone were not detected at any sample locations. Amphetamine, methamphetamine, 3,4-methylenedioxy-methamphetamine, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrolidine were not detected in the samples collected at the drinking water intake. Many of the drugs of abuse were not removed effectively in the DWTP, including cocaine, benzoylecgonine, methylenedioxyamphetamine, ephedrine, and several prescription opioids, most probably because the DWTP was operating at or above its rated treatment capacity. These data indicate that there can be transport of drugs of abuse from wastewater sources into drinking water in urban watersheds.

Digestion of municipal wastewater biosolids is a necessary prerequisite to their beneficial use in land application, in order to protect public health and the receiving environment. In this study, 13 pharmaceuticals and personal care products (PPCPs), 11 musks, and 17 polybrominated diphenyl ethers were analyzed in 84 samples including primary sludge, waste activated sludge, digested biosolids, dewatered biosolids, and dewatering centrate or filtrate collected from five wastewater treatment plants with aerobic or anaerobic digestion. Aerobic digestion processes were sampled during both warm and cold temperatures to analyze seasonal differences. Among the studied compounds, triclosan, triclocarban, galaxolide, and BDE-209 were the substances most frequently detected under different treatment processes at levels up to 30,000 ng/g dry weight. Comparing aerobic and anaerobic digestion, it was observed that the levels of certain PPCPs and musks were significantly higher in anaerobically digested biosolids, relative to the residues from aerobic digestion. Therefore, aerobic digestion has the potential advantage of reducing levels of PPCPs and musks. On the other hand, anaerobic digestion has the advantage of recovering energy from the biosolids in the form of combustible gases while retaining the nutrient and soil conditioning value of this resource.

Silver nanoparticles (AgNPs) are currently the most commonly used nanoparticles in consumer products, yet their environmental fate in natural waters is poorly understood. In the present study, we investigated the persistence, transformations and distribution of polyvinylpyrrolidone (PVP) and citrate (CT) coated AgNPs in boreal lake mesocosms dosed either with a 6-week chronic regimen or a one-time pulse treatment at environmentally relevant dosing levels. In the chronic treatments, total Ag (TAg) concentrations reached ∼40% of target concentrations by the end of the experiment, and in the pulsed mesocosms, TAg dissipated slowly, with a half-life of ∼20 days. Sediments and periphyton on the mesocosm walls were an important sink for Ag. We found little effect of AgNP loading and surface coating on the persistence of TAg. There were also no differences between treatments in the degree of agglomeration of AgNPs, as indicated by the accumulation and distribution of Ag in the particulate and colloidal fractions. The low ionic strength and relatively high dissolved organic carbon concentrations in the lake water likely contributed to the relative stability of AgNP in the water column. The low concentrations of dissolved Ag (1 μg L(-1)) in the size fraction3 kDaA reflect the importance of natural ligands in controlling the concentrations of Ag released by dissolution of AgNPs. Overall, these data indicate that AgNPs are relatively stable in the tested lake environment and appear to result in quantities of highly toxic ionic Ag(+) that are below our limit of detection.

a b s t r a c t Nanoparticles (NPs) are engineered in the nanoscale (

Contaminants of emerging concern (CECs), including pharmaceuticals, artificial sweeteners, steroid hormones, and current-use pesticides have been detected in surface waters around the world, but to date, there have been no reports in the peer-reviewed literature on the levels of these classes of contaminants in freshwater resources in the Caribbean region. In the present study, multi-residue solid phase extraction (SPE) and liquid chromatography with tandem mass spectroscopy (LC-MS/MS) were used to analyze grab samples of surface waters collected from five different watersheds in Barbados, West Indies. The artificial sweeteners (AS), acesulfame, cyclamate, saccharin, and sucralose were widely detected in the watersheds, indicating contamination from domestic wastewater, and the concentrations of these chemical tracers in water were correlated with the concentrations of the non-prescription pharmaceutical, ibuprofen (R 2 values of 0.4–0.6). Surprisingly, the concentrations of another chemical tracer of domestic wastewater, caffeine were not correlated with ibuprofen or AS concentrations. Several other prescription pharmaceuticals and the steroid hormones, estrone and androstenedione, were detected in selected watersheds at low ng/L concentrations. The fungicide, chlorothalonil was widely detected in surface waters at low (

Both freshwater and marine ecosystems are degraded by pollution from nutrients, suspended solids, pathogens, siltation, oxygen-depleting substances, metals and organic contaminants. Natural wetlands play a significant role in reducing adverse impacts on water quality associated with pollution, and decrease the need for costly infrastructure. Constructed or restored wetlands also contribute to the abatement of pollution, which is consistent with the emerging paradigm of Nature-based Solutions (NbS). Through a series of case histories, the readers will gain an understanding of the opportunities, as well as the challenges associated with constructing or managing wetlands for pollution abatement, wastewater management and adapting to possible climate change impacts, while preserving their biodiversity and ecological functions. The case histories describe experiences with both natural and constructed wetlands, and provide examples from around the world, including wetlands in polar and tropical ecosystems, as well as wetlands located in urban and remote or rural landscapes.

The sensitivity of amphibians to Ranavirus may be increased by exposure to other environmental stressors, including chemical contaminants. Neonicotinoid insecticides comprise 27% of the global insecticide market and have been detected in wetlands and other aquatic habitats. The present study focused on the effects of exposure of pre-metamorphic Xenopus laevis to the neonicotinoid, imidacloprid (IMI) on sensitivity to frog virus 3 (FV3) infection. It was hypothesized that exposure of tadpoles to IMI at sublethal concentrations of 1 and 500 μg L−1 would increase FV3 related mortalities relative to tadpole mortalities in a control treatment with only the virus. However, contrary to the predicted outcome, IMI reduced the rates of mortality following viral challenge, although the total mortalities by the 25th day after infection did not differ among the treatments. These results should not be interpreted as an indication that neonicotinoid insecticides are beneficial to aquatic ecosystems, since these insecticides cause toxic responses at low concentrations to other non-target aquatic organisms.