NP, OP and Derivatives in Freshwater Sediment Downstream of Textile Associated Municipal Wastewater Discharges.

Alkylphenol ethoxylates comprise of many anthropogenic chemicals such as nonylphenol (NP), octylphenol (OP) and nonylphenol ethoxylates (NPEOs). The objectives of this study were to assess the frequency and magnitude of detections of 4-NP, OP and NPEOs in Canadian sediment downstream of textile associated municipal wastewater treatment plants (MWWTPs) to determine if regulatory actions have had a beneficial impact on the receiving environment. Surficial sediments were obtained in four locations in the province of Québec (Canada) and were analyzed for nonylphenol, nonylphenol monoethoxylates (NP1EO), nonylphenol diethoxylates (NP2EO) and octylphenol from 2015 to 2018. Individual concentrations of the compounds varied from non detect to 419 ng/g. Of the four compounds analyzed, NP was detected the most frequently with a 75% detection rate while OPs were not detected in any of the samples. Since the Canadian regulatory actions have drastically reduced NP/NPEOs usage in textile mill factories and manufactured products, the potential source of these compounds in sediment for this study could stem from the outfall from the MWWTPs but not related to textile mills as well as from the usage of these compounds as formulants in pesticide products. Lastly, there were no exceedances to the Canadian Sediment Quality guideline toxic equivalency approach (TEQ) of 1400 ng/g or the 1310 ng/g guideline for NP in freshwater sediment from the European Scientific Committee on Health, Environmental and Emerging Risks. We hypothesize that the significant concentrations of these compounds in sediment may be a relevant and continuous source of 4NP in surface waters due to resuspension of sediment in the water column.

Disparities in high schools' vaccination coverage (COVID-19). A natural experiment in the Province of Quebec.

Teenagers' vaccination has become crucial to limit the COVID-19 transmission in the population. To increase the vaccination rate of this age group, a school-based vaccination campaign was launched in Québec, Canada from June 7 to 18, 2021. This study aimed to analyze trajectories of vaccination coverage over time among students attending 37 high schools. The study explored whether school-based vaccination campaigns contributed to the progression of the vaccination coverage and attenuated disparities in vaccination coverage across schools. On average, first dose coverage quickly increased from 30.6% to 81.5% between June 6 and 18, 2021, after the launch of the campaign. As of August 13, 2021, first dose coverage had reached 87.9% and 64.9% for the second dose coverage. Public schools with poorer student populations had 6.5 points of percentage lower first dose vaccination rates (95%CI 0.3%; 12.6%) compared to other schools. A higher level of concern related to the pandemic among students was associated with a 4.3 points of percentage increased coverage (95%CI 0.7%; 8.0%). The initial uneven distribution in first dose coverage decreased dramatically by the end of the campaign. Similar trends were observed for the second dose, although between schools' inequality at the end of the period of observation was significantly larger. The school-based vaccination campaign might have initially contributed to a prompt rise in vaccination coverage and helped the disadvantaged schools to reach similar vaccination coverage as seen in other schools. In addition to being an efficient way to achieve rapidly high vaccination coverage, the school-based approach might contribute to increase equity in vaccination distribution.

Perfluoroalkyl Substances (PFASs) in the Canadian Freshwater Environment.

Per- and polyfluoroalkyl substances (PFASs) are anthropogenic substances that are very stable in the receiving environment. Legacy perfluoroalkane sulfonates (PFSAs) and perfluoroalkyl carboxylic acids (PFCAs) are especially persistent and resistant to typical environmental degradation processes and therefore are distributed across all trophic levels and environmental compartments (soil, air, water). Since most uses of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and LC-long-chain PFCAs are banned in Canada, alternative PFASs have been in use for a number of years. Twenty-nine sites across Canada were sampled for PFASs to determine concentrations and trends. Overall, 13 PFASs were measured in 566 Canadian freshwater samples from 2013 to 2020 with a range from below the detection limit (LOD range: 0.4-1.6 ng/L) of the laboratory to a maximum of 138 ng/L (for PFBS). While PFOS and PFOA concentrations are declining significantly over time, other compounds such as PFPeA and PFBA have increased significantly over 2013-2020. Overall, the range of concentrations found in this study was similar to that of other Canadian and international studies. However, this study also found a higher frequency of detections of the replacement PFASs than that of the other, older, Canadian studies.

Nonylphenol, Octylphenol, and Nonylphenol Ethoxylates Dissemination in the Canadian Freshwater Environment.

Nonylphenol, octylphenol, and nonylphenol ethoxylates are manmade compounds that are only discharged in the environment due to anthropogenic activities. The objectives of this study were to determine the current concentrations of these substances in the Canadian freshwater environment and to determine if past regulatory actions were beneficial to the environment. Freshwater samples (n = 241) were collected and analysed for 4-nonylphenols (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), and octylphenols at 35 sites in Canada from 2014 to 2019 with individual compound concentrations ranging from 1.29 to 477.22 ng/L. In addition, 18-65% of the samples were reported to be under the laboratory detection limit, depending on the compound. Sampling sites were categorised into five groups based on the dominant activities present upstream in their watersheds: mixed use sites; municipal waste water treatment plant (MWWTP)-associated sites; textile mill-associated sites; urban; and reference sites. All four compounds in the study were detected more frequently in urban and MWWTP-associated sites than at other locations. Additionally, there is a statistically significant (p < 0.05) downward temporal trend in NP concentrations in Canadian surface waters from 2014 to 2019. There were no exceedances of the Canadian Water Quality Guideline of 1000 ng/L.

Temporal and Spatial Analysis of Surface Water Pesticide Occurrences in the Maritime Region of Canada.

This study measured both nutrient and pesticide concentrations at up to 13 different freshwater stream sites in New Brunswick, Nova Scotia and Prince Edward Island between 2013 and 2018. Up to 62 different pesticides were analysed in 248 discreet samples. A large majority of pesticides were below the detection limit of the laboratory while seven pesticides had at least 20% or more detections throughout the years of this study. The four pesticides that had the highest frequency of detection were the insecticides chlorantraniliprole, clothianidin, imidacloprid, and thiamethoxam of which the last three are categorised as neonicotinoid insecticides.

Spatial and Temporal Distribution of BPA in the Canadian Freshwater Environment.

Bisphenol A (BPA) is a manmade chemical that is only found in the environment due to anthropogenic activities. A total of 1150 surface freshwater samples were collected and analysed for BPA at 44 sampling sites in Canada from 2012 to 2018. The resultant concentrations ranged from 3.05 to 1888.51 ng/L. In addition, 64% of the samples were reported to be under the detection limit of the laboratory. In comparison, the Federal Environmental Quality Guideline for the protection of aquatic life is 3500 ng/L. Sampling sites were categorised into four groups based on the dominant activities present upstream in their watersheds: reference sites, mixed use sites, urban sites, and municipal waste water treatment plants (MWWTP) associated sites. Based on the results of this study, detections of BPA in water samples were more frequent in urban and MWWTP-associated sites. Additionally, there does not seem to be a statistically significant temporal (upward or downward) or spatial trend in BPA concentrations in Canadian surface waters from 2012 to 2018 only. Overall, Canadian BPA results are of similar concentrations to that of other countries in Asia and Europe.

Investigation of Spatial Distributions and Temporal Trends of Triclosan in Canadian Surface Waters.

Triclosan is widely used in personal care products (skin creams, toothpastes, soaps, deodorants, body spray) and cleaning products (dishwashing detergent and all-purpose cleaners) (Halden in Environ Sci Technol 48:3603-3611, 2014). In 2001, it was selected for screening-level risk assessment under the Canadian Environmental Protection Act (HC and EC in Preliminary assessment. Triclosan. Chemical abstracts Service Number 3380-34-5, 2012. http://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=6EF68BEC-1 ), and its physicochemical and toxicological characteristics indicate that there may be a risk to aquatic environments due to releases of the chemical in Canada. A surveillance initiative across Canada has included sampling at 44 sites from July 2012 to March 2018. Triclosan was detected in 226 of 918 samples; concentrations ranged from less than 6 to 874 ng L-1, and the detections averaged 54.23 ng L-1 (standard deviation; 97.6 ng L-1). However, using the entire dataset (including censored data estimated with the Kaplan-Meier model), the mean triclosan concentration was 17.95 ng L-1, and the standard deviation was 52.84 ng L-1. Three samples at Wascana Creek (downstream), Saskatchewan, had concentrations above the Federal Environmental Quality Guidelines of 470 ng L-1, indicating a potential risk to the aquatic ecosystem. In this study, triclosan in samples collected downstream from municipal wastewater treatment plant discharges usually demonstrated higher concentrations than upstream samples. Based on the results of this study, it is hypothesized that triclosan concentration have fluctuated between years of this study but not in an overall or significant increase or decreasing trend. Triclosan concentrations and detections also are more prevalent in urban than in rural or mixed development rivers. Performance evaluation of triclosan concentrations in the Canadian environment is scheduled to be reassessed by 2024. Therefore, a 3-year sampling program should be in place across Canada by 2021.

Association between junk food consumption and fast-food outlet access near school among Quebec secondary-school children: findings from the Quebec Health Survey of High School Students (QHSHSS) 2010-11.

OBJECTIVE: We investigated the association between junk food consumption at lunchtime (JCL) and fast-food outlet access near school among secondary-school children in Quebec. DESIGN: A geographic information system database was used to characterize the food environment around a sub-sample of 374 public schools in which 26 655 students were enrolled. The outcome variable was JCL during the previous week, dichotomized into low JCL (none or once) v. high JCL (twice or more). Access to fast-food outlets near school was assessed using an existing database of fast-food outlets in Quebec. Covariates included student (age, sex and self-rated perceived health), family (familial status and parental education) and school (urban/rural status and deprivation) variables. Hierarchical logistic regression models were employed for analyses using PROC GLIMMIX of SAS version 9.3. SETTING: Province of Quebec, Canada. SUBJECTS: We used data from the Quebec Health Survey of High School Students (QHSHSS) 2010-11, a survey of secondary-school Quebec students. RESULTS: Exposure to two or more fast-food outlets within a radius of 750 m around schools was associated with a higher likelihood of excess JCL (OR=1·50; 95 % CI 1·28, 1·75), controlling for the characteristics of the students, their families and their schools. CONCLUSIONS: The food environment surrounding schools can constitute a target for interventions to improve food choices among secondary-school children living in the province of Quebec. Transforming environments around schools to promote healthy eating includes modifying zoning regulations that restrict access to fast-food outlets around schools.

Formaldehyde concentration in discharge from land based aquaculture facilities in Atlantic Canada.

Formaldehyde is used in freshwater aquaculture facilities in the Maritimes region of Canada to prevent external parasites and is discharged without treatment to freshwater receiving environments. In this study, formaldehyde was measured at effluent outfalls and 100 m downstream of four land based aquaculture facilities at various post-treatment time intervals. Concentrations of formaldehyde ranged from 0.2 to 7.1 mg/L. Based on Environment Canada's environmental no effect value, all of the samples show a potential risk to aquatic life. Furthermore, based on a chronic aquatic life water quality criterion of 1.61 mg/L all but two of the samples had concentrations considered to be toxic to aquatic life. An acute water quality criteria was only exceeded once in all of the environmental measurements of formaldehyde. These results lead us to hypothesize that the discharge of formaldehyde from land-based facilities may cause adverse chronic impacts.

Explaining immigration casework in federal Members of Parliament's district offices in Canada.

In Canada, a majority of federal constituency offices deal primarily with immigration files. The few qualitative studies on the subject show that the resources dedicated to these files and the type of work carried out on the immigration files handled vary between offices, thus contributing to disparities in service between federal electoral districts. How can such variation be explained? Based on the quantitative analysis of unpublished administrative data, this article first highlights the diversity of files handled by constituency offices, as well as the types of intervention carried out by constituency assistants. It then aims to explain the variations in case processing according to the type of case and the volume of requests handled. Studies of constituents' files received and processed at constituency office level have argued that the political ideology, gender and ethnicity of the deputy as well as the demographics of the constituency are explanatory factors. This analysis shows that in the case of immigration files, constituency demography is the most important factor, while the MP's political affiliation plays a very limited role. These results shed new light on the factors involved in the processing of immigration cases at constituency level, and add nuance to previous, mainly qualitative analyses. Our results also contribute to understanding the work of constituency offices for constituents, which appears to be far less partisan than in other countries where similar offices exist.

Au Canada, une majorité de bureaux de circonscription fédérale traite principalement des dossiers d'immigration. Les quelques études qualitatives portant sur le sujet montrent que les ressources dédiées à ces dossiers et le type de travail effectué sur les dossiers dʼimmigration traités varient entre les bureaux, contribuant ainsi à des disparités de services entre les circonscriptions électorales fédérales. Comment expliquer une telle variation? En sʼappuyant sur lʼanalyse quantitative de données administratives inédites, cet article met dʼabord en évidence la diversité des dossiers traités par les bureaux de circonscription ainsi que les types d'intervention effectués par les adjoints de circonscription. Ensuite, il vise à expliquer les variations du traitement des dossiers en fonction du type de dossier et du volume des demandes traité. Les études sur les dossiers de commettants reçus et traités au niveau des bureaux de circonscription ont soutenu que lʼidéologie politique, le genre et lʼethnicité du député ainsi que la démographie de la circonscription sont des facteurs explicatifs. Cette analyse montre que dans le cas des dossiers dʼimmigration, la démographie de la circonscription est le facteur le plus important, tandis que l'appartenance politique du député joue un rôle très limité. Ces résultats apportent un nouvel éclairage sur les facteurs du traitement des dossiers dʼimmigration au niveau des circonscriptions et nuancent les analyses antérieures, principalement qualitatives. Nos résultats contribuent également à la compréhension du travail des bureaux de circonscription pour les commettants, qui semble être bien moins partisan que dans dʼautres pays où des bureaux semblables existent.

Epidemiology of Pediatric Tumors in Quebec: A 17-Year Report of Cancer in Young People in the Canada Registry.

BACKGROUND: Cancer is the leading cause of disease-related death among children of more than 1 year of age. However, childhood cancer risk factors and etiology are yet to be fully understood. The goal of this study is to identify geographic variation among children and adolescents diagnosed with pediatric tumors between 2001 and 2018 in the province of Quebec. METHODS: We analyzed pediatric patients less than 15 years of age from the Cancer in Young People in Canada (CYP-C) surveillance system who were diagnosed between 2001 and 2018 with cancer in the province of Quebec. The age-standardized age-adjusted incidence rates (AAIR) per 100,000 person years were calculated for all childhood cancers by cancer subgroups, Quebec Health regions, and age groups. RESULTS: Overall, 3904 pediatric patients less than 15 years old were diagnosed with cancer in the province of Quebec in 2001-2018. The overall incidence rate (IR) in the province of Quebec was 16.14 (95%CL [15.56-16.73]) per 100,000 person years. For childhood cancers, regions that presented a higher AAIR were Chaudière-Appalaches and Capitale-Nationale with 18.2 and 17.5 per 100,000 person years, respectively. The incidence rates (IRs) in Chaudière-Appalaches (95% CI 1.0439-1.3532) and in Capitale-Nationale (95% CI 1.0124-1.2942) were statistically higher than the incidence in the province of Quebec (p = 0.0090 and p = 0.0310, respectively). When comparing the AAIR of the CNS tumor subgroup in Chaudière-Appalaches and in Capitale-Nationale, with the provincial average, we noticed a statistically higher incidence in Chaudière-Appalaches and a trend for Capitale-Nationale (p < 0.0001 and p = 0.0602, respectively). CONCLUSION: There is evidence of spatial clusters in Chaudière-Appalaches and Capitale-Nationale as areas for all childhood cancers. Further studies should be performed to investigate potential risk factors in these regions.

Analysis of benthic invertebrate communities as a function of distance from two fish-processing plant effluent discharges in New Brunswick, Canada.

Benthic invertebrate communities have been known to change due to impacts from nutrient-rich industrial outputs, such as those from pulp and paper, sewage-treatment plants, or aquaculture. Fish-processing plants have been recognized as contributors of large volumes of nutrient rich effluent to marine and estuarine environments, but their effect on benthic invertebrate communities is unknown. Benthic invertebrates and sediment samples were obtained from marine sampling stations at 0-, 10-, 30-, and 100-m distances from two fish-processing outfalls in Atlantic Canada. Sediment grain size, total organic carbon (TOC), ammonia, sulphide, and redox, as well as invertebrate abundance, density, taxa richness, Simpson's Inverse Diversity Index, Bray-Curtis Index of (%) Similarity, and the AZTI marine biotic index (AMBI), were determined for all sampling sites. Results from this study illustrate that taxa richness and density significantly increased as distance from the outfall discharge increased. In our study, TOC was only significantly correlated to AMBI but not to the other benthic invertebrate assemblage descriptors calculated in this study (invertebrate density, taxa richness, Simpson's Inverse Diversity Index). The study results suggest that taxa richness and density may be affected by effluent from fish-processing plants.

Measurement of oxytetracycline and emamectin benzoate in freshwater sediments downstream of land based aquaculture facilities in the Atlantic Region of Canada.

This study investigated the occurrence of oxytetracycline (OTC) and emamectin benzoate (EB) in sediments located near the effluent outfall from four freshwater aquaculture facilities in Atlantic Canada. While two facilities had no detectable concentrations of EB or OTC, two facilities had detectable concentrations of one or both of these chemicals. Concentrations ranged from <0.05-18 mg/kg to <0.01-2.5 mg/kg for OTC and EB respectively. Although these values could not be compared with freshwater toxicant values, some of the concentrations of EB and OTC detected were higher than LC(50) values calculated for marine invertebrates. OTC concentrations measured in this study are also of a magnitude which has been known to produce resistant bacteria.

Trace metal concentrations in sediments and fish in the vicinity of ash lagoon discharges from coal-combustion plants in New Brunswick and Nova Scotia, Canada.

Metals that originate from coal-combustion residue (ash) deposited in water-filled lagoons are eventually released into the environment. This study measured metal concentrations in sediment and fish obtained in the vicinity of two coal-combustion ash-lagoon outfalls on the East River (Nova Scotia) and Grand Lake (New Brunswick), Canada. Of the 34 metals analysed, this study demonstrated that sediment in the immediate vicinity of the ash lagoon discharge in New Brunswick had statistically significant greater concentrations of thallium, arsenic, and antimony than did the sediment obtained from background areas. Tissue arsenic concentrations were increased in fish obtained near the lagoon discharge in New Brunswick but not statistically greater than that of fish obtained from background areas. Neither sediment nor fish obtained near the ash-lagoon discharge in Nova Scotia had significantly greater concentrations of any of the metals measured.

A comparative toxicity assessment of materials used in aquatic construction.

Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species.

Bisphenol A in the Canadian environment: A multimedia analysis.

Bisphenol A (BPA) is an industrial chemical that has been identified by some jurisdictions as an environmental concern. In 2010, Canada concluded that this substance posed a risk to the environment and human health, and implemented actions to reduce its concentrations in the environment. To support these activities, a multimedia analysis of BPA in the Canadian environment was conducted to evaluate spatial and temporal trends, and to infer mechanisms influencing the patterns. BPA was consistently detected in wastewater and biosolids across Canadian wastewater treatment plants (WWTPs) and in landfill leachate. In addition, BPA concentrations were significantly higher in surface water downstream compared to upstream of WWTPs in three of five urban areas evaluated. However, application of biosolids to Canadian agricultural fields did not contribute to elevated BPA concentrations in soil, earthworms, and European Starling (Sturnus vulgaris) plasma one and two years post-treatment. Spatial trends of BPA concentrations in surface water and sediment are influenced by human activity, with higher concentrations typically found downstream of industrial sources and WWTPs in urban areas. BPA was detected in bird plasma at locations impacted by WWTPs and landfills. However, spatial trends in birds were less clear and may have been confounded by metabolic biotransformation. In terms of temporal trends, BPA concentrations in surface water decreased significantly at 10 of 16 monitoring sites evaluated between 2008 and 2018. In contrast, recent temporal trends of BPA in six sediment cores were variable, which may be a result of biotransformation of the flame retardant tetrabromobisphenol A to BPA. Overall, our study provides evidence that Government of Canada actions have been generally successful in reducing BPA concentrations in the Canadian environment. Our results indicate that long-term monitoring programs using surface water are more effective than other media for tracking and understanding future environmental trends of BPA.

Polybrominated diphenyl ethers concentrations in fish processing plant effluent.

The total concentration of PBDEs in the wastewater from fish plants ranged from 82 to 35,055 pg/L which was higher than ambient concentrations measured in surface water samples in North America (6-158 pg/L). Based on the concentration of PDBES in the effluent, calculated daily discharge of PBDEs into the environment ranged from 0.03 to 13.34 g per day. The concentrations of PBDEs in the solid fraction of the effluent from this study has been calculated to range from 0.78 ng/g for scallop, to 3,505 ng/g for cod with herring having the second highest concentration of 1,534 ng/g.

Polybrominated diphenyl ethers (PBDEs) concentration in sediments located in the vicinity of fish plant effluent outfalls in the maritimes.

Since polybrominated biphenyl ethers (PBDEs) are known to be present in various species of fish, it is likely that fish processing effluent would contain significant amount of PBDEs. The purpose of this study was to determine the PBDE concentrations in sediments located near fish plant effluent outfalls. The range of concentrations of PBDEs in marine sediments in Canada published in the literature was very similar to the results obtained in this study (0.015-5.12 ng/g, dry weight). The concentrations measured in this study for all three technical mixtures (2.78 x 10(-3), 1.92 x 10(-3) and 2.02 x 10(-3) mg/kg, respectively) were all below known toxicity thresholds (0.031, 9.1 and 76 mg/kg, respectively).

Incidence trends in pediatric central nervous system tumors in Canada: a 15 years report from Cancer and Young People in Canada (CYP-C) registry.

BACKGROUND: The aim of this study is to present a national surveillance report on pediatric central nervous system (CNS) tumors in Canada during the period between 2001 and 2015. METHODS: All pediatric patients with a diagnosis of primary CNS tumors were collected by the Cancer in Young People in Canada (CYP-C) surveillance system that includes every patient less than 15 years of age with a tumor seen in one of the 17 pediatric oncology centres in Canada. This registry included malignant and benign CNS tumors. We calculated the age-adjusted incidence rates (AAIRs) per 100 000 person-years for CNS tumors overall and by age group, major histology subgroups, and geographical distribution over the country. RESULTS: Overall, 3306 patients less than 15 years old had been diagnosed with a CNS tumor in Canada in 2001-2015 with a 1.23:1 male to female ratio. The overall AAIR is 3.80. The three most frequent groups of tumors were low-grade gliomas (36.4%), high-grade gliomas (22.3%), and embryonal tumors (18.7%) with incidence rates of 1.41, 0.86, and 0.72 per 100 000 person-years, respectively. The incidence rate of pediatric CNS tumors is stable during the period 2001-2015 in Canada and no significant differences were seen between malignant and benign tumors over the country. CONCLUSIONS: These data represent all the pediatric patients 0-14 years old with a CNS tumor in the Canadian population. Incidence rates by age group, sex, and subgroups of tumors are similar to those seen in the literature.

Toxicity testing of sediment collected in the vicinity of effluent discharges from seafood processing plants in the maritimes.

There are over 1100 fish-processing plants in Canada and the majority of them discharge untreated effluents directly to marine or estuarine receiving environments. The purpose of this study was to evaluate chemical and toxicological characteristics of sediments near fish-processing plant effluent discharges to assess potential impacts of seafood-processing effluents on receiving environments. Eighteen sediment samples were collected near effluent discharges of six seafood-processing plant outfalls in New Brunswick, Canada in the winter of 2006. Ammonia levels ranged from <0.2 to 3480 microg/g, sulfide levels ranged from <0.4 to 6970 microg/g, and redox ranged from -255 to 443 mV. Only one sample had a Microtox Solid-Phase Test IC(50) value below 1000 mg/kg, whereas three samples caused greater than 30% reduction to amphipod survival. Redox, sulfide, and ammonia concentrations were all found to be significantly related to both Eohaustorius estuarius survival and Microto (Vibrio fischeri) IC(50). An increase in sulfide (R (2) = 0.584; 0.750) and ammonia (R (2) = 0.478; 0.552) and a decrease in redox (R (2) = 0.485; 0.651) were associated with an increase in toxicity to E. estuarius and Microtox, respectively. The highest toxicity to both test organisms, and the most contaminated sediments based on physical/chemical characteristics measured, was observed in samples from Blacks Harbour.