659 results on '"Derek C. G. Muir"'
Search Results
2. Target and Nontarget Screening of Organic Chemicals and Metals in Recycled Plastic Materials
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Leah Chibwe, Amila O. De Silva, Christine Spencer, Camilla F. Teixera, Mary Williamson, Xiaowa Wang, and Derek C. G. Muir
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Environmental Chemistry ,General Chemistry - Published
- 2023
3. Gas Chromatography-(Cyclic) Ion Mobility Mass Spectrometry: A Novel Platform for the Discovery of Unknown Per-/Polyfluoroalkyl Substances
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Amber MacNeil, Xiaolei Li, Roshanak Amiri, Derek C. G. Muir, Andre Simpson, Myrna J. Simpson, Frank L. Dorman, and Karl J. Jobst
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Fluorocarbons ,Humans ,Dust ,Gas Chromatography-Mass Spectrometry ,Mass Spectrometry ,Chromatography, Liquid ,Analytical Chemistry - Abstract
Per- and polyfluoroalkyl substances (PFASs) have been widely used since the 1940s in industry and everyday household products. They also persist in the environment and bioaccumulate in humans and wildlife. Despite these concerns, the identities of most PFASs in environmental and biological samples are unknown. Herein, we describe a novel cyclic ion mobility mass spectrometer (cIMS), hyphenated with gas chromatography (GC) atmospheric pressure chemical ionization, that can reveal the presence of unknown PFASs on the basis of the ratio of their mass and collision cross section (CCS). Prediction of the CCS of ca. 20,000 chemicals used in industry and commerce indicates that most compounds characterized by CCS values that are less than the sum of 100 Å
- Published
- 2022
4. Investigation of perfluoroalkyl substances in proglacial rivers and permafrost seep in a high Arctic watershed
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John MacInnis, Amila O. De Silva, Igor Lehnherr, Derek C. G. Muir, Kyra A. St. Pierre, Vincent L. St. Louis, and Christine Spencer
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Fluorocarbons ,010504 meteorology & atmospheric sciences ,Arctic Regions ,Public Health, Environmental and Occupational Health ,Permafrost ,General Medicine ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,6. Clean water ,Lakes ,13. Climate action ,Environmental Chemistry ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
We measured perfluoroalkyl substances (PFAS) in proglacial rivers and along a non-glacial freshwater continuum to investigate the role of snow and ice melting in their transport and fate within the Lake Hazen watershed (82° N). PFAS concentrations in glacial rivers were higher than those in surface waters of Lake Hazen, suggesting melting glacial ice increased PFAS concentrations in the lake. Stream water derived from subsurface soils along a non-glacial (permafrost thaw and snowmelt) freshwater continuum was a source of PFAS to Lake Hazen. Lower concentrations were found downstream of a meadow wetland relative to upstream locations along the continuum, suggesting PFAS partitioning into vegetation and soil as water flowed downstream towards Lake Hazen. Our estimations indicate that total PFAS inputs from glacial rivers and snowmelt were 1.6 kg (78%) and 0.44 kg (22%), respectively, into Lake Hazen, totalling 2.04 kg, and the output of PFAS from Lake Hazen was 0.64 kg. A positive net annual change of 1.4 kg indicates PFAS had notable residence times and/or net storage in Lake Hazen.
- Published
- 2022
5. The influence of a lost society, the Sadlermiut, on the environment in the Canadian Arctic
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Birgit Plessen, Reinhard Pienitz, Andrew S. Medeiros, Xiaowa Wang, Finn Viehberg, and Derek C. G. Muir
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Stable isotope analysis ,Environmental change ,Limnology ,Science ,Population ,Climate change ,Palaeoclimate ,Freshwater ecosystem ,Article ,Environmental impact ,Ecosystem ,education ,education.field_of_study ,Multidisciplinary ,Ecology ,Palaeontology ,Climate-change ecology ,Palaeoecology ,Environmental monitoring ,Sedimentology ,Climate-change adaptation ,Geochemistry ,Arctic ,Biogeography ,Sustainability ,Benthic zone ,Environmental chemistry ,Environmental science ,Freshwater ecology ,Medicine ,Climate-change impacts - Abstract
High latitude freshwater ecosystems are sentinels of human activity and environmental change. The lakes and ponds that characterize Arctic landscapes have a low resilience to buffer variability in climate, especially with increasing global anthropogenic stressors in recent decades. Here, we show that a small freshwater pond in proximity of the archaeological site “Native Point” on Southampton Island (Nunavut, Arctic Canada) is a highly sensitive environmental recorder. The sediment analyses allowed for pinpointing the first arrival of Sadlermiut culture at Native Point to ~ 1250 CE, followed by a dietary shift likely in response to the onset of cooling in the region ~ 1400 CE. The influence of the Sadlermiut on the environment persisted long after the last of their population perished in 1903. Presently, the pond remains a distorted ecosystem that has experienced fundamental shifts in the benthic invertebrate assemblages and accumulated anthropogenic metals in the sediment. Our multi-proxy paleolimnological investigation using geochemical and biological indicators emphasizes that direct and indirect anthropogenic impacts have long-term environmental implications on high latitude ecosystems.
- Published
- 2021
6. Historic Atmospheric Organochlorine Pesticide and Halogenated Industrial Compound Inputs to Glacier Ice Cores in Antarctica and the Arctic
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Elisabeth Isaksson, Derek C. G. Muir, Camilla Teixeira, Mark H. Hermanson, Richard Hann, and Rachel M. Ruggirello
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Atmospheric Science ,geography ,geography.geographical_feature_category ,Oceanography ,Ice core ,Space and Planetary Science ,Geochemistry and Petrology ,Environmental science ,Organochlorine pesticide ,Glacier ,The arctic - Published
- 2021
7. Spatial trends and temporal declines in tissue metals/metalloids in the context of wild fish health at the St. Clair River Area of Concern
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Derek C. G. Muir, Mark E. McMaster, Annette F. Muttray, James P. Sherry, and Gerald R. Tetreault
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0106 biological sciences ,Perch ,Moxostoma ,Shorthead redhorse ,Ecology ,biology ,Emerald shiner ,010604 marine biology & hydrobiology ,Wildlife ,chemistry.chemical_element ,Context (language use) ,010501 environmental sciences ,Aquatic Science ,biology.organism_classification ,01 natural sciences ,Mercury (element) ,Fishery ,chemistry ,Environmental science ,Notropis ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
The St. Clair River, which flows from Lake Huron to Lake St Clair, receives discharges and emissions from numerous petroleum refineries, petrochemical facilities, and other sources. We used a multi-factor ANOVA to test for spatial and temporal changes in concentrations of trace metals/metalloids in homogenates of fish from Lake Huron (reference site) and two river sites - an industrialized region (Stag Island) and downstream Walpole Island/Chenal Ecarte. In 2002/2003 and in 2014, we sampled 20 adult fish of each sex of the following species: shorthead redhorse (Moxostoma macrolepidotum), yellow perch (Perca flavescens); we added emerald shiner (Notropis atherinoides; unsexed) in 2014. There was a temporal decline of most metals/metalloids in shorthead redhorse at the river sites. Linear Discriminant Analysis separated the 2014 shorthead redhorse by site. Emerald shiners had higher concentrations of metals/metalloids, apart from mercury, than the other species; those concentrations were highest at Chenal Ecarte, which warrants further research. Tissue concentrations of mercury, which declined temporally at Stag Island and Walpole Island, were above the protective guidance for wildlife consumers at all sites, but were lower than predicted to affect fish health. Apart from increased liver size (ANCOVA) in shorthead redhorse at Walpole Island (2014), the health variables in the riverine fish were stable or differed slightly from reference, which indicated good health and reproductive potential. In shorthead redhorse, tissue metals correlated inconsistently with health indices. Further research could ascertain if temporal declines in metals/metalloids in riverine SHRH are benefits of remediation actions or fluctuations with other causes.
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- 2021
8. Ecological effects and causal synthesis of oil sands activity impacts on river ecosystems: water synthesis review
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Ian G. Droppo, Mark E. McMaster, Joseph M. Culp, Greg Bickerton, Peter di Cenzo, Jane L. Kirk, Derek C. G. Muir, Yonas Dibike, Robert B. Brua, Spyros Beltaos, Alexa C. Alexander, Kerry Pippy, Patricia A. Chambers, Lucie Levesque, Joanne L. Parrott, Barrie Bonsal, Nancy E. Glozier, Donald J. Baird, Daniel L. Peters, and James W. Roy
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River ecosystem ,010504 meteorology & atmospheric sciences ,River watershed ,Biomonitoring ,Environmental science ,Cumulative effects ,Oil sands ,010501 environmental sciences ,Water resource management ,Biosurveillance ,01 natural sciences ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Oil sands development in the lower Athabasca River watershed has raised considerable public and scientific concerns regarding perceived effects on environmental health. To address this issue for tributaries and the mainstem of the Athabasca River in the Athabasca Oil Sands Region, the Water Component of the Joint Oil Sands Monitoring (JOSM) plan produced monitoring assessments for seven integrated themes: atmospheric deposition, tributary water quality, river mainstem water quality, groundwater quality and quantity, water quality and quantity modelling, benthic invertebrate condition, and fish health. Our review integrates and synthesizes the large and diverse datasets assembled in the seven JOSM theme assessments to (i) evaluate possible environmental effects based on known sources and candidate proximal causes and (ii) determine the importance of cause-and-effect pathways related to contaminant, sediment, and nutrient inputs. Although JOSM research identified ecological effects that appear to be associated with contaminant exposure, the source of this exposure is confounded by co-location of, and inability to differentiate between, oil sands operations (principally released by atmospheric emission) and inputs from the natural bitumen outcrops (e.g., erosional material transported by surface and groundwater flows). Nutrient enrichment from treated municipal sewage effluent was the dominant ecological effect observed for the mainstem Athabasca River, associated with increased fish size and changes in invertebrate assemblages, likely because this pollution source is discharged directly into the river. If the direct release of treated oil sands process water occurs in the future, then the potential ecological impact of these direct industry releases will need to be evaluated carefully. The ecological causal assessment method proved to be a useful tool for better understanding how stressor sources relate to ecological effects through candidate proximate causes. Factors that confound our ability to assess the ecological effects of oil sands development focus on our inability to adequately differentiate between contaminants supplied from natural and anthropogenic contaminant sources. Our causal synthesis identifies options for changes in future monitoring to better anticipate and detect degradation in the ecosystem health of the lower Athabasca River and its tributaries.
- Published
- 2021
9. Contribution of Dietary Uptake to PAH Bioaccumulation in a Simplified Pelagic Food Chain: Modeling the Influences of Continuous vs Intermittent Feeding in Zooplankton and Fish
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Wen-Xiong Wang, Zixuan Wang, Xinghui Xia, Haotian Wang, Derek C. G. Muir, and Ran Liu
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Food Chain ,Daphnia magna ,Chlorella vulgaris ,010501 environmental sciences ,01 natural sciences ,Zooplankton ,Food chain ,Phytoplankton ,Animals ,Environmental Chemistry ,Ecosystem ,Zebrafish ,reproductive and urinary physiology ,0105 earth and related environmental sciences ,Trophic level ,biology ,fungi ,Pelagic zone ,General Chemistry ,biology.organism_classification ,Bioaccumulation ,Daphnia ,Environmental chemistry ,Water Pollutants, Chemical - Abstract
Dietary uptake is important for trophic transfer of polycyclic aromatic hydrocarbons (PAHs) in the freshwater pelagic ecosystem. In this study, we hypothesized that both the dietary uptake rate and interval significantly influenced its relative contribution to bioaccumulation. We developed a toxicokinetic model framework for the bioaccumulation of deuterated PAHs (PAHs-d10) in aquatic organisms considering different feeding intervals ranging from none for phytoplankton to approximately continuous for zooplankton to discrete for fish and built a simple artificial freshwater pelagic food chain composed of algae Chlorella vulgaris, zooplankton Daphnia magna, and zebrafish. We conducted bioaccumulation experiments and simulations for Daphnia magna and zebrafish under different algal densities based on our model. The results showed that intermittent feeding led to a large fluctuation in the PAH-d10 concentrations in zebrafish compared to a leveled-off pattern in Daphnia magna because of approximately continuous feeding. Trophic dilution of PAHs-d10 occurred in the food chain when there was waterborne-only uptake, but dietary uptake largely mitigated its extent that depended on dietary uptake rates. The assimilation efficiency, dietary uptake rate, and its relative contribution to bioaccumulation of PAHs-d10 in zebrafish were all higher than those in Daphnia magna, suggesting that dietary uptake played a more important role in bioaccumulation of PAHs at higher trophic-level organisms.
- Published
- 2021
10. Perfluoroalkyl substances in circum-ArcticRangifer:caribou and reindeer
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Rossana Bossi, Anna Roos, Anna Kärrman, Christine Cuyler, Ylva Lind, Derek C. G. Muir, Pernilla Marianne Carlsson, Mary Gamberg, and Frank F Rigét
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Canada ,Wet weight ,Health, Toxicology and Mutagenesis ,POLAR BEARS ,Greenland ,PFAS ,Carboxylic Acids ,GREENLAND CARIBOU ,FLUORINATED ALTERNATIVES ,Fluorocarbons/analysis ,Svalbard ,Animal science ,PFOS ,ACID CONCENTRATIONS ,Environmental Chemistry ,Ecotoxicology ,Animals ,TERRESTRIAL ENVIRONMENTS ,RINGED SEALS ,Sweden ,Fluorocarbons ,Porcupine caribou ,biology ,PERFLUOROOCTANE SULFONATE ,General Medicine ,biology.organism_classification ,Pollution ,POLYFLUOROALKYL SUBSTANCES ,Arctic terrestrial environment ,TEMPORAL TRENDS ,PERFLUORINATED COMPOUNDS ,Alkanesulfonic Acids ,Long-range transport ,Sulfonic Acids ,Reindeer - Abstract
Livers of caribou and reindeer (Rangifer tarandus) from Canada (n = 146), Greenland (n = 30), Svalbard (n = 7), and Sweden (n = 60) were analyzed for concentrations of eight perfluoroalkyl carboxylic acids and four perfluoroalkane sulfonic acids. In Canadian caribou, PFNA (range
- Published
- 2022
11. Recent Warming, Rather than Industrial Emissions of Bioavailable Nutrients, Is the Dominant Driver of Lake Primary Production Shifts across the Athabasca Oil Sands Region.
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Jamie C Summers, Joshua Kurek, Jane L Kirk, Derek C G Muir, Xiaowa Wang, Johan A Wiklund, Colin A Cooke, Marlene S Evans, and John P Smol
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Medicine ,Science - Abstract
Freshwaters in the Athabasca Oil Sands Region (AOSR) are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal drivers of these limnological changes. Is the enhanced primary production due to deposition of nutrients (nitrogen and phosphorus) from local industry or from recent climatic changes? Here, we use downcore, spectrally-inferred chlorophyll-a (VRS-chla) profiles (including diagenetic products) from 23 limnologically-diverse lakes with undisturbed catchments to characterize the pattern of primary production increases in the AOSR. Our aim is to better understand the relative roles of the local oil sands industry versus climate change in driving aquatic primary production trends. Nutrient deposition maps, generated using geostatistical interpolations of spring-time snowpack measurements from a grid pattern across the AOSR, demonstrate patterns of elevated total phosphorus, total nitrogen, and bioavailable nitrogen deposition around the main area of industrial activity. However, this pattern is not observed for bioavailable phosphorus. Our paleolimnological findings demonstrate consistently greater VRS-chla concentrations compared to pre-oil sands development levels, regardless of morphological and limnological characteristics, landscape position, bioavailable nutrient deposition, and dibenzothiophene (DBT)-inferred industrial impacts. Furthermore, breakpoint analyses on VRS-chla concentrations across a gradient of DBT-inferred industrial impact show limited evidence of a contemporaneous change among lakes. Despite the contribution of bioavailable nitrogen to the landscape from industrial activities, we find no consistency in the spatial pattern and timing of VRS-chla shifts with an industrial fertilizing signal. Instead, significant positive correlations were observed between VRS-chla and annual and seasonal temperatures. Our findings suggest warmer air temperatures and likely decreased ice covers are important drivers of enhanced aquatic primary production across the AOSR.
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- 2016
- Full Text
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12. Deposition of Polychlorinated Biphenyls to Firn and Ice Cores at Opposite Polar Sites: Site M, Dronning Maud Land, Antarctica, and Holtedahlfonna, Svalbard
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Camilla Teixeira, Derek C. G. Muir, Richard Hann, Mark H. Hermanson, and Elisabeth Isaksson
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Atmospheric Science ,geography ,geography.geographical_feature_category ,Plateau ,Firn ,Glacier ,Arctic ,Ice core ,Space and Planetary Science ,Geochemistry and Petrology ,Polar ,Ice sheet ,Geomorphology ,Deposition (chemistry) ,Geology - Abstract
Firn and ice cores from glaciers and ice sheets at polar opposite locations, Site M, Dronning Maud Land, East Antarctica (lat 75.00 S, long. 15.00 E), and Holtedahlfonna, Svalbard (lat 79.13 N, lon...
- Published
- 2020
13. Mercury in Ringed Seals ( Pusa hispida ) from the Canadian Arctic in Relation to Time and Climate Parameters
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Derek C. G. Muir, Steve H. Ferguson, Xiaowa Wang, Magali Houde, Zofia E. Taranu, Brent G. Young, Michael Kwan, and Pierre Gagnon
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Male ,Canada ,Time Factors ,010504 meteorology & atmospheric sciences ,Seals, Earless ,Climate ,Rain ,Health, Toxicology and Mutagenesis ,Temporal trends ,chemistry.chemical_element ,Climate change ,010501 environmental sciences ,01 natural sciences ,Inuit Nunangat ,Selenium ,Animals ,Environmental Chemistry ,Ice Cover ,Pinnipeds ,0105 earth and related environmental sciences ,Geography ,biology ,Arctic Regions ,Air ,Muscles ,Temperature ,Mercury ,biology.organism_classification ,Environmental Toxicology ,Mercury (element) ,Pusa hispida ,Oceanography ,Liver ,chemistry ,Arctic oscillation ,Arctic ,Metals ,North Atlantic oscillation ,Air temperature ,Female ,Bay ,Environmental Monitoring - Abstract
Mercury is found in Arctic marine mammals that are important in the diet of northern Indigenous peoples. The objectives of the present long‐term study, spanning a 45‐yr period, were to 1) investigate the temporal trends of total mercury (THg; muscle and liver) and selenium (Se; liver) in ringed seals (Pusa hispida) from different regions of the Canadian Arctic; and 2) examine possible relationships with age, diet, and climate parameters such as air temperature, precipitation, climatic indices, and ice‐coverage. Ringed seals were collected by hunters in northern communities in the Beaufort Sea, Central Arctic, Eastern Baffin Island, Hudson Bay, and Ungava/Nunatsiavut regions (Canada) between 1972 and 2017. Mercury levels did not change through time in seal liver, but THg levels in muscle decreased in seals from Hudson Bay (−0.91%/yr) and Ungava/Nunatsiavut (−1.30%/yr). Carbon stable isotope values in seal muscle decreased significantly through time in 4 regions. Selenium‐to‐THg ratios were found to be >1 for all years and regions. Variation partitioning analyses across regions indicated that THg trends in seals were mostly explained by age (7.3–21.7%), climate parameters (3.5–12.5%), and diet (up to 9%); climate indices (i.e., Arctic and North Atlantic Oscillations, Pacific/North American pattern) explained the majority of the climate portion. The THg levels had a positive relationship with Arctic Oscillation for multiple regions. Associations of THg with air temperature, total precipitation, and sea‐ice coverage, as well as with North Atlantic Oscillation and Pacific/North American pattern were found to vary with tissue type and geographical area. Environ Toxicol Chem 2020;39:2462–2474. © 2020 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Fisheries and Oceans Canada., Total mercury and selenium concentrations were evaluated through time (1970s–2017) in ringed seals from the Canadian Arctic. Associations between concentrations of trace metal in tissues, age and diet of seals as well as climate parameters were also investigated.
- Published
- 2020
14. Temporal Trends in Polybrominated Diphenylethers (PBDEs) in Blubber of Ringed Seals (Pusa hispida) from Ulukhaktok, NT, Canada Between 1981 and 2015
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J. Alikamik, Derek C. G. Muir, T.G. Smith, R.F. Addison, C. Dubetz, and Michael G. Ikonomou
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Male ,Canada ,endocrine system ,010504 meteorology & atmospheric sciences ,biology ,Arctic Regions ,Seals, Earless ,Health, Toxicology and Mutagenesis ,General Medicine ,010501 environmental sciences ,Toxicology ,biology.organism_classification ,01 natural sciences ,Pollution ,Pusa hispida ,Animal science ,Adipose Tissue ,Blubber ,Halogenated Diphenyl Ethers ,Animals ,Ecotoxicology ,Female ,reproductive and urinary physiology ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
Blubber taken from ringed seals (Pusa hispida) during a subsistence hunt at Ulukhaktok, NT (formerly Holman, NWT) at intervals between 2002 and 2015 was analysed for polybrominated diphenyl ether (PBDE) congeners. Results from these analyses were combined with others previously published to yield a data set of 18 tri- to hepta-substituted PBDE congeners in 102 animals sampled over a span of 19 year (females) and 34 year (males). In females, mean total PBDE concentrations increased between 1996 and 2015 by approximately 50%, from 1940 to 2780 pg/g wet wt., although not significantly so (p > 0.05) by one-way ANOVA. In males, concentrations ranged from 376 to 6470 pg/g wet wt. between 1981 and 2015 (p
- Published
- 2020
15. Comparing temporal patterns in body condition of ringed seals living within their core geographic range with those living at the edge
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David J. Yurkowski, Derek C. G. Muir, Brent G. Young, Gregory W. Thiemann, Xinhua Zhu, Steven H. Ferguson, and Aaron T. Fisk
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geography.geographical_feature_category ,biology ,spring breakup ,Ecology ,blubber depth ,Life Sciences ,Marine Biology ,Biodiversity ,Edge (geometry) ,biology.organism_classification ,sine wave ,sea ice ,Nunavut Canada ,Pusa hispida ,Core (optical fiber) ,Paleontology ,Geography ,Sea ice ,Biology ,Biochemistry, Biophysics, and Structural Biology ,Ecology, Evolution, Behavior and Systematics ,Body condition - Abstract
Ecological theory suggests that demographic responses by populations to environmental change vary depending on whether individuals inhabit central or peripheral regions within the species’ geographic range. Here, we tested this prediction by comparing a population of ringed seals Pusa hispida located at high latitudes as part of their core range (core) with a population located at the southern extremity of their range (peripheral). First, we compared the two regions’ environmental trends in timing of sea-ice breakup and freeze-up, open-water duration and the North Atlantic Oscillation (NAO). We found that the core region shifted to progressively warmer conditions in the early 1990s; whereas, in the peripheral region, the warming trend shifted in 1999 to one with no warming trend but high inter-annual variability. Next, we examined how body condition, inferred from blubber depth, responded to temporal changes in sea-ice and climatic variables – variables that have been shown to influence ringed seal demography. Core seals displayed minimal seasonal changes in body condition; whereas peripheral seals displayed a 20–60% amplitude seasonal change in body condition with a phase shift to earlier initiation of fat accumulation and loss. Finally, we tested for interannual differences and found that both core and peripheral seals responded similarly with decreased body condition following more positive NAO. Environmental variables influenced body condition in opposite directions between the two regions with core seals declining in body condition with later spring breakup and shorter open-water duration, whereas peripheral seals showed opposite relationships. Seals living at the core likely benefit from an evolved match between adaptation and environmental variation resulting in dampened seasonal and interannual fluctuations in body condition. Knowledge of how different populations respond to environmental change depending on geographic location within a species range can assist in anticipating population specific responses to climate warming.
- Published
- 2020
16. Screening New Persistent and Bioaccumulative Organics in China’s Inventory of Industrial Chemicals
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Derek C. G. Muir, Ruifen Jiang, Eddy Y. Zeng, Xianming Zhang, Elsie M. Sunderland, and Xiangfei Sun
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Waste management ,Organic chemicals ,business.industry ,General Chemistry ,Chemical industry ,010501 environmental sciences ,01 natural sciences ,Chemical production ,Bioaccumulation ,Environmental monitoring ,Environmental Chemistry ,Environmental science ,China ,business ,0105 earth and related environmental sciences - Abstract
Over a third of the world’s annual chemical production and sales occur in China. Thus, knowledge of the properties of the substances produced and emitted there is important from a global perspectiv...
- Published
- 2020
17. Chlorines Are Not Evenly Substituted in Chlorinated Paraffins: A Predicted NMR Pattern Matching Framework for Isomeric Discrimination in Complex Contaminant Mixtures
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Daniel H. Lysak, Ronald Soong, Dimitris S. Argyropoulos, Arvin Moser, Derek C. G. Muir, Arika Hisatsune, Bo Yuan, André J. Simpson, Sergey Golotvin, and Andrew Haddad
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Ecology ,Health, Toxicology and Mutagenesis ,010401 analytical chemistry ,chemistry.chemical_element ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,Pollution ,Article ,0104 chemical sciences ,NMR spectra database ,chemistry ,Chlorinated paraffins ,13. Climate action ,Computational chemistry ,Environmental Chemistry ,Spectral matching ,Pattern matching ,Spectroscopy ,Waste Management and Disposal ,Carbon ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Chlorinated paraffins (CPs) can be mixtures of nearly a half-million possible isomers. Despite the extensive use of CPs, their isomer composition and effects on the environment remain poorly understood. Here, we reveal the isomeric distributions of nine CP mixtures with single-chain lengths (C14/15) and varying degrees of chlorination. The molar distribution of C n H2n+2-m Cl m in each mixture was determined using high-resolution mass spectrometry (MS). Next, the mixtures were analyzed by applying both one-dimensional 1H, 13C and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Due to substantially overlapping signals in the experimental NMR spectra, direct assignment of individual isomers was not possible. As such, a new NMR spectral matching approach that used massive NMR databases predicted by a neural network algorithm to provide the top 100 most likely structural matches was developed. The top 100 isomers appear to be an adequate representation of the overall mixture. Their modeled physicochemical and toxicity parameters agree with previous experimental results. Chlorines are not evenly distributed in any of the CP mixtures and show a general preference at the third carbon. The approach described here can play a key role in understanding of complex isomeric mixtures such as CPs that cannot be resolved by MS alone.
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- 2020
18. Contrasting Temporal Patterns of Mercury, Niche Dynamics, and Body Fat Indices of Polar Bears and Ringed Seals in a Melting Icescape
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Cassandra D Debets, Brent G. Young, Amy C. Johnson, David J. Yurkowski, Magali Houde, Nicholas J. Lunn, Gregory W. Thiemann, Steven H. Ferguson, Andrew E. Derocher, Derek C. G. Muir, Evan S. Richardson, Luana Sciullo, and Ashley D. Ehrman
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Seals, Earless ,Ursus maritimus ,Niche ,Zoology ,010501 environmental sciences ,01 natural sciences ,biology.animal ,Sea ice ,Animals ,Environmental Chemistry ,14. Life underwater ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,δ13C ,biology ,Arctic Regions ,Mercury ,General Chemistry ,δ15N ,15. Life on land ,biology.organism_classification ,Pusa hispida ,Adipose Tissue ,Arctic ,13. Climate action ,Bay ,Ursidae - Abstract
Polar bears (Ursus maritimus) and ringed seals (Pusa hispida) have a strong predator-prey relationship and are facing climate-associated Arctic habitat loss and harmful dietary exposure to total mercury (THg) and other pollutants. However, little is known about whether both species inhabiting the same area exhibit similar temporal patterns in Hg concentration, niche dynamics, and body fat indices. We used THg, δ13C, and δ15N values of western Hudson Bay polar bear hair (2004-2016) and ringed seal muscle samples (2003-2015) to investigate temporal trends of these variables and multidimensional niche metrics, as well as body fat indices for both species. We found a decline in THg concentration (by 3.8% per year) and δ13C (by 1.5‰) in ringed seals suggesting a change in feeding habits and carbon source use over time, whereas no significant changes occurred in polar bears. In contrast, the polar bear 3-dimensional niche size decreased by nearly half with no change in ringed seal niche size. The δ13C spacing between both species increased by approximately 1.5× suggesting different responses to annual changes in sympagic-pelagic carbon source production. Ringed seal body fat index was higher in years of earlier sea ice breakup with no change occurring in polar bears. These findings indicate that both species are responding differently to a changing environment suggesting a possible weakening of their predator-prey relationship in western Hudson Bay.
- Published
- 2020
19. Glacial Melt Inputs of Organophosphate Ester Flame Retardants to the Largest High Arctic Lake
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Derek C. G. Muir, Igor Lehnherr, John J. MacInnis, Amila O. De Silva, Yuxin Sun, Kyra A. St. Pierre, and Christine Spencer
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geography ,geography.geographical_feature_category ,Arctic Regions ,Aquatic ecosystem ,Esters ,Glacier ,General Chemistry ,010501 environmental sciences ,Permafrost ,01 natural sciences ,Organophosphates ,Lakes ,Deposition (aerosol physics) ,Arctic ,Environmental chemistry ,Tributary ,Environmental Chemistry ,Environmental science ,Ecosystem ,Glacial period ,Environmental Monitoring ,Flame Retardants ,0105 earth and related environmental sciences - Abstract
Organophosphate esters (OPEs) have been detected in the Arctic environment, but the influence of glacial melt on the environmental behavior of OPEs in recipient Arctic aquatic ecosystems is still unknown. In this study, water samples were collected from Lake Hazen (LH) and its tributaries to investigate the distribution of 14 OPEs in LH and to explore the input of OPEs from glacial rivers to LH and the output of OPEs from LH in 2015 and 2018. Σ14OPE concentrations in water of LH were lower than glacial rivers and its outflow, the Ruggles River. In 2015, a high melt year, we estimated that glacial rivers contributed 7.0 ± 3.2 kg OPEs to LH, compared to a 16.5 ± 0.3 kg OPEs output by the Ruggles River, suggesting that residence time and/or additional inputs via direct wet and dry deposition and permafrost melt likely result in OPE retention in the LH watershed. In 2018, a lower melt year, Σ14OPE concentrations in glacial rivers were much lower, indicating that the rate of glacier melt may govern, in part, the concentrations of OPEs in the tributaries of LH. This study highlights long-range transport of OPEs, their deposition in Arctic glaciers, landscapes, and lakes.
- Published
- 2020
20. Enhancing Scientific Support for the Stockholm Convention's Implementation: An Analysis of Policy Needs for Scientific Evidence
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Zhanyun Wang, Sam Adu-Kumi, Miriam L. Diamond, Ramon Guardans, Tom Harner, Agustín Harte, Natsuko Kajiwara, Jana Klánová, Jianguo Liu, Estefania Gastaldello Moreira, Derek C. G. Muir, Noriyuki Suzuki, Victorine Pinas, Timo Seppälä, Roland Weber, and Bo Yuan
- Subjects
Technology ,ADDITIVES ,science-policy interface ,persistent organic pollutants ,policy formulation ,policy adoption ,effectiveness evaluation ,multilateral environmental agreements ,hazardous substances ,PLANETARY BOUNDARY ,Environmental Sciences & Ecology ,PERFLUOROALKYL ACIDS ,CHEMICALS ,PLASTICS ,Engineering ,Environmental Chemistry ,Science & Technology ,MICROPLASTICS ,Engineering, Environmental ,SCIENCE ,General Chemistry ,Policy ,Environmental Pollutants ,POPS ,Life Sciences & Biomedicine ,Environmental Sciences ,ALTERNATIVES - Abstract
The Stockholm Convention is key to addressing the global threats of persistent organic pollutants (POPs) to humanity and the environment. It has been successful in identifying new POPs, but its national implementation remains challenging, particularly by low- and middle-income Parties. Concerted action is needed to assist Parties in implementing the Convention’s obligations. This analysis aims to identify and recommend research and scientific support needed for timely implementation of the Convention. We aim this analysis at scientists and experts from a variety of natural and social sciences and from all sectors (academia, civil society, industry, and government institutions), as well as research funding agencies. Further, we provide practical guidance to scientists and experts to promote the visibility and accessibility of their work for the Convention’s implementation, followed by recommendations for sustaining scientific support to the Convention. This study is the first of a series on analyzing policy needs for scientific evidence under global governance on chemicals and waste., Environmental Science & Technology, 56 (5), ISSN:0013-936X, ISSN:1520-5851
- Published
- 2022
21. Influences of climate change on long-term time series of persistent organic pollutants (POPs) in Arctic and Antarctic biota
- Author
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Katrin Vorkamp, Pernilla Carlsson, Simonetta Corsolini, Cynthia A. de Wit, Rune Dietz, Matthew O. Gribble, Magali Houde, Vrinda Kalia, Robert J. Letcher, Adam Morris, Frank F. Rigét, Heli Routti, and Derek C. G. Muir
- Subjects
Environmental Pollutants/analysis ,Time Factors ,Arctic Regions ,Climate Change ,Public Health, Environmental and Occupational Health ,Antarctic Regions ,General Medicine ,Management, Monitoring, Policy and Law ,Biota ,Persistent Organic Pollutants ,Environmental Chemistry ,Environmental Pollutants ,Ecosystem ,Environmental Monitoring - Abstract
Time series of contaminants in the Arctic are an important instrument to detect emerging issues and to monitor the effectiveness of chemicals regulation, based on the assumption of a direct reflection of changes in primary emissions. Climate change has the potential to influence these time trends, through direct physical and chemical processes and/or changes in ecosystems. This study was part of an assessment of the Arctic Monitoring and Assessment Programme (AMAP), analysing potential links between changes in climate-related physical and biological variables and time trends of persistent organic pollutants (POPs) in Arctic biota, with some additional information from the Antarctic. Several correlative relationships were identified between POP temporal trends in freshwater and marine biota and physical climate parameters such as oscillation indices, sea-ice coverage, temperature and precipitation, although the mechanisms behind these observations remain poorly understood. Biological data indicate changes in the diet and trophic level of some species, especially seabirds and polar bears, with consequences for their POP exposure. Studies from the Antarctic highlight increased POP availability after iceberg calving. Including physical and/or biological parameters in the POP time trend analysis has led to small deviations in some declining trends, but did generally not change the overall direction of the trend. In addition, regional and temporary perturbations occurred. Effects on POP time trends appear to have been more pronounced in recent years and to show time lags, suggesting that climate-related effects on the long time series might be gaining importance.
- Published
- 2022
22. The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs
- Author
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Katrine Borgå, Melissa A. McKinney, Heli Routti, Kim J. Fernie, Julia Giebichenstein, Ingeborg Hallanger, and Derek C. G. Muir
- Subjects
Persistent Organic Pollutants ,Food Chain ,Arctic Regions ,Climate Change ,Public Health, Environmental and Occupational Health ,Water ,Environmental Chemistry ,Environmental Pollutants ,General Medicine ,Management, Monitoring, Policy and Law ,Ecosystem ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
This review summarizes current understanding of how climate change-driven physical and ecological processes influence the levels of persistent organic pollutants (POPs) and contaminants of emerging Arctic concern (CEACs) in Arctic biota and food webs. The review also highlights how climate change may interact with other stressors to impact contaminant toxicity, and the utility of modeling and newer research tools in closing knowledge gaps on climate change-contaminant interactions. Permafrost thaw is influencing the concentrations of POPs in freshwater ecosystems. Physical climate parameters, including climate oscillation indices, precipitation, water salinity, sea ice age, and sea ice quality show statistical associations with POPs concentrations in multiple Arctic biota. Northward range-shifting species can act as biovectors for POPs and CEACs into Arctic marine food webs. Shifts in trophic position can alter POPs concentrations in populations of Arctic species. Reductions in body condition are associated with increases in levels of POPs in some biota. Although collectively understudied, multiple stressors, including contaminants and climate change, may act to cumulatively impact some populations of Arctic biota. Models are useful for predicting the net result of various contrasting climate-driven processes on POP and CEAC exposures; however, for some parameters, especially food web changes, insufficient data exists with which to populate such models. In addition to the impact of global regulations on POP levels in Arctic biota, this review demonstrates that there are various direct and indirect mechanisms by which climate change can influence contaminant exposure, accumulation, and effects; therefore, it is important to attribute POP variations to the actual contributing factors to inform future regulations and policies. To do so, a broad range of habitats, species, and processes must be considered for a thorough understanding and interpretation of the consequences to the distribution, accumulation, and effects of environmental contaminants. Given the complex interactions between climate change, contaminants, and ecosystems, it is important to plan for long-term, integrated pan-Arctic monitoring of key biota and ecosystems, and to collect ancillary data, including information on climate-related parameters, local meteorology, ecology, and physiology, and when possible, behavior, when carrying out research on POPs and CEACs in biota and food webs of the Arctic.
- Published
- 2022
23. Microplastic Impacts on Microalgae Growth: Effects of Size and Humic Acid
- Author
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Eddy Y. Zeng, Ge Liu, Jing You, Ruifen Jiang, and Derek C. G. Muir
- Subjects
chemistry.chemical_classification ,congenital, hereditary, and neonatal diseases and abnormalities ,Microplastics ,Chemistry ,nutritional and metabolic diseases ,General Chemistry ,010501 environmental sciences ,Photosynthesis ,01 natural sciences ,Cell wall ,Environmental chemistry ,Toxicity ,Dissolved organic carbon ,Microalgae ,Environmental Chemistry ,Humic acid ,Particle size ,Surface charge ,skin and connective tissue diseases ,Plastics ,Humic Substances ,Water Pollutants, Chemical ,0105 earth and related environmental sciences - Abstract
Research has already demonstrated the toxic effects of microplastics (MPs) on different biota. However, the underlying toxic mechanism of MPs remains to be elucidated, especially the effect of particle size and the presence of dissolved organic matter in water. This study investigated the impact on Scenedesmus obliquus exposed in five types of polystyrene particle suspensions with different sizes and surface charges, in the presence and absence of humic acid (HA). Results indicated that the 50% growth inhibition rate of S. obliquus showed no significant difference between the five types of MPs, but the toxic mechanism varied with particle size. Larger size MPs caused adverse effects by blocking the light transport and affecting photosynthesis, while smaller ones destroyed the cell wall by adsorbing onto the algae surface. Also, the addition of HA significantly alleviated the toxicity of smaller size MPs, but not of the larger ones. Scanning electron microscopy images and the reactive oxygen species assay demonstrated that the HA could form a corona on the surface of MPs, reduce the affinity to microalgae, and minimize the adverse effect. Together, these findings identified important factors in determining the toxicity of MPs, providing valuable data for risk assessment of MPs.
- Published
- 2019
24. Which of the (Mixed) Halogenated n-Alkanes Are Likely To Be Persistent Organic Pollutants?
- Author
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Xiaolei Li, Karl J. Jobst, Myrna J. Simpson, Sonya Kleywegt, Tannia Chevez, André J. Simpson, Derek C. G. Muir, and Amila O. De Silva
- Subjects
Pollutant ,Bromine ,010401 analytical chemistry ,chemistry.chemical_element ,General Chemistry ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,0104 chemical sciences ,Persistent Organic Pollutants ,Chlorinated paraffins ,chemistry ,13. Climate action ,Environmental chemistry ,Alkanes ,Chlorine ,Fluorine ,Hydrocarbons, Chlorinated ,Environmental Chemistry ,Density functional theory ,Environmental Pollutants ,Carbon ,0105 earth and related environmental sciences ,Environmental Monitoring ,Flame Retardants - Abstract
Short-chain polychlorinated n-alkanes are ubiquitous industrial chemicals widely recognized as persistent organic pollutants. They represent only a small fraction of the 184,600 elemental compositions (C10-25) and the myriad isomers of all possible (mixed) halogenated n-alkanes (PXAs). This study prioritizes the PXAs on the basis of their potential to persist, bioaccumulate, and undergo long-range transport guided by quantitative structure-property relationships (QSPRs), density functional theory (DFT), chemical fate models, and partitioning space. The QSPR results narrow the list to 966 elemental compositions, of which 352 (23 Br, 83 Cl/F, 119 Br/Cl, and 127 Br/F) are likely constituents of substances used as lubricants, plasticizers, and flame retardants. Complementary DFT calculations suggest that an additional 1367 elemental compositions characterized by a greater number of carbon and fluorine atoms but fewer chlorine and bromine atoms may also pose a risk. The results of this study underline the urgent need to identify and monitor these suspected pollutants, most appropriately using mass spectrometry. We estimate that the resolving power required to distinguish ∼74% of the prioritized elemental compositions from the most likely interferents, i.e., chlorinated alkanes, is approximately 60,000 (full width at half-maximum). This indicates that accurate identification of the PXAs is achievable using most high-resolution mass spectrometers.
- Published
- 2021
25. Quantification of Spatial and Temporal Trends in Atmospheric Mercury Deposition across Canada over the Past 30 Years
- Author
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Benjamin D. Barst, Xiaowa Wang, Greg Lawson, Jane L. Kirk, Marlene S. Evans, Johan A. Wiklund, Ashu Dastoor, Paul E. Drevnick, Sarah Roberts, Amber Gleason, Jonathan Keating, Martin Pilote, Jason M. E. Ahad, Allison Tam, Fan Yang, Derek C. G. Muir, Andrei Ryjkov, and Colin A. Cooke
- Subjects
Pollutant ,Pollution ,Canada ,Geologic Sediments ,Point source ,media_common.quotation_subject ,Sediment ,chemistry.chemical_element ,General Chemistry ,Mercury ,Atmospheric sciences ,Mercury (element) ,Lakes ,Deposition (aerosol physics) ,chemistry ,Spatial ecology ,Environmental Chemistry ,Environmental science ,Longitude ,Environmental Pollution ,media_common ,Environmental Monitoring - Abstract
Mercury (Hg) is a pollutant of concern across Canada and transboundary anthropogenic Hg sources presently account for over 95% of national anthropogenic Hg deposition. This study applies novel statistical analyses of 82 high-resolution dated lake sediment cores collected from 19 regions across Canada, including nearby point sources and in remote regions and spanning a full west-east geographical range of ∼4900 km (south of 60°N and between 132 and 64°W) to quantify the recent (1990-2018) spatial and temporal trends in anthropogenic atmospheric Hg deposition. Temporal trend analysis shows significant synchronous decreasing trends in post-1990 anthropogenic Hg fluxes in western Canada in contrast to increasing trends in the east, with spatial patterns largely driven by longitude and proximity to known point source(s). Recent sediment-derived Hg fluxes agreed well with the available wet deposition monitoring. Sediment-derived atmospheric Hg deposition rates also compared well to the modeled values derived from the Hg model, when lake sites located nearby (
- Published
- 2021
26. Response to Comment on 'Screening New Persistent and Bioaccumulative Organics in China's Inventory of Industrial Chemicals': A Call for Further Environmental Research on Organosilicons Produced in China
- Author
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Eddy Y. Zeng, Derek C. G. Muir, Xiangfei Sun, Xianming Zhang, Elsie M. Sunderland, and Ruifen Jiang
- Subjects
China ,business.industry ,Environmental protection ,Research ,Environmental Chemistry ,Environmental science ,Environmental research ,Industry ,General Chemistry ,Chemical industry ,business ,Environmental Pollution - Published
- 2021
27. Correlation of Mercury Occurrence with Age, Elemental Composition, and Life History in Sea-Run Food Fish from the Canadian Arctic Archipelago's Lower Northwest Passage
- Author
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Peter J. Van Coeverden de Groot, Bronte E. McPhedran, Iris Koch, James Qitsualik, Virginia K. Walker, Derek C. G. Muir, John M. Casselman, Stephan Schott, Kristy Moniz, and Pranab Das
- Subjects
0106 biological sciences ,Coregonus clupeaformis ,Health (social science) ,cisco ,lake trout ,chemistry.chemical_element ,Plant Science ,TP1-1185 ,010501 environmental sciences ,01 natural sciences ,Health Professions (miscellaneous) ,Microbiology ,Article ,Arctic char ,14. Life underwater ,Sardinella ,isotopes ,0105 earth and related environmental sciences ,Salvelinus ,Fish migration ,biology ,lake whitefish ,010604 marine biology & hydrobiology ,Chemical technology ,biology.organism_classification ,Mercury (element) ,Fishery ,Trout ,Geography ,otoliths ,chemistry ,Arctic ,anadromous salmonids ,Food Science - Abstract
As mercury emissions continue and climate-mediated permafrost thaw increases the burden of this contaminant in northern waters, Inuit from a Northwest passage community in the Canadian Arctic Archipelago pressed for an assessment of their subsistence catches. Sea-run salmonids (n = 537) comprising Arctic char (Salvelinus alpinus), lake trout (S. namaycush), lake whitefish (Coregonus clupeaformis), and cisco (C. autumnalis, C. sardinella) were analyzed for muscle mercury. Methylmercury is a neurotoxin and bioaccumulated with fish age, but other factors including selenium and other elements, diet and trophic level as assessed by stable isotopes of nitrogen (δ15N) and carbon (δ13C), as well as growth rate, condition, and geographic origin, also contributed depending on the species, even though all the fish shared a similar anadromous or sea-run life history. Although mean mercury concentrations for most of the species were ~0.09 µg·g−1 wet weight (ww), below the levels described in several jurisdictions for subsistence fisheries (0.2 µg·g−1 ww), 70% of lake trout were above this guideline (0.35 µg·g−1 ww), and 19% exceeded the 2.5-fold higher levels for commercial sale. We thus urge the development of consumption advisories for lake trout for the protection of pregnant women and young children and that additionally, periodic community-based monitoring be initiated.
- Published
- 2021
28. Persistent, Bioaccumulative, and Toxic Chemicals I
- Author
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ROBERT L. LIPNICK, JOOP L. M. HERMENS, KEVIN C. JONES, DEREK C. G. MUIR, Robert L. Lipnick, Derek C. G. Muir, D. T. H. M. Sijm, Steven J. Eisenreich, Cari L. Gigliotti, Paul A. Brunciak, Jordi Dachs, Thomas R. Glenn, Eric D. Nelson, Lisa A. Totten, Daryl A. Van Ry, Wei Chen, Amy T. Kan, Mason B. Tom
- Published
- 2000
29. Towards a better understanding of deep convolutional neural network processes for recognizing organic chemicals of environmental concern
- Author
-
Yuanxin Li, Luyao Wang, Xiangfei Sun, Eddy Y. Zeng, Derek C. G. Muir, and Xianming Zhang
- Subjects
Environmental Engineering ,Correlation coefficient ,Computer science ,Process (engineering) ,business.industry ,Health, Toxicology and Mutagenesis ,Pattern recognition ,Pollution ,Convolutional neural network ,Categorization ,Molecular descriptor ,Principal component analysis ,Redundancy (engineering) ,Environmental Chemistry ,Segmentation ,Artificial intelligence ,Neural Networks, Computer ,Organic Chemicals ,business ,Waste Management and Disposal - Abstract
Deep convolutional neural network (DCNN) has proved to be a promising tool for identifying organic chemicals of environmental concern. However, the uncertainty associated with DCNN predictions remains to be quantified. The training process contains many random configurations, including dataset segmentation, input sequences, and initial weight, etc. Moreover, the DCNN working mechanism is non-linear and opaque. To increase confidence to use this novel approach, persistent, bioaccumulative, and toxic substances (PBTs) were utilized as representative chemicals of environmental concern to estimate the prediction uncertainty under five distinguished datasets and ten different molecular descriptor (MD) arrangements with 111,852 chemicals and 2424 available MDs. An internal correlation coefficient test indicated that the prediction confidence reached 0.98 when a mean of 50 DCNNs’ predictions was used instead of a sing DCNN prediction. A threshold for PBT categorization was determined by considering costs between false-negative and false-positive predictions. As revealed by the guided backpropagation–class activation mapping (GBP-CAM) saliency images, only 12% of all selected MDs were activated by DCNN and influenced decision-making process. However, the activated MDs not only varied among chemical classes but also shifted with different DCNNs. Principal component analysis indicated that 2424 MDs could transform into 370 orthogonal variables. Both results suggest that redundancy exists among selected MDs. Yet, DCNN was found to adapt to redundant data by focusing on the most important information for better prediction performance.
- Published
- 2021
30. C12–30 α-Bromo-Chloro 'Alkenes': Characterization of a Poorly Identified Flame Retardant and Potential Environmental Implications
- Author
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Leah Chibwe, Karl J. Jobst, Amila O. De Silva, Bo Yuan, Eric J. Reiner, Derek C. G. Muir, and Anne L. Myers
- Subjects
Alkane ,chemistry.chemical_classification ,Pollutant ,Bromine ,Halogenation ,chemistry.chemical_element ,General Chemistry ,010501 environmental sciences ,01 natural sciences ,Partition coefficient ,chemistry ,Chlorinated paraffins ,13. Climate action ,Computational chemistry ,Environmental Chemistry ,Molecule ,0105 earth and related environmental sciences ,Fire retardant - Abstract
Bromo-chloro alkenes (Br-Cl PXAs) have been used for over 30 years as flame retardants and are listed on several national chemical inventories. Very little publicly available information is available on Br-Cl PXAs, and thus preliminary ecological risk screening is challenging due to the lack of basic information such as molecular structure and associated physicochemical properties. Due to their likely similarity with chlorinated paraffins (CPs), Br-Cl PXAs may pose a similar environmental hazard. Several structural databases list such substances as "alkenes", although the industrial synthesis involves halogenation of linear alpha-olefins and would be expected to produce linear alkanes. In this study, a combination of high-resolution separation and mass spectrometric techniques were used to characterize a Br-Cl PXA industrial technical product, C12-30 bromo-chloro alpha-alkenes (CAS RN 68527-01-5). The results show this product is dominated by C18 carbon chain lengths, substituted with 3-7 chlorine atoms and 1-3 bromine atoms on an alkane chain. Long-chain C18 chlorinated paraffins are also present, although they represent a relatively minor component. Experimental log KOW (6.9 to 8.6) and estimated log KOA (10.5 to 13.5) and log KAW (-5.1 to -0.6) partition coefficients suggest that this chemical will behave similarly to medium- and long-chain CPs as well as other persistent organic pollutants, such as highly chlorinated pesticides and polychlorinated biphenyls. The results of this study provide an initial step toward understanding the environmental behavior and persistence of Br-Cl PXAs, highlighting the need for further assessment and re-evaluation of the current structure(s) assigned to these compounds.
- Published
- 2019
31. Fate and Transport of Perfluoroalkyl Substances from Snowpacks into a Lake in the High Arctic of Canada
- Author
-
John J. MacInnis, Kyra A. St. Pierre, Igor Lehnherr, Amila O. De Silva, Derek C. G. Muir, Christine Spencer, and Vincent L. St. Louis
- Subjects
Canada ,Fluorocarbons ,Arctic Regions ,Nunavut ,Context (language use) ,General Chemistry ,010501 environmental sciences ,Mineral dust ,Snowpack ,Snow ,Sea spray ,01 natural sciences ,Lakes ,Water column ,Arctic ,13. Climate action ,Snowmelt ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
The delivery of perfluoroalkyl substances (PFAS) from snowpacks into Lake Hazen, located on Ellesmere Island (Nunavut, Canada, 82° N) indicates that annual atmospheric deposition is a major source of PFAS that undergo complex cycling in the High Arctic. Perfluoroalkyl carboxylic acids (PFCA) in snowpacks display odd-even concentration ratios characteristic of long-range atmospheric transport and oxidation of volatile precursors. Major ion analysis in snowpacks suggests that sea spray, mineral dust, and combustion aerosol are all relevant to the fate of PFAS in the Lake Hazen watershed. Distinct drifts of light and dark snow (enriched with light absorbing particles, LAPs) facilitate the study of particle loads on the fate of PFAS in the snowpack. Total PFAS (ΣPFAS, ng m-2) loads are lower in snowpacks enriched with LAPs and are attributed to reductions in snowpack albedo combined with enhanced post-depositional melting. Elevated concentrations of PFCA are observed in the top 5 m of the water column during snowmelt periods compared to ice-covered or ice-free periods. PFAS concentrations in deep waters of the Lake Hazen water column were consistent between snowmelt, ice-free, and ice-covered periods, which is ascribed to the delivery of dense and turbid glacier meltwaters mixing PFAS throughout the Lake Hazen water column. These observations highlight the underlying mechanisms in PFAS cycling in High Arctic Lakes particularly in the context of increased particle loads and melting.
- Published
- 2019
32. Bioaccumulation and translocation of tetrabromobisphenol A and hexabromocyclododecanes in mangrove plants from a national nature reserve of Shenzhen City, South China
- Author
-
Yuxin Sun, Jinli Xie, Xiang-Rong Xu, Derek C. G. Muir, Bi-Xian Mai, Nancai Pei, Xiao-Jun Luo, Yanmei Xiong, Weiwei Wang, Yong-Xia Hu, Huawei Li, and Amila O. De Silva
- Subjects
China ,010504 meteorology & atmospheric sciences ,Polybrominated Biphenyls ,Intertidal zone ,Wetland ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Ecosystem ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,General Environmental Science ,Flame Retardants ,Mangrove plants ,Pollutant ,lcsh:GE1-350 ,geography ,geography.geographical_feature_category ,Plants ,Hydrocarbons, Brominated ,chemistry ,Environmental chemistry ,Bioaccumulation ,Environmental science ,Tetrabromobisphenol A ,Mangrove - Abstract
Brominated flame retardants (BFRs) such as tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) are of ecological concern due to their ubiquitous presence and adverse effects. There is a paucity of data on environmental fate of such compounds in mangrove wetlands, which are unique ecosystems in coastal intertidal areas and act as natural sinks for many pollutants. In this study, mangrove plants and sediments were collected from an urban nature reserve in South China to investigate bioaccumulation and translocation of TBBPA and HBCDs. The mean (range) concentrations of TBBPA and ΣHBCD in roots, stems and leaves were 67 (
- Published
- 2019
33. Source Analysis of Pollutant Elements in Winter Air Deposition in the Athabasca Oil Sands Region: A Temporal and Spatial Study
- Author
-
Greg Lawson, Xiaowa Wang, Erin N. Kelly, Amber Gleason, Yamini Gopalapillai, Colin A. Cooke, Jane L. Kirk, David W. Schindler, Derek C. G. Muir, Matthew S. Landis, and Allie Ho
- Subjects
Pollutant ,Atmospheric Science ,Deposition (aerosol physics) ,Space and Planetary Science ,Geochemistry and Petrology ,Asphalt ,Environmental science ,Oil sands ,Ecosystem ,Extraction (military) ,Snowpack ,Snow ,Atmospheric sciences - Abstract
The extraction and upgrading of bitumen have been identified as sources of enhanced atmospheric deposition of pollutant elements to ecosystems in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada. Bitumen extraction became increasingly efficient, and oil prices surged in the 1990s, resulting in rapid expansion and increased production over the last two decades. Here, we examine temporal and spatial trends in wintertime atmospheric deposition of pollutant elements in 1978, 1981, 2008, and 2011–2016 at broad spatial scales using snowpack measurements. A hybrid source analysis was conducted, including (i) simple and multiple linear regression (MLR) of identified source locations and elemental deposition, (ii) spatially resolved aluminum enrichment factors (Al EFs), and (iii) positive matrix factorization (PMF) to determine source profiles. Temporal trends revealed a general decrease in atmospheric loadings; however, near-field V, Ti, and Al loadings in 2016 were an order of magnitude greater ...
- Published
- 2019
34. Toward Sustainable Environmental Quality: Priority Research Questions for North America
- Author
-
Helen C. Poynton, Doris E. Vidal-Dorsch, Derek C. G. Muir, Mary Ann Ottinger, Elijah J. Petersen, Bryan W. Brooks, Pamela J. Rice, Anne Fairbrother, David A. Dreier, Peter R. Wilson, Charles Lee Meyer, Jeffery A. Steevens, Linda M. Campbell, Kevin L. Armbrust, Sigrun A. Kullik, Bonnie J. Blalock, Scott M. Weir, Gabriela Rodríguez-Fuentes, Roman P. Lanno, Tim Verslycke, Sarah R. Bowman, Gerald T. Ankley, Carol J. Henry, Marlene S. Evans, Murray A. Rudd, Keith R. Solomon, Alistair B.A. Boxall, Kristin A. Connors, George P. Cobb, Joseph R. Shaw, Jennifer N. Apell, Rebecca D. Klaper, Robert A. Hoke, Alan Samel, Elias M. Oziolor, Magali Houde, and Stephen J. Klaine
- Subjects
Conservation of Natural Resources ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,Ecotoxicology ,01 natural sciences ,Political science ,Chemical contaminants ,Humans ,Environmental toxicology ,Environmental planning ,Environmental quality ,0105 earth and related environmental sciences ,Grand Challenges ,Sustainable development ,Emerging concerns ,Research ,Stressor ,Critical Review ,Environmental hazard/risk assessment ,Sustainable Development ,Identification (information) ,Global megatrends ,Sustainability ,Sustainable management ,Environmental chemistry ,North America ,Research questions - Abstract
Anticipating, identifying, and prioritizing strategic needs represent essential activities by research organizations. Decided benefits emerge when these pursuits engage globally important environment and health goals, including the United Nations Sustainable Development Goals. To this end, horizon scanning efforts can facilitate identification of specific research needs to address grand challenges. We report and discuss 40 priority research questions following engagement of scientists and engineers in North America. These timely questions identify the importance of stimulating innovation and developing new methods, tools, and concepts in environmental chemistry and toxicology to improve assessment and management of chemical contaminants and other diverse environmental stressors. Grand challenges to achieving sustainable management of the environment are becoming increasingly complex and structured by global megatrends, which collectively challenge existing sustainable environmental quality efforts. Transdisciplinary, systems‐based approaches will be required to define and avoid adverse biological effects across temporal and spatial gradients. Similarly, coordinated research activities among organizations within and among countries are necessary to address the priority research needs reported here. Acquiring answers to these 40 research questions will not be trivial, but doing so promises to advance sustainable environmental quality in the 21st century. Environ Toxicol Chem 2019;38:1606–1624. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
- Published
- 2019
35. Do intraspecific life history patterns follow interspecific predictions? A test using latitudinal variation in ringed seals
- Author
-
Brent G. Young, Xinhua Zhu, Cornelia Willing, Steven H. Ferguson, Gregory W. Thiemann, Derek C. G. Muir, Aaron T. Fisk, and David J. Yurkowski
- Subjects
environmental predictability ,0106 biological sciences ,010604 marine biology & hydrobiology ,Zoology ,latitude ,Interspecific competition ,Test (biology) ,Biology ,Body size ,Mating system ,010603 evolutionary biology ,01 natural sciences ,Intraspecific competition ,Latitude ,Variation (linguistics) ,age of maturity ,mating system ,14. Life underwater ,Life history ,body size ,Ecology, Evolution, Behavior and Systematics - Abstract
Mammals adapted to unpredictable and low-energy environments often evolve a “bet-hedging” life history strategy characterized by less costly reproductive outputs over a longer and slower-growing life. In contrast, species adapted to more predictable (i.e., low variation) and higher energy environments may evolve greater fecundity over a shorter and faster-growing life. We tested whether this known interspecific pattern also occurs within a species. We compared life history traits of the ringed seal (Pusa hispida) in the Canadian High Arctic to those closer to the southern limit of the species' circumpolar distribution. We found that northern seals grew slower than southern seals (Brody growth coefficient), achieved a greater asymptotic body weight (82 and 69 kg vs. 74 and 54 kg female and male, respectively), reached sexual maturity later (6.1 years vs. 4.5 years), had lower fecundity (1.8 years vs. 1.3 years interbirth interval), longer average lifespan (5 years vs. 3 years median age), and greater movements (1,269 vs. 681 km). Mating systems also likely differed with northern seals showing morphological evidence of a promiscuous mating system with potential sperm competition as indicated by greater relative testes size. The northern region was also characterized by more unpredictable environmental timing of seasonal events, such as spring sea ice breakup. Life history variation between the intraspecific groups of seals appears to agree with interspecific patterns and provides a better understanding of how species' life history parameters shift in concert with environmental conditions.
- Published
- 2019
36. Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes
- Author
-
Derek C. G. Muir, Gretchen L. Lescord, Xiaowa Wang, Nelson J. O'Driscoll, Jane L. Kirk, Meredith G. Clayden, and Karen A. Kidd
- Subjects
010504 meteorology & atmospheric sciences ,chemistry.chemical_element ,Environmental engineering ,sulfate ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Nutrient ,GE1-350 ,Methylmercury ,0105 earth and related environmental sciences ,General Environmental Science ,Stable isotope ratio ,Biogeochemistry ,Biota ,methylmercury ,TA170-171 ,Isotopes of nitrogen ,Mercury (element) ,Environmental sciences ,bioaccumulation ,chemistry ,oligotrophic ,Environmental chemistry ,food webs ,General Earth and Planetary Sciences ,Environmental science ,General Agricultural and Biological Sciences ,Eutrophication - Abstract
Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.
- Published
- 2019
37. Bioaccumulation of Selected Halogenated Organic Flame Retardants in Lake Ontario
- Author
-
Benjamin de Jourdan, Sean Backus, Heather Embers, Jessica Epp Martindale, Derek C. G. Muir, Camilla Teixeira, Xiaowa Wang, Perihan Binnur Kurt-Karakus, and Michael J. Keir
- Subjects
Food Chain ,010504 meteorology & atmospheric sciences ,Trout ,Health, Toxicology and Mutagenesis ,Biomagnification ,Ether ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Polybrominated diphenyl ethers ,Animals ,Environmental Chemistry ,Ecosystem ,Flame Retardants ,0105 earth and related environmental sciences ,Trophic level ,Salvelinus ,Ontario ,Geography ,biology ,Hydrocarbons, Halogenated ,Plankton ,biology.organism_classification ,Bioaccumulation ,Food web ,Lakes ,chemistry ,Environmental chemistry ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The trophic magnification of polybrominated diphenyl ethers (PBDEs) and selected nonlegacy halogenated organic compounds (HOCs) was determined in the food web of Lake Ontario (ON, Canada). In all, 28 Br3 -Br8 -PBDEs and 24 HOCs (10 of which had not been targeted previously) were analyzed. Average concentrations of Σ28 PBDEs in fish ranged between 79.7 ± 54.2 ng/g lipid weight in alewife (Alosa pseudoharengus) and 815 ± 695 ng/g lipid weight in lake trout (Salvelinus namaycush). For invertebrates, concentrations were between 13.4 ng/g lipid weight (net plankton; >110 μm) and 41.9 ng/g lipid weight in Diaporeia (Diaporeia hoyi). Detection frequency (DF) for HOCs was highest for anti-Dechlorane Plus (anti-DDC-CO), 1,3-diiodobenzene (1,3-DiiB), tribromo-methoxy-methylbenzene (ME-TBP), allyl 2,4,6-tribromophenyl ether (TBP-AE), pentabromocyclododecene (PBCYD), α+β-tetrabromocylcooctane (TBCO), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE), and pentabromotoluene (PBT; DF for all = 100% in lake trout). Tetrabromoxylene (TBX), dibromopropyl 2,4,6-tribromophenyl ether (TBP-DBPE), and syn-DDC-CO were also frequently detected in trout (DF = 70-78%), whereas 2,3,4,5,6-pentabromoethyl benzene (PBEB) was detected only in plankton. Several HOCs were reported in aquatic biota in the Great Lakes (USA/Canada) for the first time in the present study, including PBCYD, 1,3DiiB, BATE, TBP-DBPE, PBT, α + β-TBCO, and ME-TBP. The Br4-6 -BDEs (-47, -85, -99, -100, -153, and -154) all had prey-weighted biomagnification factors (BMFPW ) values >6, whereas BMFPW values for Br7-8 -BDEs were
- Published
- 2019
38. Trends of persistent organic pollutants in ringed seals (Phoca hispida) from the Canadian Arctic
- Author
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R.F. Addison, Magali Houde, Steven H. Ferguson, Michael G. Ikonomou, Derek C. G. Muir, C. Dubetz, Pierre Gagnon, Xiaowa Wang, and T.-L. L. Colson
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Male ,Canada ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Climate ,Phoca ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Blubber ,Animals ,Environmental Chemistry ,Ice Cover ,Waste Management and Disposal ,0105 earth and related environmental sciences ,biology ,Arctic Regions ,Temperature ,Environmental Exposure ,Hexachlorobenzene ,biology.organism_classification ,Pollution ,Fishery ,Adipose Tissue ,chemistry ,Arctic oscillation ,Arctic ,North Atlantic oscillation ,Indicator species ,Environmental science ,Female ,Bay ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Ringed seals (Phoca hispida) have been used as bioindicator species of environmental contamination in Canada since the 1970s. In the present study, seals were harvested during subsistence hunts in four regions of the Canadian Arctic: Beaufort Sea, Arctic Archipelago, Hudson Bay, and coastal Labrador. An extensive suite of persistent organic pollutants (POPs) was determined in seal blubber collected for multiple years between 1972 and 2016. Results from this long-term study indicate geographical differences in the contaminant concentrations in seals and the significant general decrease of most POPs, including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and related compounds, chlordanes (CHL), and hexachlorocyclohexanes (HCH) over time in ringed seals. The highest decrease rates (up to −9.1%/year for α-HCH) were found in seals from the Hudson Bay region where all chemicals investigated have significantly decreased since 1986. Significant increases in concentrations of hexachlorobenzene (HCB) in seals from Labrador and β-HCH in Sachs Harbour, NT and Arctic Archipelago were observed. Site-specific and contaminant-specific associations between climate pattern (i.e., Arctic Oscillation, North Atlantic Oscillation, and Pacific/North American pattern) and mean ice-coverage (total, first-year ice, and old-ice) were found at sites with the longest time trend data (i.e., Arviat, Sachs Harbour/Ulukhaktok and Resolute Bay). Overall, results suggest that North American and international regulations have led to the long-term reduction of most POPs in Canadian Arctic ringed seals by reducing emissions from primary sources. However, other sources of legacy compounds (e.g., environmental reservoirs) as well changes in food web composition and structure in relation to climate changes could also be influencing the very slow rates of decline, or stable levels, of contaminants found in seals at some sites. Further work is warranted to discern between co-variation of climate changes and contaminant concentrations and cause-and-effect relationships.
- Published
- 2019
39. Contemporary limnology of the rapidly changing glacierized watershed of the world’s largest High Arctic lake
- Author
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Alex S. Gardner, Alexandre J. Poulain, Mang Ma, Derek C. G. Muir, Sherry L. Schiff, Igor Lehnherr, Willie J. Findlay, V. L. St. Louis, John P. Smol, K. St Pierre, David L. Findlay, Shelley E. Arnott, and C. Talbot
- Subjects
0301 basic medicine ,geography ,Multidisciplinary ,Watershed ,geography.geographical_feature_category ,Limnology ,lcsh:R ,Climate change ,lcsh:Medicine ,Freshwater ecosystem ,Article ,Sink (geography) ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Oceanography ,Arctic ,Environmental science ,Cryosphere ,lcsh:Q ,Glacial period ,lcsh:Science ,030217 neurology & neurosurgery - Abstract
Glacial runoff is predicted to increase in many parts of the Arctic with climate change, yet little is known about the biogeochemical impacts of meltwaters on downstream freshwater ecosystems. Here we document the contemporary limnology of the rapidly changing glacierized watershed of the world’s largest High Arctic lake (Lake Hazen), where warming since 2007 has increased delivery of glacial meltwaters to the lake by up to 10-times. Annually, glacial meltwaters accounted for 62–98% of dissolved nutrient inputs to the lake, depending on the chemical species and year. Lake Hazen was a strong sink for NO3−-NO2−, NH4+ and DOC, but a source of DIC to its outflow the Ruggles River. Most nutrients entering Lake Hazen were, however, particle-bound and directly transported well below the photic zone via dense turbidity currents, thus reinforcing ultraoligotrophy in the lake rather than overcoming it. For the first time, we apply the land-to-ocean aquatic continuum framework in a large glacierized Arctic watershed, and provide a detailed and holistic description of the physical, chemical and biological limnology of the rapidly changing Lake Hazen watershed. Our findings highlight the sensitivity of freshwater ecosystems to the changing cryosphere, with implications for future water quality and productivity at high latitudes.
- Published
- 2019
40. Deposition and Source Identification of Nitrogen Heterocyclic Polycyclic Aromatic Compounds in Snow, Sediment, and Air Samples from the Athabasca Oil Sands Region
- Author
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Dayue Shang, Tom Harner, Derek C. G. Muir, Beau Atkinson, Leah Chibwe, Chris Marvin, Camilla Teixeira, Amila O. De Silva, Xiaowa Wang, Carlos Manzano, and Jane L. Kirk
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Nitrogen ,Sediment ,chemistry.chemical_element ,General Chemistry ,010501 environmental sciences ,Snow ,01 natural sciences ,Alberta ,Deposition (aerosol physics) ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Oil sands ,Oil and Gas Fields ,Polycyclic Aromatic Hydrocarbons ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
Polycyclic aromatic compounds (PACs) can have multiple sources in the Athabasca Oil Sands Region (AOSR). The current study was designed to identify and explore the potential of nitrogen heterocyclic PACs (NPACs) as source indicators in snowpack, lake sediment and passive air samples from the AOSR during 2014-2015. Source samples including petroleum coke (petcoke), haul road dust, and unprocessed oil sands were also analyzed. Samples were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry, and liquid chromatography-high resolution Orbitrap mass spectrometry. Over 200 NPACs were identified and classified into at least 24 isomer groups, including alkylated carbazoles, benzocarbazoles, and indenoquinolines. Levels of NPACs in environmental samples decreased with distance from the main developments and with increasing depth in lake sediments but were detected within 50 km from the major developments. The composition profiles of several NPAC isomer classes, such as dimethylcarbazoles, showed that petcoke had a distinct distribution of NPACs compared to the haul road dust and unprocessed oil sands ores and was the most similar source material to near-field environmental samples. These results suggest that petcoke is a major contributing source for the identified NPACs and that these compounds have the potential to be used as source indicators for future research in the AOSR.
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- 2019
41. Temporal trends of persistent organic pollutants in Arctic marine and freshwater biota
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Katrin S. Hoydal, Derek C. G. Muir, Norman Whitaker Green, Rune Dietz, Anders Bignert, Christian Sonne, Marlene S. Evans, Maria Dam, Helga Gunnlaugsdóttir, Birgit M. Braune, John R. Kucklick, Stacy S. Schuur, Gregg T. Tomy, Simon Wilson, Frank Rigét, Gary A. Stern, Robert J. Letcher, and Katrin Vorkamp
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Time Factors ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Mytilus edulis ,Oceans and Seas ,POLAR BEARS ,Temporal trends ,Fresh Water ,010501 environmental sciences ,01 natural sciences ,Freshwater ecosystem ,Charadriiformes ,chemistry.chemical_compound ,Arctic ,FLAME RETARDANTS ,CLIMATE VARIABILITY ,Environmental monitoring ,Animals ,Environmental Chemistry ,POPs ,Waste Management and Disposal ,RINGED SEALS ,0105 earth and related environmental sciences ,Mammals ,ORGANOCHLORINE PESTICIDES ,Pollutant ,Hexabromocyclododecane ,TECHNICAL CHLORDANE ,Arctic Regions ,POLYBROMINATED DIPHENYL ETHERS ,Fishes ,Biota ,Environmental Exposure ,Pollution ,TRANS-NONACHLOR ,CHLORDANE COMPONENTS ,NORTHWATER POLYNYA ,Congener ,chemistry ,Environmental chemistry ,Brominated flame retardant ,Environmental science ,Seasons ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
More than 1000 time-series of persistent organic pollutants (POPs) in Arctic biota from marine and freshwater ecosystems some extending back to the beginning of 1980s were analyzed using a robust statistical method. The Arctic area encompassed extended from Alaska, USA in the west to northern Scandinavian in the cast, with data gaps for Arctic Russia and Arctic Finland. The aim was to investigate whether temporal trends for different animal groups and matrices were consistent across a larger geographical area. In general, legacy POPs showed decreasing concentrations over the last two to three decades, which were most pronounced for aHCH and least pronounced for HCB and p-HCH. Few lime-series of legacy POPs showed increasing trends and only at sites suspected to be influenced by local source. The brominated flame retardant congener BDE-47 showed a typical trend of increasing concentration up to approximately the mid-2000s followed by a decreasing concentration. A similar trend was found for perfluorooctane sulfonic add (PFOS). These trends are likely related to the relatively recent introduction of national and international controls of hexa- and hepta-BDE congeners and the voluntary phase-out of PFOS production in the USA in 2000. Hexabromocyclododecane (HBCDD) was the only compound in this study showing a consistent increasing trend. Only 12% of the long-term time-series were able to detect a 5% annual change with a statistical power of 80% at alpha 20 years monitoring before this requirement would be fulfilled. (C) 2018 Elsevier B.V. All tights reserved.
- Published
- 2019
42. Identifying further chemicals of emerging arctic concern based on ‘in silico’ screening of chemical inventories
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Derek C. G. Muir, Katrin Vorkamp, Xianming Zhang, Cynthia A. de Wit, and Simon Wilson
- Subjects
Health, Toxicology and Mutagenesis ,In silico ,0208 environmental biotechnology ,Public Health, Environmental and Occupational Health ,Environmental media ,02 engineering and technology ,010501 environmental sciences ,Toxicology ,01 natural sciences ,020801 environmental engineering ,The arctic ,lcsh:Environmental pollution ,Transfer efficiency ,Arctic ,Bioaccumulation ,Environmental health ,lcsh:TD172-193.5 ,Environmental science ,media_common.cataloged_instance ,European union ,0105 earth and related environmental sciences ,media_common - Abstract
In the past 12 years several studies have screened lists of thousands of chemicals available in the industrial chemical inventories of the European Union, the USA and Canada with the goal of identifying and prioritizing chemicals which are persistent (P), bioaccumulative (B) and toxic (T). Most studies have selected chemicals based on whether their predicted P and B properties and their long-range transport potential exceed guideline thresholds for evaluation of persistent organic pollutants (POPs). A major goal of this study was to review this recent literature on computer-based or ‘in silico’ screening for POPs. A second goal was to review other approaches for finding previously unidentified chemicals of concern including targeted and non-target analytical approaches that might use lists of suspect chemicals developed from ‘in silico’ screening studies. Eight studies were reviewed along with several others which examined the screening process and its uncertainties. From these studies we assembled a list of 3421 chemicals, after removing duplicates and substances already on the Stockholm Convention on POPs. About 52% of these were halogenated, while 48% consisted of a broad range of non-halogenated organics. This list was then further analysed by calculating an overall “POPs score” for transport and accumulation in the Arctic for each substance using predicted partition coefficients, overall persistence, transfer efficiency, and bioaccumulation factor. A shorter list of twenty-five substances was developed based on their POPs score ranking. These substances had not been previously analysed in environmental media but were nevertheless on current or recent chemical inventories indicating significant commercial use. Keywords: Persistent organic pollutants, Persistence, Bioaccumulation, Long-range transport, Non-target screening
- Published
- 2019
43. Sources and environmental fate of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in the Arctic
- Author
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Robert J. Letcher, Jennifer E. Balmer, Yong Yu, Derek C. G. Muir, and Hayley Hung
- Subjects
chemistry.chemical_classification ,business.industry ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Fossil fuel ,Public Health, Environmental and Occupational Health ,Northern Hemisphere ,Sediment ,Biota ,02 engineering and technology ,010501 environmental sciences ,Toxicology ,01 natural sciences ,020801 environmental engineering ,lcsh:Environmental pollution ,Arctic ,chemistry ,Environmental chemistry ,lcsh:TD172-193.5 ,Soil water ,Biological dispersal ,Environmental science ,Organic matter ,business ,0105 earth and related environmental sciences - Abstract
Polycyclic aromatic hydrocarbons (PAHs) are large class of hydrophobic, semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic activities. Pyrogenic PAHs arise from the incomplete combustion of fossil fuels and organic matter and following dispersal via long-range transport and may subsequently deposit in surface waters, soils and sediments of remote regions, including the Arctic. The current review summarizes and discusses Arctic data that is available for combustion-derived PAHs between 2004 and early 2018, focusing largely on data collected from remote, unexploited Arctic regions and from studies that provide some evidence of a pyrogenic origin. The increasing use of attribution ratios, which aid in discriminating PAHs from petrogenic or pyrogenic sources, suggest PAHs found in Arctic marine waters and sediment predominantly originate from natural underwater seeps, while those measured in air, freshwater, and terrestrial environments are likely to have originated from atmospheric and combustion-derived sources. Modeling efforts indicate that atmospheric PAHs in the Canadian and Norwegian Arctic are likely to have originated in the northern hemisphere – predominantly from Western Russia, northern Europe, and North America. East Asia appears to be a minor source of PAHs to the Arctic, despite contributing more than 50% of global PAH emissions. In comparison to the growing data for atmospheric PAHs, environmental data for these compounds in terrestrial and freshwater environments remain scarce. PAHs have been detected in Arctic biota from terrestrial, freshwater and marine environments, indicating exposure, however, levels are generally low, as most organisms efficiently metabolize parent PAHs. Globally, PAH emissions are expected to decline in the future, however models suggest the Arctic may not experience the same magnitude of decline projected for other world regions. Furthermore, future changes in climate may contribute to a re-volatilization of environmental PAHs, providing a source of secondary emissions to the Arctic atmosphere, emphasizing the importance of future monitoring for understanding the sources, fate and impacts of PAHs in the Arctic. Keywords: Contaminants, Air, Biota, Pyrogenic, Petrogenic, Review
- Published
- 2019
44. Spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region (Alberta, Canada)
- Author
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Colin A Cooke, Jane L Kirk, Derek C G Muir, Johan A Wiklund, Xiaowa Wang, Amber Gleason, and Marlene S Evans
- Subjects
oil sands ,heavy metals ,lake sediment ,pollution ,Alberta ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Science ,Physics ,QC1-999 - Abstract
The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for decades; however, a lack of consistent regional monitoring has obscured the long-term environmental impact. Here, we present sediment core results to reconstruct spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region. Early mining operations (during the 1970s and 1980s) led to elevated V and Pb inputs to lakes located
- Published
- 2017
- Full Text
- View/download PDF
45. Drivers of Mercury Cycling in the Rapidly Changing Glacierized Watershed of the High Arctic’s Largest Lake by Volume (Lake Hazen, Nunavut, Canada)
- Author
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Derek C. G. Muir, V. L. St. Louis, Johan A. Wiklund, K. St Pierre, Alex S. Gardner, J. A. Serbu, C. Talbot, D Lemire, Igor Lehnherr, L Szostek, and Colleen Mortimer
- Subjects
Canada ,chemistry.chemical_element ,Nunavut ,Fjord ,010501 environmental sciences ,Permafrost ,01 natural sciences ,Sink (geography) ,Environmental Chemistry ,14. Life underwater ,Glacial period ,Ecosystem ,0105 earth and related environmental sciences ,Hydrology ,geography ,geography.geographical_feature_category ,Arctic Regions ,Aquatic ecosystem ,Glacier ,Mercury ,General Chemistry ,Methylmercury Compounds ,Mercury (element) ,Lakes ,Arctic ,chemistry ,13. Climate action ,Environmental science ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Across the Arctic, glaciers are melting and permafrost is thawing at unprecedented rates, releasing not only water to downstream aquatic systems, but also contaminants like mercury, archived in ice over centuries. Using concentrations from samples collected over 4 years and calibrated modeled hydrology, we calculated methylmercury (MeHg) and total mercury (THg) mass balances for Lake Hazen, the world's largest High Arctic lake by volume, for 2015 and 2016. Glacial rivers were the most important source of MeHg and THg to Lake Hazen, accounting for up to 53% and 94% of the inputs, respectively. However, due to the MeHg and THg being primarily particle-bound, Lake Hazen was an annual MeHg and THg sink. Exports of MeHg and THg out the Ruggles River outflow were consequently very low, but erosion and permafrost slumping downstream of the lake increased river MeHg and THg concentrations significantly before entering coastal waters in Chandler Fjord. Since 2001, glacial MeHg and THg inputs to Lake Hazen have increased by 0.01 and 0.400 kg yr
- Published
- 2018
46. Legacy and Emerging Persistent Organic Pollutants (POPs) in Terrestrial Compartments in the High Arctic: Sorption and Secondary Sources
- Author
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Ana Cabrerizo, Amila O. De Silva, Derek C. G. Muir, Xiaowa Wang, Scott F. Lamoureux, and Melissa J. Lafrenière
- Subjects
chemistry.chemical_classification ,Canada ,010504 meteorology & atmospheric sciences ,Arctic Regions ,Soil organic matter ,Soil classification ,General Chemistry ,010501 environmental sciences ,Polychlorinated Biphenyls ,complex mixtures ,01 natural sciences ,Soil contamination ,chemistry ,Arctic ,Environmental chemistry ,Soil water ,Soil Pollutants ,Environmental Chemistry ,Environmental science ,Environmental Pollutants ,Organic matter ,Arctic vegetation ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
Legacy persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and emerging perfluoroalkyl substances (PFASs) were measured in vegetation and soil samples collected at remote lakes in the Canadian High Arctic. Field studies were carried out in 2015 and 2016 to assess concentrations of POPs, study the relevant sorbing phases, and determine whether Arctic soils were sinks or sources of legacy POPs to the atmosphere and to neighboring lakes. The patterns of legacy POPs in vegetation and soils were dominated by low molecular weight PCB congeners along with OCPs, confirming the importance of long-range atmospheric transport. Lipid and non-lipid organic matter was a key determinant of legacy POPs in Arctic vegetation. Soil organic matter was the main descriptor of hydrophobic PCBs and OCPs in soils, while soil inorganic carbon content, was an important driver of the sorption of PFASs in soils. While contaminant concentrations were low in soil and vegetation, higher PCBs and PFOS organic and inorganic carbon-normalized concentrations were found at Resolute Lake indicating the presence of local sources of contamination. Comparison of fugacities of PCBs in soil and air from Resolute Lake indicated soils as net sources of PCBs to the atmosphere.
- Published
- 2018
47. Air synthesis review: polycyclic aromatic compounds in the oil sands region
- Author
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Frank Wania, Gregory R. Wentworth, Jean-Pierre Charland, Cynthia H. Whaley, Matthew S. Landis, Narumol Jariyasopit, Leiming Zhang, George Marson, Yifeng Zhang, Sunny Cho, Bruce D. Pauli, Elisabeth Galarneau, Paul A. Makar, Jason M. E. Ahad, Jennifer B. Korosi, Derek C. G. Muir, Jonathan W. Martin, John G. Watson, Jane L. Kirk, Xiaoliang Wang, Andrzej Wnorowski, Tom Harner, Yu-Mei Hsu, Cassandra Rauert, Kim J. Fernie, Jasmin K. Schuster, Judith C. Chow, Irene Cheng, and Ewa Dabek
- Subjects
010504 meteorology & atmospheric sciences ,Environmental chemistry ,Environmental science ,Oil sands ,010501 environmental sciences ,Current (fluid) ,01 natural sciences ,Deposition (chemistry) ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
This air synthesis review presents the current state of knowledge on the sources, fates, and effects for polycyclic aromatic compounds (PACs) and related chemicals released to air in the oil sands region (OSR) in Alberta, Canada. Through the implementation of the Joint Canada–Alberta Oil Sands Monitoring Program in 2012 a vast amount of new information on PACs has been acquired through directed monitoring and research projects and reported to the scientific community and public. This new knowledge addresses questions related to cumulative effects and informs the sustainable management of the oil sands resource while helping to identify gaps in understanding and priorities for future work. As a result of this air synthesis review on PACs, the following topics have been identified as new science priorities: (i) improving emissions reporting to better account for fugitive mining emissions of PACs that includes a broader range of PACs beyond the conventional polycyclic aromatic hydrocarbons (PAHs) including, inter alia, alkylated-PAHs (alk-PAHs), dibenzothiophene (DBT), alk-DBTs, nitro-PAHs, oxy-PAHs including quinones and thia- and aza-arenes; (ii) improving information on the ambient concentrations, long-range transport, and atmospheric deposition of these broader classes of PACs and their release (with co-contaminants) from different types of mining activities; (iii) further optimizing electricity-free and cost-effective approaches for assessing PAC deposition (e.g., snow sampling, lichens, passive ambient sampling) spatially across the OSR and downwind regions; (iv) designing projects that integrate monitoring efforts with source attribution models and ecosystem health studies to improve understanding of sources, receptors, and effects; (v) further optimizing natural deposition archives (e.g., sediment, peat, tree rings) and advanced forensic techniques (e.g., isotope analysis, marker compounds) to provide better understanding of sources of PACs in the OSR over space and time; (vi) conducting process research to improve model capabilities for simulating atmospheric chemistry of PACs and assessing exposure to wildlife and humans; and (vii) developing tools and integrated strategies for assessing cumulative risk to wildlife and humans by accounting for the toxicity of the mixture of chemicals in air rather than on a single compound basis.
- Published
- 2018
48. A Deep Dive into the Complex Chemical Mixture and Toxicity of Tire Wear Particle Leachate in Fathead Minnow
- Author
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Amila O. De Silva, Joanne L. Parrott, Hufsa Khan, Chelsea M. Rochman, Kallie Shires, Derek C. G. Muir, Leah Chibwe, Cheryl Sullivan, Stacey Clarence, Anna M O'Brien, and Christine Lavalle
- Subjects
biology ,Chemistry ,Health, Toxicology and Mutagenesis ,Aquatic ecosystem ,Cyprinidae ,Minnow ,Ecotoxicology ,Environmental chemistry ,biology.animal ,Environmental toxicology ,Toxicity ,Toxicity Tests ,Environmental Chemistry ,Animals ,Leachate ,Pimephales promelas ,Leaching (agriculture) ,Deep dive ,Ecosystem ,Water Pollutants, Chemical - Abstract
The ecological impact of tire wear particles in aquatic ecosystems is a growing environmental concern. We combined toxicity testing, using fathead minnow (Pimephales promelas) embryos, with nontarget high-resolution liquid chromatography Orbitrap mass spectrometry to characterize the toxicity and chemical mixture of organic chemicals associated with tire particle leachates. We assessed: 1) exposure to tire particle leachates after leaching for 1-, 3-, and 10-d; and 2) the effect of the presence and absence of small tire particulates in the leachates. We observed a decrease in embryonic heart rates, hatching success, and lengths, as well as an increase in the number of embryos with severe deformities and diminished eye and body pigmentation, after exposure to the leachates. Overall, there was a pattern whereby we observed more toxicity in the 10-d leachates, and greater toxicity in unfiltered leachates. Redundancy analysis showed that several benzothiazoles and aryl-amines were correlated with the toxic effects observed in the embryos. These included benzothiazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, N,N'-diphenylguanidine, and N,N'-diphenylurea. However, many other chemicals characterized as unknowns are likely to also play a key role in the adverse effects observed. Our study provides insight into the types of chemicals likely to be important toxicological drivers in tire leachates, and improves our understanding of the ecotoxicological impacts of tire wear particles. Environ Toxicol Chem 2022;41:1144-1153. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
- Published
- 2021
49. Polycyclic aromatic compounds in the Canadian Environment: Aquatic and terrestrial environments
- Author
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Gregg T. Tomy, Chris Marvin, Joanne L. Parrott, Alice Dove, Peter V. Hodson, L. Mark Hewitt, Alicia Berthiaume, Derek C. G. Muir, Leah Chibwe, Marlene S. Evans, Philippe J. Thomas, and Deborah A. Burniston
- Subjects
Watershed ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Alberta ,Environmental protection ,Urbanization ,Impervious surface ,Organic matter ,Oil and Gas Fields ,Polycyclic Compounds ,Polycyclic Aromatic Hydrocarbons ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,business.industry ,Fossil fuel ,General Medicine ,Pollution ,Arctic ,chemistry ,Environmental science ,Oil sands ,business ,Surface water ,Environmental Monitoring - Abstract
Polycyclic aromatic compounds (PACs) are ubiquitous across environmental media in Canada, including surface water, soil, sediment and snowpack. Information is presented according to pan-Canadian sources, and key geographical areas including the Great Lakes, the Alberta Oil Sands Region (AOSR) and the Canadian Arctic. Significant PAC releases result from exploitation of fossil fuels containing naturally-derived PACs, with anthropogenic sources related to production, upgrading and transport which also release alkylated PACs. Continued expansion of the oil and gas industry indicates contamination by PACs may increase. Monitoring networks should be expanded, and include petrogenic PACs in their analytical schema, particularly near fuel transportation routes. National-scale roll-ups of emission budgets may not expose important details for localized areas, and on local scales emissions can be substantial without significantly contributing to total Canadian emissions. Burning organic matter produces mainly parent or pyrogenic PACs, with forest fires and coal combustion to produce iron and steel being major sources of pyrogenic PACs in Canada. Another major source is the use of carbon electrodes at aluminum smelters in British Columbia and Quebec. Temporal trends in PAC levels across the Great Lakes basin have remained relatively consistent over the past four decades. Management actions to reduce PAC loadings have been countered by increased urbanization, vehicular emissions and areas of impervious surfaces. Major cities within the Great Lakes watershed act as diffuse sources of PACs, and result in coronas of contamination emanating from urban centres, highlighting the need for non-point source controls to reduce loadings.
- Published
- 2021
50. Spatial and Temporal Trends of Perfluoroalkyl Substances in Global Ocean and Coastal Waters
- Author
-
Derek C. G. Muir and Luc T. Miaz
- Subjects
Mass discharge ,Fluorocarbons ,Oceans and Seas ,General Chemistry ,010501 environmental sciences ,01 natural sciences ,Lakes ,Oceanography ,Alkanesulfonic Acids ,Rivers ,Western europe ,Period (geology) ,Environmental Chemistry ,Environmental science ,China ,Long chain ,Water Pollutants, Chemical ,0105 earth and related environmental sciences ,Environmental Monitoring - Abstract
Per- and polyfluoroalkyl substances (PFAS) have been widely detected in global surface waters since the early 2000s. Here, we have compiled and analyzed the published data for perfluorocarboxylates (PFCAs) and perfluorosulfonates (PFSAs) in surface waters of coastal seas, the Great Lakes, and open oceans to examine temporal and geospatial trends. Mass discharges from major rivers were also estimated. A large number of measurements of individual PFAS have been made in these surface waters (29 500 values), with seven C4-C10 PFSAs and nine C4-C12 PFCAs accounting for 83% of all data. However, most results (85% for PFSAs; 80% for PFCAs) were for the coastal seas of Western Europe, China, Korea, and Japan, while results were limited for coastal North America and lacking for South America and Africa. Highest median concentrations of PFCAs and PFSAs were reported in the Bohai and Yellow Seas region of China as well as in the North and Baltic seas in Europe. Significant declines in median PFSAs and C7-C12 PFCAs were also observed for the period 2012-2018 in these same regions, and for 2004-2017 in the Great Lakes. Mass discharge estimates indicated continued substantial riverine emissions of long chain (C7-C12) PFCAs in the period 2015-2019 for the coastal seas of China and reductions in emissions for Western European rivers compared to earlier time periods.
- Published
- 2021
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