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Cooke CA, Holland KM, Emmerton CA, Drevnick PE, Criscitiello AS, Newton B. Mountaintop Removal Coal Mining Contaminates Snowpack across a Broad Region. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11718-11726. [PMID: 38889109 PMCID: PMC11223467 DOI: 10.1021/acs.est.4c02596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 06/20/2024]
Abstract
Mountaintop removal coal mining is a source of downstream pollution. Here, we show that mountaintop removal coal mining also pollutes ecosystems downwind. We sampled regional snowpack near the end of winter along a transect of sites located 3-60 km downwind of coal mining in the Elk River valley of British Columbia, Canada. Vast quantities of polycyclic aromatic compounds (PACs), a toxic class of organic contaminants, are emitted and transported atmospherically far from emission sources. Summed PAC (ΣPAC) snowpack concentrations ranged from 29-94,866 ng/L. Snowpack ΣPAC loads, which account for variable snowpack depth, ranged from <10 μg/m2 at sites >50 km southeast of the mines to >1000 μg/m2 at sites in the Elk River valley near mining operations, with one site >15,000 μg/m2. Outside of the Elk River valley, snowpack ΣPAC loads exhibited a clear spatial pattern decreasing away from the mines. The compositional fingerprint of this PAC pollution matches closely with Elk River valley coal. Beyond our study region, modeling results suggest a depositional footprint extending across western Canada and the northwestern United States. These findings carry important implications for receiving ecosystems and for communities located close to mountaintop removal coal mines exposed to air pollution elevated in PACs.
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Affiliation(s)
- Colin A. Cooke
- Environment
and Protected Areas, Government of Alberta, 9888 Jasper Ave, Edmonton, Alberta T5J 5C6, Canada
- Department
of Earth and Atmospheric Sciences, University
of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Kira M. Holland
- Department
of Earth and Atmospheric Sciences, University
of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Craig A. Emmerton
- Environment
and Protected Areas, Government of Alberta, 9888 Jasper Ave, Edmonton, Alberta T5J 5C6, Canada
- Department
of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Paul E. Drevnick
- Environment
and Protected Areas, Government of Alberta, 3535 Research Road NW, Calgary, Alberta T2L 2K8, Canada
- Department
of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Alison S. Criscitiello
- Department
of Earth and Atmospheric Sciences, University
of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Brandi Newton
- Environment
and Protected Areas, Government of Alberta, 3535 Research Road NW, Calgary, Alberta T2L 2K8, Canada
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2
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Liu H, Zheng W, Gao Y, Yang L, Yue F, Huang T, Xie Z. Increased Contribution of Circumpolar Deep Water Upwelling to Methylmercury in the Upper Ocean around Antarctica: Evidence from Mercury Isotopes in the Ornithogenic Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2762-2773. [PMID: 38294849 DOI: 10.1021/acs.est.3c06923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Upwelling plays a pivotal role in supplying methylmercury (MeHg) to the upper oceans, contributing to the bioaccumulation of MeHg in the marine food web. However, the influence of the upwelling of Circumpolar Deep Water (CDW), the most voluminous water mass in the Southern Ocean, on the MeHg cycle in the surrounding oceans and marine biota of Antarctica remains unclear. Here, we study the mercury (Hg) isotopes in an ornithogenic sedimentary profile strongly influenced by penguin activity on Ross Island, Antarctica. Results indicate that penguin guano is the primary source of Hg in the sediments, and the mass-independent isotope fractionation of Hg (represented by Δ199Hg) can provide insights on the source of marine MeHg accumulated by penguin. The Δ199Hg in the sediments shows a significant decrease at ∼1550 CE, which is primarily attributed to the enhanced upwelling of CDW that brought more MeHg with lower Δ199Hg from the deeper seawater to the upper ocean. We estimate that the contribution of MeHg from the deeper seawater may reach more than 38% in order to explain the decline in Δ199Hg at ∼1550 CE. Moreover, we found that the intensified upwelling may have increased the MeHg exposure for marine organisms, highlighting the importance of CDW upwelling on the MeHg cycle in Antarctic coastal ecosystems.
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Affiliation(s)
- Hongwei Liu
- Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Wang Zheng
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, United States
| | - Yuesong Gao
- Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lianjiao Yang
- Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fange Yue
- Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tao Huang
- School of Resources and Environmental Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Zhouqing Xie
- Department of Environmental Science and Engineering, Anhui Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, China
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3
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Yue F, Angot H, Blomquist B, Schmale J, Hoppe CJM, Lei R, Shupe MD, Zhan L, Ren J, Liu H, Beck I, Howard D, Jokinen T, Laurila T, Quéléver L, Boyer M, Petäjä T, Archer S, Bariteau L, Helmig D, Hueber J, Jacobi HW, Posman K, Xie Z. The Marginal Ice Zone as a dominant source region of atmospheric mercury during central Arctic summertime. Nat Commun 2023; 14:4887. [PMID: 37580358 PMCID: PMC10425351 DOI: 10.1038/s41467-023-40660-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 08/01/2023] [Indexed: 08/16/2023] Open
Abstract
Atmospheric gaseous elemental mercury (GEM) concentrations in the Arctic exhibit a clear summertime maximum, while the origin of this peak is still a matter of debate in the community. Based on summertime observations during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and a modeling approach, we further investigate the sources of atmospheric Hg in the central Arctic. Simulations with a generalized additive model (GAM) show that long-range transport of anthropogenic and terrestrial Hg from lower latitudes is a minor contribution (~2%), and more than 50% of the explained GEM variability is caused by oceanic evasion. A potential source contribution function (PSCF) analysis further shows that oceanic evasion is not significant throughout the ice-covered central Arctic Ocean but mainly occurs in the Marginal Ice Zone (MIZ) due to the specific environmental conditions in that region. Our results suggest that this regional process could be the leading contributor to the observed summertime GEM maximum. In the context of rapid Arctic warming and the observed increase in width of the MIZ, oceanic Hg evasion may become more significant and strengthen the role of the central Arctic Ocean as a summertime source of atmospheric Hg.
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Affiliation(s)
- Fange Yue
- Institute of Polar Environment & Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hélène Angot
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland.
- Institute for Arctic and Alpine Research (INSTAAR), University of Colorado Boulder, Boulder, CO, USA.
- Univ. Grenoble Alpes, CNRS, INRAE, IRD, Grenoble INP, IGE, 38000, Grenoble, France.
| | - Byron Blomquist
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
- NOAA, Physical Sciences Laboratory, Boulder, CO, USA
| | - Julia Schmale
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland
| | - Clara J M Hoppe
- Alfred Wegener Institut-Helmholtzzentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Ruibo Lei
- Key Laboratory for Polar Science of the MNR, Polar Research Institute of China, Shanghai, China
| | - Matthew D Shupe
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
- NOAA, Physical Sciences Laboratory, Boulder, CO, USA
| | - Liyang Zhan
- Third Institute of Oceanography, Ministry of natural resources, Xiamen, China
| | - Jian Ren
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China
| | - Hailong Liu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Ivo Beck
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland
| | - Dean Howard
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
- NOAA, Physical Sciences Laboratory, Boulder, CO, USA
| | - Tuija Jokinen
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
- Climate & Atmosphere Research Centre (CARE-C), The Cyprus Institute, Nicosia, Cyprus
| | - Tiia Laurila
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Lauriane Quéléver
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Matthew Boyer
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Tuukka Petäjä
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Stephen Archer
- Bigelow Laboratory for Ocean Sciences, Boothbay, ME, USA
| | - Ludovic Bariteau
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
- NOAA, Physical Sciences Laboratory, Boulder, CO, USA
| | - Detlev Helmig
- Boulder Atmosphere Innovation Research, Boulder, CO, USA
| | | | - Hans-Werner Jacobi
- Univ. Grenoble Alpes, CNRS, INRAE, IRD, Grenoble INP, IGE, 38000, Grenoble, France
| | - Kevin Posman
- Bigelow Laboratory for Ocean Sciences, Boothbay, ME, USA
| | - Zhouqing Xie
- Institute of Polar Environment & Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
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4
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Jonsson S, Mastromonaco MN, Wang F, Bravo AG, Cairns WRL, Chételat J, Douglas TA, Lescord G, Ukonmaanaho L, Heimbürger-Boavida LE. Arctic methylmercury cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157445. [PMID: 35882324 DOI: 10.1016/j.scitotenv.2022.157445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic mercury (Hg) undergoes long-range transport to the Arctic where some of it is transformed into methylmercury (MeHg), potentially leading to high exposure in some Arctic inhabitants and wildlife. The environmental exposure of Hg is determined not just by the amount of Hg entering the Arctic, but also by biogeochemical and ecological processes occurring in the Arctic. These processes affect MeHg uptake in biota by regulating the bioavailability, methylation and demethylation, bioaccumulation and biomagnification of MeHg in Arctic ecosystems. Here, we present a new budget for pools and fluxes of MeHg in the Arctic and review the scientific advances made in the last decade on processes leading to environmental exposure to Hg. Methylation and demethylation are key processes controlling the pool of MeHg available for bioaccumulation. Methylation of Hg occurs in diverse Arctic environments including permafrost, sediments and the ocean water column, and is primarily a process carried out by microorganisms. While microorganisms carrying the hgcAB gene pair (responsible for Hg methylation) have been identified in Arctic soils and thawing permafrost, the formation pathway of MeHg in oxic marine waters remains less clear. Hotspots for methylation of Hg in terrestrial environments include thermokarst wetlands, ponds and lakes. The shallow sub-surface enrichment of MeHg in the Arctic Ocean, in comparison to other marine systems, is a possible explanation for high MeHg concentrations in some Arctic biota. Bioconcentration of aqueous MeHg in bacteria and algae is a critical step in the transfer of Hg to top predators, which may be dampened or enhanced by the presence of organic matter. Variable trophic position has an important influence on MeHg concentrations among populations of top predator species such as ringed seal and polar bears distributed across the circumpolar Arctic. These scientific advances highlight key processes that affect the fate of anthropogenic Hg deposited to Arctic environments.
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Affiliation(s)
- Sofi Jonsson
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
| | | | - Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
| | - Warren R L Cairns
- CNR Institute of Polar Sciences and Ca' Foscari University, Venice, Italy
| | - John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
| | - Gretchen Lescord
- Wildlife Conservation Society Canada and Laurentian University, Vale Living with Lakes Center, Sudbury, Ontario, Canada
| | - Liisa Ukonmaanaho
- Natural Resources Institute Finland (Luke), P.O. Box 2, FI-00791 Helsinki, Finland
| | - Lars-Eric Heimbürger-Boavida
- CNRS/INSU,Aix Marseille Université,Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
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5
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Dastoor A, Wilson SJ, Travnikov O, Ryjkov A, Angot H, Christensen JH, Steenhuisen F, Muntean M. Arctic atmospheric mercury: Sources and changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156213. [PMID: 35623517 DOI: 10.1016/j.scitotenv.2022.156213] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Global anthropogenic and legacy mercury (Hg) emissions are the main sources of Arctic Hg contamination, primarily transported there via the atmosphere. This review summarizes the state of knowledge of the global anthropogenic sources of Hg emissions, and examines recent changes and source attribution of Hg transport and deposition to the Arctic using models. Estimated global anthropogenic Hg emissions to the atmosphere for 2015 were ~2220 Mg, ~20% higher than 2010. Global anthropogenic, legacy and geogenic Hg emissions were, respectively, responsible for 32%, 64% (wildfires: 6-10%) and 4% of the annual Arctic Hg deposition. Relative contributions to Arctic deposition of anthropogenic origin was dominated by sources in East Asia (32%), Commonwealth of Independent States (12%), and Africa (12%). Model results exhibit significant spatiotemporal variations in Arctic anthropogenic Hg deposition fluxes, driven by regional differences in Hg air transport routes, surface and precipitation uptake rates, and inter-seasonal differences in atmospheric circulation and deposition pathways. Model simulations reveal that changes in meteorology are having a profound impact on contemporary atmospheric Hg in the Arctic. Reversal of North Atlantic Oscillation phase from strongly negative in 2010 to positive in 2015, associated with lower temperature and more sea ice in the Canadian Arctic, Greenland and surrounding ocean, resulted in enhanced production of bromine species and Hg(0) oxidation and lower evasion of Hg(0) from ocean waters in 2015. This led to increased Hg(II) (and its deposition) and reduced Hg(0) air concentrations in these regions in line with High Arctic observations. However, combined changes in meteorology and anthropogenic emissions led to overall elevated modeled Arctic air Hg(0) levels in 2015 compared to 2010 contrary to observed declines at most monitoring sites, likely due to uncertainties in anthropogenic emission speciation, wildfire emissions and model representations of air-surface Hg fluxes.
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Affiliation(s)
- Ashu Dastoor
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada.
| | - Simon J Wilson
- Arctic Monitoring and Assessment Programme (AMAP). The Fram Centre, Box 6606 Stakkevollan, 9296 Tromsø, Norway.
| | - Oleg Travnikov
- Meteorological Synthesizing Centre-East, EMEP, 2nd Roshchinsky proezd, 8/5, 115419 Moscow, Russia
| | - Andrei Ryjkov
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada
| | - Hélène Angot
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland
| | - Jesper H Christensen
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Frits Steenhuisen
- Arctic Centre, University of Groningen, Aweg 30, 9718CW Groningen, the Netherlands
| | - Marilena Muntean
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749 (T.P. 123), I-21027 Ispra, VA, Italy
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6
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Skogsberg E, McGovern M, Poste A, Jonsson S, Arts MT, Varpe Ø, Borgå K. Seasonal pollutant levels in littoral high-Arctic amphipods in relation to food sources and terrestrial run-off. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 306:119361. [PMID: 35523379 DOI: 10.1016/j.envpol.2022.119361] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 03/09/2022] [Accepted: 04/23/2022] [Indexed: 06/14/2023]
Abstract
Increasing terrestrial run-off from melting glaciers and thawing permafrost to Arctic coastal areas is expected to facilitate re-mobilization of stored legacy persistent organic pollutants (POPs) and mercury (Hg), potentially increasing exposure to these contaminants for coastal benthic organisms. We quantified chlorinated POPs and Hg concentrations, lipid content and multiple dietary markers, in a littoral deposit-feeding amphipod Gammarus setosus and sediments during the melting period from April to August in Adventelva river estuary in Svalbard, a Norwegian Arctic Aarchipelago. There was an overall decrease in concentrations of ∑POPs from April to August (from 58 ± 23 to 13 ± 4 ng/g lipid weight; lw), Hg (from 5.6 ± 0.7 to 4.1 ± 0.5 ng/g dry weight; dw) and Methyl Hg (MeHg) (from 5 ± 1 to 0.8 ± 0.7 ng/g dw) in G. setosus. However, we observed a seasonal peak in penta- and hexachlorobenzene (PeCB and HCB) in May (2.44 ± 0.3 and 23.6 ± 1.7 ng/g lw). Sediment concentrations of POPs and Hg (dw) only partly correlated with the contaminant concentrations in G. setosus. Dietary markers, including fatty acids and carbon and nitrogen stable isotopes, indicated a diet of settled phytoplankton in May-July and a broader range of carbon sources after the spring bloom. Phytoplankton utilization and chlorobenzene concentrations in G. setosus exhibited similar seasonal patterns, suggesting a dietary uptake of chlorobenzenes that is delivered to the aquatic environment during spring snowmelt. The seasonal decrease in contaminant concentrations in G. setosus could be related to seasonal changes in dietary contaminant exposure and amphipod ecology. Furthermore, this decrease implies that terrestrial run-off is not a significant source of re-mobilized Hg and legacy POPs to littoral amphipods in the Adventelva river estuary during the melt season.
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Affiliation(s)
- Emelie Skogsberg
- University of Oslo, Department of Biosciences, Oslo, Norway; The University Centre in Svalbard, Department of Arctic Biology, Longyearbyen, Norway
| | - Maeve McGovern
- Norwegian Institute for Water Research, Oslo, Norway; The Arctic University of Norway, Tromsø, Norway
| | - Amanda Poste
- Norwegian Institute for Water Research, Oslo, Norway; The Arctic University of Norway, Tromsø, Norway
| | - Sofi Jonsson
- Stockholm University, Department of Environmental Science, Stockholm, Sweden
| | - Michael T Arts
- Ryerson University, Department of Chemistry and Biology, Toronto, M5B 2K3, Canada
| | - Øystein Varpe
- The University Centre in Svalbard, Department of Arctic Biology, Longyearbyen, Norway; Norwegian Institute for Nature Research, Bergen, Norway; University of Bergen, Department of Biological Sciences, Bergen, Norway
| | - Katrine Borgå
- University of Oslo, Department of Biosciences, Oslo, Norway.
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7
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Chételat J, McKinney MA, Amyot M, Dastoor A, Douglas TA, Heimbürger-Boavida LE, Kirk J, Kahilainen KK, Outridge PM, Pelletier N, Skov H, St Pierre K, Vuorenmaa J, Wang F. Climate change and mercury in the Arctic: Abiotic interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153715. [PMID: 35149079 DOI: 10.1016/j.scitotenv.2022.153715] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Dramatic environmental shifts are occuring throughout the Arctic from climate change, with consequences for the cycling of mercury (Hg). This review summarizes the latest science on how climate change is influencing Hg transport and biogeochemical cycling in Arctic terrestrial, freshwater and marine ecosystems. As environmental changes in the Arctic continue to accelerate, a clearer picture is emerging of the profound shifts in the climate and cryosphere, and their connections to Hg cycling. Modeling results suggest climate influences seasonal and interannual variability of atmospheric Hg deposition. The clearest evidence of current climate change effects is for Hg transport from terrestrial catchments, where widespread permafrost thaw, glacier melt and coastal erosion are increasing the export of Hg to downstream environments. Recent estimates suggest Arctic permafrost is a large global reservoir of Hg, which is vulnerable to degradation with climate warming, although the fate of permafrost soil Hg is unclear. The increasing development of thermokarst features, the formation and expansion of thaw lakes, and increased soil erosion in terrestrial landscapes are increasing river transport of particulate-bound Hg and altering conditions for aquatic Hg transformations. Greater organic matter transport may also be influencing the downstream transport and fate of Hg. More severe and frequent wildfires within the Arctic and across boreal regions may be contributing to the atmospheric pool of Hg. Climate change influences on Hg biogeochemical cycling remain poorly understood. Seasonal evasion and retention of inorganic Hg may be altered by reduced sea-ice cover and higher chloride content in snow. Experimental evidence indicates warmer temperatures enhance methylmercury production in ocean and lake sediments as well as in tundra soils. Improved geographic coverage of measurements and modeling approaches are needed to better evaluate net effects of climate change and long-term implications for Hg contamination in the Arctic.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, National Wildlife Research Centre, Ottawa, ON K1A 0H3, Canada.
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Marc Amyot
- Groupe de recherche interuniversitaire en limnologie (GRIL), Département de sciences biologiques, Complexe des Sciences, Montréal, QC H2V 0B3, Canada
| | - Ashu Dastoor
- Environment and Climate Change Canada, Air Quality Research Division, Dorval, QC H9P 1J3, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK 99709, USA
| | - Lars-Eric Heimbürger-Boavida
- Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Marseille, France
| | - Jane Kirk
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Burlington, ON L7S 1A1, Canada
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, FI-16900 Lammi, Finland
| | - Peter M Outridge
- Geological Survey of Canada, Natural Resources Canada, Ottawa, ON K1A 0E8, Canada
| | - Nicolas Pelletier
- Geography and Environmental Studies, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Henrik Skov
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Kyra St Pierre
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jussi Vuorenmaa
- Finnish Environment Institute (SYKE), Latokartanonkaari 11, FI-00790 Helsinki, Finland
| | - Feiyue Wang
- Centre for Earth Observation Sciences (CEOS), Dept. of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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8
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Varty S, Lehnherr I, St Pierre K, Kirk J, Wisniewski V. Methylmercury Transport and Fate Shows Strong Seasonal and Spatial Variability along a High Arctic Freshwater Hydrologic Continuum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:331-340. [PMID: 33356178 DOI: 10.1021/acs.est.0c05051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The presence of toxic methylmercury (MeHg) in Arctic freshwater ecosystems and foodwebs is a potential health concern for northern Indigenous people. Addressing this issue requires a better understanding of MeHg production, fate during transport, and uptake into foodwebs. We used methylation assays and spatiotemporal surveys of MeHg concentrations, during the ice-covered and open water seasons, across a hydrologic continuum (composed of thaw seeps, lake/ponds, and a wetland) to identify Hg methylation hotspots and seasonal differences in MeHg cycling unique to Arctic ecosystems. Ponds and saturated wetland soils support methylation hotspots during the open water season, but subsequent export of MeHg to downstream ecosystems is limited by particle settling, binding of MeHg on soil organic matter, and/or demethylation in drier wetland soils. During the ice-covered season, MeHg concentrations in lake waters were approximately ten-fold greater than in summer; however, zooplankton MeHg concentrations were paradoxically five times lower at this time. Despite limited evidence of snow-phase methylation, the snowpack is an important MeHg reservoir. Changes in ice-cover duration will alter MeHg production and bioaccumulation in lakes, while increased thaw and surface water flow will likely result in higher methylation rates at the aquatic-terrestrial interface and more efficient downstream transport of MeHg.
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Affiliation(s)
- Stephanie Varty
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Kyra St Pierre
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Jane Kirk
- Canada Centre for Inland Waters, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Victoria Wisniewski
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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9
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Bishop K, Shanley JB, Riscassi A, de Wit HA, Eklöf K, Meng B, Mitchell C, Osterwalder S, Schuster PF, Webster J, Zhu W. Recent advances in understanding and measurement of mercury in the environment: Terrestrial Hg cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137647. [PMID: 32197286 DOI: 10.1016/j.scitotenv.2020.137647] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/23/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
This review documents recent advances in terrestrial mercury cycling. Terrestrial mercury (Hg) research has matured in some areas, and is developing rapidly in others. We summarize the state of the science circa 2010 as a starting point, and then present the advances during the last decade in three areas: land use, sulfate deposition, and climate change. The advances are presented in the framework of three Hg "gateways" to the terrestrial environment: inputs from the atmosphere, uptake in food, and runoff with surface water. Among the most notable advances: These and other advances reported here are of value in evaluating the effectiveness of the Minamata Convention on reducing environmental Hg exposure to humans and wildlife.
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Affiliation(s)
- Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | | | - Ami Riscassi
- Department of Environmental Sciences, University of Virginia, P.O. Box 400123, Charlottesville, VA 22904-4123, USA.
| | - Heleen A de Wit
- Norwegian Institute for Water Research, Gaustadalléen 21, NO-0349, Norway.
| | - Karin Eklöf
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
| | - Carl Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
| | - Stefan Osterwalder
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble 18 INP, 38000 Grenoble, France.
| | - Paul F Schuster
- U.S. Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303-1066, USA.
| | - Jackson Webster
- Department of Civil Engineering, California State University, 400 W. 1st Street, 21 95929-0930 Chico, CA, USA.
| | - Wei Zhu
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden.
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10
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Wasiuta V, Kirk JL, Chambers PA, Alexander AC, Wyatt FR, Rooney RC, Cooke CA. Accumulating Mercury and Methylmercury Burdens in Watersheds Impacted by Oil Sands Pollution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:12856-12864. [PMID: 31621313 DOI: 10.1021/acs.est.9b02373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Bitumen mining and upgrading in northeastern Alberta, Canada, releases toxic pollutants into the atmosphere, including mercury (Hg) and methylmercury (MeHg). This Hg and MeHg is then deposited to the surrounding landscape; however, the fate of these contaminants remains unknown. Here, we compare snowpack chemistry to high-frequency measurements of river water quality across six watersheds (five impacted by oil sands development and one unimpacted). Catchment scale snowpack Hg and MeHg loads normalized to watershed area were highest near oil sands operations. River water Hg concentrations and loads tracked discharge and tended to be higher downstream of mining operations, while MeHg concentrations and loads increased through the summer, reflecting peak summer MeHg production rates. Except in the reference watershed, snowpack Hg and MeHg loads equaled or exceeded the amount of Hg and MeHg exported during freshet and, in some cases, the entire hydrologic year. This suggests landscapes across the oil sands region, which are dominated by low-relief wetlands and other shallow-water systems, are accumulating Hg and MeHg. Importantly, during years of high discharge, these low-relief systems appear to become better connected and flush MeHg (and Hg) from the watershed. Thus, these watersheds may act as temporary, rather than as permanent, natural repositories of oil sands contaminants.
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Affiliation(s)
- Vivian Wasiuta
- Department of Earth and Atmospheric Sciences , University of Alberta , 1-26 Earth Sciences Building , Edmonton , Alberta , Canada T6G 2E3
| | - Jane L Kirk
- Water Science and Technology Directorate , Environment and Climate Change Canada , 867 Lakeshore Road , Burlington , Ontario , Canada L7R 4A6
| | - Patricia A Chambers
- Water Science and Technology Directorate , Environment and Climate Change Canada , 867 Lakeshore Road , Burlington , Ontario , Canada L7R 4A6
| | - Alexa C Alexander
- Water Science and Technology Directorate, Environment and Climate Change Canada, Department of Biology , University of New Brunswick , 10 Bailey Drive , Fredericton , New Brunswick , Canada , E3B 5A3
| | - Faye R Wyatt
- Environmental Monitoring and Science Division , Alberta Environment and Parks , 9888 Jasper Avenue , Edmonton , Alberta , Canada T5J5C6
| | - Rebecca C Rooney
- Department of Biology , University of Waterloo , ESC 350, 200 University Avenue , Waterloo , Ontario , Canada , N2L 3G1
| | - Colin A Cooke
- Department of Earth and Atmospheric Sciences , University of Alberta , 1-26 Earth Sciences Building , Edmonton , Alberta , Canada T6G 2E3
- Environmental Monitoring and Science Division , Alberta Environment and Parks , 9888 Jasper Avenue , Edmonton , Alberta , Canada T5J5C6
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11
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Sontag PT, Steinberg DK, Reinfelder JR. Patterns of total mercury and methylmercury bioaccumulation in Antarctic krill (Euphausia superba) along the West Antarctic Peninsula. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:174-183. [PMID: 31229815 DOI: 10.1016/j.scitotenv.2019.06.176] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/19/2019] [Accepted: 06/11/2019] [Indexed: 06/09/2023]
Abstract
We examined mercury (Hg) accumulation in juvenile and adult subpopulations of Antarctic krill (Euphausia superba) collected west of the Antarctic Peninsula. Samples were collected along a northern cross-shelf transect beginning near Anvers Island and farther south near the sea ice edge in the austral summers of 2011, 2013, 2014, and 2015. Regardless of geographical position, mean concentrations of total Hg and methylmercury (MeHg), the form of Hg that biomagnifies in marine food webs, were significantly higher in juvenile than adult krill in all years. In 2013, juvenile Antarctic krill collected along the coast near Anvers Island had significantly higher MeHg concentrations than krill collected farther offshore, and in 2013 and 2014, coastal juvenile krill exhibited some of the highest MeHg concentrations of all subpopulations sampled. Across all sampling years, collection in northern (sea ice-free) or southern (sea ice edge) transects did not affect MeHg concentrations of juvenile or adult krill, suggesting similar levels and routes of MeHg exposure across the latitudes sampled. Developmental stage, feeding near the coast, and annual variations in sea ice-driven primary and export production were identified as potentially important factors leading to greater MeHg accumulation in juvenile than adult krill. Krill-dependent predators feeding primarily on juveniles may thus accumulate more MeHg than consumers foraging on older krill. These results report MeHg concentrations in Antarctic krill and will be useful for predicting Hg biomagnification in higher-level consumers in this productive Antarctic ecosystem.
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Affiliation(s)
- Philip T Sontag
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA.
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USA.
| | - John R Reinfelder
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA.
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