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Pilote M, Houle D, Gagnon C, Couture S, Dastoor A, Ryjkov A. Key factors influencing Hg levels and trends in unperturbed oligotrophic temperate and boreal lakes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 356:124232. [PMID: 38823549 DOI: 10.1016/j.envpol.2024.124232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/15/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024]
Abstract
Mercury (Hg) is a toxic metal that presents a major risk to ecosystems, biota, human health, and remains a priority concern. In temperate and boreal lakes Hg and methylmercury (MMHg) are expected to vary as a function of atmospheric Hg deposition, lake water chemistry, catchment characteristics and climate variables. The aim of this study was to quantify Hg and MMHg in unperturbed oligotrophic lakes and to identify the factors controlling their distribution. We first hypothesized that lake Hg (and MMHg to lesser extent) spatial variations are linked to atmospheric deposition, catchment characteristics, and terrestrial exportation of dissolved organic carbon (DOC). We secondly examined if lake Hg concentrations have followed the decrease in atmospheric Hg emission observed between the mid-1990s to the end-2010s. We found that overall, atmospheric Hg has little impact on lake Hg and MMHg concentrations, which are both primarily influenced by DOC input originating from the forest catchment. The relationship between DOC and Hg differed between the spring and the fall, with a Hg-to-DOC ratio twice as high in spring. This seems related to snowmelt input of Hg (with a relatively reduced input of DOC) or the internal lake build-up of Hg during the ice-covered period. Of the 10 lakes intensively visited over a 20-year period, only 3 showed significant lake Hg decreases despite significant negative trends in atmospheric Hg concentrations, suggesting a lag between atmospheric and surface water temporal trends. Overall, terrestrial catchments retain around 80% of atmospheric Hg implying that large Hg pools have been built up in soils in the last decades. As such, the reduction of atmospheric Hg alone will not necessarily result in Hg decreases in lakes, since the Hg concentrations may be modulated by DOC export trends and catchment characteristics. This stresses the need to improve our understanding of the processes governing Hg transfers from catchments into lakes.
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Affiliation(s)
- M Pilote
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada.
| | - D Houle
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - C Gagnon
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - S Couture
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - A Dastoor
- Environment and Climate Change Canada, Atmospheric Science and Technology, Air Quality Research Division, 2121 route Transcanadienne, Dorval, Qc, H9P 1J3, Canada
| | - A Ryjkov
- Environment and Climate Change Canada, Atmospheric Science and Technology, Air Quality Research Division, 2121 route Transcanadienne, Dorval, Qc, H9P 1J3, Canada
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2
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Kim YG, Kwon SY, Washburn SJ, Brooks SC, Yoon JW, Besnard L. Reconsidering mercury sources and exposure pathways to bivalves: Insights from mercury stable isotopes. WATER RESEARCH 2024; 248:120843. [PMID: 37976947 DOI: 10.1016/j.watres.2023.120843] [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: 06/30/2023] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023]
Abstract
Identifying mercury (Hg) sources and exposure pathways to bivalves, particularly in relation to sediment, is important for expanding the utility of bivalves as a monitoring organism for sediment quality. Here we use Hg isotope ratios to decipher Hg sources accumulated into bivalves by conducting field studies and in situ experiments. In the first part of this study, we characterized Hg isotope ratios in individual geochemical fractions of riverine sediment, contaminated by liquid Hg in South Korea (Hyeongsan River; HS). Asian clams (Corbicula fluminea) were then deployed at the contaminated sites to evaluate the isotopic turnover. Over the two-month period, the isotope ratios of the clams shifted toward the labile/exchangeable Hg pools (F1, F2 fractions) of the sediment. Conversely, in the control site where sediment Hg is low, we observed similar Hg isotope ratios between Asian clams and the samples of precipitation and dissolved phase of water column. In East Fork Poplar Creek, (Oak Ridge) U.S., Asian clams also displayed similar Hg isotope ratios with the dissolved phase of water column, which have undergone substantial in-stream processing or input from Hg-contaminated groundwater from the hyporheic zones and riparian tributary during high hydrologic flow seasons. Our study demonstrates that the dissolved Hg phases within the water column, whether originating via sediment diffusion or derived externally, act as the primary source and exposure pathways to bivalves. The results of our study also shed new light to the prior Hg isotope measurement in bivalves collected from estuarine, lake, and coastal systems, which showed significant isotopic deviation from bulk sediment. The fact that bivalves are sensitive to in situ and external dissolved Hg phases provides additional insight into the existing biomonitoring program, which uses bivalves as a bioindicator for sediment quality.
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Affiliation(s)
- Young Gwang Kim
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea
| | - Sae Yun Kwon
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea; Institute for Convergence Research and Education in Advanced Technology, Yonsei University, 85 Songdogwahak-Ro, Yeonsu-Gu, Incheon 21983, Republic of Korea.
| | - Spencer J Washburn
- Environmental Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States
| | - Scott C Brooks
- Environmental Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States
| | - Ji Won Yoon
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea
| | - Lucien Besnard
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea
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3
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Feinberg A, Dlamini T, Jiskra M, Shah V, Selin NE. Evaluating atmospheric mercury (Hg) uptake by vegetation in a chemistry-transport model. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1303-1318. [PMID: 35485923 PMCID: PMC9491292 DOI: 10.1039/d2em00032f] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mercury (Hg), a neurotoxic heavy metal, is transferred to marine and terrestrial ecosystems through atmospheric transport. Recent studies have highlighted the role of vegetation uptake as a sink for atmospheric elemental mercury (Hg0) and a source of Hg to soils. However, the global magnitude of the Hg0 vegetation uptake flux is highly uncertain, with estimates ranging 1000-4000 Mg per year. To constrain this sink, we compare simulations in the chemical transport model GEOS-Chem with a compiled database of litterfall, throughfall, and flux tower measurements from 93 forested sites. The prior version of GEOS-Chem predicts median Hg0 dry deposition velocities similar to litterfall measurements from Northern hemisphere temperate and boreal forests (∼0.03 cm s-1), yet it underestimates measurements from a flux tower study (0.04 cm s-1vs. 0.07 cm s-1) and Amazon litterfall (0.05 cm s-1vs. 0.17 cm s-1). After revising the Hg0 reactivity within the dry deposition parametrization to match flux tower and Amazon measurements, GEOS-Chem displays improved agreement with the seasonality of atmospheric Hg0 observations in the Northern midlatitudes. Additionally, the modelled bias in Hg0 concentrations in South America decreases from +0.21 ng m-3 to +0.05 ng m-3. We calculate a global flux of Hg0 dry deposition to land of 2276 Mg per year, approximately double previous model estimates. The Amazon rainforest contributes 29% of the total Hg0 land sink, yet continued deforestation and climate change threatens the rainforest's stability and thus its role as an important Hg sink. In an illustrative worst-case scenario where the Amazon is completely converted to savannah, GEOS-Chem predicts that an additional 283 Mg Hg per year would deposit to the ocean, where it can bioaccumulate in the marine food chain. Biosphere-atmosphere interactions thus play a crucial role in global Hg cycling and should be considered in assessments of future Hg pollution.
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Affiliation(s)
- Aryeh Feinberg
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Thandolwethu Dlamini
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Martin Jiskra
- Environmental Geosciences, University of Basel, Basel, Switzerland
| | - Viral Shah
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Noelle E Selin
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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4
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Deng GZ, Liu XW, Deng JJ, Cao Y, Kang XJ, Zhu HY. Investigation of novel mercapto-functionalized nanofiber membrane for the adsorption of mercury in air. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-021-01927-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Assessment of Mercury Concentrations and Fluxes Deposited from the Atmosphere on the Territory of the Yamal-Nenets Autonomous Area. ATMOSPHERE 2021. [DOI: 10.3390/atmos13010037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The problem of mercury input and its further distribution in the Arctic environment is actively debated, especially in recent times, due to the observed processes of permafrost thawing causing the enhanced release of mercury into the Arctic atmosphere and further distribution in the terrestrial and aquatic ecosystem. The atmospheric mercury deposition occurs via dry deposition and wet scavenging by precipitation events. Here we present a study of Hg in wet precipitation on the remote territory of the Russian Arctic; the data were obtained at the monitoring stations Nadym and Salekhard in 2016–2018. Mercury pollution of the Salekhard atmosphere in cold time is mainly determined by regional and local sources, while in Nadym, long-range transport of mercury and local fuel combustion are the main sources of pollutants in the cold season, while internal regional sources have a greater impact on the warm season. Total mercury concentrations in wet precipitation in Nadym varied from <0.5 to 63.3 ng/L. The highest Hg concentrations in the springtime were most likely attributed to atmospheric mercury depletion events (AMDE). The contributions of wet atmospheric precipitation during the AMDE period to the annual Hg deposition were 16.7% and 9.8% in 2016/2017 and 2017/2018, respectively. The average annual volume-weighted Hg concentration (VWC) in the atmospheric precipitation in Nadym is notably higher than the values reported for the remote regions in the Arctic and comparable with the values obtained for the other urbanized regions of the world. Annual Hg fluxes in Nadym are nevertheless close to the average annual fluxes for remote territories of the Arctic zone and significantly lower than the annual fluxes reported for unpolluted sites of continental-scale monitoring networks of the different parts of the world (USA, Europe, and China). The increase of Hg deposition flux with wet precipitation in Nadym in 2018 might be caused by regional emissions of gas and oil combustion, wildfires, and Hg re-emission from soils due to the rising air temperature. The 37 cm increase of the seasonally thawed layer (STL) in 2018 compared to the 10-year average reflects that the climatic changes in the Nadym region might increase Hg(0) evasion, considering a great pool of Hg is contained in permafrost.
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Angot H, Rutkowski E, Sargent M, Wofsy SC, Hutyra LR, Howard D, Obrist D, Selin NE. Atmospheric mercury sources in a coastal-urban environment: a case study in Boston, Massachusetts, USA. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:1914-1929. [PMID: 34739015 DOI: 10.1039/d1em00253h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) is an environmental toxicant dangerous to human health and the environment. Its anthropogenic emissions are regulated by global, regional, and local policies. Here, we investigate Hg sources in the coastal city of Boston, the third largest metropolitan area in the Northeastern United States. With a median of 1.37 ng m-3, atmospheric Hg concentrations measured from August 2017 to April 2019 were at the low end of the range reported in the Northern Hemisphere and in the range reported at North American rural sites. Despite relatively low ambient Hg concentrations, we estimate anthropogenic emissions to be 3-7 times higher than in current emission inventories using a measurement-model framework, suggesting an underestimation of small point and/or nonpoint emissions. We also test the hypothesis that a legacy Hg source from the ocean contributes to atmospheric Hg concentrations in the study area; legacy emissions (recycling of previously deposited Hg) account for ∼60% of Hg emitted annually worldwide (and much of this recycling takes place through the oceans). We find that elevated concentrations observed during easterly oceanic winds can be fully explained by low wind speeds and recirculating air allowing for accumulation of land-based emissions. This study suggests that the influence of nonpoint land-based emissions may be comparable in size to point sources in some regions and highlights the benefits of further top-down studies in other areas.
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Affiliation(s)
- Hélène Angot
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais, Wallis, Sion, Switzerland
| | - Emma Rutkowski
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Maryann Sargent
- School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Steven C Wofsy
- School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Lucy R Hutyra
- Department of Earth and Environment, Boston University, Boston, MA, USA
| | - Dean Howard
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts-Lowell, MA, USA
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Daniel Obrist
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts-Lowell, MA, USA
| | - Noelle E Selin
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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7
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Roberts SL, Kirk JL, Muir DCG, Wiklund JA, Evans MS, Gleason A, Tam A, Drevnick PE, Dastoor A, Ryjkov A, Yang F, Wang X, Lawson G, Pilote M, Keating J, Barst BD, Ahad JME, Cooke CA. Quantification of Spatial and Temporal Trends in Atmospheric Mercury Deposition across Canada over the Past 30 Years. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15766-15775. [PMID: 34792335 DOI: 10.1021/acs.est.1c04034] [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: 06/13/2023]
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 (<100 km) point sources were omitted due to difficulties in comparison between the sediment-derived and modeled values at deposition "hot spots". This highlights the applicability of multi-core approaches to quantify spatio-temporal changes in Hg deposition over broad geographic ranges and assess the effectiveness of regional and global Hg emission reductions to address global Hg pollution concerns.
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Affiliation(s)
- Sarah L Roberts
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Jane L Kirk
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Johan A Wiklund
- Biology Department, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Marlene S Evans
- Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan S7N 3H5, Canada
| | - Amber Gleason
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Allison Tam
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Paul E Drevnick
- Alberta Environment and Parks, 3535 Research Road NW, Calgary, Alberta T2L 2K8, Canada
- National Institute of Scientific Research, Centre Eau Terre Environment, 490 rue de la Couronne, Québec, Québec G1K 9A9, Canada
| | - Ashu Dastoor
- Air Quality Research Division, Environment and Climate Change Canada, Québec H9P 1J3, Canada
| | - Andrei Ryjkov
- Air Quality Research Division, Environment and Climate Change Canada, Québec H9P 1J3, Canada
| | - Fan Yang
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Xiaowa Wang
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Greg Lawson
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - Martin Pilote
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Montréal, Québec H2Y 2E7, Canada
| | - Jonathan Keating
- Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan S7N 3H5, Canada
| | - Benjamin D Barst
- National Institute of Scientific Research, Centre Eau Terre Environment, 490 rue de la Couronne, Québec, Québec G1K 9A9, Canada
- Water and Environment Research Center, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Jason M E Ahad
- Geological Survey of Canada─Québec Division, Québec G1K 9A9, Canada
| | - Colin A Cooke
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
- Alberta Environment and Parks, 9888 Jasper Ave, Edmonton, Alberta T5J 5C6, Canada
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8
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Ma Y, Hobson KA, Kardynal KJ, Guglielmo CG, Branfireun BA. Inferring spatial patterns of mercury exposure in migratory boreal songbirds: Combining feather mercury and stable isotope (δ 2H) measurements. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143109. [PMID: 33162143 DOI: 10.1016/j.scitotenv.2020.143109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Migratory songbirds breeding in the Canadian Boreal forest are exposed to mercury (Hg), a potent neurotoxin that impairs avian health, however, the degree of exposure depends on many factors. As breeding grounds are geographically remote and vast, the measurement of Hg in individual birds is impractical particularly at large spatial scales. Here, we present a Canada-wide dataset of nearly 2000 migratory songbirds that were used to assess summer Hg exposure of 15 songbird species sampled during fall migration. We measured Hg concentrations in tail feathers and related those to dietary guild, geographic capture location, age, sex and probable breeding ground locations using feather δ2H. Overall mean (±SE) feather Hg concentration was 1.49 ± 0.03 μg/g (N = 1946): however, a clear geographic gradient in feather Hg concentrations emerged being highest in East and lowest in West. Dietary guild was the next strongest predictor of feather Hg with insectivorous songbirds in Eastern Canada at particular risk due to Hg exposure on summer breeding grounds. This broad-scale assessment of Hg exposure in migratory songbirds in Canada can be used to guide future studies on finer-scale determinants of Hg exposure in birds.
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Affiliation(s)
- Yanju Ma
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Kevin J Kardynal
- Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Christopher G Guglielmo
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Brian A Branfireun
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Centre for Environment and Sustainability, University of Western Ontario, London, Ontario, Canada.
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9
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Environmental Partitioning, Spatial Distribution, and Transport of Atmospheric Mercury (Hg) Originating from a Site of Former Chlor-Alkali Plant. ATMOSPHERE 2021. [DOI: 10.3390/atmos12020275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mercury (Hg) is one of the trace toxic and bioaccumulative global pollutants, and due to its long atmospheric lifetime, it presents a significant global challenge. The present study (1) utilizes total gaseous mercury (TGM) measurements made around a former Hg-cell chlor-alkali plant (CAP) located in Pavlodar, Kazakhstan, and predicts the spatial distribution of Hg over its premises and the nearby city. It then (2) estimates the environmental repartition of Hg deposited by the CAP using three fugacity models of varying complexity: Level I, QWASI, and HERMES. Finally, it (3) predicts long-range Hg transport via forward trajectory-based cluster analysis. The atmospheric Hg levels measured in Pavlodar and around Lake Balkyldak were elevated: in the range of 1–37 ng/m3 with an urban background level at 4.9 ng/m3. Specifically, concentrations up to 37 ng/m3 close to Lake Balkyldak and up to 22 ng/m3 nearby the city’s industrial zone (where the CAP was located) had been observed. Interpolation maps created using kriging also suggest these locations as the primary sources of atmospheric Hg in the city. The Level I fugacity model indicated that almost all of Hg is expected to end up in the atmosphere. The modeling results obtained using more complex QWASI and HERMES models showed that some significant quantity of Hg would still be associated with the sediments of Lake Balkyldak (a large wastewater discharge pond nearby the CAP). The forward trajectory-based cluster analysis method revealed the long-range atmospheric transportation routes and local, regional, and global impact zones. Furthermore, a source-receptor relationship using air transportation pathways to identify “areas of impact” was addressed. During both heating and non-heating seasons, the frequency-based analysis identified the distribution of Hg reaching the territories of Mongolia, northwest China, southwest Kazakhstan. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT-4) model forward trajectory analysis has confirmed similar patterns during heating and non-heating seasons, except with shorter impact distances during the non-heating period. Even though the CAP was closed more than 30 years ago and those past remediation efforts cleaned up the site, the residual Hg pollution seems significant and should be further investigated in different environmental media.
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Houde M, Taranu ZE, Wang X, Young B, Gagnon P, Ferguson SH, Kwan M, Muir DC. Mercury in Ringed Seals (Pusa hispida) from the Canadian Arctic in Relation to Time and Climate Parameters. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:2462-2474. [PMID: 33025637 PMCID: PMC7756774 DOI: 10.1002/etc.4865] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/16/2020] [Accepted: 08/19/2020] [Indexed: 05/05/2023]
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.
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Affiliation(s)
- Magali Houde
- Environment and Climate Change CanadaMontrealQuebecCanada
| | | | - Xiaowa Wang
- Environment and Climate Change CanadaBurlingtonOntarioCanada
| | - Brent Young
- Arctic Aquatic Research DivisionDepartment of Fisheries and OceansWinnipegManitobaCanada
| | - P. Gagnon
- Environment and Climate Change CanadaMontrealQuebecCanada
| | - Steve H. Ferguson
- Arctic Aquatic Research DivisionDepartment of Fisheries and OceansWinnipegManitobaCanada
| | | | - Derek C.G. Muir
- Environment and Climate Change CanadaBurlingtonOntarioCanada
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11
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Pyta H, Widziewicz-Rzońca K, Słaby K. Inhalation Exposure to Gaseous and Particulate Bound Mercury Present in the Ambient Air over the Polluted Area of Southern Poland. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17144999. [PMID: 32664556 PMCID: PMC7399863 DOI: 10.3390/ijerph17144999] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/26/2020] [Accepted: 07/07/2020] [Indexed: 11/16/2022]
Abstract
This study concerns the concentrations of gaseous and particle-bound mercury present in ambient air of two Polish sites, differing in terms of emission structure, and the estimation of inhalation risks related to those Hg species. The measurements of total gaseous mercury (TGM) and PM2.5-bound mercury (PBM) were performed at an urban station in Zabrze and a rural station in Złoty Potok, in 2014–2015. Both sites are located in Silesia, considered one of the European air pollution hot-spots. TGM was measured on-line (Tekran 2537). PM2.5 samples were taken with the use of low volume samplers. Hg contents in PM were determined by the CVAAS method following thermal decomposition. The median concentrations of TGM and PBM in Zabrze were 2.48 ng m−3 and 37.87 pg m−3, respectively; meanwhile in Zloty Potok, these were 1.69 ng m−3 and 27.82 pg m−3, respectively. Clearly, seasonal variability of TGM and PBM concentrations were observed, reflecting the importance of Hg and PM emissions from coal combustion for power and heating purposes. Health risk assessment was performed using a deterministic approach by the most conservative exposure scenario. The obtained HQ ratios and the cumulative HI indexes were below the limit value (<1). This means an unlikely health hazard due mercury inhalation.
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Lyman SN, Cheng I, Gratz LE, Weiss-Penzias P, Zhang L. An updated review of atmospheric mercury. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:135575. [PMID: 31784172 DOI: 10.1016/j.scitotenv.2019.135575] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
The atmosphere is a key component of the biogeochemical cycle of mercury, acting as a reservoir, transport mechanism, and facilitator of chemical reactions. The chemical and physical behavior of atmospheric mercury determines how, when, and where emitted mercury pollution impacts ecosystems. In this review, we provide current information about what is known and what remains uncertain regarding mercury in the atmosphere. We discuss new ambient, laboratory, and theoretical information about the chemistry of mercury in various atmospheric media. We review what is known about mercury in and on solid- and liquid-phase aerosols. We present recent findings related to wet and dry deposition and spatial and temporal trends in atmospheric mercury concentrations. We also review atmospheric measurement methods that are in wide use and those that are currently under development.
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Affiliation(s)
- Seth N Lyman
- Bingham Research Center, Utah State University, 320 N Aggie Blvd., Vernal, UT, USA; Department of Chemistry and Biochemistry, Utah State University, 4820 Old Main Hill, Logan, UT, USA.
| | - Irene Cheng
- Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin St., Toronto, Ontario, Canada
| | - Lynne E Gratz
- Environmental Studies Program, Colorado College, 14 East Cache la Poudre St., Colorado Springs, CO, USA
| | - Peter Weiss-Penzias
- Chemistry and Biochemistry Department, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA; Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
| | - Leiming Zhang
- Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin St., Toronto, Ontario, Canada
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13
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Nguyen LSP, Sheu GR, Lin DW, Lin NH. Temporal changes in atmospheric mercury concentrations at a background mountain site downwind of the East Asia continent in 2006-2016. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:1049-1056. [PMID: 31200303 DOI: 10.1016/j.scitotenv.2019.05.425] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/06/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Atmospheric mercury (Hg) has been monitored at the Lulin Atmospheric Background Station (LABS) in Taiwan since April 2006 and is still continuing. Here we reported the trend in gaseous elemental Hg (GEM) concentrations at LABS between April 2006 and December 2016, before the Minamata Convention on Mercury entered into force in 2017. Previous research indicated nighttime (0-8 am) data collected at LABS are better representative of regional influence. Therefore, only nighttime GEM data were used for trend analysis. A significant decreasing trend in GEM at a rate of -1.5% yr-1 (-0.022 ng m-3 yr-1, p < 0.01) was found, comparable to the decreasing trends observed in Europe, North America, South Africa, and over the North Atlantic Ocean. Five major GEM source regions to the LABS were identified, including northern Indochina Peninsula, China, Northeast Asia, the Pacific Ocean, and South China Sea. Significant decreasing trends in GEM were found for air masses coming from northern Indochina Peninsula (-0.042 ng m-3 yr-1, -2.6% yr-1, p < 0.01), China (-0.041 ng m-3 yr-1, -2.4% yr-1, p < 0.01), Northeast Asia (-0.031 ng m-3 yr-1, -2.0% yr-1, p < 0.05), and the Pacific Ocean (-0.022 ng m-3 yr-1, -1.7% yr-1, p < 0.05). Decreasing GEM trend (-0.020 ng m-3 yr-1, -1.5% yr-1), but insignificant (p > 0.05), was also found for air masses coming from South China Sea. The decreasing trends observed with air from the Pacific Ocean and South China Sea indicated declining background GEM concentrations in Northern Hemisphere. Decrease in GEM concentrations at the LABS was in agreement with the reduction in atmospheric Hg export from the East Asia continent caused by changes in Hg emission quantity and speciation, and temporal and spatial distribution in emission sources that have been suggested by recent research. Additionally, changes in the frequency distribution of air mass origins and transport paths may also contribute to the changes in GEM concentrations at LABS.
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Affiliation(s)
- Ly Sy Phu Nguyen
- Department of Atmospheric Sciences, National Central University, Jhongli 320, Taiwan
| | - Guey-Rong Sheu
- Department of Atmospheric Sciences, National Central University, Jhongli 320, Taiwan.
| | - Da-Wei Lin
- Department of Atmospheric Sciences, National Central University, Jhongli 320, Taiwan
| | - Neng-Huei Lin
- Department of Atmospheric Sciences, National Central University, Jhongli 320, Taiwan
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14
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St Louis VL, Graydon JA, Lehnherr I, Amos HM, Sunderland EM, St Pierre KA, Emmerton CA, Sandilands K, Tate M, Steffen A, Humphreys ER. Atmospheric Concentrations and Wet/Dry Loadings of Mercury at the Remote Experimental Lakes Area, Northwestern Ontario, Canada. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8017-8026. [PMID: 31250626 DOI: 10.1021/acs.est.9b01338] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Mercury (Hg) is a global pollutant released from both natural and human sources. Here we compare long-term records of wet deposition loadings of total Hg (THg) in the open to dry deposition loadings of THg in throughfall and litterfall under four boreal mixedwood canopy types at the remote Experimental Lakes Area (ELA) in Northwestern Ontario, Canada. We also present long-term records of atmospheric concentrations of gaseous elemental (GEM), gaseous oxidized (GOM), and particle bound (PBM) Hg measured at the ELA. We show that dry THg loadings in throughfall and litterfall are 2.7 to 6.1 times greater than wet THg loadings in the open. GEM concentrations showed distinct monthly and daily patterns, correlating positively in spring and summer with rates of gross ecosystem productivity and respiration. GOM and PBM concentrations were less variable throughout the year but were highest in the winter, when concentrations of anthropogenically sourced particles and gases were also high. Forest fires, Arctic air masses, and road salt also impacted GEM, GOM, and PBM concentrations at the ELA. A nested GEOS-Chem simulation for the ELA region produced a dry/wet deposition ratio of >5, suggesting that the importance of dry deposition in forested regions can be reasonably modeled by existing schemes for trace gases.
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Affiliation(s)
- Vincent L St Louis
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - Jennifer A Graydon
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - Igor Lehnherr
- Department of Geography , University of Toronto-Mississauga , 3359 Mississauga Road , Mississauga , Ontario L5L 1C6 , Canada
| | - Helen M Amos
- Harvard T.H. Chan School of Public Health , Department of Environmental Health , Boston , Massachusetts 02215 , United States
| | - Elsie M Sunderland
- Harvard T.H. Chan School of Public Health , Department of Environmental Health , Boston , Massachusetts 02215 , United States
- Harvard John A. Paulson School of Engineering and Applied Sciences , Cambridge , Massachusetts 02138 , United States
| | - Kyra A St Pierre
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - Craig A Emmerton
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - Ken Sandilands
- International Institute of Sustainable Development - Experimental Lakes Area (IISD-ELA) , 111 Lombard Avenue, Suite 325 , Winnipeg , Manitoba R3B 0T4 , Canada
| | - Michael Tate
- University of Wisconsin , Aquatic Science Center , 1975 Willow Drive , Madison , Wisconsin 53706 , United States
| | - Alexandra Steffen
- Environment and Climate Change Canada, Science and Technology Branch , Air Quality Research , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| | - Elyn R Humphreys
- Department of Geography and Environmental Studies , Carleton University , Ottawa , Ontario K1S 5B6 , Canada
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15
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Wang F, Outridge PM, Feng X, Meng B, Heimbürger-Boavida LE, Mason RP. How closely do mercury trends in fish and other aquatic wildlife track those in the atmosphere? - Implications for evaluating the effectiveness of the Minamata Convention. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 674:58-70. [PMID: 31003088 DOI: 10.1016/j.scitotenv.2019.04.101] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/07/2019] [Accepted: 04/08/2019] [Indexed: 05/28/2023]
Abstract
The Minamata Convention to reduce anthropogenic mercury (Hg) emissions entered into force in 2017, and attention is now focused on how to best monitor its effectiveness at reducing Hg exposure to humans. A key question is how closely Hg concentrations in the human food chain, especially in fish and other aquatic wildlife, will track the changes in atmospheric Hg that are expected to occur following anthropogenic emission reductions. We investigated this question by evaluating several regional groups of case studies where Hg concentrations in aquatic biota have been monitored continuously or intermittently for several decades. Our analysis shows that in most cases Hg time trends in biota did not agree with concurrent Hg trends in atmospheric deposition or concentrations, and the divergence between the two trends has become more apparent over the past two decades. An over-arching general explanation for these results is that the impact of changing atmospheric inputs on biotic Hg is masked by two factors: 1) The aquatic environment contains a large inventory of legacy emitted Hg that remains available for bio-uptake leading to a substantial lag in biotic response time to a change in external inputs; and 2) Biotic Hg trends reflect the dominant effects of changes in multi-causal, local and regional processes (e.g., aquatic or terrestrial biogeochemical processes, feeding ecology, climate) that control the speciation, bioavailability, and bio-uptake of both present-day and legacy emitted Hg. Globally, climate change has become the most prevalent contributor to the divergence. A wide range of biotic Hg outcomes can thus be expected as anthropogenic atmospheric Hg emissions decline, depending on how these processes operate on specific regions and specific organisms. Therefore, evaluating the effectiveness of the Minamata Convention will require biomonitoring of multiple species that represent different trophic and ecological niches in multiple regions of the world.
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Affiliation(s)
- Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| | - Peter M Outridge
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; Geological Survey of Canada, Natural Resources Canada, 601 Booth St., Ottawa, ON K1A 0E8, Canada
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Road, Guiyang 550002, China
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Road, Guiyang 550002, China
| | - Lars-Eric Heimbürger-Boavida
- Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, 13288 Marseille, France
| | - Robert P Mason
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA
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16
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Gratz LE, Eckley CS, Schwantes SJ, Mattson E. Ambient Mercury Observations near a Coal-Fired Power Plant in a Western U.S. Urban Area. ATMOSPHERE 2019; 10:176. [PMID: 31456887 PMCID: PMC6711202 DOI: 10.3390/atmos10040176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
We report on the continuous ambient measurements of total gaseous mercury (TGM) and several ancillary air quality parameters that were collected in Colorado Springs, CO. This urban area, which is located adjacent to the Front Range of the Rocky Mountains, is the second largest metropolitan area in Colorado and has a centrally located coal-fired power plant that installed mercury (Hg) emission controls the year prior to our study. There are few other Hg point sources within the city. Our results, which were obtained from a measurement site < 1 km from the power plant, show a distinct diel pattern in TGM, with peak concentrations occurring during the night (1.7 ± 0.3 ng m−3) and minimum concentrations mid-day (1.5 ± 0.2 ng m−3). The TGM concentrations were not correlated with wind originating from the direction of the plant or with sulfur dioxide (SO2) mixing ratios, and they were not elevated when the atmospheric mixing height was above the effective stack height. These findings suggest that the current Hg emissions from the CFPP did not significantly influence local TGM, and they are consistent with the facility’s relatively low reported annual emissions of 0.20 kg Hg per year. Instead, variability in the regional signal, diurnal meteorological conditions, and/or near-surface emission sources appears to more greatly influence TGM at this urban site.
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Affiliation(s)
- Lynne E. Gratz
- Colorado College, Environmental Studies Program, Colorado Springs, CO 80903, USA
- Correspondence:
| | - Chris S. Eckley
- U.S. Environmental Protection Agency, Region 10, Seattle, WA 98101, USA
| | - Story J. Schwantes
- Colorado College, Environmental Studies Program, Colorado Springs, CO 80903, USA
| | - Erick Mattson
- Colorado Department of Public Health and Environment, Air Pollution Control Division, Glendale, CO 80246, USA
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St Pierre KA, St Louis VL, Lehnherr I, Gardner AS, Serbu JA, Mortimer CA, Muir DCG, Wiklund JA, Lemire D, Szostek L, Talbot C. Drivers of Mercury Cycling in the Rapidly Changing Glacierized Watershed of the High Arctic's Largest Lake by Volume (Lake Hazen, Nunavut, Canada). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:1175-1185. [PMID: 30596413 DOI: 10.1021/acs.est.8b05926] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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-1, respectively, in step with dramatic increases in glacial melt. This study highlights the potential for increases in mercury inputs to arctic ecosystems downstream of glaciers despite recent reductions in global mercury emissions.
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Affiliation(s)
- K A St Pierre
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - V L St Louis
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - I Lehnherr
- Department of Geography , University of Toronto Mississauga , Mississauga , Ontario L5L 1C6 , Canada
| | - A S Gardner
- NASA Jet Propulsion Laboratory , California Institute of Technology , Pasadena , California 91109 , United States
| | - J A Serbu
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - C A Mortimer
- Department of Earth and Atmospheric Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 Canada
| | - D C G Muir
- Environment and Climate Change Canada , Canadian Centre for Inland Waters , Burlington , Ontario , L7S 1A1 , Canada
| | - J A Wiklund
- Department of Biology , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - D Lemire
- Department of Geography , University of Toronto Mississauga , Mississauga , Ontario L5L 1C6 , Canada
| | - L Szostek
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada
| | - C Talbot
- Environment and Climate Change Canada , Canadian Centre for Inland Waters , Burlington , Ontario , L7S 1A1 , Canada
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18
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St Pierre KA, Zolkos S, Shakil S, Tank SE, St Louis VL, Kokelj SV. Unprecedented Increases in Total and Methyl Mercury Concentrations Downstream of Retrogressive Thaw Slumps in the Western Canadian Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:14099-14109. [PMID: 30474969 DOI: 10.1021/acs.est.8b05348] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Retrogressive thaw slumps (RTSs) are thermokarst features created by the rapid thaw of ice-rich permafrost, and can mobilize vast quantities of sediments and solutes downstream. However, the effect of slumping on downstream concentrations and yields of total mercury (THg) and methylmercury (MeHg) is unknown. Fluvial concentrations of THg and MeHg downstream of RTSs on the Peel Plateau (Northwest Territories, Canada) were up to 2 orders of magnitude higher than upstream, reaching concentrations of 1,270 ng L-1 and 7 ng L-1, respectively, the highest ever measured in uncontaminated sites in Canada. MeHg concentrations were particularly elevated at sites downstream of RTSs where debris tongues dammed streams to form reservoirs where microbial Hg methylation was likely enhanced. However, > 95% of the Hg downstream was typically particle-bound and potentially not readily bioavailable. Mean open-water season yields of THg (610 mg km-2 d-1) and MeHg (2.61 mg km-2 d-1) downstream of RTSs were up to an order of magnitude higher than those for the nearby large Yukon, Mackenzie and Peel rivers. We estimate that ∼5% of the Hg stored for centuries or millennia in northern permafrost soils (88 Gg) is susceptible to release into modern-day Hg biogeochemical cycling from further climate changes and thermokarst formation.
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Affiliation(s)
- Kyra A St Pierre
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Scott Zolkos
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Sarah Shakil
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Suzanne E Tank
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Vincent L St Louis
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Steven V Kokelj
- Northwest Territories Geological Survey , Yellowknife , Northwest Territories X1A 2L9 , Canada
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Giang A, Song S, Muntean M, Janssens-Maenhout G, Harvey A, Berg E, Selin NE. Understanding factors influencing the detection of mercury policies in modelled Laurentian Great Lakes wet deposition. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:1373-1389. [PMID: 30247491 DOI: 10.1039/c8em00268a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We used chemical transport modelling to better understand the extent to which policy-related anthropogenic mercury emissions changes (a policy signal) can be statistically detected in wet deposition measurements in the Great Lakes region on the subdecadal scale, given sources of noise. In our modelling experiment, we consider hypothetical regional (North American) and global (rest of the world) policy changes, consistent with existing policy efforts (Δglobal = -18%; Δregional = -30%) that divide an eight-year period. The magnitude of statistically significant (p < 0.1) pre- and post-policy period wet deposition differences, holding all else constant except for the policy change, ranges from -0.3 to -2.0% for the regional policy and -0.8 to -2.7% for the global policy. We then introduce sources of noise-trends and variability in factors that are exogenous to the policy action-and evaluate the extent to which the policy signals can still be detected. For instance, technology-related variability in emissions magnitude and speciation can shift the magnitude of differences between periods, in some cases dampening the policy effect. We have found that the interannual variability in meteorology has the largest effect of the sources of noise considered, driving deposition differences between periods to ±20%, exceeding the magnitude of the policy signal. However, our simulations suggest that gaseous elemental mercury concentration may be more robust to this meteorological variability in this region, and a stronger indicator of local/regional emissions changes. These results highlight the potential challenges of detecting statistically significant policy-related changes in Great Lakes wet deposition within the subdecadal scale.
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Affiliation(s)
- Amanda Giang
- Institute for Data, Systems and Society, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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20
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Obrist D, Kirk JL, Zhang L, Sunderland EM, Jiskra M, Selin NE. A review of global environmental mercury processes in response to human and natural perturbations: Changes of emissions, climate, and land use. AMBIO 2018; 47:116-140. [PMID: 29388126 PMCID: PMC5794683 DOI: 10.1007/s13280-017-1004-9] [Citation(s) in RCA: 350] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We review recent progress in our understanding of the global cycling of mercury (Hg), including best estimates of Hg concentrations and pool sizes in major environmental compartments and exchange processes within and between these reservoirs. Recent advances include the availability of new global datasets covering areas of the world where environmental Hg data were previously lacking; integration of these data into global and regional models is continually improving estimates of global Hg cycling. New analytical techniques, such as Hg stable isotope characterization, provide novel constraints of sources and transformation processes. The major global Hg reservoirs that are, and continue to be, affected by anthropogenic activities include the atmosphere (4.4-5.3 Gt), terrestrial environments (particularly soils: 250-1000 Gg), and aquatic ecosystems (e.g., oceans: 270-450 Gg). Declines in anthropogenic Hg emissions between 1990 and 2010 have led to declines in atmospheric Hg0 concentrations and HgII wet deposition in Europe and the US (- 1.5 to - 2.2% per year). Smaller atmospheric Hg0 declines (- 0.2% per year) have been reported in high northern latitudes, but not in the southern hemisphere, while increasing atmospheric Hg loads are still reported in East Asia. New observations and updated models now suggest high concentrations of oxidized HgII in the tropical and subtropical free troposphere where deep convection can scavenge these HgII reservoirs. As a result, up to 50% of total global wet HgII deposition has been predicted to occur to tropical oceans. Ocean Hg0 evasion is a large source of present-day atmospheric Hg (approximately 2900 Mg/year; range 1900-4200 Mg/year). Enhanced seawater Hg0 levels suggest enhanced Hg0 ocean evasion in the intertropical convergence zone, which may be linked to high HgII deposition. Estimates of gaseous Hg0 emissions to the atmosphere over land, long considered a critical Hg source, have been revised downward, and most terrestrial environments now are considered net sinks of atmospheric Hg due to substantial Hg uptake by plants. Litterfall deposition by plants is now estimated at 1020-1230 Mg/year globally. Stable isotope analysis and direct flux measurements provide evidence that in many ecosystems Hg0 deposition via plant inputs dominates, accounting for 57-94% of Hg in soils. Of global aquatic Hg releases, around 50% are estimated to occur in China and India, where Hg drains into the West Pacific and North Indian Oceans. A first inventory of global freshwater Hg suggests that inland freshwater Hg releases may be dominated by artisanal and small-scale gold mining (ASGM; approximately 880 Mg/year), industrial and wastewater releases (220 Mg/year), and terrestrial mobilization (170-300 Mg/year). For pelagic ocean regions, the dominant source of Hg is atmospheric deposition; an exception is the Arctic Ocean, where riverine and coastal erosion is likely the dominant source. Ocean water Hg concentrations in the North Atlantic appear to have declined during the last several decades but have increased since the mid-1980s in the Pacific due to enhanced atmospheric deposition from the Asian continent. Finally, we provide examples of ongoing and anticipated changes in Hg cycling due to emission, climate, and land use changes. It is anticipated that future emissions changes will be strongly dependent on ASGM, as well as energy use scenarios and technology requirements implemented under the Minamata Convention. We predict that land use and climate change impacts on Hg cycling will be large and inherently linked to changes in ecosystem function and global atmospheric and ocean circulations. Our ability to predict multiple and simultaneous changes in future Hg global cycling and human exposure is rapidly developing but requires further enhancement.
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Affiliation(s)
- Daniel Obrist
- Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, One University Ave, Lowell, MA 01854 USA
| | - Jane L. Kirk
- Environment and Climate Change, Canada, 867 Lakeshore Road, Burlington, ON L7P 2X3 Canada
| | - Lei Zhang
- School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023 Jiangsu China
| | - Elsie M. Sunderland
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard T.H. Chan School of Public Health, Harvard University, 29 Oxford Street, Cambridge, MA 02138 USA
| | - Martin Jiskra
- Géosciences Environnement Toulouse, GET-CNRS, CNRS – OMP, 14 Avenue Edouard Belin, 31400 Toulouse, France
| | - Noelle E. Selin
- Institute for Data, Systems, and Society and Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
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21
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Nasr M, Arp PA. Relating Fish Hg to Variations in Sediment Hg, Climate and Atmospheric Deposition. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/ajcc.2018.73024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kerr JG, Cooke CA. Erosion of the Alberta badlands produces highly variable and elevated heavy metal concentrations in the Red Deer River, Alberta. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 596-597:427-436. [PMID: 28448918 DOI: 10.1016/j.scitotenv.2017.04.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 02/27/2017] [Accepted: 04/05/2017] [Indexed: 06/07/2023]
Abstract
Erosion is important in the transport of heavy metals from terrestrial to fluvial environments. In this study, we investigated riverine heavy metal (Cd, Cu, Hg and Pb) dynamics in the Red Deer River (RDR) watershed at sites upstream (n=2) and downstream (n=7) of the Alberta badlands, an area of naturally high erosion. At sites draining the badlands, total water column Cd, Cu, Hg and Pb concentrations frequently exceeded guidelines for the protection of freshwater biota. Furthermore, peak concentrations of total Cd (9.8μgL-1), Cu (212μgL-1), Hg (649ngL-1) and Pb (361μgL-1) were higher than, or comparable to, values reported for rivers and streams heavily impacted by anthropogenic activities. Total suspended solids (TSS) explained a large proportion (r2=0.34-0.83) of the variation in total metal concentrations in the RDR and tributaries and metal fluxes were dominated by the particulate fraction (60-98%). Suspended sediment concentrations (Csed) and metal to aluminum ratios were generally not indicative of substantial sediment enrichment. Rather, the highly variable and elevated metal concentrations in the RDR watershed were a function of the high and variable suspended sediment fluxes which characterize the river system. While the impact of this on aquatic biota requires further investigation, we suggest erosion in the Alberta badlands may be contributing to Hg-based fish consumption advisories in the RDR. Importantly, this highlights a broader need for information on contaminant dynamics in watersheds subject to elevated rates of erosion.
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Affiliation(s)
- Jason G Kerr
- Alberta Environment and Parks, Environmental Monitoring and Science Division, 2938 11 St NE, Calgary T2E 7L7, AB, Canada.
| | - Colin A Cooke
- Alberta Environment and Parks, Environmental Monitoring and Science Division, 2938 11 St NE, Calgary T2E 7L7, AB, Canada
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Wiklund JA, Kirk JL, Muir DCG, Evans M, Yang F, Keating J, Parsons MT. Anthropogenic mercury deposition in Flin Flon Manitoba and the Experimental Lakes Area Ontario (Canada): A multi-lake sediment core reconstruction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 586:685-695. [PMID: 28238379 DOI: 10.1016/j.scitotenv.2017.02.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/05/2017] [Accepted: 02/05/2017] [Indexed: 06/06/2023]
Abstract
High-resolution records of anthropogenic mercury (Hg) deposition were constructed from 9 lakes located 5-75km from the Flin Flon, Manitoba smelter (formerly one of North America's largest atmospheric Hg point sources) and 5 lakes in Experimental Lakes Area (ELA), Ontario; a region remote from major Hg point sources. Anthropogenic Hg deposition, as both a flux and inventory, was determined after accounting for lake-specific natural Hg background concentrations, changes in sedimentation and sediment focusing. Results show that records of anthropogenic flux and inventory of Hg were remarkably consistent among the ELA lakes, but varied by 2 orders of magnitude among Flin Flon lakes. The relation between Hg inventories (normalized for prevailing wind direction) and distance from the smelter was used to estimate the total Hg fallout within a 50km radius in 5year time-steps, thus providing a quantitative spatial-temporal Hg depositional history for the Flin Flon region. The same relation solved for 8 cardinal directions weighted by the inverse of the previously applied wind direction normalization generates a map of Hg inventory and deposition on the landscape (Supplementary video). This novel application of sediment core data constructs a landscape model and allows for a visualization of contaminant deposition with respect to a point major source in both space and time. The propensity for Hg to undergo long-range, even global transport explains why Hg deposition within 50km of Flin Flon was ~11% of estimated releases. That is until smelter releases were reduced >10-fold (post-2000), after which observed deposition exceeded smelter releases, suggesting landscape re-emission/remobilization of legacy Hg is a major ongoing regional source of Hg.
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Affiliation(s)
- Johan A Wiklund
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada.
| | - Jane L Kirk
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada
| | - Marlene Evans
- Aquatic Contaminants Research Division, Environment Canada, Saskatoon, SK, Canada
| | - Fan Yang
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada
| | - Jonathan Keating
- Aquatic Contaminants Research Division, Environment Canada, Saskatoon, SK, Canada
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Champoux L, Boily M, Fitzgerald G. Thyroid Hormones, Retinol and Clinical Parameters in Relation to Mercury and Organohalogen Contaminants in Great Blue Heron (Ardea herodias) Nestlings from the St. Lawrence River, Québec, Canada. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 72:200-214. [PMID: 28102440 DOI: 10.1007/s00244-017-0364-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
The exposure and effects of persistent environmental contaminants were investigated in great blue heron (Ardea herodias) nestlings sampled in 2001, 2002, 2006, and 2007 in freshwater and estuarine heronries along the St. Lawrence River, Québec (Canada). Biomarkers (retinoids, thyroid hormones, and clinical parameters) and contaminants (organochlorine contaminants, polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), and mercury (Hg)) were analyzed in blood, and Hg was analyzed in feathers (generally 9 nestlings per colony and 4 colonies per year). Feather Hg and most contaminants detected in blood were found in higher concentrations in birds from freshwater than estuarine colonies more distant from the pollution sources. Among freshwater colonies, Ile aux Hérons showed the highest levels of contaminants, with mean Hg concentrations of 8.4 and 0.55 mg/kg in feathers and plasma, respectively, and plasma ΣBFRs of 19.6 ng/g ww. The highest mean ΣPCBs, 56.5 ng/g ww, was measured at Grande Ile in 2001. The levels of contaminants in heron nestlings were generally below critical thresholds for adverse effects observed on reproduction or survival. Retinol, dehydroretinol (DROH), and thyroid hormone concentrations differed significantly among colonies. Retinol concentrations were negatively related to ΣPCBs, whereas DROH concentrations were negatively related to Hg and total and free triiodothyronine (T3) concentrations were negatively related to ΣBFRs. These results indicate that contaminants from the St. Lawrence River could impair the development and fitness of great blue heron nestlings and emphasize the need for more research on the great blue heron population to assess their health and nutritional status.
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Affiliation(s)
- Louise Champoux
- Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment and Climate Change Canada, 801-1550 av d'Estimauville, Québec, QC, G1J 0C3, Canada.
| | - Monique Boily
- Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal, QC, H3C 3P8, Canada
| | - Guy Fitzgerald
- Faculté de Médecine Vétérinaire, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, QC, J2S 7C6, Canada
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Marusczak N, Sonke JE, Fu X, Jiskra M. Tropospheric GOM at the Pic du Midi Observatory-Correcting Bias in Denuder Based Observations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:863-869. [PMID: 27960251 DOI: 10.1021/acs.est.6b04999] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Gaseous elemental mercury (GEM, Hg) emissions are transformed to divalent reactive Hg (RM) forms throughout the troposphere and stratosphere. RM is often operationally quantified as the sum of particle bound Hg (PBM) and gaseous oxidized Hg (GOM). The measurement of GOM and PBM is challenging and under mounting criticism. Here we intercompare six months of automated GOM and PBM measurements using a Tekran (TK) KCl-coated denuder and quartz regenerable particulate filter method (GOMTK, PBMTK, and RMTK) with RMCEM collected on cation exchange membranes (CEMs) at the high altitude Pic du Midi Observatory. We find that RMTK is systematically lower by a factor of 1.3 than RMCEM. We observe a significant relationship between GOMTK (but not PBMTK) and Tekran flushTK blanks suggesting significant loss (36%) of labile GOMTK from the denuder or inlet. Adding the flushTK blank to RMTK results in good agreement with RMCEM (slope = 1.01, r2 = 0.90) suggesting we can correct bias in RMTK and GOMTK. We provide a bias corrected (*) Pic du Midi data set for 2012-2014 that shows GOM* and RM* levels in dry free tropospheric air of 198 ± 57 and 229 ± 58 pg m-3 which agree well with in-flight observed RM and with model based GOM and RM estimates.
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Affiliation(s)
- Nicolas Marusczak
- Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse, 14, avenue Édouard Belin, 31400 Toulouse, France
| | - Jeroen E Sonke
- Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse, 14, avenue Édouard Belin, 31400 Toulouse, France
| | - Xuewu Fu
- Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse, 14, avenue Édouard Belin, 31400 Toulouse, France
| | - Martin Jiskra
- Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse, 14, avenue Édouard Belin, 31400 Toulouse, France
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Gworek B, Dmuchowski W, Baczewska AH, Brągoszewska P, Bemowska-Kałabun O, Wrzosek-Jakubowska J. Air Contamination by Mercury, Emissions and Transformations-a Review. WATER, AIR, AND SOIL POLLUTION 2017; 228:123. [PMID: 28316351 PMCID: PMC5336545 DOI: 10.1007/s11270-017-3311-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/24/2017] [Indexed: 05/09/2023]
Abstract
The present and future air contamination by mercury is and will continue to be a serious risk for human health. This publication presents a review of the literature dealing with the issues related to air contamination by mercury and its transformations as well as its natural and anthropogenic emissions. The assessment of mercury emissions into the air poses serious methodological problems. It is particularly difficult to distinguish between natural and anthropogenic emissions and re-emissions from lands and oceans, including past emissions. At present, the largest emission sources include fuel combustion, mainly that of coal, and "artisanal and small-scale gold mining" (ASGM). The distinctly highest emissions can be found in South and South-East Asia, accounting for 45% of the global emissions. The emissions of natural origin and re-emissions are estimated at 45-66% of the global emissions, with the largest part of emissions originating in the oceans. Forecasts on the future emission levels are not unambiguous; however, most forecasts do not provide for reductions in emissions. Ninety-five percent of mercury occurring in the air is Hg0-GEM, and its residence time in the air is estimated at 6 to 18 months. The residence times of its HgII-GOM and that in Hgp-TPM are estimated at hours and days. The highest mercury concentrations in the air can be found in the areas of mercury mines and those of ASGM. Since 1980 when it reached its maximum, the global background mercury concentration in the air has remained at a relatively constant level.
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Affiliation(s)
- Barbara Gworek
- Institute of Environmental Protection-National Research Institute, Krucza 5/11d St., Warsaw, 00-548 Poland
| | - Wojciech Dmuchowski
- Department of Agriculture and Biology, Warsaw University of Life Sciences, Nowoursynowska 159 St., Warsaw, 02-776 Poland
- Polish Academy of Sciences, Botanical Garden - Center for Biological Diversity Conservation, Prawdziwka 2 St., 02-973 Warsaw, Poland
| | - Aneta H. Baczewska
- Institute of Environmental Protection-National Research Institute, Krucza 5/11d St., Warsaw, 00-548 Poland
| | - Paulina Brągoszewska
- Institute of Environmental Protection-National Research Institute, Krucza 5/11d St., Warsaw, 00-548 Poland
| | - Olga Bemowska-Kałabun
- Institute of Environmental Protection-National Research Institute, Krucza 5/11d St., Warsaw, 00-548 Poland
| | - Justyna Wrzosek-Jakubowska
- Institute of Environmental Protection-National Research Institute, Krucza 5/11d St., Warsaw, 00-548 Poland
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Tong Y, Yin X, Lin H, Wang H, Deng C, Chen L, Li J, Zhang W, Schauer JJ, Kang S, Zhang G, Bu X, Wang X, Zhang Q. Recent Decline of Atmospheric Mercury Recorded by Androsace tapete on the Tibetan Plateau. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:13224-13231. [PMID: 27993077 DOI: 10.1021/acs.est.6b04632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We combined the mercury passive sampling method and plant biomonitoring together to understand the long-term changes of atmospheric mercury concentrations on the Tibetan Plateau. Through the analysis of leaves of Androsace tapete that represent growing periods spanning the past decade, we explored the historical records of atmospheric mercury from 2006 to 2015. Mercury concentration was stable in the leaves of Androsace tapete during the period between 2006 and 2009, while a significant decrease occurred after the year of 2010. The decreasing trend is consistent with the monitoring data of the ground-based stations in other regions globally. Despite the potential uncertainties using a passive sampling method and biomonitoring technique, we suggest that Androsace tapete is a potential biomarker that could provide reliable and effective historical records of atmospheric mercury concentrations and offer new perspectives in monitoring mercury and perhaps other atmospheric pollutants in regions where long-term active monitoring was missing.
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Affiliation(s)
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences , Lanzhou, 730000 P.R. China
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
- University of Chinese Academy of Sciences , Beijing, 100049 P.R. China
| | - Huiming Lin
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Huanhuan Wang
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Chunyan Deng
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Long Chen
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Jinling Li
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Wei Zhang
- School of Environment and Natural Resources, Renmin University of China , Beijing, 100872 P.R. China
| | - James Jay Schauer
- Civil & Environmental Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53703, United States
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences , Lanzhou, 730000 P.R. China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences , Beijing, 100101 P.R. China
| | - Guoshuai Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
| | | | - Xuejun Wang
- College of Urban and Environmental Sciences, Peking University , Beijing, 100871 P.R. China
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing, 100101 P.R. China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences , Beijing, 100101 P.R. China
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28
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Weiss-Penzias PS, Gay DA, Brigham ME, Parsons MT, Gustin MS, Ter Schure A. Trends in mercury wet deposition and mercury air concentrations across the U.S. and Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:546-556. [PMID: 26803218 DOI: 10.1016/j.scitotenv.2016.01.061] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 12/12/2015] [Accepted: 01/11/2016] [Indexed: 05/04/2023]
Abstract
This study examined the spatial and temporal trends of mercury (Hg) in wet deposition and air concentrations in the United States (U.S.) and Canada between 1997 and 2013. Data were obtained from the National Atmospheric Deposition Program (NADP) and Environment Canada monitoring networks, and other sources. Of the 19 sites with data records from 1997-2013, 53% had significant negative trends in Hg concentration in wet deposition, while no sites had significant positive trends, which is in general agreement with earlier studies that considered NADP data up until about 2010. However, for the time period 2007-2013 (71 sites), 17% and 13% of the sites had significant positive and negative trends, respectively, and for the time period 2008-2013 (81 sites) 30% and 6% of the sites had significant positive and negative trends, respectively. Non-significant positive tendencies were also widespread. Regional trend analyses revealed significant positive trends in Hg concentration in the Rocky Mountains, Plains, and Upper Midwest regions for the recent time periods in addition to significant positive trends in Hg deposition for the continent as a whole. Sulfate concentration trends in wet deposition were negative in all regions, suggesting a lower importance of local Hg sources. The trend in gaseous elemental Hg from short-term datasets merged as one continuous record was broadly consistent with trends in Hg concentration in wet deposition, with the early time period (1998-2007) producing a significantly negative trend (-1.5±0.2%year(-1)) and the recent time period (2008-2013) displaying a flat slope (-0.3±0.1%year(-1), not significant). The observed shift to more positive or less negative trends in Hg wet deposition primarily seen in the Central-Western regions is consistent with the effects of rising Hg emissions from regions outside the U.S. and Canada and the influence of long-range transport in the free troposphere.
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Affiliation(s)
| | - David A Gay
- National Atmospheric Deposition Program, University of Illinois - Urbana Champaign, USA
| | | | - Matthew T Parsons
- Meteorological Service of Canada, Environment Canada, Edmonton, Alberta, Canada
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29
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Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions. Proc Natl Acad Sci U S A 2016; 113:526-31. [PMID: 26729866 DOI: 10.1073/pnas.1516312113] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Observations of elemental mercury (Hg(0)) at sites in North America and Europe show large decreases (∼ 1-2% y(-1)) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (<1% y(-1)). These decreases are inconsistent with current global emission inventories indicating flat or increasing emissions over that period. However, the inventories have three major flaws: (i) they do not account for the decline in atmospheric release of Hg from commercial products; (ii) they are biased in their estimate of artisanal and small-scale gold mining emissions; and (iii) they do not properly account for the change in Hg(0)/Hg(II) speciation of emissions from coal-fired utilities after implementation of emission controls targeted at SO2 and NOx. We construct an improved global emission inventory for the period 1990 to 2010 accounting for the above factors and find a 20% decrease in total Hg emissions and a 30% decrease in anthropogenic Hg(0) emissions, with much larger decreases in North America and Europe offsetting the effect of increasing emissions in Asia. Implementation of our inventory in a global 3D atmospheric Hg simulation [GEOS-Chem (Goddard Earth Observing System-Chemistry)] coupled to land and ocean reservoirs reproduces the observed large-scale trends in atmospheric Hg(0) concentrations and in Hg(II) wet deposition. The large trends observed in North America and Europe reflect the phase-out of Hg from commercial products as well as the cobenefit from SO2 and NOx emission controls on coal-fired utilities.
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30
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Castro MS, Sherwell J. Effectiveness of Emission Controls to Reduce the Atmospheric Concentrations of Mercury. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:14000-14007. [PMID: 26606506 DOI: 10.1021/acs.est.5b03576] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Coal-fired power plants in the United States are required to reduce their emissions of mercury (Hg) into the atmosphere to lower the exposure of Hg to humans. The effectiveness of power-plant emission controls on the atmospheric concentrations of Hg in the United States is largely unknown because there are few long-term high-quality atmospheric Hg data sets. Here, we present the atmospheric concentrations of Hg and sulfur dioxide (SO2) measured from 2006 to 2015 at a relatively pristine location in western Maryland that is several (>50 km) kilometers downwind of power plants in Ohio, Pennsylvania, and West Virginia. Annual average atmospheric concentrations of gaseous oxidized mercury (GOM), SO2, fine particulate mercury (PBM2.5), and gaseous elemental mercury (GEM) declined by 75%, 75%, 43%, and 13%, respectively, and were strongly correlated with power-plant Hg emissions from the upwind states. These results provide compelling evidence that reductions in Hg emissions from power plants in the United States had their intended impact to reduce regional Hg pollution.
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Affiliation(s)
- Mark S Castro
- Appalachian Laboratory, University of Maryland Center for Environmental Science , 301 Braddock Road, Frostburg, Maryland 21532, United States
| | - John Sherwell
- Power Plant Research Program, Maryland Department of Natural Resources , Annapolis, Maryland 21401, United States
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31
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Homann PS, Darbyshire RL, Bormann BT, Morrissette BA. Forest Structure Affects Soil Mercury Losses in the Presence and Absence of Wildfire. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12714-12722. [PMID: 26485585 DOI: 10.1021/acs.est.5b03355] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Soil is an important, dynamic component of regional and global mercury (Hg) cycles. This study evaluated how changes in forest soil Hg masses caused by atmospheric deposition and wildfire are affected by forest structure. Pre and postfire soil Hg measurements were made over two decades on replicate experimental units of three prefire forest structures (mature unthinned, mature thinned, clear-cut) in Douglas-fir dominated forest of southwestern Oregon. In the absence of wildfire, O-horizon Hg decreased by 60% during the 14 years after clearcutting, possibly the result of decreased atmospheric deposition due to the smaller-stature vegetative canopy; in contrast, no change was observed in mature unthinned and thinned forest. Wildfire decreased O-horizon Hg by >88% across all forest structures and decreased mineral-soil (0 to 66 mm depth) Hg by 50% in thinned forest and clear-cut. The wildfire-associated soil Hg loss was positively related to the amount of surface fine wood that burned during the fire, the proportion of area that burned at >700 °C, fire severity as indicated by tree mortality, and soil C loss. Loss of soil Hg due to the 200,000 ha wildfire was more than four times the annual atmospheric Hg emissions from human activities in Oregon.
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Affiliation(s)
- Peter S Homann
- Huxley College of the Environment, Western Washington University , Bellingham, Washington 98225-9181, United States
| | - Robyn L Darbyshire
- Pacific Northwest Region, USDA Forest Service , Portland, Oregon 97204-3440, United States
| | - Bernard T Bormann
- School of Environmental and Forest Sciences, College of the Environment, University of Washington , Seattle, Washington 98195, United States
| | - Brett A Morrissette
- Department of Forest Ecosystems and Society, Oregon State University , Corvallis, Oregon 97331, United States
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Eckley CS, Blanchard P, McLennan D, Mintz R, Sekela M. Soil-Air Mercury Flux near a Large Industrial Emission Source before and after Closure (Flin Flon, Manitoba, Canada). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:9750-9757. [PMID: 26189758 DOI: 10.1021/acs.est.5b01995] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Prior to its closure, the base-metal smelter in Flin Flon, Manitoba, Canada was one of the North America's largest mercury (Hg) emission sources. Our project objective was to understand the exchange of Hg between the soil and the air before and after the smelter closure. Field and laboratory Hg flux measurements were conducted to identify the controlling variables and used for spatial and temporal scaling. Study results showed that deposition from the smelter resulted in the surrounding soil being enriched in Hg (up to 99 μg g(-1)) as well as other metals. During the period of smelter operation, air concentrations were elevated (30 ± 19 ng m(-3)), and the soil was a net Hg sink (daily flux: -3.8 ng m(-2) h(-1)). Following the smelter closure, air Hg(0) concentrations were reduced, and the soils had large emissions (daily flux: 108 ng m(-2) h(-1)). The annual scaling of soil Hg emissions following the smelter closure indicated that the landscape impacted by smelter deposition emitted or re-emitted almost 100 kg per year. Elevated soil Hg concentrations and emissions are predicted to continue for hundreds of years before background concentrations are re-established. Overall, the results indicate that legacy Hg deposition will continue to cycle in the environment long after point-source reductions.
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Affiliation(s)
- Chris S Eckley
- †Air Quality Research Division, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
| | - Pierrette Blanchard
- †Air Quality Research Division, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
| | - Daniel McLennan
- ‡Meteorological Service of Canada, Environment Canada, 9250-49 Street NW, Edmonton, Alberta T6B 1K54, Canada
| | - Rachel Mintz
- ‡Meteorological Service of Canada, Environment Canada, 9250-49 Street NW, Edmonton, Alberta T6B 1K54, Canada
| | - Mark Sekela
- §Pacific and Yukon Regional Office, Environment Canada, 201-401 Burrard Street, Vancouver, British Columbus V6C 3S5, Canada
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