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Bank MS. The mercury science-policy interface: History, evolution and progress of the Minamata Convention. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 722:137832. [PMID: 32208250 DOI: 10.1016/j.scitotenv.2020.137832] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/04/2020] [Accepted: 03/08/2020] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) pollution is an important environmental and public health issue that has garnered significant interest from policy makers and the global regulatory community. Consumption of seafood is the primary mechanism of methyl Hg (MeHg) exposure in humans, globally, and marine fish represent an important linkage between atmospheric dynamics, aquatic biogeochemistry and trophic transfer of this highly neurotoxic and easily assimilated form of Hg. Hg policies and management are highly interdisciplinary and at their foundation are relatively well established scientific principles related to Hg methylation, MeHg cycling and bioaccumulation, and subsequent trophic transfer to humans; however, certain fine-scale aspects of these processes remain poorly understood. After several years of intergovernmental negotiations the Minamata Convention on Mercury (MCM) entered into force in August 2017. Anthropogenic releases (water) and emissions (air) of Hg, human exposure, and environmental health are of considerable importance within the framework and policies outlined in the MCM. Additionally, the overall risk of Hg from artisanal and small-scale gold mining (ASGM) is considered a significant source of human exposure and commonly occurs in low and middle income countries, where miners use elemental Hg to extract gold from ore. Here I outline the history, evolution and progress of the MCM as it relates to the science-policy interface and offer a brief synthesis of the state of Hg science in the context of modeling, temporal assessments of Hg trends and global environmental change and ecosystem sensitivity.
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Affiliation(s)
- Michael S Bank
- Department of Contaminants and Biohazards, Institute of Marine Research, Bergen, Norway; Department of Environmental Conservation, University of Massachusetts, Amherst, MA, USA.
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102
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Sommar J, Osterwalder S, Zhu W. Recent advances in understanding and measurement of Hg in the environment: Surface-atmosphere exchange of gaseous elemental mercury (Hg 0). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137648. [PMID: 32182462 DOI: 10.1016/j.scitotenv.2020.137648] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 05/26/2023]
Abstract
The atmosphere is the major transport pathway for distribution of mercury (Hg) globally. Gaseous elemental mercury (GEM, hereafter Hg0) is the predominant form in both anthropogenic and natural emissions. Evaluation of the efficacy of reductions in emissions set by the UN's Minamata Convention (UN-MC) is critically dependent on the knowledge of the dynamics of the global Hg cycle. Of these dynamics including e.g. red-ox reactions, methylation-demethylation and dry-wet deposition, poorly constrained atmosphere-surface Hg0 fluxes especially limit predictability of the timescales of its global biogeochemical cycle. This review focuses on Hg0 flux field observational studies, namely the theory, applications, strengths, and limitations of the various experimental methodologies applied to gauge the exchange flux and decipher active sub-processes. We present an in-depth review, a comprehensive literature synthesis, and methodological and instrumentation advances for terrestrial and marine Hg0 flux studies in recent years. In particular, we outline the theory of a wide range of measurement techniques and detail the operational protocols. Today, the most frequently used measurement techniques to determine the net Hg0 flux (>95% of the published flux data) are dynamic flux chambers for small-scale and micrometeorological approaches for large-scale measurements. Furthermore, top-down approaches based on Hg0 concentration measurements have been applied as tools to better constrain Hg emissions as an independent way to e.g. challenge emission inventories. This review is an up-dated, thoroughly revised edition of Sommar et al. 2013 (DOI: 10.1080/10643389.2012.671733). To the tabulation of >100 cited flux studies 1988-2009 given in the former publication, we have here listed corresponding studies published during the last decade with a few exceptions (2008-2019). During that decade, Hg stable isotope ratios of samples involved in atmosphere-terrestrial interaction is at hand and provide in combination with concentration and/or flux measurements novel constraints to quantitatively and qualitatively assess the bi-directional Hg0 flux. Recent efforts in the development of relaxed eddy accumulation and eddy covariance Hg0 flux methods bear the potential to facilitate long-term, ecosystem-scale flux measurements to reduce the prevailing large uncertainties in Hg0 flux estimates. Standardization of methods for Hg0 flux measurements is crucial to investigate how land-use change and how climate warming impact ecosystem-specific Hg0 sink-source characteristics and to validate frequently applied model parameterizations describing the regional and global scale Hg cycle.
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Affiliation(s)
- Jonas Sommar
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China.
| | - Stefan Osterwalder
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble INP, Grenoble, France
| | - Wei Zhu
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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103
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Bishop K, Shanley JB, Riscassi A, de Wit HA, Eklöf K, Meng B, Mitchell C, Osterwalder S, Schuster PF, Webster J, Zhu W. Recent advances in understanding and measurement of mercury in the environment: Terrestrial Hg cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137647. [PMID: 32197286 DOI: 10.1016/j.scitotenv.2020.137647] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/23/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
This review documents recent advances in terrestrial mercury cycling. Terrestrial mercury (Hg) research has matured in some areas, and is developing rapidly in others. We summarize the state of the science circa 2010 as a starting point, and then present the advances during the last decade in three areas: land use, sulfate deposition, and climate change. The advances are presented in the framework of three Hg "gateways" to the terrestrial environment: inputs from the atmosphere, uptake in food, and runoff with surface water. Among the most notable advances: These and other advances reported here are of value in evaluating the effectiveness of the Minamata Convention on reducing environmental Hg exposure to humans and wildlife.
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Affiliation(s)
- Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | | | - Ami Riscassi
- Department of Environmental Sciences, University of Virginia, P.O. Box 400123, Charlottesville, VA 22904-4123, USA.
| | - Heleen A de Wit
- Norwegian Institute for Water Research, Gaustadalléen 21, NO-0349, Norway.
| | - Karin Eklöf
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
| | - Carl Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
| | - Stefan Osterwalder
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble 18 INP, 38000 Grenoble, France.
| | - Paul F Schuster
- U.S. Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303-1066, USA.
| | - Jackson Webster
- Department of Civil Engineering, California State University, 400 W. 1st Street, 21 95929-0930 Chico, CA, USA.
| | - Wei Zhu
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden.
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104
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Liu J, Wang D, Zhang J, Liem-Nguyen V, Huang R, Jiang T. Evaluation of Hg methylation in the water-level-fluctuation zone of the Three Gorges Reservoir region by using the MeHg/Hg T ratio. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110468. [PMID: 32200146 DOI: 10.1016/j.ecoenv.2020.110468] [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: 12/16/2019] [Revised: 03/05/2020] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
In the recent decade, the hydroelectric reservoir is identified as a methylmercury (MeHg) hotspot and gained much attention. The artificial water level management in the Three Gorges Reservoir (TGR) in China formed a water-level-fluctuation zone (WLFZ) undergoing flooding drying rotations annually. However, the mercury (Hg) methylation and major geochemical driving factors at different elevations in the WLFZ remain unclear. Here we use total Hg (HgT) normalized MeHg (MeHg/HgT ratio) to evaluate Hg methylation degree in a one-year field study at 155, 165 m elevations in the WLFZ and with >175 m elevation as the reference. Results demonstrate that MeHg/HgT ratio at the WLFZ could reach 4.1% in soils, and both 155 and 165 m elevations have a higher Hg methylation degree than the >175 m elevation. However, the differences in MeHg/HgT ratios both in soils and waters between 155 and 165 m elevations are not significant. This indicates the influence of different submerging periods on the MeHg/HgT at the WLFZ elevations is not observed. The significant correlation between the MeHg/HgT ratio and soil organic carbon (SOC) content implies a MeHg retention in re-exposed soils after flooding. Decoupling of MeHg/HgT ratios between submerged soil and overlying water are found at both elevations and therefore make MeHg/HgT in waters alone cannot be used to evaluate Hg methylation degree in this study. The calculation of HgT and MeHg partitioning coefficient (Kd) found an immobilization of MeHg by submerged soils at the WLFZ during the flooding period. Major geochemical factors, determined through principal component analysis (PCA), in affecting Hg methylation are the redox cycling of sulfur and the distribution of organic matters in the WLFZ.
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Affiliation(s)
- Jiang Liu
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China; Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
| | - Jinzhong Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
| | - Van Liem-Nguyen
- Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
| | - Rong Huang
- College of Resources, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
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105
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Feng Y, Liu P, Wang Y, Liu W, Liu Y, Finfrock YZ. Mechanistic investigation of mercury removal by unmodified and Fe-modified biochars based on synchrotron-based methods. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 719:137435. [PMID: 32114231 DOI: 10.1016/j.scitotenv.2020.137435] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
Improved surface characteristics and incorporated Fe, S, and Cl species are reported in Fe-modified biochar, which makes it a prospective material for Hg(II) removal. In this study, aqueous Hg(II) was removed from solution by unmodified, FeCl3-modified, and FeSO4-modified biochars pyrolyzed at 300, 600, or 900 °C. Higher pyrolytic temperature resulted in higher removal efficiency, with the biochars pyrolyzed at 900 °C removing >96% of Hg(II). Fe-modification enhanced Hg(II) removal for biochars pyrolyzed at 600 °C (from 88% to >95%) or 900 °C (from 96% to 99%). Based on synchronous extended X-ray absorption fine structure (EXAFS) analysis, Hg coordinated to S in modified and unmodified biochars pyrolyzed at 900 °C, where thiol was reported, and in FeSO4-modified biochars pyrolyzed at 600 or 900 °C, where sulfide was recognized; in other biochars, Hg bound to O or Cl. Additionally, confocal micro-X-ray fluorescence imaging (CMXRFI) demonstrated Hg was distributed in agreement with S in biochars where HgS was formed; otherwise, Hg distribution was influenced by Hg species in solution and the pore characteristics of the biochar. This investigation provides information on the effectiveness and mechanisms of Hg removal that is critical for evaluating biochar applications and optimizing modification methods in groundwater remediation.
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Affiliation(s)
- Yu Feng
- School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Peng Liu
- School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
| | - Yanxin Wang
- School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Wenfu Liu
- School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - YingYing Liu
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Y Zou Finfrock
- CLS@APS sector 20, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; Science Division, Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada
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106
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Xu J, Zhang J, Lv Y, Xu K, Lu S, Liu X, Yang Y. Effect of soil mercury pollution on ginger (Zingiber officinale Roscoe): Growth, product quality, health risks and silicon mitigation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110472. [PMID: 32199219 DOI: 10.1016/j.ecoenv.2020.110472] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/08/2020] [Accepted: 03/10/2020] [Indexed: 06/10/2023]
Abstract
The mercury residue in soil not only poisons plants, but also bioaccumulates and biomagnifies through the food chain, causing a significant risk to human health. As an essential condiment on the table, the food safety of ginger should be focused on. Using soil culture experiments, this study aimed to identify the response of ginger growth to mercury pollution, assess the transmission and residue of mercury in different product organs and explore the mitigation mechanism of silicon on mercury toxicity. Effects of soil mercury pollution on ginger growth showed hormesis and time effect. Long-term mercury pollution led to growth inhibition and quality degradation of ginger, eventually reducing its yield by 25.96% (mercury = 9 mg kg-1). Contents of mercury and silicon in different organs both were the highest in root, followed by rhizome, less in stem and leaf, especially the mercury residue in rhizome manifested as Mother-ginger > Son-ginger > Grandson-ginger. At 6 mg kg-1 soil mercury level, the mercury residue of Mother-ginger exceeds the edible pollutant limit standard (China) by 10.7 times, which makes no obvious risk after being consumed by adults, but poses a potential health threat to children. Notably, it is safer to consume the newly sprouted and inflated tender ginger. Application of silicon fertilizer could alleviate mercury toxicity, mainly by promoting ginger root growth and leaf pigment synthesis, stimulating water-gas exchange system, fluorescence system and antioxidant system to make an anti-stress response. 2 mg kg-1 silicon fertilizer had the most significant mitigation effect on mercury stress, which increased the yield of ginger by 24.85% and reduced the mercury residue of ginger block by 44.44%-60.17%.
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Affiliation(s)
- Jiamin Xu
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China; Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jing Zhang
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China
| | - Yao Lv
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China
| | - Kun Xu
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China.
| | - Shaoyong Lu
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Xiaohui Liu
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; School of Environment, Tsinghua University, Beijing, 100084, China
| | - Yong Yang
- China National Environmental Monitoring Centre, Beijing, 100012, China
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107
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Watson LC, Hurtado-Gonzales JL, Chin CJ, Persaud J. Survey of Methylmercury Exposures and Risk Factors Among Indigenous Communities in Guyana, South America. J Health Pollut 2020; 10:200604. [PMID: 32509405 PMCID: PMC7269323 DOI: 10.5696/2156-9614-10.26.200604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/11/2020] [Indexed: 05/12/2023]
Abstract
BACKGROUND Gold mining activities in forested areas across Guyana have been a common practice for more than a century. The intensification of artisanal and small-scale gold mining (ASGM) in recent decades caused by global market demand is contributing to the mobilization of mercury into aquatic systems. Indigenous populations who consume high levels of locally sourced fish are greater at risk for methylmercury poisoning from ingestion of contaminated fish. OBJECTIVES The aim of the present study was to investigate the levels of mercury contamination and identify the risk factors associated with hair mercury levels in four indigenous communities in Guyana. METHODS Concentrations of total mercury were measured in hair samples from 99 participants from four indigenous communities in the south Rupununi region in Guyana. The findings of this study were compared with those of previous studies to assess the prevalence of mercury contamination in indigenous communities across Guyana. RESULTS Hair mercury levels were found to be above the World Health Organization (WHO) reference value for residents who live close to ASGM activities and who consume high quantities of locally sourced fish. Our results are not only consistent with those obtained in previous studies, but also evidence that mercury poisoning has become a generalized problem for indigenous communities in Guyana. CONCLUSIONS Fish is the main source of protein for many riverine communities and consumption of mercury-contaminated fish poses a serious health hazard for these vulnerable populations. The situation is especially dire for community members of Parabara with 100% of participants showing elevated (>15 μg*g-1) hair mercury levels. It is therefore crucial that Parabara residents be evaluated by relevant health agencies for clinical symptoms related to mercury toxicity. PARTICIPANT CONSENT Obtained. ETHICS APPROVAL The study protocol was approved by the Institutional Review Board of the Ministry of Public Health, Guyana. COMPETING INTERESTS The authors declare no competing financial interests.
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Affiliation(s)
- L. Cynthia Watson
- Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | | | | | - Juliana Persaud
- World Wildlife Fund, Guianas, Guyana Office, Georgetown, Guyana
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108
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Recent developments in environmental mercury bioremediation and its toxicity: A review. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.enmm.2020.100283] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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109
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Monteiro DA, Taylor EW, McKenzie DJ, Rantin FT, Kalinin AL. Interactive effects of mercury exposure and hypoxia on ECG patterns in two Neotropical freshwater fish species: Matrinxã, Brycon amazonicus and traíra, Hoplias malabaricus. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:375-388. [PMID: 32166694 DOI: 10.1007/s10646-020-02186-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
Hypoxia and mercury contamination often co-occur in tropical freshwater ecosystems, but the interactive effects of these two stressors on fish populations are poorly known. The effects of mercury (Hg) on recorded changes in the detailed form of the electrocardiogram (ECG) during exposure to progressive hypoxia were investigated in two Neotropical freshwater fish species, matrinxã, Brycon amazonicus and traíra, Hoplias malabaricus. Matrinxã were exposed to a sublethal concentration of 0.1 mg L-1 of HgCl2 in water for 96 h. Traíra were exposed to dietary doses of Hg by being fed over a period of 30 days with juvenile matrinxãs previously exposed to HgCl2, resulting in a dose of 0.45 mg of total Hg per fish, each 96 h. Both species showed a bradycardia in progressive hypoxia. Hg exposure impaired cardiac electrical excitability, leading to first-degree atrioventricular block, plus profound extension of the ventricular action potential (AP) plateau. Moreover, there was the development of cardiac arrhythmias and anomalies such as occasional absence of QRS complexes, extra systoles, negative Q-, R- and S-waves (QRS complex), and T wave inversion, especially in hypoxia below O2 partial pressures (PO2) of 5.3 kPa. Sub-chronic dietary Hg exposure induced intense bradycardia in normoxia in traira, plus lengthening of ventricular AP duration coupled with prolonged QRS intervals. This indicates slower ventricular AP conduction during ventricular depolarization. Overall, the data indicate that both acute waterborne and sub-chronic dietary exposure (trophic level transfer), at sublethal concentrations of mercury, cause damage in electrical stability and rhythm of the heartbeat, leading to myocardial dysfunction, which is further intensified during hypoxia. These changes could lead to impaired cardiac output, with consequences for swimming ability, foraging capacity, and hence growth and/or reproductive performance.
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Affiliation(s)
- Diana A Monteiro
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
| | - Edwin W Taylor
- School of Biological Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - David J McKenzie
- UMR Marbec, CNRS - IRD - Ifremer - University of Montpellier, Montpellier, France
| | - Francisco T Rantin
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
| | - Ana L Kalinin
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
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110
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Gębka K, Bełdowska M, Saniewska D, Korejwo E, Saniewski M. Meteorological phenomenon as a key factor controlling variability of labile particulate mercury in rivers and its inflow into coastal zone of the sea. ENVIRONMENTAL RESEARCH 2020; 184:109355. [PMID: 32172076 DOI: 10.1016/j.envres.2020.109355] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) is recognized as a global pollutant, which can be transported to the sea by suspended particulate matter (SPM) via rivers constituting the main source of mercury in the southern Baltic sea. The aim of the present study was to characterize the mercury fractions in suspended particulate matter, as well as the transformations of Hg during its riverine transportation into the sea. The thermo-desorption method was used to determine the labile and stable mercury fractions in SPM of rivers (Reda, Zagórska Struga, Gizdepka, Płutnica) within the Baltic Sea basin. In this paper six "periods" were designated (heating, non-heating, drought, rains, downpour/flood and thaws), during which the river suspended particulate matter was enriched with various fractions of mercury. Meteorological and hydrological phenomena such as downpours and thaws intensified surface runoff, causing an increase in the share of Hgabs and Hgads1 mercury fractions in suspended particulate matter. Whereas, droughts contributed to the formation of HgS in a large river and to an inflow of adsorbed Hg in smaller rivers decrease of air temperature leads to increase of fossil fuel combustion and then increases the share of adsorbed Hg (mainly bound with halides) in riverine particulate matter. In the non-heating season, the main fraction was the mercury absorbed inside organic matter.
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Affiliation(s)
- Karolina Gębka
- Institute of Oceanography, University of Gdańsk, Piłsudski 46 Alley, 81-378, Gdynia, Poland.
| | - Magdalena Bełdowska
- Institute of Oceanography, University of Gdańsk, Piłsudski 46 Alley, 81-378, Gdynia, Poland
| | - Dominika Saniewska
- Institute of Oceanography, University of Gdańsk, Piłsudski 46 Alley, 81-378, Gdynia, Poland
| | - Ewa Korejwo
- Institute of Oceanography, University of Gdańsk, Piłsudski 46 Alley, 81-378, Gdynia, Poland
| | - Michał Saniewski
- Institute of Meteorology and Water Management - National Research Institute, Marine Branch, Waszyngton 42 Street, 81-342, Gdynia, Poland
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111
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Tang WL, Liu YR, Guan WY, Zhong H, Qu XM, Zhang T. Understanding mercury methylation in the changing environment: Recent advances in assessing microbial methylators and mercury bioavailability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136827. [PMID: 32018974 DOI: 10.1016/j.scitotenv.2020.136827] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/17/2020] [Accepted: 01/18/2020] [Indexed: 06/10/2023]
Abstract
Methylmercury (MeHg) is a neurotoxin, mainly derived from microbial mercury methylation in natural aquatic environments, and poses threats to human health. Polar regions and paddy soils are potential hotspots of mercury methylation and represent environmental settings that are susceptible to natural and anthropogenic perturbations. The effects of changing environmental conditions on the methylating microorganisms and mercury speciation due to global climate change and farming practices aimed for sustainable agriculture were discussed for polar regions and paddy soils, respectively. To better understand and predict microbial mercury methylation in the changing environment, we synthesized current understanding of how to effectively identify active mercury methylators and assess the bioavailability of different mercury species for methylation. The application of biomarkers based on the hgcAB genes have demonstrated the occurrence of potential mercury methylators, such as sulfate-reducing bacteria, iron-reducing bacteria, methanogen and syntrophs, in a diverse variety of microbial habitats. Advanced techniques, such as enriched stable isotope tracers, whole-cell biosensor and diffusive gradient thin film (DGT) have shown great promises in quantitatively assessing mercury availability to microbial methylators. Improved understanding of the complex structure of microbial communities consisting mercury methylators and non-methylators, chemical speciation of inorganic mercury under geochemically relevant conditions, and the pathway of cellular mercury uptake will undoubtedly facilitate accurate assessment and prediction of in situ microbial mercury methylation.
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Affiliation(s)
- Wen-Li Tang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yu-Rong Liu
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan 430070, China
| | - Wen-Yu Guan
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, China; Environmental and Life Science Program (EnLS), Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Xiao-Min Qu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Tong Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China.
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112
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Yang L, Zhang W, Ren M, Cao F, Chen F, Zhang Y, Shang L. Mercury distribution in a typical shallow lake in northern China and its re-emission from sediment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 192:110316. [PMID: 32061981 DOI: 10.1016/j.ecoenv.2020.110316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) re-emission from sediment is an important process in the biogeochemistry cycles of Hg in the aquatic ecosystem. The contribution of Hg released from sediment to water remains unclear for some shallow lakes. Lake Nansi is a typical shallow lake in northern China that is divided into upper and lower lakes by a dam. The Hg species in the water profile and sediment were measured from two sampling sites in the lake. Nansi Lake was not markedly contaminated by Hg. The Hg profile in the sediment indicated that the demand for energy and the policy management in the catchment influenced the Hg accumulation in its sediment. On the basis of Fick's first law and the sedimentation rate, the diffusion flux of dissolved Hg from sediment to overlying water and the accumulation flux were estimated. According to one-year scale estimation, approximately 10%-13% the Hg in the sediments can be re-released into the overlying water. The Hg diffused from the sediment accounted for 7.9%-16% of the Hg in the overlying water. These results of this study improve the understanding of the sources of pollution in water and enable researchers to focus on the contribution of sediment to the pollution of water in shallow lakes.
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Affiliation(s)
- Liyuan Yang
- School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China.
| | - Wei Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mingyi Ren
- School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China
| | - Feifei Cao
- School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China
| | - Fengfeng Chen
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, 550025, China
| | - Yutao Zhang
- Engineering Technology Center for Control and Remediation of Soil Contamination, Anshun University, Anshun, 561000, China
| | - Lihai Shang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
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113
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Eckley CS, Gilmour CC, Janssen S, Luxton TP, Randall PM, Whalin L, Austin C. The assessment and remediation of mercury contaminated sites: A review of current approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:136031. [PMID: 31869604 PMCID: PMC6980986 DOI: 10.1016/j.scitotenv.2019.136031] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/07/2019] [Accepted: 12/07/2019] [Indexed: 04/13/2023]
Abstract
Remediation of mercury (Hg) contaminated sites has long relied on traditional approaches, such as removal and containment/capping. Here we review contemporary practices in the assessment and remediation of industrial-scale Hg contaminated sites and discuss recent advances. Significant improvements have been made in site assessment, including the use of XRF to rapidly identify the spatial extent of contamination, Hg stable isotope fractionation to identify sources and transformation processes, and solid-phase characterization (XAFS) to evaluate Hg forms. The understanding of Hg bioavailability for methylation has been improved by methods such as sequential chemical extractions and porewater measurements, including the use of diffuse gradient in thin-film (DGT) samplers. These approaches have shown varying success in identifying bioavailable Hg fractions and further study and field applications are needed. The downstream accumulation of methylmercury (MeHg) in biota is a concern at many contaminated sites. Identifying the variables limiting/controlling MeHg production-such as bioavailable inorganic Hg, organic carbon, and/or terminal electron acceptors (e.g. sulfate, iron) is critical. Mercury can be released from contaminated sites to the air and water, both of which are influenced by meteorological and hydrological conditions. Mercury mobilized from contaminated sites is predominantly bound to particles, highly correlated with total sediment solids (TSS), and elevated during stormflow. Remediation techniques to address Hg contamination can include the removal or containment of Hg contaminated materials, the application of amendments to reduce mobility and bioavailability, landscape/waterbody manipulations to reduce MeHg production, and food web manipulations through stocking or extirpation to reduce MeHg accumulated in desired species. These approaches often rely on knowledge of the Hg forms/speciation at the site, and utilize physical, chemical, thermal and biological methods to achieve remediation goals. Overall, the complexity of Hg cycling allows many different opportunities to reduce/mitigate impacts, which creates flexibility in determining suitable and logistically feasible remedies.
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Affiliation(s)
- Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA 98101, USA.
| | - Cynthia C Gilmour
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd., Edgewater, MD 21037-0028, USA.
| | - Sarah Janssen
- USGS Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA.
| | - Todd P Luxton
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA.
| | - Paul M Randall
- US Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
| | - Lindsay Whalin
- San Francisco Bay Water Board, 1515 Clay St., Ste. 1400, Oakland, CA 94612, USA.
| | - Carrie Austin
- San Francisco Bay Water Board, 1515 Clay St., Ste. 1400, Oakland, CA 94612, USA.
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114
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Wang J, Shaheen SM, Anderson CWN, Xing Y, Liu S, Xia J, Feng X, Rinklebe J. Nanoactivated Carbon Reduces Mercury Mobility and Uptake by Oryza sativa L: Mechanistic Investigation Using Spectroscopic and Microscopic Techniques. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2698-2706. [PMID: 32045518 DOI: 10.1021/acs.est.9b05685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) contamination of paddy field poses a health risk to rice consumers, and its remediation is a subject of global scientific attention. In recent years focus has been given to in situ techniques which reduce the risk of Hg entering the food chain. Here, we investigate the use of nanoactivated carbon (NAC) as a soil amendment to minimize Hg uptake by rice plants. Application of 1-3% NAC to soil (by weight) reduced Hg concentration in the pore water (by 61-76%) and its bioaccumulation in the tissues of rice plants (by 15-63%), relative to the corresponding control. Specifically, NAC reduced the Hg concentration of polished rice by 47-63% compared to the control, to a level that was 29-49% lower than the food safety value (20 ng g-1) defined by the Chinese government. The NAC induced a change in Hg binding from organic matter to nano-HgS in the soil as a function of soil amendment. This Hg speciation transformation might be coupled to the reduction of sulfoxide to reduced sulfur species (S0) by NAC. The NAC amendment may be a practical and effective solution to mitigate the risk of Hg transferring from contaminated soil to rice grains at locations around the world.
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Affiliation(s)
- Jianxu Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, P. R. China
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
- CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, P. R. China
| | - Sabry M Shaheen
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
- King Abdulaziz University, Faculty of Meteorology, Environment, and Arid Land Agriculture, Department of Arid Land Agriculture, Jeddah 21589, Kingdom of Saudi Arabia
- University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33516 Kafr El-Sheikh, Egypt
| | - Christopher W N Anderson
- Environmental Sciences, School of Agriculture and Environment, Massey University, 4442 Palmerston North, New Zealand
| | - Ying Xing
- School of Chemistry and Materials Science, Guizhou Normal University, 550001 Guiyang, P. R. China
| | - Shirong Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, P. R. China
| | - Jicheng Xia
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, P. R. China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, P. R. China
- CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, P. R. China
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
- University of Sejong, Department of Environment, Energy and Geoinformatics, 98 Gunja-Dong, Guangjin-Gu, Seoul 05006, Republic of Korea
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115
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Proteomic response of Euglena gracilis to heavy metal exposure – Identification of key proteins involved in heavy metal tolerance and accumulation. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101764] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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116
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Gygax S, Gfeller L, Wilcke W, Mestrot A. Emerging investigator series: mercury mobility and methylmercury formation in a contaminated agricultural flood plain: influence of flooding and manure addition. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:2008-2019. [PMID: 31617529 DOI: 10.1039/c9em00257j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The fate and the methylation of mercury (Hg) in the terrestrial environment are still poorly understood and although the main drivers of release and methylation of mercury in soils are known (low redox potential and microbial carbon availability) their interactions are not well understood. This is of concern since many agriculturally used floodplains, where the recurring flooding and agricultural practices (e.g. manure amendments) may have an impact on the fate and the biomethylation of Hg, are at the same time Hg-contaminated. In this study, we modified and validated existing methods to extract and analyze methylmercury (MeHg) by HPLC-ICP-MS in soils and we assessed the Hg and MeHg concentrations in three fields situated in a Hg polluted agricultural floodplain. Further, we incubated the top soil from the three studied fields for 11 days under flooded conditions in presence or absence of 2 mass% of cow manure, a common agricultural amendment in the area. Total Hg and MeHg concentrations ranged from <limit of detection (LOD, 0.012 mg kg-1) to 28.2 mg kg-1 and from 1.2 to 7.8 μg kg-1 respectively. Hg was released to the soil solution after 12 hours with a maximum between day 2 and day 7. MeHg levels in the soil solution were <LOD although it was found in the soil before and after the incubation. The addition of cow manure to saturated soils led to an increase in the MeHg concentrations of the soil solid phase by up to fivefold to a maximum of 26.4 ± 1.1 μg kg-1 (n = 3). Our study demonstrates that the combination of low redox potential because of flooding with common agricultural practices such as the amendment of manures enhances the formation of toxic MeHg.
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Affiliation(s)
- Sebastian Gygax
- Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland
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117
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Nuclear Magnetic Resonance parameters of mercury atom and water molecule complex: Relativistic calculations. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.136775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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118
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Liu M, Xie H, He Y, Zhang Q, Sun X, Yu C, Chen L, Zhang W, Zhang Q, Wang X. Sources and transport of methylmercury in the Yangtze River and the impact of the Three Gorges Dam. WATER RESEARCH 2019; 166:115042. [PMID: 31520812 DOI: 10.1016/j.watres.2019.115042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/29/2019] [Accepted: 09/02/2019] [Indexed: 05/22/2023]
Abstract
The magnitude of environmental change due to anthropogenic impacts might greatly exceed that of natural disturbances. In this work, we quantitatively examine the impacts of river damming, soil erosion, and point-source release on the transport of methylmercury (MeHg) throughout the Yangtze River, the third longest river in the world. Based on seasonal observations and the subsequent material flow analysis, we found that in 2016, the Yangtze River discharged 470 ± 200 kg MeHg to the coastal and shelf areas, a value at least ten-fold larger than existing observations in other large rivers around the world. The construction of the Three Gorges Dam (TGD), the world's largest hydropower dam, induced a substantial amount of MeHg (at least 250 ± 220 kg) accumulation in the reservoir and a relatively small amount of MeHg (150 ± 37 kg) discharge to the downstream region in 2016. The reservoir itself is not expected to be more contaminated by MeHg than the downstream areas of the river after the TGD, and the TGD has an additive effect on downstream MeHg transport. The riverine MeHg flux in the river mouth was 3-fold that discharged from the TGD mainly due to TGD-induced resuspension of MeHg from the downstream riverbed, as well as MeHg imports to the downstream area from tributaries, soil erosion, municipal wastewater, and in situ production. Our analysis offers new evidence that in future decades, the increase in estuarine MeHg contamination resulting from the increasing construction of large dams might pose a challenge for global coastal fisheries.
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Affiliation(s)
- Maodian Liu
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Science, Peking University, Beijing, 100871, China
| | - Han Xie
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Science, Peking University, Beijing, 100871, China
| | - Yipeng He
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd., Groton, CT, 06340, USA
| | - Qianru Zhang
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Science, Peking University, Beijing, 100871, China
| | - Xuejun Sun
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chenghao Yu
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Science, Peking University, Beijing, 100871, China
| | - Long Chen
- Key Laboratory of Geographic Information Science (Ministry of Education), East China Normal University, Shanghai, 200241, China
| | - Wei Zhang
- School of Environment and Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xuejun Wang
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Science, Peking University, Beijing, 100871, China.
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119
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Liu YR, Yang Z, Zhou X, Qu X, Li Z, Zhong H. Overlooked Role of Putative Non-Hg Methylators in Predicting Methylmercury Production in Paddy Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:12330-12338. [PMID: 31603332 DOI: 10.1021/acs.est.9b03013] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Rice ingestion has been recognized as an important route of dietary exposure to neurotoxic methylmercury (MeHg) that is commonly synthesized in rice paddy soils. Although Hg methylators are known to regulate soil MeHg formation, the effect of non-Hg methylating communities on MeHg production remains unclear. Here, we collected 141 paddy soil samples from main rice-producing areas across China to identify associations between bacterial community composition (including both Hg and putative non-Hg methylators) and MeHg production. Results showed that the MeHg content in the paddy soils varied from 0.11 to 8.36 ng g-1 at a national spatial scale, which could be due to the shifts of soil microbial community composition across different areas. Our structure equation modeling suggested a strong link between bacterial community composition and MeHg content and %MeHg. More importantly, random forest analyses suggested a more significant role of putative non-Hg methylators than Hg methylators in predicting variations of soil MeHg content. The relative abundance of putative non-Hg methylators such as unclassified Xanthomonadales and Chitinophagaceae were strongly correlated with soil MeHg contents. Further, microbial network analysis revealed strong co-occurrence patterns between the putative non-Hg and Hg methylators. These findings highlight an overlooked role of non-Hg methylating communities in predicting MeHg production in paddy soils.
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Affiliation(s)
| | - Ziming Yang
- Department of Chemistry , Oakland University , Rochester , Michigan 48309 , United States
| | | | | | - Zizhu Li
- School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Huan Zhong
- School of the Environment , Nanjing University , Nanjing 210023 , China
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120
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Curtis AN, Bourne K, Borsuk ME, Buckman KL, Demidenko E, Taylor VF, Chen CY. Effects of temperature, salinity, and sediment organic carbon on methylmercury bioaccumulation in an estuarine amphipod. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:907-916. [PMID: 31412494 PMCID: PMC6697058 DOI: 10.1016/j.scitotenv.2019.06.094] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 05/21/2023]
Abstract
Mercury (Hg) is a global contaminant that poses a human health risk in its organic form, methylmercury (MeHg), through consumption of fish and fishery products. Bioaccumulation of Hg in the aquatic environment is controlled by a number of factors expected to be altered by climate change. We examined the individual and combined effects of temperature, sediment organic carbon, and salinity on the bioaccumulation of MeHg in an estuarine amphipod, Leptocheirus plumulosus, when exposed to sediment from two locations in the Gulf of Maine (Kittery and Bass Harbor) that contained different levels of MeHg and organic carbon. Higher temperatures and lower organic carbon levels individually increased uptake of MeHg by L. plumulosus as measured by the biota-sediment accumulation factor (BSAF), while the effect of salinity on BSAF differed by sediment source. Multi-factor statistical modeling using all data revealed a significant interaction between temperature and organic carbon for both sediments, in which increased temperature had a negative effect on BSAF at the lowest carbon levels and a positive effect at higher levels. Our results suggest that increased temperature and carbon loading, of a magnitude expected as a result from climate change, could be associated with a net decrease in amphipod BSAF of 50 to 71%, depending on sediment characteristics. While these are only first-order projections, our results indicate that the future fate of MeHg in marine food webs is likely to depend on a number of factors beyond Hg loading.
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Affiliation(s)
- Amanda N Curtis
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, United States.
| | - Kimberly Bourne
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, United States
| | - Mark E Borsuk
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, United States
| | - Kate L Buckman
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, United States
| | - Eugene Demidenko
- Department of Biomedical Data Science, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, United States; Department of Mathematics, Dartmouth College, NH 03755, United States
| | - Vivien F Taylor
- Department of Earth Science, Dartmouth College, Hanover, NH 03755, United States
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, United States
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121
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Willacker JJ, Eagles-Smith CA, Kowalski BM, Danehy RJ, Jackson AK, Adams EM, Evers DC, Eckley CS, Tate MT, Krabbenhoft DP. Timber harvest alters mercury bioaccumulation and food web structure in headwater streams. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:636-645. [PMID: 31330355 PMCID: PMC6799996 DOI: 10.1016/j.envpol.2019.07.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/02/2019] [Accepted: 07/05/2019] [Indexed: 05/15/2023]
Abstract
Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest's influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in 10 paired catchments that were either clear-cut in their entirety, clear-cut except for an 8-m wide riparian buffer, or left unharvested. Average mercury concentrations in aquatic biota from clear-cut catchments were 50% higher than in reference catchments and 165% higher than in catchments with a riparian buffer. Mercury concentrations in aquatic invertebrates and salamanders were not correlated with aqueous THg or MeHg concentrations, but rather treatment effects appeared to correspond with differences in the utilization of terrestrial and aquatic basal resources in the stream food webs. Carbon and nitrogen isotope data suggest that a diminished shredder niche in the clear-cut catchments contributed to lower basal resource diversity compared with the reference of buffered treatments, and that elevated Hg concentrations in the clear-cut catchments reflect an increased reliance on aquatic resources in clear-cut catchments. In contrast, catchments with riparian buffers had higher basal resource diversity than the reference catchments, indicative of more balanced utilization of terrestrial and aquatic resources. Further, following timber harvest THg concentrations in riparian songbirds were elevated, suggesting an influence of timber harvest on Hg export to riparian food webs. These data, coupled with comparisons of individual feeding guilds, indicate that changes in organic matter sources and associated effects on stream food web structure are important mechanisms by which timber harvest modifies Hg bioaccumulation in headwater streams and riparian consumers.
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Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
| | - Brandon M Kowalski
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Robert J Danehy
- Catchment Aquatic Ecology, 5335 Saratoga St., Eugene, OR, 97405, USA
| | - Allyson K Jackson
- Oregon State University, Department of Fisheries and Wildlife, 104 Nash Hall, Corvallis, OR, 97331, USA
| | - Evan M Adams
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA, 98101, USA
| | - Michael T Tate
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
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122
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Christensen GA, Gionfriddo CM, King AJ, Moberly JG, Miller CL, Somenahally AC, Callister SJ, Brewer H, Podar M, Brown SD, Palumbo AV, Brandt CC, Wymore AM, Brooks SC, Hwang C, Fields MW, Wall JD, Gilmour CC, Elias DA. Determining the Reliability of Measuring Mercury Cycling Gene Abundance with Correlations with Mercury and Methylmercury Concentrations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8649-8663. [PMID: 31260289 DOI: 10.1021/acs.est.8b06389] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Methylmercury (MeHg) is a bioaccumulative toxic contaminant in many ecosystems, but factors governing its production are poorly understood. Recent work has shown that the anaerobic microbial conversion of mercury (Hg) to MeHg requires the Hg-methylation genes hgcAB and that these genes can be used as biomarkers in PCR-based estimators of Hg-methylator abundance. In an effort to determine reliable methods for assessing hgcA abundance and diversity and linking them to MeHg concentrations, multiple approaches were compared including metagenomic shotgun sequencing, 16S rRNA gene pyrosequencing and cloning/sequencing hgcAB gene products. Hg-methylator abundance was also determined by quantitative hgcA qPCR amplification and metaproteomics for comparison to the above measurements. Samples from eight sites were examined covering a range of total Hg (HgT; 0.03-14 mg kg-1 dry wt. soil) and MeHg (0.05-27 μg kg-1 dry wt. soil) concentrations. In the metagenome and amplicon sequencing of hgcAB diversity, the Deltaproteobacteria were the dominant Hg-methylators while Firmicutes and methanogenic Archaea were typically ∼50% less abundant. This was consistent with metaproteomics estimates where the Deltaproteobacteria were steadily higher. The 16S rRNA gene pyrosequencing did not have sufficient resolution to identify hgcAB+ species. Metagenomic and hgcAB results were similar for Hg-methylator diversity and clade-specific qPCR-based approaches for hgcA are only appropriate when comparing the abundance of a particular clade across various samples. Weak correlations between Hg-methylating bacteria and soil Hg concentrations were observed for similar environmental samples, but overall total Hg and MeHg concentrations poorly correlated with Hg-cycling genes.
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Affiliation(s)
- Geoff A Christensen
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Caitlin M Gionfriddo
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Andrew J King
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - James G Moberly
- College of Engineering , University of Idaho , Moscow , Idaho 83844 , United States
| | - Carrie L Miller
- School of Theoretical and Applied Science , Ramapo College of New Jersey , Mahwah , New Jersey 07430 , United States
| | - Anil C Somenahally
- Department of Soil and Crop Sciences , Texas A&M University , Overton , Texas 77843-2474 , United States
| | - Stephen J Callister
- Biological Sciences Division , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Heather Brewer
- Biological Sciences Division , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Mircea Podar
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Steven D Brown
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Anthony V Palumbo
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Craig C Brandt
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Ann M Wymore
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
| | - Scott C Brooks
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37830 , United States
| | - Chiachi Hwang
- Center for Biofilm Engineering , Montana State University , Bozeman , Montana 59717 , United States
| | - Matthew W Fields
- Department of Microbiology and Immunology , Montana State University , Bozeman , Montana 59717 , United States
- Center for Biofilm Engineering , Montana State University , Bozeman , Montana 59717 , United States
| | - Judy D Wall
- Department of Biochemistry , University of Missouri , Columbia , Missouri 65211 , United States
| | - Cynthia C Gilmour
- Smithsonian Environmental Research Center , Edgewater , Maryland 21037 , United States
| | - Dwayne A Elias
- Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6342 , United States
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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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Rivera NA, Bippus PM, Hsu-Kim H. Relative Reactivity and Bioavailability of Mercury Sorbed to or Coprecipitated with Aged Iron Sulfides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7391-7399. [PMID: 31173690 PMCID: PMC8412064 DOI: 10.1021/acs.est.9b00768] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The potential for inorganic mercury (Hg) to be converted to methylmercury depends, in part, on the chemical form of Hg and its bioavailability to anaerobic microorganisms that can methylate Hg. In anaerobic settings, Hg can be associated with sulfide phases, including ferrous iron sulfide (FeS), which can sorb or be coprecipitated with Hg. The objective of this study was to determine if the aging state of FeS alters the Hg coordination environment as well as the reactivity and bioavailability of sorbed and coprecipitated Hg species. FeS particles were synthesized with and without Hg2+ and aged in anaerobic conditions for multiple time frames spanning from 1 h to 1 month. For FeS particles synthesized without Hg, Hg2+ was subsequently sorbed to the FeS for 1 day. Analysis of Hg speciation of these materials by X-ray absorption near edge spectroscopy revealed a predominance of four-coordinate Hg-S species in the sorbed Hg-FeS solids and a mixture of two- and four-coordinate Hg-S in the coprecipitated Hg-FeS. The leaching potential of the Hg was assessed by exposing the particles to a solution of dissolved glutathione (a thiolate-based Hg chelator). As expected, the sorbed Hg-FeS released more soluble Hg compared to the coprecipitated Hg-FeS. However, when these particles were exposed to Desulfovibrio desulfuricans ND132 (a known Hg methylator), more Hg was methylated from the coprecipitated Hg-FeS than the sorbed Hg-FeS, consistent with expectations from the Hg-S coordination state and inconsistent with the selective leaching results. Overall, these results suggest that the bioavailability of particulate Hg cannot be easily discerned by its leaching potential into bulk solution. Rather, bioavailability entails more subtle interactions at particle-cell interfaces and perhaps correlates with the local Hg-S coordination state in the particles.
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Affiliation(s)
- Nelson A. Rivera
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Paige M. Bippus
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
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Wang J, Shaheen SM, Swertz AC, Rennert T, Feng X, Rinklebe J. Sulfur-modified organoclay promotes plant uptake and affects geochemical fractionation of mercury in a polluted floodplain soil. JOURNAL OF HAZARDOUS MATERIALS 2019; 371:687-693. [PMID: 30889465 DOI: 10.1016/j.jhazmat.2019.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/11/2019] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
We investigated effects of the application of a sulfur-modified organoclay (SMOC) at doses of 1%, 3% and 5% (w/w) on the geochemical fractionation of mercury (Hg) and its accumulation by pea and corn in a polluted floodplain soil. Soil Hg was fractionated sequentially to five operationally defined fractions as follows: F1: water soluble Hg; F2: "human stomach acid" soluble Hg; F3: organo-chelated Hg; F4: elemental Hg; and F5: Hg-sulfur-compounds/residual Hg. The high dosage of SMOC caused a decrease of Hg in F3 (18%) and F5 (36-63%), and 6.7 fold increase of Hg in the mobile fraction (MF = F1+F2) as compared to control soil. The transformation of Hg from F5 to the MF in SMOC-treated soil might be due to the associated decrease of soil pH. Pea accumulated more Hg than corn. Mercury contents were larger in roots than in shoots of both plants and increased significantly by a factor of up to 11 by SMOC addition. The potential transformation of Hg from the hardly soluble to the MF by SMOC addition and the associated increase of Hg accumulation by plants imply a great potential of the SMOC for enhancing Hg phytoremediation.
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Affiliation(s)
- Jianxu Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550082 Guiyang, PR China; University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, PR China.
| | - Sabry M Shaheen
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33516 Kafr El-Sheikh, Egypt; King Abdulaziz University, Faculty of Meteorology, Environment, and Arid Land Agriculture, Department of Arid Land Agriculture, Jeddah 21589, Saudi Arabia.
| | - Ann-Christin Swertz
- University of Wuppertal, Faculty of Mechanical Engineering and Safety Engineering, Department of Safety Technology and Environmental Protection, Rainer-Gruenter-Straße, 42119 Wuppertal, Germany.
| | - Thilo Rennert
- Department of Soil Chemistry and Pedology, Institute of Soil Science and Land Evaluation, University of Hohenheim, Emil-Wolff-Str. 27, 70599 Stuttgart, Germany.
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550082 Guiyang, PR China.
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Sejong, Department of Environment, Energy and Geoinformatics, 98 Gunja-Dong, Guangjin-Gu, Seoul, Republic of Korea.
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126
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Buckman KL, Seelen EA, Mason RP, Balcom P, Taylor VF, Ward JE, Chen CY. Sediment organic carbon and temperature effects on methylmercury concentration: A mesocosm experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:1316-1326. [PMID: 30970496 PMCID: PMC6461384 DOI: 10.1016/j.scitotenv.2019.02.302] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/01/2019] [Accepted: 02/19/2019] [Indexed: 05/21/2023]
Abstract
The fate and mobility of mercury, and its bioaccumulation primarily as methylmercury (MeHg), in marine ecosystems are influenced by climate related environmental factors, including increased temperature and carbon loading. To investigate the interactions between sediment organic carbon and temperature MeHg bioaccumulation, mesocosm experiments were conducted examining relationships between sediment, water column and biota (sediment-dwelling amphipod and juvenile oyster) MeHg concentration. Experimental treatments consisted of a two by two design of high and low temperature (15 & 25 °C) and high and low sediment organic carbon (4-5% and 13% LOI, pre-experiment). Sediment organic carbon had significant individual effects on MeHg concentration in water and biota, with higher carbon associated with lower MeHg. Temperature individual effects were significant for sediment, water, and only amphipod MeHg concentration, with higher temperature treatments indicating higher MeHg concentration. There were significant temperature × carbon interactions observed for sediment, dissolved, and oyster MeHg concentration. Sediment carbon reduction had greater influence than temperature on increasing MeHg concentrations in both the water column and biota. MeHg concentrations in the bulk sediment were not correlated with MeHg in the water column or in the biota, indicating that even when sediments are the only source of MeHg, bulk sediment measurements do not provide a good proxy for bioaccumulation and that the concentration in bulk sediments is not the primary determinant of MeHg entry into the food web.
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Affiliation(s)
- K L Buckman
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States of America.
| | - E A Seelen
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - R P Mason
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - P Balcom
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America; Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, United States of America
| | - V F Taylor
- Department of Earth Science, Dartmouth College, Hanover, NH, United States of America
| | - J E Ward
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - C Y Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States of America
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127
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Mason RP, Baumann Z, Hansen G, Yao KM, Coulibaly M, Coulibaly S. An assessment of the impact of artisanal and commercial gold mining on mercury and methylmercury levels in the environment and fish in Cote d'Ivoire. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 665:1158-1167. [PMID: 30893747 DOI: 10.1016/j.scitotenv.2019.01.393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) activities are an important source of mercury (Hg) to the atmosphere globally, and in most countries in West Africa, where gold production has increased dramatically in the last decade from both commercial and ASGM activities. This study focused on examining the concentrations of Hg and methylmercury (MeHg) in water, sediments and fish in four regions associated with gold mining activities in Cote d'Ivoire to assess the potential exposure of the local communities to MeHg from fish consumption. Concentrations of dissolved total Hg and MeHg in water and sediment were elevated at some locations sample and were indicative of local contamination. Several locations had sediment total Hg above 100 ng g-1 and sediment %MeHg ranged from 0.03 to 4.4%. Fish concentrations exceeded 0.3 μg/ g wet wt., especially for carnivores and fish caught in the western region of the country. Bioaccumulation factors, relative to dissolved MeHg, were higher for carnivores than omnivores and varied with region, suggesting other factors besides MeHg concentration alone were impacting uptake and trophic transfer. Given that people in Cote d'Ivoire consume fish at a higher level than other countries, the levels in fish were sufficient to exceed the US EPA's guidance criteria even at average consumption levels, and particularly for people consuming fish at a higher rate. Overall, this study provides compelling evidence that ASGM activities in Cote d'Ivoire are leading to elevated exposure and likely impacting the health of the local populations in regions where such activity is occurring.
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Affiliation(s)
- Robert P Mason
- Dept. Marine Sciences, University of Connecticut, Groton, CT, USA.
| | - Zofia Baumann
- Dept. Marine Sciences, University of Connecticut, Groton, CT, USA
| | - Gunnar Hansen
- Dept. Marine Sciences, University of Connecticut, Groton, CT, USA
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128
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Beau F, Bustamante P, Michaud B, Brischoux F. Environmental causes and reproductive correlates of mercury contamination in European pond turtles (Emys orbicularis). ENVIRONMENTAL RESEARCH 2019; 172:338-344. [PMID: 30825684 DOI: 10.1016/j.envres.2019.01.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/18/2019] [Accepted: 01/26/2019] [Indexed: 06/09/2023]
Abstract
Assessing Hg contamination in aquatic ecosystems is difficult because wetlands are part of large and complex networks, and potential sources of Hg contamination are highly diverse. To investigate environmental determinants of Hg contamination, we studied one of the largest continental French wetlands structured as a dense network of artificial ponds. Such context allows to investigate the influence of pond characteristics on Hg contamination in an area relatively disconnected from direct sources of pollution. We relied on a bioindicator organism, the European pond turtle (Emys orbicularis) to assess Hg contamination in a relatively large number of sites (N > 255 turtles from 15 ponds sampled in 2016 and 2017). Non-invasive sampling in the claws of turtles show that Hg concentrations were not related to their sex or size, but we found an effect of age (1.62 ± 0.20 in juveniles and 2.21 ± 0.06 µg g-1 dw in adults), suggesting that turtles do bioaccumulate Hg through their life. Turtle Hg was different between ponds, and we found that pond age and pond usage (draining events linked to pond maintenance) were the main environmental determinants of Hg concentrations in turtles. Finally, and more importantly, our dataset allowed us to highlight potential negative effect of Hg concentrations on the proportion of reproductive females, suggesting an influence of Hg on reproductive mechanisms in this species. This result indicates that Hg contamination, even in absence of direct and strong sources of pollution, may have a critical impact on reproduction and thus the persistence of a long-lived vertebrate.
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Affiliation(s)
- Frédéric Beau
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS-Université de La Rochelle, 79360 Villiers en Bois, France; Réserve Naturelle Nationale de Chérine, Maison de la Nature et de la Réserve, 36290 Saint-Michel-en-Brenne, France.
| | - Paco Bustamante
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Bruno Michaud
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS-Université de La Rochelle, 79360 Villiers en Bois, France
| | - François Brischoux
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS-Université de La Rochelle, 79360 Villiers en Bois, France
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129
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Wang Y, Yin D, Xiang Y, Xu Q, Zhang C, Xie Q, Wang D. A Review of Studies on the Biogeochemical Behaviors of Mercury in the Three Gorges Reservoir, China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 102:686-694. [PMID: 30859245 DOI: 10.1007/s00128-019-02586-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
The Three Gorges Reservoir (TGR) is a relatively large reservoir, and its water level management actions produce a widespread water level fluctuation zone (WLFZ), which has characteristics of both terrestrial and aquatic ecosystems. Here, an integrated overview of current knowledge on Hg behaviors in the TGR, especially the WLFZ, as well as exposure risk to local residents was presented. Hg levels in the TGR were comparable with other natural aquatic systems. WLFZ in the TGR was confirmed to be an environment favorable for Hg methylation by enhancing microbial activity, promoting sulfur cycling and increasing the level of low-molecular-weight organic matters. However, elevated fish Hg concentrations did not follow the impoundment of TGR, indicating no obvious reservoir effect, while it is still noteworthy that frequently consuming fish is likely to be a methylmercury (MeHg) exposure pathway for specific populations e.g. fishermen around the TGR.
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Affiliation(s)
- Yongmin Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
- Chongqing Key Laboratory of Agricultural Resources and Environment, 400715, Chongqing, China
| | - Deliang Yin
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Yuping Xiang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Qinqin Xu
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Cheng Zhang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
- Chongqing Key Laboratory of Agricultural Resources and Environment, 400715, Chongqing, China
| | - Qing Xie
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China.
- Chongqing Key Laboratory of Agricultural Resources and Environment, 400715, Chongqing, China.
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130
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Olsen M, Fjeld E, Lydersen E. The influence of a submerged meadow on uptake and trophic transfer of legacy mercury from contaminated sediment in the food web in a brackish Norwegian fjord. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:209-217. [PMID: 30445322 DOI: 10.1016/j.scitotenv.2018.11.055] [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: 07/30/2018] [Revised: 11/03/2018] [Accepted: 11/04/2018] [Indexed: 06/09/2023]
Abstract
There are contradicting results on the importance of legacy mercury (Hg) contaminated sediments to Hg fish tissue concentrations. Still, sediment remediation actions often aim at minimizing ecosystem exposure and human risk caused by the consumption of fish and seafood. The aim of this study was to investigate the possible influence of a permanently submerged meadow on the availability and transfer of Hg from sediment to biota, three decades after the Hg discharges was halted and the previous biota survey was carried out, in the severely contaminated brackish fjord Gunneklevfjorden in southern Norway. We examined total Hg (Tot-Hg) and methyl-Hg (MeHg) concentrations and stable isotopes of nitrogen (N) and carbon (C) in zooplankton, benthic invertebrates, and fish to map the food web and to investigate the trophic transfer of Hg. Sediment and water data were available from a previous study. Overlap in δ13C in benthos and fish reveals that benthos is a preferred prey to fish, though despite elevated Tot-Hg concentrations in benthos, fish predator (perch, pike and eel) Hg concentrations are comparable to concentrations reported in nearby lakes without contaminated sediments (mean 1.6 ± 1.3 mg Tot-Hg kg-1 dw). We propose that habitat reliance is an important factor controlling the uptake of Hg from sediments, as both benthos and fish prefer to forage within the meadow where sediment concentrations of Tot-Hg are lower than outside the macrophyte meadow, though %MeHg is higher than outside. Further, we propose that sediment remediation actions performed outside the meadow may have limited effect on the Hg concentrations in fish.
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Affiliation(s)
- Marianne Olsen
- University College of Southeast Norway, Gullbringvegen 36, N-3800 Bø, Norway; The Norwegian Institute for Water Research, Gaustadalléen 21, N-0349 Oslo, Norway.
| | - Eirik Fjeld
- Fjeld og Vann AS, Terrasseveien 31A, 1363 Høvik, Norway
| | - Espen Lydersen
- University College of Southeast Norway, Gullbringvegen 36, N-3800 Bø, Norway
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131
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Budnik LT, Casteleyn L. Mercury pollution in modern times and its socio-medical consequences. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:720-734. [PMID: 30448663 DOI: 10.1016/j.scitotenv.2018.10.408] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 05/27/2023]
Abstract
Mercury plays a critical role in serious health problems due to environmental or occupational exposures. Aquatic ecosystems are an essential component of the global biogeochemical cycle of mercury, as inorganic mercury can be converted to toxic methyl mercury in these environments and reemissions of elemental mercury rival anthropogenic mercury releases on a global scale. The history of the Minamata disease, a typical example of industrial pollution, has shown how corporate secrecy and ignorance on part of the health authorities may influence the devastating spread of environmental contamination and the progress of disease. While the Minamata Convention, in place since 2017, is aiming to lower mercury exposure and to prevent adverse effects, there are still knowledge gaps in the areas of global environmental mercury exposure. Areas of uncertainty in the global biogeochemical cycle of mercury include oxidation processes in the atmosphere, land-atmosphere and ocean-atmosphere cycling, and methylation processes in the ocean. Pollution related to climate change (especially in boreal and arctic regions), bioaccumulation and biomagnification of methyl mercury in the food chain, especially in fish and marine mammals, needs to be addressed in more detail. Information is lacking on numerous hidden contaminant exposures i.e. from globally applied traditional medicine, mercury containing skin creams and soaps, dental amalgam, ethyl mercury containing vaccines and latex paint additives, as well as on mercury releases from power plants, e-waste/fluorescent lamps, wildfire emissions, and global artisanal small-scale gold mining activities. Mercury occurs in various forms with different levels of toxicity. While much is already known and documented on the health effects of mercury, present knowledge and translation into preventive actions is still incomplete. Risks for long term health effects trough prolonged low dose exposure and trough cumulative exposures of various mercury forms should be further addressed. Preventive actions should include adequate human biomonitoring programs. Research data should be translated swiftly into management tools for local policy makers and health professionals, also paying attention at the major differences in mercury contamination across the globe.
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Affiliation(s)
- Lygia Therese Budnik
- University Medical Center Hamburg-Eppendorf, Institute for Occupational and Maritime Medicine, Translational Toxicology and Immunology Unit, Hamburg, Germany.
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132
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Olson CI, Beaubien GB, McKinney AD, Otter RR. Identifying contaminants of potential concern in remote headwater streams of Tennessee's Appalachian Mountains. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:176. [PMID: 30788643 DOI: 10.1007/s10661-019-7305-7] [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: 12/12/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
The susceptibility of Tennessee's Appalachian Mountains to anthropogenic stressors has remained largely uninvestigated likely due to a lack of known point source contamination. However, a growing body of scientific evidence suggests that depositional inputs can lead to concerning levels of contamination, even in remote areas. To investigate potential concerns, water quality parameters, contaminants in water (nitrogen, TSS, and metals), and contaminants in eastern brook trout (mercury, polychlorinated biphenyls [PCBs], organochlorine [OC] pesticides, dioxins, furans, and phthalates) were measured in four Appalachian Mountain streams from 2015 to 2017. Concentrations were compared to literature and/or model-derived (e.g., biotic ligand model) threshold values to determine whether levels exceeded those acceptable for stream health. Dioxins and furans were detectable in fish tissue at all sites with an average 2,3,7,8-tetrachlorodinbenzodioxin toxicity equivalence (TEQ) of 0.0015 ng/kg. Concentrations of PCBs, phthalates, and organochlorine pesticides were never above analytical quantitation limits, although several OC pesticides (e.g., alpha-chlordane) were detectable in fish. Aluminum concentrations in water were found at levels shown previously to cause mortality in brook trout during acidic rain events. The average whole-body methylmercury concentrations in fish among sites were 0.037 ± 0.003 μg/kg and were on average 75 ± 2% of total mercury.
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Affiliation(s)
- Connor I Olson
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Gale B Beaubien
- Molecular Biosciences, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | | | - Ryan R Otter
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
- Molecular Biosciences, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
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133
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Pestana IA, Bastos WR, Almeida MG, Mussy MH, Souza CM. Methylmercury in environmental compartments of a hydroelectric reservoir in the Western Amazon, Brazil. CHEMOSPHERE 2019; 215:758-765. [PMID: 30359948 DOI: 10.1016/j.chemosphere.2018.10.106] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 06/08/2023]
Abstract
Damming rivers to generate electricity creates a lentic environment that favors methylmercury (MeHg) formation. Reservoirs in the Amazon are critical environments for MeHg formation, considering its old soils and the use of Hg in gold mining in the region. The objective of this study was to evaluate MeHg accumulation in three environmental compartments (aquatic macrophytes, suspended particulate matter (SPM) and sediment) of the Samuel reservoir (Western Amazon, Brazil), during the low water, ebb and high water hydrological periods, characterizing the dry season, the end of the rainy season and the rainy season, respectively. MeHg concentrations were determined through GC-AFS. The aquatic macrophytes presented higher %MeHg in their roots (up to 12%) compared to their other tissues. This ratio was 1.7 and 5.9 times higher than those observed for SPM and the sediment, but MeHg concentrations were the lowest (0.5-4.5 ng g-1) among the three environmental compartments. Contrary, the highest MeHg concentration was observed in SPM (104 ng g-1) during the low water period. The MeHg concentration in the sediment profile decreased with increasing depth (0.93-0.48 ng g-1) and with decreasing organic matter lability (increasing C:N ratio). In the SPM, on the other hand, MeHg concentration showed a positive association with increasing C:N ratio. We conclude that MeHg dynamics in the SPM are associated with the hydrological periods, with peaks during the low water period. The organic matter lability of the sediments is more limiting to the production of MeHg than the total Hg concentrations.
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Affiliation(s)
- Inacio A Pestana
- Ecology and Natural Resources Postgraduate Program, Laboratory of Environmental Sciences, Biosciences and Biotechnology Center, Norte Fluminense Darcy Ribeiro State University, Av. Alberto Lamego, 2000, Parque Califórnia, CEP 28013-602, Campos dos Goytacazes, Rio de Janeiro, Brazil.
| | - Wanderley R Bastos
- Regional Development and Environment Postgraduate Program, Environmental Biogeochemistry Wolfgang C. Pfeiffer, Rondônia Federal University, Av. Pres. Dutra, 2967 - Olaria, CEP 76801-059, Porto Velho, Rondônia, Brazil
| | - Marcelo G Almeida
- Ecology and Natural Resources Postgraduate Program, Laboratory of Environmental Sciences, Biosciences and Biotechnology Center, Norte Fluminense Darcy Ribeiro State University, Av. Alberto Lamego, 2000, Parque Califórnia, CEP 28013-602, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Marilia H Mussy
- Biological Sciences, Biophysics Postgraduate Program, Carlos Chagas Filho Institute of Biophysics, Rio de Janeiro Federal University, Av. Pedro Calmon, 550 - Cidade Universitária, CEP 21941-901, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cristina Mm Souza
- Ecology and Natural Resources Postgraduate Program, Laboratory of Environmental Sciences, Biosciences and Biotechnology Center, Norte Fluminense Darcy Ribeiro State University, Av. Alberto Lamego, 2000, Parque Califórnia, CEP 28013-602, Campos dos Goytacazes, Rio de Janeiro, Brazil
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134
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Basu N. The Minamata Convention on Mercury and the role for the environmental sciences community. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:2951-2952. [PMID: 30480865 DOI: 10.1002/etc.4269] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 08/05/2018] [Indexed: 06/09/2023]
Affiliation(s)
- Niladri Basu
- McGill Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
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135
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McCarter CPR, Weber TKD, Price JS. Competitive transport processes of chloride, sodium, potassium, and ammonium in fen peat. JOURNAL OF CONTAMINANT HYDROLOGY 2018; 217:17-31. [PMID: 30201556 DOI: 10.1016/j.jconhyd.2018.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/01/2018] [Accepted: 08/11/2018] [Indexed: 05/21/2023]
Abstract
There is sparse information on reactive solute transport in peat; yet, with increasing development of peatland dominated landscapes, purposeful and accidental contaminant releases will occur, so it is important to assess their mobility. Previous experiments with peat have only evaluated single-component solutions, such that no information exists on solute transport of potentially competitively adsorbing ions to the peat matrix. Additionally, recent studies suggest chloride (Cl-) might not be conservative in peat, as assumed by many past peat solute transport studies. Based on measured and modelled adsorption isotherms, this study illustrates concentration dependent adsorption of Cl- to peat occurred in equilibrium adsorption batch (EAB) experiments, which could be described with a Sips isotherm. However, Cl- adsorption was insignificant for low concentrations (<500 mg L-1) as used in breakthrough curve experiments (BTC). We found that competitive adsorption of Na+, K+, and NH4+ transport could be observed in EAB and BTC, depending on the dissolved ion species present. Na+ followed a Langmuir isotherm, K+ a linear isotherm within the tested concentration range (~10 - 1500 mg L-1), while the results for NH4+ are inconclusive due to potential microbial degradation. Only Na+ showed clear evidence of competitive behaviour, with an order of magnitude decrease in maximum adsorption capacity in the presence of NH4+ (0.22 to 0.02 mol kg-1), which was confirmed by the BTC data where the Na+ retardation coefficient differed between the experiments with different cations. Thus, solute mobility in peatlands is affected by competitive adsorption.
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Affiliation(s)
- Colin P R McCarter
- Dep. of Geography and Environmental Management, University of Waterloo, 200 University Ave West, Waterloo, ON, N2L 3G1, Canada.
| | - Tobias K D Weber
- Institute for Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Emil-Wolff-Straße 27, DE-70599 Stuttgart, Germany
| | - Jonathan S Price
- Dep. of Geography and Environmental Management, University of Waterloo, 200 University Ave West, Waterloo, ON, N2L 3G1, Canada
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136
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Chen CY, Driscoll CT, Eagles-Smith CA, Eckley CS, Gay DA, Hsu-Kim H, Keane SE, Kirk JL, Mason RP, Obrist D, Selin H, Selin NE, Thompson MR. A Critical Time for Mercury Science to Inform Global Policy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9556-9561. [PMID: 30067020 PMCID: PMC6200401 DOI: 10.1021/acs.est.8b02286] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Mercury is a global pollutant released into the biosphere by varied human activities including coal combustion, mining, artisanal gold mining, cement production, and chemical production. Once released to air, land and water, the addition of carbon atoms to mercury by bacteria results in the production of methylmercury, the toxic form that bioaccumulates in aquatic and terrestrial food chains resulting in elevated exposure to humans and wildlife. Global recognition of the mercury contamination problem has resulted in the Minamata Convention on Mercury, which came into force in 2017. The treaty aims to protect human health and the environment from human-generated releases of mercury curtailing its movement and transformations in the biosphere. Coincident with the treaty's coming into force, the 13th International Conference of Mercury as a Global Pollutant (ICMGP-13) was held in Providence, Rhode Island USA. At ICMGP-13, cutting edge research was summarized and presented to address questions relating to global and regional sources and cycling of mercury, how that mercury is methylated, the effects of mercury exposure on humans and wildlife, and the science needed for successful implementation of the Minamata Convention. Human activities have the potential to enhance mercury methylation by remobilizing previously released mercury, and increasing methylation efficiency. This synthesis concluded that many of the most important factors influencing the fate and effects of mercury and its more toxic form, methylmercury, stem from environmental changes that are much broader in scope than mercury releases alone. Alterations of mercury cycling, methylmercury bioavailability and trophic transfer due to climate and land use changes remain critical uncertainties in effective implementation of the Minamata Convention. In the face of these uncertainties, important policy and management actions are needed over the short-term to support the control of mercury releases to land, water and air. These include adequate monitoring and communication on risk from exposure to various forms of inorganic mercury as well as methylmercury from fish and rice consumption. Successful management of global and local mercury pollution will require integration of mercury research and policy in a changing world.
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Affiliation(s)
- Celia Y Chen
- Dartmouth College , Department of Biological Sciences , Hanover , New Hampshire 03755 United States
| | - Charles T Driscoll
- Syracuse University , Department of Civil and Environmental Engineering , Syracuse , New York 13244 United States
| | | | - Chris S Eckley
- U.S. Environmental Protection Agency , Region-10 , Seattle , Washington 98101 United States
| | - David A Gay
- University of Wisconsin , Madison , Wisconsin 53706 United States
| | - Heileen Hsu-Kim
- Duke University , Department of Civil & Environmental Engineering , Durham , North Carolina 27708 United States
| | - Susan E Keane
- Natural Resources Defense Council , Washington , D.C. 20005 United States
| | - Jane L Kirk
- Environment and Climate Change, Canada , Burlington , ON L7P2X3 Canada
| | - Robert P Mason
- University of Connecticut , Department of Marine Sciences , Groton , Connecticut 06340 United States
| | - Daniel Obrist
- University of Massachusetts, Lowell , Department of Environmental, Earth and Atmospheric Sciences , Lowell , Massachusetts 01854 United States
| | - Henrik Selin
- Boston University , Frederick S. Pardee School of Global Studies , Boston , Massachusetts 02215 United States
| | - Noelle E Selin
- Massachusetts Institute of Technology, Institute for Data, Systems, and Society , Department of Earth, Atmospheric and Planetary Sciences , Boston , Massachusetts 02139 United States
| | - Marcella R Thompson
- University of Rhode Island , College of Nursing , Providence , Rhode Island 02903 United States
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137
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Ndu U, Christensen GA, Rivera NA, Gionfriddo CM, Deshusses MA, Elias DA, Hsu-Kim H. Quantification of Mercury Bioavailability for Methylation Using Diffusive Gradient in Thin-Film Samplers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8521-8529. [PMID: 29920204 PMCID: PMC6085726 DOI: 10.1021/acs.est.8b00647] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/03/2018] [Accepted: 06/19/2018] [Indexed: 05/25/2023]
Abstract
Mercury-contaminated sediment and water contain various Hg species, with a small fraction available for microbial conversion to the bioaccumulative neurotoxin monomethylmercury (MeHg). Quantification of this available Hg pool is needed to prioritize sites for risk management. This study compared the efficacy of diffusive gradient in thin-film (DGT) passive samplers to a thiol-based selective extraction method with glutathione (GSH) and conventional filtration (<0.2 μm) as indicators of Hg bioavailability. Anaerobic sediment slurry microcosms were amended with isotopically labeled inorganic Hg "endmembers" (dissolved Hg2+, Hg-humic acid, Hg-sorbed to FeS, HgS nanoparticles) with a known range of bioavailability and methylation potentials. Net MeHg production (expressed as percent of total Hg as MeHg) over 1 week correlated with mass accumulation of Hg endmembers on the DGTs and only sometimes correlated with the 0.2 μm filter passing Hg fraction and the GSH-extractable Hg fraction. These results suggest for the first time that inorganic Hg uptake in DGTs may indicate bioavailability for methylating microbes. Moreover, the methylating microbial community assessed by hgcA gene abundance was not always consistent with methylation rates between the experiments, indicating that knowledge of the methylating community should target the transcript or protein level. Altogether, these results suggest that DGTs could be used to quantify the bioavailable Hg fraction as part of a method to assess net MeHg production potential in the environment.
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Affiliation(s)
- Udonna Ndu
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Geoff A. Christensen
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Nelson A. Rivera
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Caitlin M. Gionfriddo
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Marc A. Deshusses
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Dwayne A. Elias
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Heileen Hsu-Kim
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
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138
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Graham EB, Gabor RS, Schooler S, McKnight DM, Nemergut DR, Knelman JE. Oligotrophic wetland sediments susceptible to shifts in microbiomes and mercury cycling with dissolved organic matter addition. PeerJ 2018; 6:e4575. [PMID: 29632744 PMCID: PMC5888151 DOI: 10.7717/peerj.4575] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/15/2018] [Indexed: 12/26/2022] Open
Abstract
Recent advances have allowed for greater investigation into microbial regulation of mercury toxicity in the environment. In wetlands in particular, dissolved organic matter (DOM) may influence methylmercury (MeHg) production both through chemical interactions and through substrate effects on microbiomes. We conducted microcosm experiments in two disparate wetland environments (oligotrophic unvegetated and high-C vegetated sediments) to examine the impacts of plant leachate and inorganic mercury loadings (20 mg/L HgCl2) on microbiomes and MeHg production in the St. Louis River Estuary. Our research reveals the greater relative capacity for mercury methylation in vegetated over unvegetated sediments. Further, our work shows how mercury cycling in oligotrophic unvegetated sediments may be susceptible to DOM inputs in the St. Louis River Estuary: unvegetated microcosms receiving leachate produced substantially more MeHg than unamended microcosms. We also demonstrate (1) changes in microbiome structure towards Clostridia, (2) metagenomic shifts toward fermentation, and (3) degradation of complex DOM; all of which coincide with elevated net MeHg production in unvegetated microcosms receiving leachate. Together, our work shows the influence of wetland vegetation in controlling MeHg production in the Great Lakes region and provides evidence that this may be due to both enhanced microbial activity as well as differences in microbiome composition.
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Affiliation(s)
- Emily B Graham
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Rachel S Gabor
- School of Environment and Natural Resources, Ohio State University, Columbus, OH, United States of America
| | - Shon Schooler
- Lake Superior National Estuarine Research Reserve, Superior, WI, United States of America
| | - Diane M McKnight
- Institute for Arctic and Alpine Research, University of Colorado at Boulder, Boulder, CO, United States of America.,Civil Engineering Department, University of Colorado at Boulder, Boulder, CO, United States of America.,Environmental Studies Program, University of Colorado at Boulder, Boulder, CO, United States of America
| | - Diana R Nemergut
- Institute for Arctic and Alpine Research, University of Colorado at Boulder, Boulder, CO, United States of America.,Biology Department, Duke University, Durham, NC, United States of America
| | - Joseph E Knelman
- Institute for Arctic and Alpine Research, University of Colorado at Boulder, Boulder, CO, United States of America
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139
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Selin H, Keane SE, Wang S, Selin NE, Davis K, Bally D. Linking science and policy to support the implementation of the Minamata Convention on Mercury. AMBIO 2018; 47:198-215. [PMID: 29388129 PMCID: PMC5794682 DOI: 10.1007/s13280-017-1003-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The Minamata Convention on Mercury, with its objective to protect human health and the environment from the dangers of mercury (Hg), entered into force in 2017. The Convention outlines a life-cycle approach to the production, use, emissions, releases, handling, and disposal of Hg. As it moves into the implementation phase, scientific work and information are critically needed to support decision-making and management. This paper synthesizes existing knowledge and examines three areas in which researchers across the natural sciences, engineering, and social sciences can mobilize and disseminate knowledge in support of Hg abatement and the realization of the Convention's objective: (1) uses, emissions, and releases; (2) support, awareness raising, and education; and (3) impacts and effectiveness. The paper ends with a discussion of the future of Hg science and policy.
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Affiliation(s)
- Henrik Selin
- Frederick S Pardee School of Global Studies, Boston University, 154 Bay State Road, Boston, MA 02215 USA
| | - Susan Egan Keane
- Natural Resources Defense Council, 1152 15th St, NW, Suite 300, Washington, DC 20005 USA
| | - Shuxiao Wang
- School of Environment, Tsinghua University, Beijing, 100084 China
| | - 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
| | - Kenneth Davis
- United Nations Environment Programme, Chemicals and Health Branch, International Environment House I, 11-13 chemin des Anemones, 1219 Geneva, Switzerland
| | - Dominique Bally
- African Center for Environmental Health, BP 826, Cidex 03 Abidjan, Côte d’Ivoire
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140
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Affiliation(s)
- Celia Y. Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH USA
| | - Charles T. Driscoll
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244 USA
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141
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Eagles-Smith CA, Silbergeld EK, Basu N, Bustamante P, Diaz-Barriga F, Hopkins WA, Kidd KA, Nyland JF. Modulators of mercury risk to wildlife and humans in the context of rapid global change. AMBIO 2018; 47:170-197. [PMID: 29388128 PMCID: PMC5794686 DOI: 10.1007/s13280-017-1011-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.
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Affiliation(s)
| | - Ellen K. Silbergeld
- Johns Hopkin Bloomberg School of Public Health, 615 N. Wolfe Street, E6644, Baltimore, MD 21205 USA
| | - Niladri Basu
- McGill University, 204-CINE Building, Montreal, QC H9X 3V9 Canada
| | - Paco Bustamante
- University of La Rochelle, laboratory of Littoral Environment and Societies, Littoral Environnement et Sociétés (LIENSs), LIENSs UMR 7266 CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Fernando Diaz-Barriga
- Center for Applied Research in Environment and Health at, Universidad Autonoma de San Luis Potosi, Avenida Venustiano Carranza No. 2405, Col Lomas los Filtros Código Postal, 78214 San Luis Potosí, SLP Mexico
| | - William A. Hopkins
- Department of Fish and Wildlife Conservation, 310 West Campus Drive Virginia Tech, Cheatham Hall, Room 106 (MC 0321), Blacksburg, VA 24061 USA
| | - Karen A. Kidd
- Department of Biology & School of Geography and Earth Sciences, McMaster University, 1280 Main Street W., Hamilton, ON L8S 4K1 Canada
| | - Jennifer F. Nyland
- Department of Biological Sciences, 1101 Camden Ave, Salisbury, MD 21801 USA
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142
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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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