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Zhang Q, Pu Q, Hao Z, Liu J, Zhang K, Meng B, Feng X. Warming inhibits Hg II methylation but stimulates methylmercury demethylation in paddy soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172832. [PMID: 38688367 DOI: 10.1016/j.scitotenv.2024.172832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
Inorganic mercury (HgII) can be transformed into neurotoxic methylmercury (MeHg) by microorganisms in paddy soils, and the subsequent accumulation in rice grains poses an exposure risk for human health. Warming as an important manifestation of climate change, changes the composition and structure of microbial communities, and regulates the biogeochemical cycles of Hg in natural environments. However, the response of specific HgII methylation/demethylation to the changes in microbial communities caused by warming remain unclear. Here, nationwide sampling of rice paddy soils and a temperature-adjusted incubation experiment coupled with isotope labeling technique (202HgII and Me198Hg) were conducted to investigate the effects of temperature on HgII methylation, MeHg demethylation, and microbial mechanisms in paddy soils along Hg gradients. We showed that increasing temperature significantly inhibited HgII methylation but promoted MeHg demethylation. The reduction in the relative abundance of Hg-methylating microorganisms and increase in the relative abundance of MeHg-demethylating microorganisms are the likely reasons. Consequently, the net Hg methylation production potential in rice paddy soils was largely inhibited under the increasing temperature. Collectively, our findings offer insights into the decrease in net MeHg production potential associated with increasing temperature and highlight the need for further evaluation of climate change for its potential effect on Hg transformation in Hg-sensitive ecosystems.
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Affiliation(s)
- Qianshuo 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
| | - Qiang Pu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Zhengdong Hao
- 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
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Kun 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
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Xinbin Feng
- 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
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2
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Li X, Hu D, Du J, He L. Understanding mercury accumulation in mosses of two subalpine forests in China. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134266. [PMID: 38626682 DOI: 10.1016/j.jhazmat.2024.134266] [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: 12/19/2023] [Revised: 03/10/2024] [Accepted: 04/08/2024] [Indexed: 04/18/2024]
Abstract
The role of forest ecosystems in the global mercury (Hg) biogeochemical cycle is widely recognized; however, using litterfall as a surrogate to assess the Hg sink function of forests encounters limitations. We investigated the accumulation characteristics and influencing factors of Hg in mosses from two remote subalpine forests in southwestern China. The results indicated that there was high Hg accumulation in subalpine forest mosses, with average concentrations of 82 ± 49 ng g-1 for total mercury (THg) and 1.3 ± 0.8 ng g-1 for methylmercury (MeHg). We demonstrated that the accumulation capacity of Hg in mosses was significantly dependent on species and substrates (micro-habitats), the mosses on tree trunks exhibited significantly elevated Hg accumulation levels (THg 132 ± 56 ng g-1, MeHg 1.6 ± 0.2 ng g-1) compared to mosses in other substrates. The surface morphologies and biochemical components of leaf (phyllidia), such as cation exchange capacity (CEC), pectin, uronic acid, and metallothionein, play a crucial role in the accumulation of Hg by mosses. These findings provide valuable insights into Hg accumulation in forest mosses. Suggesting that the contribution of mosses Hg accumulation should be considered when assessing atmospheric Hg sinks of forests.
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Affiliation(s)
- Xiaohui Li
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Dan Hu
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Jie Du
- Jiuzhaigou Scenic Area Administration, Zhangzha, Jiuzhaigou, Sichuan 623402, China.
| | - Lei He
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
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3
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Zhang S, Xia M, Pan Z, Wang J, Yin Y, Lv J, Hu L, Shi J, Jiang T, Wang D. Soil organic matter degradation and methylmercury dynamics in Hg-contaminated soils: Relationships and driving factors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120432. [PMID: 38479282 DOI: 10.1016/j.jenvman.2024.120432] [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: 11/06/2023] [Revised: 02/01/2024] [Accepted: 02/17/2024] [Indexed: 04/07/2024]
Abstract
Biodegradation of soil organic matter (SOM), which involves greenhouse gas (GHG) emissions, plays an essential role in the global carbon cycle. Over the past few decades, this has become an important research focus, particularly in natural ecosystems. SOM biodegradation significantly affects contaminants in the environment, such as mercury (Hg) methylation, producing highly toxic methylmercury (MeHg). However, the potential link between GHG production from SOM turnover in contaminated soils and biogeochemical processes involving contaminants remains unclear. In this study, we investigated the dynamics of GHG, MeHg production, and the relationship between biogeochemical processes in soils from two typical Hg mining sites. The two contaminated soils have different pathways, explaining the significant variations in GHG and MeHg production. The divergence of the microbial communities in these two biogeochemical processes is essential. In addition to the microbial role, abiotic factors such as Hg species can significantly affect MeHg production. On the other hand, we found an inverse relationship between CH4 and MeHg, suggesting that carbon emission reduction policies and management could inadvertently increase the MeHg levels. This highlights the need for an eclectic approach to organic carbon sequestration and contaminant containment. These findings suggest that it is difficult to establish a general pattern to describe and explain the SOM degradation and MeHg production in contaminated soils within the specific scenarios. However, this study provides a case study and helpful insights for further understanding the links between environmental risks and carbon turnover in Hg mining areas.
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Affiliation(s)
- Siqi Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing, 400716, China
| | - Meng Xia
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing, 400716, China
| | - Zhaoyang Pan
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing, 400716, China; 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
| | - Jianxu Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Yongguang Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Jitao Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Ligang Hu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Jianbo Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing, 400716, China; Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan, 430056, China.
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing, 400716, China
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4
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Masinga P, Simbanegavi TT, Makuvara Z, Marumure J, Chaukura N, Gwenzi W. Emerging organic contaminants in the soil-plant-receptor continuum: transport, fate, health risks, and removal mechanisms. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:367. [PMID: 38488937 DOI: 10.1007/s10661-023-12282-7] [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: 09/13/2023] [Accepted: 12/29/2023] [Indexed: 03/17/2024]
Abstract
There is a lack of comprehensive reviews tracking emerging organic contaminants (EOCs) within the soil-plant continuum using the source-pathway-receptor-impact-mitigation (SPRIM) framework. Therefore, this review examines existing literature to gain insights into the occurrence, behaviour, fate, health hazards, and strategies for mitigating EOCs within the soil-plant system. EOCs identified in the soil-plant system encompass endocrine-disrupting chemicals, surfactants, pharmaceuticals, personal care products, plasticizers, gasoline additives, flame retardants, and per- and poly-fluoroalkyl substances (PFAS). Sources of EOCs in the soil-plant system include the land application of biosolids, wastewater, and solid wastes rich in EOCs. However, less-studied sources encompass plastics and atmospheric deposition. EOCs are transported from their sources to the soil-plant system and other receptors through human activities, wind-driven processes, and hydrological pathways. The behaviour, persistence, and fate of EOCs within the soil-plant system are discussed, including sorption, degradation, phase partitioning, (bio)transformation, biouptake, translocation, and bioaccumulation in plants. Factors governing the behaviour, persistence, and fate of EOCs in the soil-plant system include pH, redox potential, texture, temperature, and soil organic matter content. The review also discusses the environmental receptors of EOCs, including their exchange with other environmental compartments (aquatic and atmospheric), and interactions with soil organisms. The ecological health risks, human exposure via inhalation of particulate matter and consumption of contaminated food, and hazards associated with various EOCs in the soil-plant system are discussed. Various mitigation measures including removal technologies of EOCs in the soil are discussed. Finally, future research directions are presented.
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Affiliation(s)
- Privilege Masinga
- Department of Soil Science and Environment, Faculty of Agriculture, Environment, and Food Systems, University of Zimbabwe, Mount Pleasant, P. O. Box MP 167, Harare, Zimbabwe
| | - Tinoziva T Simbanegavi
- Department of Soil Science and Environment, Faculty of Agriculture, Environment, and Food Systems, University of Zimbabwe, Mount Pleasant, P. O. Box MP 167, Harare, Zimbabwe
| | - Zakio Makuvara
- Department of Physics, Geography and Environmental Science, School of Natural Sciences, Great Zimbabwe University, Masvingo, Zimbabwe
- Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Pretoria, South Africa
| | - Jerikias Marumure
- Department of Physics, Geography and Environmental Science, School of Natural Sciences, Great Zimbabwe University, Masvingo, Zimbabwe
- Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Pretoria, South Africa
| | - Nhamo Chaukura
- Department of Physical and Earth Sciences, Sol Plaatje University, Kimberley, 8301, South Africa
| | - Willis Gwenzi
- Biosystems and Engineering Research Group, 380 New Adylin, Marlborough, Harare, Zimbabwe.
- Biosystems and Environmental Engineering Research Group, 380 New Adylin, Marlborough, Harare, Zimbabwe.
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5
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Carrasco N, McGovern M, Evenset A, Søreide JE, Arts MT, Jonsson S, Poste AE. Seasonal riverine inputs may affect diet and mercury bioaccumulation in Arctic coastal zooplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167643. [PMID: 37806586 DOI: 10.1016/j.scitotenv.2023.167643] [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: 07/26/2023] [Revised: 09/17/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Climate change driven increases in permafrost thaw and terrestrial runoff are expected to facilitate the mobilization and transport of mercury (Hg) from catchment soils to coastal areas in the Arctic, potentially increasing Hg exposure of marine food webs. The main aim of this study was to determine the impacts of seasonal riverine inputs on land-ocean Hg transport, zooplankton diet and Hg bioaccumulation in an Arctic estuary (Adventfjorden, Svalbard). The Adventelva River was a source of dissolved and particulate Hg to Adventfjorden, especially in June and July during the river's main discharge period. Stable isotope and fatty acid analyses suggest that zooplankton diet varied seasonally with diatoms dominating during the spring phytoplankton bloom in May and with increasing contributions of dinoflagellates in the summer months. In addition, there was evidence of increased terrestrial carbon utilization by zooplankton in June and July, when terrestrial particles contributed substantially to the particulate organic matter pool. Total (TotHg) and methyl Hg (MeHg) concentrations in zooplankton increased from April to August related to increased exposure to riverine inputs, and to shifts in zooplankton diet and community structure. Longer and warmer summer seasons will probably increase riverine runoff and thus Hg exposure to Arctic zooplankton.
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Affiliation(s)
- Nathalie Carrasco
- Department of Arctic Marine Biology, UiT, The Arctic University of Norway, 9019 Tromsø, Norway; Oceanographic Institute - Prince Albert I Foundation, 98000, Monaco; Norwegian Institute for Water Research, 9007 Tromsø, Norway.
| | - Maeve McGovern
- Norwegian Institute for Water Research, 9007 Tromsø, Norway
| | | | | | - Michael T Arts
- Toronto Metropolitan University, Toronto M5B 2K3, Canada
| | - Sofi Jonsson
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Amanda E Poste
- Department of Arctic Marine Biology, UiT, The Arctic University of Norway, 9019 Tromsø, Norway; Norwegian Institute for Water Research, 9007 Tromsø, Norway; Norwegian Institute for Nature Research, 9296 Tromsø, Norway.
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6
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Liu Q, Liu S, Zhou XQ, Liu YR. Assessing microbial degradation potential of methylmercury in different types of paddy soil through short-term incubation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 337:122603. [PMID: 37748640 DOI: 10.1016/j.envpol.2023.122603] [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: 05/30/2023] [Revised: 09/03/2023] [Accepted: 09/20/2023] [Indexed: 09/27/2023]
Abstract
The neurotoxic methylmercury (MeHg) in paddy soils can accumulate in rice grains. Microbial demethylation is an important pathway of MeHg degradation in soil, but the effect of soil type on microbial degradation of MeHg remains unclear. Therefore, we investigated MeHg degradation in eight typical paddy soils and analyzed the associations between soil physiochemical properties and microbial degradation efficiencies of MeHg. Results showed that MeHg was significantly degraded in unsterilized paddy soils, and the microbial degradation efficiency ranged from 10.8% to 64.6% after a 30-day incubation. The high microbial degradation efficiency of MeHg was observed in the soils with high levels of clay content, whereas relatively low degradation efficiency was found in the red paddy soils. We identified that Paenibacillaceae was the most important microbial predictor of MeHg degradation and was positively correlated with the degradation efficiency in the soils. The abundances of these microbial taxa associated with MeHg degradation were positively correlated with clay content. In addition, Eh, pH, and SOC could influence microbial degradation of MeHg by regulating certain microbial communities. Our results indicate that soil type is crucial in driving MeHg degradation, which has important implications for the mitigation of MeHg pollution in various croplands.
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Affiliation(s)
- Qin Liu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Siyuan Liu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Xin-Quan Zhou
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Yu-Rong Liu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, 430070, China.
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7
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Wenwen Z, Yuan X, Zhongsheng Z, Xuehui Z, Haitao W. Accelerated Hg loss and increased methylmercury covary with soil organic matter mineralization and dissolved organic matter humification under warming conditions in permafrost marsh, Northeast China. ENVIRONMENTAL RESEARCH 2023; 234:116593. [PMID: 37423359 DOI: 10.1016/j.envres.2023.116593] [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: 05/24/2023] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Currently, little is available on how mercury (Hg) methylation couples with soil organic matter decomposition in degraded permafrost in high northern latitudes, where the climate is becoming warmer rapidly. Here, we revealed the complex interactions between soil organic matter (SOM) mineralization, dissolved organic matter (DOM) and methylmercury (MeHg) production based on an 87-day anoxic warming incubation experiment. Results supported remarkably promotion effects of warming on MeHg production, by 130%-205% on average. Total mercury (THg) loss under warming treatment depended on marsh types but showed an increasing trend on the whole. Warming yielded higher proportions of MeHg to THg (%MeHg), increased by 123%-569%. As expected, greenhouse gas emission was significantly enhanced by warming. Warming also strengthened fluorescence intensities of fulvic-like and protein-like DOM, with contributions to total fluorescence intensities of 49%-92% and 8%-51%, respectively. DOM and its spectral features explained 60% variation of MeHg, and the explanation increased to 82% in conjunction with greenhouse gas emissions. The structural equation model implied that warming, greenhouse gas emission, and humification of DOM had positive effects on Hg methylation potential, while microbial-derived DOM showed negative effects on MeHg. These results showed that accelerated Hg loss and increased methylation covaried with greenhouse gas emission and DOM formation under warming conditions in permafrost marsh.
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Affiliation(s)
- Zhao Wenwen
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin Yuan
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhang Zhongsheng
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
| | - Zhang Xuehui
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Beijing Normal University, Beijing, 136000, China
| | - Wu Haitao
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
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8
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Zhang L, Yin Y, Sun Y, Liang X, Graham DE, Pierce EM, Löffler FE, Gu B. Inhibition of Methylmercury and Methane Formation by Nitrous Oxide in Arctic Tundra Soil Microcosms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5655-5665. [PMID: 36976621 PMCID: PMC10100821 DOI: 10.1021/acs.est.2c09457] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/03/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Climate warming causes permafrost thaw predicted to increase toxic methylmercury (MeHg) and greenhouse gas [i.e., methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O)] formation. A microcosm incubation study with Arctic tundra soil over 145 days demonstrates that N2O at 0.1 and 1 mM markedly inhibited microbial MeHg formation, methanogenesis, and sulfate reduction, while it slightly promoted CO2 production. Microbial community analyses indicate that N2O decreased the relative abundances of methanogenic archaea and microbial clades implicated in sulfate reduction and MeHg formation. Following depletion of N2O, both MeHg formation and sulfate reduction rapidly resumed, whereas CH4 production remained low, suggesting that N2O affected susceptible microbial guilds differently. MeHg formation strongly coincided with sulfate reduction, supporting prior reports linking sulfate-reducing bacteria to MeHg formation in the Arctic soil. This research highlights complex biogeochemical interactions in governing MeHg and CH4 formation and lays the foundation for future mechanistic studies for improved predictive understanding of MeHg and greenhouse gas fluxes from thawing permafrost ecosystems.
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Affiliation(s)
- Lijie Zhang
- Environmental
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department
of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Yongchao Yin
- Biosciences
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Center
for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Department
of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Yanchen Sun
- Center
for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Department
of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xujun Liang
- Environmental
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David E. Graham
- Biosciences
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Eric M. Pierce
- Environmental
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Frank E. Löffler
- Biosciences
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Center
for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Department
of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department
of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department
of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Baohua Gu
- Environmental
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department
of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee 37996, United States
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9
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Xin Y, Zhang X, Zheng D, Zhang Z, Jiang M. Impacts of spectral characteristics of dissolved organic matter on methylmercury contents in peatlands, Northeast China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:913-923. [PMID: 35366716 DOI: 10.1007/s10653-022-01257-1] [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: 09/02/2021] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Dissolved organic matter (DOM) plays an important role in promoting or suppressing methylmercury (MeHg) production in wetlands. However, the effects of DOM spectral characteristics on MeHg levels remain poorly understood in boreal peatlands in Northeast China, where is undergoing remarkable climate warming. In the present work, soil samples were collected from 22 peatlands in the Greater Khingan Mountains (GKM) to test the hypothesis that DOM spectral properties control MeHg levels. DOM was characterized by UV-Vis absorption and fluorescence spectroscopy; the three-dimensional fluorescence excitation-emission matrix (EEM) was used to unveil the origin of DOM. The average total mercury (THg) and MeHg contents were 112.76 µg/kg and 12.43 µg/kg across all peatlands, respectively. There was a significantly positive correlation between MeHg and the longitude spanning the range from 120 to 123°E (p < 0.05). Proportions of MeHg to THg (%MeHg), 12.3% on average, were positively correlated with DOM humification degree at p < 0.05 level. Protein-like components of DOM (P-like) were negatively related to %MeHg. DOM had positive effects on THg, and P-like components, HIX and BIX can negatively affect THg as well as MeHg. Our findings demonstrate that the spectral characteristics of DOM in soil are crucial to the content of methyl mercury in the GKM soil.
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Affiliation(s)
- Yuan Xin
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
- Environmental College, Shenyang University, Shenyang, 110044, China
- Key Laboratory of Regional Environment and Eco-Remediation, Ministry of Education, Shenyang University, Shenyang, 110044, China
| | - Xuehui Zhang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dongmei Zheng
- Environmental College, Shenyang University, Shenyang, 110044, China
- Key Laboratory of Regional Environment and Eco-Remediation, Ministry of Education, Shenyang University, Shenyang, 110044, China
| | - Zhongsheng Zhang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China.
| | - Ming Jiang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
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10
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Jonsson S, Mastromonaco MN, Wang F, Bravo AG, Cairns WRL, Chételat J, Douglas TA, Lescord G, Ukonmaanaho L, Heimbürger-Boavida LE. Arctic methylmercury cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157445. [PMID: 35882324 DOI: 10.1016/j.scitotenv.2022.157445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic mercury (Hg) undergoes long-range transport to the Arctic where some of it is transformed into methylmercury (MeHg), potentially leading to high exposure in some Arctic inhabitants and wildlife. The environmental exposure of Hg is determined not just by the amount of Hg entering the Arctic, but also by biogeochemical and ecological processes occurring in the Arctic. These processes affect MeHg uptake in biota by regulating the bioavailability, methylation and demethylation, bioaccumulation and biomagnification of MeHg in Arctic ecosystems. Here, we present a new budget for pools and fluxes of MeHg in the Arctic and review the scientific advances made in the last decade on processes leading to environmental exposure to Hg. Methylation and demethylation are key processes controlling the pool of MeHg available for bioaccumulation. Methylation of Hg occurs in diverse Arctic environments including permafrost, sediments and the ocean water column, and is primarily a process carried out by microorganisms. While microorganisms carrying the hgcAB gene pair (responsible for Hg methylation) have been identified in Arctic soils and thawing permafrost, the formation pathway of MeHg in oxic marine waters remains less clear. Hotspots for methylation of Hg in terrestrial environments include thermokarst wetlands, ponds and lakes. The shallow sub-surface enrichment of MeHg in the Arctic Ocean, in comparison to other marine systems, is a possible explanation for high MeHg concentrations in some Arctic biota. Bioconcentration of aqueous MeHg in bacteria and algae is a critical step in the transfer of Hg to top predators, which may be dampened or enhanced by the presence of organic matter. Variable trophic position has an important influence on MeHg concentrations among populations of top predator species such as ringed seal and polar bears distributed across the circumpolar Arctic. These scientific advances highlight key processes that affect the fate of anthropogenic Hg deposited to Arctic environments.
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Affiliation(s)
- Sofi Jonsson
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
| | | | - Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
| | - Warren R L Cairns
- CNR Institute of Polar Sciences and Ca' Foscari University, Venice, Italy
| | - John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
| | - Gretchen Lescord
- Wildlife Conservation Society Canada and Laurentian University, Vale Living with Lakes Center, Sudbury, Ontario, Canada
| | - Liisa Ukonmaanaho
- Natural Resources Institute Finland (Luke), P.O. Box 2, FI-00791 Helsinki, Finland
| | - Lars-Eric Heimbürger-Boavida
- CNRS/INSU,Aix Marseille Université,Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
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11
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Zhou XQ, Qu XM, Yang Z, Zhao J, Hao YY, Feng J, Huang Q, Liu YR. Increased water inputs fuel microbial mercury methylation in upland soils. JOURNAL OF HAZARDOUS MATERIALS 2022; 439:129578. [PMID: 35853337 DOI: 10.1016/j.jhazmat.2022.129578] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/28/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Mercury (Hg) can be converted to neurotoxic methylmercury (MeHg) by certain microbes typically in anaerobic environments, threatening human health due to its bioaccumulation in food webs. However, it is unclear whether and how Hg can be methylated in legacy aerobic uplands with increasing water. Here, we conducted a series of incubation experiments to investigate the effects of increased water content on MeHg production in two typical upland soils (i.e., long-term and short-term use). Results showed that marked MeHg production occurred in water-saturated upland soils, which was strongly correlated with the proportions of significantly stimulated Hg methylating taxon (i.e., Geobacter). Elevated temperature further enhanced MeHg production by blooming proportions of typical Hg methylators (i.e., Clostridium, Acetonema, and Geobacter). Water saturation could also enhance microbial Hg methylation by facilitating microbial syntrophy between non-Hg methylators and Hg methylators. Taken together, the present work suggests that uplands could turn into a potential MeHg reservoir in response to water inputs resulting from rainfall or anthropogenic irrigation.
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Affiliation(s)
- Xin-Quan Zhou
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiao-Min Qu
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI 48309, United States
| | - Jiating Zhao
- Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Yun-Yun Hao
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiao Feng
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan 430070, China
| | - Yu-Rong Liu
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan 430070, China.
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12
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Dastoor A, Wilson SJ, Travnikov O, Ryjkov A, Angot H, Christensen JH, Steenhuisen F, Muntean M. Arctic atmospheric mercury: Sources and changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156213. [PMID: 35623517 DOI: 10.1016/j.scitotenv.2022.156213] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Global anthropogenic and legacy mercury (Hg) emissions are the main sources of Arctic Hg contamination, primarily transported there via the atmosphere. This review summarizes the state of knowledge of the global anthropogenic sources of Hg emissions, and examines recent changes and source attribution of Hg transport and deposition to the Arctic using models. Estimated global anthropogenic Hg emissions to the atmosphere for 2015 were ~2220 Mg, ~20% higher than 2010. Global anthropogenic, legacy and geogenic Hg emissions were, respectively, responsible for 32%, 64% (wildfires: 6-10%) and 4% of the annual Arctic Hg deposition. Relative contributions to Arctic deposition of anthropogenic origin was dominated by sources in East Asia (32%), Commonwealth of Independent States (12%), and Africa (12%). Model results exhibit significant spatiotemporal variations in Arctic anthropogenic Hg deposition fluxes, driven by regional differences in Hg air transport routes, surface and precipitation uptake rates, and inter-seasonal differences in atmospheric circulation and deposition pathways. Model simulations reveal that changes in meteorology are having a profound impact on contemporary atmospheric Hg in the Arctic. Reversal of North Atlantic Oscillation phase from strongly negative in 2010 to positive in 2015, associated with lower temperature and more sea ice in the Canadian Arctic, Greenland and surrounding ocean, resulted in enhanced production of bromine species and Hg(0) oxidation and lower evasion of Hg(0) from ocean waters in 2015. This led to increased Hg(II) (and its deposition) and reduced Hg(0) air concentrations in these regions in line with High Arctic observations. However, combined changes in meteorology and anthropogenic emissions led to overall elevated modeled Arctic air Hg(0) levels in 2015 compared to 2010 contrary to observed declines at most monitoring sites, likely due to uncertainties in anthropogenic emission speciation, wildfire emissions and model representations of air-surface Hg fluxes.
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Affiliation(s)
- Ashu Dastoor
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada.
| | - Simon J Wilson
- Arctic Monitoring and Assessment Programme (AMAP). The Fram Centre, Box 6606 Stakkevollan, 9296 Tromsø, Norway.
| | - Oleg Travnikov
- Meteorological Synthesizing Centre-East, EMEP, 2nd Roshchinsky proezd, 8/5, 115419 Moscow, Russia
| | - Andrei Ryjkov
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada
| | - Hélène Angot
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland
| | - Jesper H Christensen
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Frits Steenhuisen
- Arctic Centre, University of Groningen, Aweg 30, 9718CW Groningen, the Netherlands
| | - Marilena Muntean
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749 (T.P. 123), I-21027 Ispra, VA, Italy
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13
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Beet CR, Hogg ID, Cary SC, McDonald IR, Sinclair BJ. The Resilience of Polar Collembola (Springtails) in a Changing Climate. CURRENT RESEARCH IN INSECT SCIENCE 2022; 2:100046. [PMID: 36683955 PMCID: PMC9846479 DOI: 10.1016/j.cris.2022.100046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/30/2022] [Accepted: 09/08/2022] [Indexed: 06/17/2023]
Abstract
Assessing the resilience of polar biota to climate change is essential for predicting the effects of changing environmental conditions for ecosystems. Collembola are abundant in terrestrial polar ecosystems and are integral to food-webs and soil nutrient cycling. Using available literature, we consider resistance (genetic diversity; behavioural avoidance and physiological tolerances; biotic interactions) and recovery potential for polar Collembola. Polar Collembola have high levels of genetic diversity, considerable capacity for behavioural avoidance, wide thermal tolerance ranges, physiological plasticity, generalist-opportunistic feeding habits and broad ecological niches. The biggest threats to the ongoing resistance of polar Collembola are increasing levels of dispersal (gene flow), increased mean and extreme temperatures, drought, changing biotic interactions, and the arrival and spread of invasive species. If resistance capacities are insufficient, numerous studies have highlighted that while some species can recover from disturbances quickly, complete community-level recovery is exceedingly slow. Species dwelling deeper in the soil profile may be less able to resist climate change and may not recover in ecologically realistic timescales given the current rate of climate change. Ultimately, diverse communities are more likely to have species or populations that are able to resist or recover from disturbances. While much of the Arctic has comparatively high levels of diversity and phenotypic plasticity; areas of Antarctica have extremely low levels of diversity and are potentially much more vulnerable to climate change.
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Affiliation(s)
- Clare R. Beet
- Te Aka Mātuatua - School of Science, Te Whare Wānanga o Waikato - University of Waikato, Hamilton, New Zealand
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton, New Zealand
| | - Ian D. Hogg
- Te Aka Mātuatua - School of Science, Te Whare Wānanga o Waikato - University of Waikato, Hamilton, New Zealand
- Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, Nunavut, Canada
| | - S. Craig Cary
- Te Aka Mātuatua - School of Science, Te Whare Wānanga o Waikato - University of Waikato, Hamilton, New Zealand
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton, New Zealand
| | - Ian R. McDonald
- Te Aka Mātuatua - School of Science, Te Whare Wānanga o Waikato - University of Waikato, Hamilton, New Zealand
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton, New Zealand
| | - Brent J. Sinclair
- Department of Biology, University of Western Ontario, London, ON, Canada
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14
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Zhang Z, Zhang X, Xin Y, Wu H. Ant colonization increased total mercury but reduced methylmercury contents in boreal mires, Northeast China. J Environ Sci (China) 2022; 119:50-58. [PMID: 35934465 DOI: 10.1016/j.jes.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 06/15/2023]
Abstract
Soil macroinvertebrates as ecosystem engineers play significant, but largely ignored, roles in affecting mercury (Hg) cycle by altering soil physical-chemical properties. Ant is likely expanded into boreal mires with climate warming, however, its impacts on Hg cycle remained poorly understood. We compared total Hg (THg) and methylmercury (MeHg) contents in soils from antmounds (Lasius flavus) and the nearby ambient in a boreal mire in Northeast China. The present work seeks to unravel factors that controlling MeHg levels in case of ant appearance or absence. The average THg was 179 µg/kg in the ant mound and was 106.1 µg/kg in nearby soils, respectively. The average MeHg was 10.9 µg/kg in the ant mound and was 12.9 µg/kg in nearby soils, respectively. The ratios of MeHg to THg (%MeHg) were 7.61% in ant mounds and 16.75% in nearby soils, respectively. Ant colonization caused THg enrichment and MeHg depletion, and this change was obvious in the 10-20 cm depth soil layer where ants mainly inhabited. Spectrometry characteristics of soil dissolved organic matter (DOM) exert a stronger control than microorganisms on MeHg variation in soils. A structural equation model revealed that the molecular weight of DOM inhibited MeHg irrespective of ant presence or absence, while humification conducive to MeHg significantly in ant mound soils. Microorganisms mainly affected Hg methylation by altering the molecular weight and humification of DOM. We propose that the effects of ant colonization on MeHg rested on DOM feature variations caused by microorganisms in boreal mires.
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Affiliation(s)
- Zhongsheng Zhang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China.
| | - Xuehui Zhang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Xin
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China; Shengyang University, Shenyang 110044, China
| | - Haitao Wu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China
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15
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Chételat J, McKinney MA, Amyot M, Dastoor A, Douglas TA, Heimbürger-Boavida LE, Kirk J, Kahilainen KK, Outridge PM, Pelletier N, Skov H, St Pierre K, Vuorenmaa J, Wang F. Climate change and mercury in the Arctic: Abiotic interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153715. [PMID: 35149079 DOI: 10.1016/j.scitotenv.2022.153715] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Dramatic environmental shifts are occuring throughout the Arctic from climate change, with consequences for the cycling of mercury (Hg). This review summarizes the latest science on how climate change is influencing Hg transport and biogeochemical cycling in Arctic terrestrial, freshwater and marine ecosystems. As environmental changes in the Arctic continue to accelerate, a clearer picture is emerging of the profound shifts in the climate and cryosphere, and their connections to Hg cycling. Modeling results suggest climate influences seasonal and interannual variability of atmospheric Hg deposition. The clearest evidence of current climate change effects is for Hg transport from terrestrial catchments, where widespread permafrost thaw, glacier melt and coastal erosion are increasing the export of Hg to downstream environments. Recent estimates suggest Arctic permafrost is a large global reservoir of Hg, which is vulnerable to degradation with climate warming, although the fate of permafrost soil Hg is unclear. The increasing development of thermokarst features, the formation and expansion of thaw lakes, and increased soil erosion in terrestrial landscapes are increasing river transport of particulate-bound Hg and altering conditions for aquatic Hg transformations. Greater organic matter transport may also be influencing the downstream transport and fate of Hg. More severe and frequent wildfires within the Arctic and across boreal regions may be contributing to the atmospheric pool of Hg. Climate change influences on Hg biogeochemical cycling remain poorly understood. Seasonal evasion and retention of inorganic Hg may be altered by reduced sea-ice cover and higher chloride content in snow. Experimental evidence indicates warmer temperatures enhance methylmercury production in ocean and lake sediments as well as in tundra soils. Improved geographic coverage of measurements and modeling approaches are needed to better evaluate net effects of climate change and long-term implications for Hg contamination in the Arctic.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, National Wildlife Research Centre, Ottawa, ON K1A 0H3, Canada.
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Marc Amyot
- Groupe de recherche interuniversitaire en limnologie (GRIL), Département de sciences biologiques, Complexe des Sciences, Montréal, QC H2V 0B3, Canada
| | - Ashu Dastoor
- Environment and Climate Change Canada, Air Quality Research Division, Dorval, QC H9P 1J3, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK 99709, USA
| | - Lars-Eric Heimbürger-Boavida
- Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Marseille, France
| | - Jane Kirk
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Burlington, ON L7S 1A1, Canada
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, FI-16900 Lammi, Finland
| | - Peter M Outridge
- Geological Survey of Canada, Natural Resources Canada, Ottawa, ON K1A 0E8, Canada
| | - Nicolas Pelletier
- Geography and Environmental Studies, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Henrik Skov
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Kyra St Pierre
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jussi Vuorenmaa
- Finnish Environment Institute (SYKE), Latokartanonkaari 11, FI-00790 Helsinki, Finland
| | - Feiyue Wang
- Centre for Earth Observation Sciences (CEOS), Dept. of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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16
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Wu Z, Li Z, Shao B, Zhang Y, He W, Lu Y, Gusvitskii K, Zhao Y, Liu Y, Wang X, Tong Y. Impact of dissolved organic matter and environmental factors on methylmercury concentrations across aquatic ecosystems inferred from a global dataset. CHEMOSPHERE 2022; 294:133713. [PMID: 35074323 DOI: 10.1016/j.chemosphere.2022.133713] [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: 10/14/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Mercury (Hg) input into ecosystems is estimated to have increased by twofold to fivefold since the industrial revolution. In aquatic ecosystems, methylmercury (MeHg) receives the most attentions of all the Hg species due to its neurotoxicity and strong bioaccumulation capacity in food chain. Dissolved organic matter (DOM) is crucial in impacting aquatic Hg transformation. However, only few spatially constrained studies have attempted to quantify the relative importance of DOM and other factors (e.g., Hg availability, temperature, pH, and land-use type) on MeHg concentration. In this study, we collected data of 585 water samples at 373 sites globally, including lakes, rivers, estuaries, and wetlands, and characterized the global pattern of MeHg distribution and environmental drivers of aquatic MeHg concentration. Our results showed that MeHg concentrations ranged from detection limits to 11 (geometric mean 0.11 and average 0.29) ng/L, and the highest MeHg concentration and Hg methylation potential were observed in wetlands. A positive relationship was observed between MeHg fraction in the total mercury (THg) and DOM for all the aquatic ecosystems. Using the structural equation modeling, we found that Hg availability was a dominant factor in impacting water MeHg concentration followed by DOM. According to 129 samples of specific DOM source information, we found that the percentage of THg as MeHg (%MeHg) in water dominated by the autochthonous DOM was higher than that dominated by the allochthonous DOM. Our results could advance understanding of aquatic Hg cycling and their environmental drivers, which are fundamental for predicting and mitigating MeHg productions and its potential health risks for humans.
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Affiliation(s)
- Zhengyu Wu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Zhike Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Bo Shao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yiyan Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Wei He
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Yiren Lu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Kair Gusvitskii
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yingxin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yurong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xuejun Wang
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.
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17
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Zhang L, Philben M, Taş N, Johs A, Yang Z, Wullschleger SD, Graham DE, Pierce EM, Gu B. Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 299:118878. [PMID: 35085651 DOI: 10.1016/j.envpol.2022.118878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Arctic tundra soils store a globally significant amount of mercury (Hg), which could be transformed to the neurotoxic methylmercury (MeHg) upon warming and thus poses serious threats to the Arctic ecosystem. However, our knowledge of the biogeochemical drivers of MeHg production is limited in these soils. Using substrate addition (acetate and sulfate) and selective microbial inhibition approaches, we investigated the geochemical drivers and dominant microbial methylators in 60-day microcosm incubations with two tundra soils: a circumneutral fen soil and an acidic bog soil, collected near Nome, Alaska, United States. Results showed that increasing acetate concentration had negligible influences on MeHg production in both soils. However, inhibition of sulfate-reducing bacteria (SRB) completely stalled MeHg production in the fen soil in the first 15 days, whereas addition of sulfate in the low-sulfate bog soil increased MeHg production by 5-fold, suggesting prominent roles of SRB in Hg(II) methylation. Without the addition of sulfate in the bog soil or when sulfate was depleted in the fen soil (after 15 days), both SRB and methanogens contributed to MeHg production. Analysis of microbial community composition confirmed the presence of several phyla known to harbor microorganisms associated with Hg(II) methylation in the soils. The observations suggest that SRB and methanogens were mainly responsible for Hg(II) methylation in these tundra soils, although their relative contributions depended on the availability of sulfate and possibly syntrophic metabolisms between SRB and methanogens.
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Affiliation(s)
- Lijie Zhang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA; Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Michael Philben
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Neslihan Taş
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, USA
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI, 48309, USA
| | - Stan D Wullschleger
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - David E Graham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Eric M Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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18
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Analysing Historical and Modelling Future Soil Temperature at Kuujjuaq, Quebec (Canada): Implications on Aviation Infrastructure. FORECASTING 2022. [DOI: 10.3390/forecast4010006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The impact of climate change on soil temperatures at Kuujjuaq, Quebec in northern Canada is assessed. First, long-term historical soil temperature records (1967–1995) are statistically analyzed to provide a climatological baseline for soils at 5 to 150 cm depths. Next, the nature of the relationship between atmospheric variables and soil temperature are determined using a statistical downscaling model (SDSM) and National Centers for Environmental Prediction (NCEP), a climatological data set. SDSM was found to replicate historic soil temperatures well and used to project soil temperatures for the remainder of the century using climate model output Canadian Second Generation Earth System Model (CanESM2). Three Representative Concentration Pathway scenarios (RCP 2.6, 4.5 and 8.5) were used from the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). This study found that the soil temperature at this location may warm at 0.9 to 1.2 °C per decade at various depths. Annual soil temperatures at all depths are projected to rise to above 0 °C for the 1997–2026 period for all climate scenarios. The melting soil poses a hazard to the airport infrastructure and will require adaptation measures.
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19
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Maddela NR, Ramakrishnan B, Kakarla D, Venkateswarlu K, Megharaj M. Major contaminants of emerging concern in soils: a perspective on potential health risks. RSC Adv 2022; 12:12396-12415. [PMID: 35480371 PMCID: PMC9036571 DOI: 10.1039/d1ra09072k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/06/2022] [Indexed: 12/16/2022] Open
Abstract
Soil pollution by the contaminants of emerging concern (CECs) or emerging contaminants deserves attention worldwide because of their toxic health effects and the need for developing regulatory guidelines. Though the global soil burden by certain CECs is in several metric tons, the source-tracking of these contaminants in soil environments is difficult due to heterogeneity of the medium and complexities associated with the interactive mechanisms. Most CECs have higher affinities towards solid matrices for adsorption. The CECs alter not only soil functionalities but also those of plants and animals. Their toxicities are at nmol to μmol levels in cell cultures and test animals. These contaminants have a higher propensity in accumulating mostly in root-based food crops, threatening human health. Poor understanding on the fate of certain CECs in anaerobic environments and their transfer pathways in the food web limits the development of effective bioremediation strategies and restoration of the contaminated soils and endorsement of global regulatory efforts. Despite their proven toxicities to the biotic components, there are no environmental laws or guidelines for certain CECs. Moreover, the information available on the impact of soil pollution with CECs on human health is fragmentary. Therefore, we provide here a comprehensive account on five significantly important CECs, viz., (i) PFAS, (ii) micro/nanoplastics, (iii) additives (biphenyls, phthalates), (iv) novel flame retardants, and (v) nanoparticles. The emphasis is on (a) degree of soil burden of CECs and the consequences, (b) endocrine disruption and immunotoxicity, (c) genotoxicity and carcinogenicity, and (d) soil health guidelines. Contaminants of emerging concern: sources, soil burden, human exposure, and toxicities.![]()
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Affiliation(s)
- Naga Raju Maddela
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Salud, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador
- Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador
| | | | - Dhatri Kakarla
- University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, 515003, India
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Faculty of Science, The University of Newcastle, Callaghan, NSW 2308, Australia
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20
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Tarbier B, Hugelius G, Kristina Sannel AB, Baptista-Salazar C, Jonsson S. Permafrost Thaw Increases Methylmercury Formation in Subarctic Fennoscandia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6710-6717. [PMID: 33902281 PMCID: PMC8277125 DOI: 10.1021/acs.est.0c04108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Methylmercury (MeHg) forms in anoxic environments and can bioaccumulate and biomagnify in aquatic food webs to concentrations of concern for human and wildlife health. Mercury (Hg) pollution in the Arctic environment may worsen as these areas warm and Hg, currently locked in permafrost soils, is remobilized. One of the main concerns is the development of Hg methylation hotspots in the terrestrial environment due to thermokarst formation. The extent to which net methylation of Hg is enhanced upon thaw is, however, largely unknown. Here, we have studied the formation of Hg methylation hotspots using existing thaw gradients at five Fennoscandian permafrost peatland sites. Total Hg (HgT) and MeHg concentrations were analyzed in 178 soil samples from 14 peat cores. We observed 10 times higher concentrations of MeHg and 13 times higher %MeHg in the collapse fen (representing thawed conditions) as compared to the peat plateau (representing frozen conditions). This suggests significantly greater net methylation of Hg when thermokarst wetlands are formed. In addition, we report HgT to soil organic carbon ratios representative of Fennoscandian permafrost peatlands (median and interquartile range of 0.09 ± 0.07 μg HgT g-1 C) that are of value for future estimates of circumpolar HgT stocks.
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Affiliation(s)
- Brittany Tarbier
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
| | - Gustaf Hugelius
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
- Bolin
Centre for Climate Research, Stockholm University, Stockholm 106 91, Sweden
| | - Anna Britta Kristina Sannel
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
- Bolin
Centre for Climate Research, Stockholm University, Stockholm 106 91, Sweden
| | | | - Sofi Jonsson
- Department
of Environmental Science, Stockholm University, Stockholm 106 91, Sweden
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21
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Dai SS, Yang Z, Tong Y, Chen L, Liu SY, Pan R, Li Y, Zhang CJ, Liu YR, Huang Q. Global distribution and environmental drivers of methylmercury production in sediments. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124700. [PMID: 33333388 DOI: 10.1016/j.jhazmat.2020.124700] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/11/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Neurotoxic methylmercury (MeHg) in environments poses substantial risks to human health. Saturated sediments are basic sources of MeHg in food chains; however, distribution patterns and environmental drivers of MeHg at a global scale remain largely unexplored. Here, we characterized global patterns of MeHg distribution and environmental drivers of MeHg production based on 495 sediment samples across five typical ecosystems from the literature (1995-2018) and our own field survey. Our results showed the MeHg concentration ranged from 0.009 to 55.7 μg kg-1 across the different ecosystems, and the highest MeHg concentration and Hg methylation potential were from the sediments of paddy and marine environments, respectively. Further, using combined analysis of random forest and structural equation modeling, we identified temperature and precipitation as important regulators of MeHg production after accounting for the well-known drivers including Hg availability and sediment geochemistry. More importantly, we found increased MeHg production in sediments with elevated mean annual Hg precipitation, and warmer temperature could also accelerate MeHg production by facilitating activities of microbial methylators. Together, this work advances our understanding of global MeHg distribution in sediments and environmental drivers, which are fundamental to the prediction and management of MeHg production and its potential health risk globally.
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Affiliation(s)
- Shu-Shen Dai
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI 48309, United States
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Long Chen
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Si-Yuan Liu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Rong Pan
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Yanbin Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Cui-Jing Zhang
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Yu-Rong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China.
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China
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22
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Etique M, Bouchet S, Byrne JM, ThomasArrigo LK, Kaegi R, Kretzschmar R. Mercury Reduction by Nanoparticulate Vivianite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3399-3407. [PMID: 33554594 PMCID: PMC7931808 DOI: 10.1021/acs.est.0c05203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/15/2021] [Accepted: 01/22/2021] [Indexed: 05/24/2023]
Abstract
Mercury (Hg) is a toxic trace element of global environmental concern which has been increasingly dispersed into the environment since the industrial revolution. In aquatic and terrestrial systems, Hg can be reduced to elemental Hg (Hg0) and escape to the atmosphere or converted to methylmercury (MeHg), a potent neurotoxin that accumulates in food webs. FeII-bearing minerals such as magnetite, green rusts, siderite, and mackinawite are recognized HgII reducers. Another potentially Hg-reducing mineral, which commonly occurs in Fe- and organic/P-rich sediments and soils, is the ferrous iron phosphate mineral vivianite (FeII3(PO4)2·8H2O), but its reaction with HgII has not been studied to date. Here, nanoparticulate vivianite (particle size ∼ 50 nm; FeII content > 98%) was chemically synthesized and characterized by a combination of chemical, spectroscopic, and microscopic analyses. Its ability to reduce HgII was investigated at circumneutral pH under anoxic conditions over a range of FeII/HgII ratios (0.1-1000). For FeII/HgII ratios ≥1, which are representative of natural environments, HgII was very quickly and efficiently reduced to Hg0. The ability of vivianite to reduce HgII was found to be similar to those of carbonate green rust and siderite, two of the most effective Hg-reducing minerals. Our results suggest that vivianite may be involved in abiotic HgII reduction in Fe and organic/P-rich soils and sediments, potentially contributing to Hg evasion while also limiting MeHg formation in these ecosystems.
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Affiliation(s)
- Marjorie Etique
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - Sylvain Bouchet
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - James M. Byrne
- School of Earth Sciences, University of
Bristol, Wills Memorial Building, Queens Road, BS8 1RJ Bristol,
U.K.
| | - Laurel K. ThomasArrigo
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - Ralf Kaegi
- Eawag, Swiss Federal Institute of Aquatic
Science and Technology, Überlandstrasse 133, 8600 Dübendorf,
Switzerland
| | - Ruben Kretzschmar
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
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23
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Varty S, Lehnherr I, St Pierre K, Kirk J, Wisniewski V. Methylmercury Transport and Fate Shows Strong Seasonal and Spatial Variability along a High Arctic Freshwater Hydrologic Continuum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:331-340. [PMID: 33356178 DOI: 10.1021/acs.est.0c05051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The presence of toxic methylmercury (MeHg) in Arctic freshwater ecosystems and foodwebs is a potential health concern for northern Indigenous people. Addressing this issue requires a better understanding of MeHg production, fate during transport, and uptake into foodwebs. We used methylation assays and spatiotemporal surveys of MeHg concentrations, during the ice-covered and open water seasons, across a hydrologic continuum (composed of thaw seeps, lake/ponds, and a wetland) to identify Hg methylation hotspots and seasonal differences in MeHg cycling unique to Arctic ecosystems. Ponds and saturated wetland soils support methylation hotspots during the open water season, but subsequent export of MeHg to downstream ecosystems is limited by particle settling, binding of MeHg on soil organic matter, and/or demethylation in drier wetland soils. During the ice-covered season, MeHg concentrations in lake waters were approximately ten-fold greater than in summer; however, zooplankton MeHg concentrations were paradoxically five times lower at this time. Despite limited evidence of snow-phase methylation, the snowpack is an important MeHg reservoir. Changes in ice-cover duration will alter MeHg production and bioaccumulation in lakes, while increased thaw and surface water flow will likely result in higher methylation rates at the aquatic-terrestrial interface and more efficient downstream transport of MeHg.
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Affiliation(s)
- Stephanie Varty
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Kyra St Pierre
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Jane Kirk
- Canada Centre for Inland Waters, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Victoria Wisniewski
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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24
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Zaporski J, Jamison M, Zhang L, Gu B, Yang Z. Mercury methylation potential in a sand dune on Lake Michigan's eastern shoreline. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 729:138879. [PMID: 32371207 DOI: 10.1016/j.scitotenv.2020.138879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
Lake Michigan hosts the largest freshwater sand dune system in the world and is economically important for the fishery industry and tourism. Due to industrial pollution and atmospheric mercury (Hg) deposition, toxic levels of methylmercury (MeHg) have been found in the Lake biota, but little information is known regarding MeHg sources and Hg methylation potential in the shoreline sand dunes. We conducted anaerobic incubation experiments with beach sands collected from Ludington, Michigan, and examined the effects of organic carbon substrate addition, inorganic nitrogen, and mineral magnetite on Hg methylation. Despite nutrient poor and low-organic carbon conditions, appreciable Hg methylation activity coupled with carbon degradation was observed in the sands. Addition of acetate as a carbon source substantially increased MeHg production from 2 to 380 ng/kg sediment while acetate was rapidly degraded in the first 19 days of incubation. Ammonium addition showed little influence on carbon degradation or Hg methylation, whereas iron oxide addition (~1% dry weight) significantly inhibited both carbon degradation and MeHg production (by up to 90%), highlighting strongly coupled interactions between microbes, carbon substrates, and minerals. This research demonstrates the potential of microbial Hg methylation in the sand dunes, which may play a role in MeHg input and bioaccumulation in the Lake Michigan ecosystem.
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Affiliation(s)
- Jared Zaporski
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Megan Jamison
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Lijie Zhang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.
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25
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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: 38] [Impact Index Per Article: 9.5] [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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26
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Mu C, Schuster PF, Abbott BW, Kang S, Guo J, Sun S, Wu Q, Zhang T. Permafrost degradation enhances the risk of mercury release on Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 708:135127. [PMID: 31787283 DOI: 10.1016/j.scitotenv.2019.135127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/19/2019] [Accepted: 10/21/2019] [Indexed: 05/21/2023]
Abstract
Permafrost on the Qinghai-Tibetan Plateau (QTP) has been degrading in the past decades. While the degradation may mobilize previously protected material from the permafrost profile, little is known about the stocks and stability of mercury (Hg) in the QTP permafrost. Here we measured total soil Hg in 265 samples from 15 permafrost cores ranging from 3 to 18 m depth, and 45 active layer (AL) soil samples from different land cover types on the QTP. Approximately 21.7 Gg of Hg was stored in surficial permafrost (0-3 m), with 16.58 Gg of Hg was stored in the active layer. Results from six permafrost collapse areas showed that much of the thawed Hg is mobile, with decreases in total Hg mass of 17.6-30.9% for the AL (top 30 cm) in comparison with non-thermokarst surfaces. We conclude that the QTP permafrost region has a large mercury pool, and the stored mercury is sensitive to permafrost degradation.
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Affiliation(s)
- Cuicui Mu
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China; State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China; State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China.
| | - Paul F Schuster
- U.S. Geological Survey, National Research Program, Boulder, CO, USA
| | - Benjamin W Abbott
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, USA
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100875, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Shiwei Sun
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Qingbai Wu
- State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resource, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Tingjun Zhang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China; University Corporation for Polar Research, Beijing 100875, China.
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27
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Sirota JI, Kolka RK, Sebestyen SD, Nater EA. Mercury dynamics in the pore water of peat columns during experimental freezing and thawing. JOURNAL OF ENVIRONMENTAL QUALITY 2020; 49:404-416. [PMID: 33016431 DOI: 10.1002/jeq2.20046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 09/24/2019] [Indexed: 06/11/2023]
Abstract
Biogeochemical processes in northern peatland ecosystems are influenced by seasonal temperature fluctuations that are changing with the climate. Methylmercury (MeHg), commonly produced in peatlands, affects downstream waters; therefore, it is important to understand how temperature transitions affect mercury (Hg) dynamics. We investigated how the freeze-thaw cycle influences belowground peat pore water total Hg (THg), MeHg, and dissolved organic carbon (DOC). Four large, intact peat columns were removed from an ombrotrophic peat bog and experimentally frozen and thawed. Pore water was sampled across seven depths in the peat columns during the freeze-thaw cycle and analyzed for THg, MeHg, and DOC concentrations. Freezing results showed increased concentrations of THg below the ice layers and limited change in MeHg concentrations. During thawing, THg concentrations significantly increased, whereas MeHg concentrations decreased. Limited bromide movement and depth decreases in THg and DOC concentrations were associated with increased bulk density and degree of humification in the peat. The experiment demonstrates the effects of the freeze-thaw cycle on Hg concentrations in northern peatlands. Changes to freeze-thaw cycles with climate change may exacerbate Hg cycling and transport processes in peatland environments.
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Affiliation(s)
- Jennie I Sirota
- Dep. of Forest Resources, Univ. of Minnesota, 1530 Cleveland Ave. N, St. Paul, MN, 55108
| | - Randall K Kolka
- Northern Research Station, USDA Forest Service, 1831 Hwy 169 East, Grand Rapids, MN, 55744
| | - Stephen D Sebestyen
- Northern Research Station, USDA Forest Service, 1831 Hwy 169 East, Grand Rapids, MN, 55744
| | - Edward A Nater
- Dep. of Soil, Water, and Climate, Univ. of Minnesota, 1991 Upper Buford Circle, St. Paul, MN, 55108
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28
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Kenny TA, Archambault P, Ayotte P, Batal M, Chan HM, Cheung W, Eddy TD, Little M, Ota Y, Pétrin-Desrosiers C, Plante S, Poitras J, Polanco F, Singh G, Lemire M. Oceans and human health—navigating changes on Canada’s coasts. Facets (Ott) 2020. [DOI: 10.1139/facets-2020-0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ocean conditions can affect human health in a variety of ways that are often overlooked and unappreciated. Oceans adjacent to Canada are affected by many anthropogenic stressors, with implications for human health and well-being. Climate change further escalates these pressures and can expose coastal populations to unique health hazards and distressing conditions. However, current research efforts, education or training curriculums, and policies in Canada critically lack explicit consideration of these ocean–public health linkages. The objective of this paper is to present multiple disciplinary perspectives from academics and health practitioners to inform the development of future directions for research, capacity development, and policy and practice at the interface of oceans and human health in Canada. We synthesize major ocean and human health linkages in Canada, and identify climate-sensitive drivers of change, drawing attention to unique considerations in Canada. To support effective, sustained, and equitable collaborations at the nexus of oceans and human health, we recommend the need for progress in three critical areas: ( i) holistic worldviews and perspectives, ( ii) capacity development, and ( iii) structural supports. Canada can play a key role in supporting the global community in addressing the health challenges of climate and ocean changes.
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Affiliation(s)
- Tiff-Annie Kenny
- Département de médecine sociale et préventive, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Axe santé des populations et pratiques optimales en santé, Centre de recherche du CHU de québec, Université Laval, Québec, QC G1S 4L8, Canada
| | - Philippe Archambault
- Département de biologie, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
- ArcticNet, Université Laval, Québec, QC G1V 0A6, Canada
| | - Pierre Ayotte
- Axe santé des populations et pratiques optimales en santé, Centre de recherche du CHU de québec, Université Laval, Québec, QC G1S 4L8, Canada
| | - Malek Batal
- Département de nutrition, Faculté de médecine, Université de Montréal, Montréal, QC H3C 3J7, Canada
- Centre de recherche en santé publique (CReSP), Montréal, QC H3C 3J7, Canada
| | - Hing Man Chan
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - William Cheung
- Institute of Oceans and Fisheries (IOF), University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Tyler D. Eddy
- Centre for Fisheries Ecosystems Research, Fisheries & Marine Institute, Memorial University of Newfoundland, St. John’s, NL A1C 5R3, Canada
| | - Matthew Little
- School of Public Health and Social Policy, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Yoshitaka Ota
- Nippon Foundation Ocean Nexus Center, EarthLab, University of Washington, Seattle, WA 98195-5674, USA
- School of Marine and Environmental Affairs (SMEA), University of Washington, Seattle, WA 98195-5685, USA
| | - Claudel Pétrin-Desrosiers
- Département de médecine familiale et de médecine d’urgence, Faculté de médecine, Université de Montréal, Montréal, QC H3C 3J7, Canada
- Association canadienne des médecins pour l’environnement/Canadian Association of Physicians for the Environment (ACME/CAPE), Toronto, ON M5T 2C2, Canada
| | - Steve Plante
- Département Sociétés territoires et développement, Université du Québec à Rimouski, Rimouski, QC G5L 3A1, Canada
| | - Julien Poitras
- Département de médecine familiale et de médecine d’urgence, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Fernando Polanco
- School of Medicine, St. George’s University, St. George’s, Grenada, West Indies
| | - Gerald Singh
- Department of Geography, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
| | - Mélanie Lemire
- Département de médecine sociale et préventive, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Axe santé des populations et pratiques optimales en santé, Centre de recherche du CHU de québec, Université Laval, Québec, QC G1S 4L8, Canada
- Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec, QC G1V 0A6, Canada
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29
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Haskins DL, Gogal RM, Tuberville TD. Snakes as Novel Biomarkers of Mercury Contamination: A Review. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 249:133-152. [PMID: 30879139 DOI: 10.1007/398_2019_26] [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] [Indexed: 06/09/2023]
Abstract
Mercury (Hg) is an environmental contaminant that has been reported in many wildlife species worldwide. The organic form of Hg bioaccumulates in higher trophic levels, and thus, long-lived predators are at risk for higher Hg exposure. Although ecological risk assessments for contaminants such as Hg include pertinent receptor species, snakes are rarely considered, despite their high trophic status and potential to accumulate high levels of Hg. Our current knowledge of these reptiles suggests that snakes may be useful novel biomarkers to monitor contaminated environments. The few available studies show that snakes can bioaccumulate significant amounts of Hg. However, little is known about the role of snakes in Hg transport in the environment or the individual-level effects of Hg exposure in this group of reptiles. This is a major concern, as snakes often serve as important prey for a variety of taxa within ecosystems (including humans). In this review, we compiled and analyzed the results of over 30 studies to discuss the impact of Hg on snakes, specifically sources of exposure, bioaccumulation, health consequences, and specific scientific knowledge gaps regarding these moderate to high trophic predators.
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Affiliation(s)
- David L Haskins
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA, USA.
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA.
| | - Robert M Gogal
- Department of Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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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: 27] [Impact Index Per Article: 5.4] [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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31
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Haynes KM, Kane ES, Potvin L, Lilleskov EA, Kolka RK, Mitchell CPJ. Impacts of experimental alteration of water table regime and vascular plant community composition on peat mercury profiles and methylmercury production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 682:611-622. [PMID: 31129544 DOI: 10.1016/j.scitotenv.2019.05.072] [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: 01/31/2019] [Revised: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Climate change is expected to alter the hydrology and vascular plant communities in peatland ecosystems. These changes may have as yet unexplored impacts on peat mercury (Hg) concentrations and net methylmercury (MeHg) production. In this study, peat was collected from PEATcosm, an outdoor, controlled mesocosm experiment where peatland water table regimes and vascular plant functional groups were manipulated over several years to simulate potential climate change effects. Potential Hg(II) methylation and MeHg demethylation rate constants were assessed using enriched stable isotope incubations at the end of the study in 2015, and ambient peat total Hg (THg) and MeHg concentration depth profiles were tracked annually from 2011 to 2014. Peat THg and MeHg concentrations and the proportion of THg methylated (%MeHg) increased significantly within the zone of water table fluctuation when water tables were lowered, but potential Hg(II) methylation rate constants were similar regardless of water table treatment. When sedges dominate over ericaceous shrubs, MeHg concentrations and %MeHg became significantly elevated within the sedge rooting zone. Increased desorption of Hg(II) and MeHg from the solid phase peat into pore water occurred with a lowered water table and predominant sedge cover, likely due to greater aerobic peat decomposition. Deeper, more variable water tables and a transition to sedge-dominated communities coincided with increased MeHg accumulation within the zone of water table fluctuation. Sustained high water tables promoted the net downward migration of Hg(II) and MeHg. The simultaneous decrease in Hg(II) and MeHg concentrations in the near-surface peat and accumulation deeper in the peat profile, combined with the trends in Hg(II) and MeHg partitioning to mobile pore waters, suggest that changes to peatland hydrology and vascular plant functional groups redistribute peat Hg(II) and MeHg via vertical hydrochemical transport mechanisms.
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Affiliation(s)
- Kristine M Haynes
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada.
| | - Evan S Kane
- Michigan Technological University, School of Forest Resources and Environmental Science, Houghton, MI 49931, USA; USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Lynette Potvin
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Erik A Lilleskov
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Randall K Kolka
- USDA Forest Service Northern Research Station, Grand Rapids, MN 55744, USA
| | - Carl P J Mitchell
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada
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32
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Zhang L, Wu S, Zhao L, Lu X, Pierce EM, Gu B. Mercury Sorption and Desorption on Organo-Mineral Particulates as a Source for Microbial Methylation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2426-2433. [PMID: 30702880 DOI: 10.1021/acs.est.8b06020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In natural freshwater and sediments, mercuric mercury (Hg(II)) is largely associated with particulate minerals and organics, but it remains unclear under what conditions particulates may become a sink or a source for Hg(II) and whether the particulate-bound Hg(II) is bioavailable for microbial uptake and methylation. In this study, we investigated Hg(II) sorption-desorption characteristics on three organo-coated hematite particulates and a Hg-contaminated natural sediment and evaluated the potential of particulate-bound Hg(II) for microbial methylation. Mercury rapidly sorbed onto particulates, especially the cysteine-coated hematite and sediment, with little desorption observed (0.1-4%). However, the presence of Hg-binding ligands, such as low-molecular-weight thiols and humic acids, resulted in up to 60% of Hg(II) desorption from the Hg-laden hematite particulates but <6% from the sediment. Importantly, the particulate-bound Hg(II) was bioavailable for uptake and methylation by a sulfate-reducing bacterium Desulfovibrio desulfuricans ND132 under anaerobic incubations, and the methylation rate was 4-10 times higher than the desorption rate of Hg(II). These observations suggest direct contacts and interactions between bacterial cells and the particulate-bound Hg(II), resulting in rapid exchange or uptake of Hg(II) by the bacteria. The results highlight the importance of Hg(II) partitioning at particulate-water interfaces and the role of particulates as a significant source of Hg(II) for methylation in the environment.
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Affiliation(s)
- Lijie Zhang
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Shan Wu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- School of Resource, Environmental and Chemical Engineering , Nanchang University , Nanchang 330031 , China
| | - Linduo Zhao
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Xia Lu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Eric M Pierce
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Baohua Gu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Biosystems Engineering and Soil Science , University of Tennessee , Knoxville , Tennessee 37996 , United States
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Xie M, Zhang C, Liao X, Fan Z, Xie X, Huang C. Mechanisms of radical-initiated methylmercury degradation in soil with coexisting Fe and Cu. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 652:52-58. [PMID: 30359801 DOI: 10.1016/j.scitotenv.2018.10.178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/12/2018] [Accepted: 10/12/2018] [Indexed: 06/08/2023]
Abstract
Methylmercury (MeHg) is a toxic compound. It forms mainly in reducing environments, and then degrades through biogeochemical processes. Photodegradation and microorganism degradation of MeHg are among the processes that have been reported. However, little attention has been focused on the abiotic degradation of MeHg in soil/sediment without light. In our study, the percent MeHg of total Hg in Guangzhou soil in southern China was found to be variable and exhibited a significant negative correlation with the content of Fe or Cu where annite (KFe2+3(AlSi3O10)(OH)2), a Fe-bearing mineral, was identified. To understand the mechanisms of radical-initiated MeHg degradation by Fe/Cu-containing components, batch experiments were done. Results showed that annite in the soils could activate O2 to generate OH and O2- and facilitate MeHg degradation under oxic conditions. Meanwhile, Cu components in the soil further enhanced the production of O2-, and was oxidized to Cu(III) promoting degradation of MeHg directly. These findings help us understand that the distribution of MeHg in soil depends on not only external pollution sources, but also on biogeochemical processes in subsurface environments.
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Affiliation(s)
- Mengying Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Caixiang Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China.
| | - Xiaoping Liao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Zenghui Fan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Xinmo Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Changsheng Huang
- Wuhan Center of China Geological Survey, Wuhan 430205, Hubei, PR China
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Ding LY, He NN, Yang S, Zhang LJ, Liang P, Wu SC, Wong MH, Tao HC. Inhibitory effects of Skeletonema costatum on mercury methylation by Geobacter sulfurreducens PCA. CHEMOSPHERE 2019; 216:179-185. [PMID: 30368082 DOI: 10.1016/j.chemosphere.2018.10.121] [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: 04/25/2018] [Revised: 10/04/2018] [Accepted: 10/16/2018] [Indexed: 06/08/2023]
Abstract
Algae and mercury (Hg) are ubiquitous in marine environments. In this study, we investigated the effects of a typical marine algae of diatom Skeletonema costatum on Hg methylation by an iron-reducing bacterium of Geobacter sulfurreducens (G. sulfurreducens) PCA. In the absence of Skeletonema costatum, the bacterial MeHg production rate maximized at 104.06 ± 11.7 ng L-1 h-1 with a high Hg level, while the highest methylation efficiency was achieved at a low Hg concentration. The existence of Skeletonema costatum greatly inhibited the capability of G. sulfurreducens PCA to methylate Hg. With the increase in algal biomass, there was a significant mitigation of MeHg formation and Hg0 release, leaving a considerable proportion of immobilized Hg2+ species (up to 47%) associated with algal cell materials. These results suggest that marine algae are crucial in determining the bioavailability of Hg contaminants and the methylating potential of G. sulfurreducens PCA.
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Affiliation(s)
- Ling-Yun Ding
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, Guangdong, PR China
| | - Ning-Ning He
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, Guangdong, PR China
| | - Sai Yang
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, Guangdong, PR China
| | - Li-Juan Zhang
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, Guangdong, PR China
| | - Peng Liang
- School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Linan, 311300, Zhejiang, PR China
| | - Sheng-Chun Wu
- School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Linan, 311300, Zhejiang, PR China
| | - Ming Hung Wong
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, and State Environmental Protection Key Laboratory of Integrated Water-Groundwater Pollution Control, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, PR China; Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, Hong Kong, PR China
| | - Hu-Chun Tao
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, Guangdong, PR China.
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35
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Ahonen SA, Hayden B, Leppänen JJ, Kahilainen KK. Climate and productivity affect total mercury concentration and bioaccumulation rate of fish along a spatial gradient of subarctic lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:1586-1596. [PMID: 29801252 DOI: 10.1016/j.scitotenv.2018.04.436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 06/08/2023]
Abstract
Climate change is resulting in increased temperatures and precipitation in subarctic regions of Europe. These changes are extending tree lines to higher altitudes and latitudes, and enhancing tree growth enabling intensification of forestry into previously inhospitable subarctic regions. The combined effects of climate change and land-use intensification extend the warm, open-water season in subarctic lakes and increase lake productivity and may also increase leaching and methylation activity of mercury within the lakes. To assess the joint effects of climate and productivity on total mercury (THg) bioaccumulation in fish, we conducted a space-for-time substitution study in 18 tributary lakes of a subarctic watercourse forming a gradient from cold pristine oligotrophic lakes in the northern headwaters to warmer and increasingly human-altered mesotrophic and eutrophic systems in the southern lower reaches. Increasing temperature, precipitation, and lake productivity were predicted to elevate length- and age-adjusted THg concentrations, as well as THg bioaccumulation rate (the rate of THg bioaccumulation relative to length or age) in muscle tissue of European whitefish (Coregonus lavaretus), vendace (Coregonus albula), perch (Perca fluviatilis), pike (Esox lucius), roach (Rutilus rutilus) and ruffe (Gymnocephalus cernua). A significant positive relationship was observed between age-adjusted THg concentration and lake climate-productivity in vendace (r2 = 0.50), perch (r2 = 0.51), pike (r2 = 0.55) and roach (r2 = 0.61). Higher climate-productivity values of the lakes also had a positive linear (pike; r2 = 0.40 and whitefish; r2 = 0.72) or u-shaped (perch; r2 = 0.64 and ruffe; r2 = 0.50) relationship with THg bioaccumulation rate. Our findings of increased adjusted THg concentrations in planktivores and piscivores reveal adverse effects of warming climate and increasing productivity on these subarctic fishes, whereas less distinct trends in THg bioaccumulation rate suggest more complex underlying processes. Joint environmental stressors such as climate and productivity should be considered in ongoing and future monitoring of mercury concentrations.
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Affiliation(s)
- Salla A Ahonen
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014, Finland.
| | - Brian Hayden
- Canadian Rivers Institute, Biology Department, University of New Brunswick, Canada
| | - Jaakko J Leppänen
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014, Finland
| | - Kimmo K Kahilainen
- Faculty of Biosciences, Fisheries and Economics, The Norwegian College Fishery Science, UiT The Arctic University of Norway, 9037 Tromsø, Norway
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36
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The Fate of Chemical Pollutants with Soil Properties and Processes in the Climate Change Paradigm—A Review. SOIL SYSTEMS 2018. [DOI: 10.3390/soilsystems2030051] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Heavy metal(loid)s and organic contaminants are two major groups of pollutants in soils. The fate and exposure of such pollutants in soil depends on their chemical properties, speciation, and soil properties. Soil properties and processes that control the toxicological aspects of pollutants include temperature, moisture, organic matter, mineral fractions, and microbial activities. These processes are vulnerable to climate change associated with global warming, including increased incidences of extreme rainfall, extended dry periods, soil erosion, and a rise in sea level. Here we explain evidence that relates to the effects of climate change-driven soil processes on the mobility, transport, and storage of pollutants in soil. The review found that changes in climate could increase human exposure to soil contaminants mainly due to processes involving soil organic carbon (SOC), surface runoff, redox state, and microbial community. However, uncertainties remain in relation to the extent of contaminant toxicity to human health, which is linked to global change drivers.
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37
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Tao Z, Bian R, Chai X. Methylmercury levels in cover soils from two landfills in Xi'an and Shanghai, China: Implications for mercury methylation potentials. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 78:331-336. [PMID: 32559919 DOI: 10.1016/j.wasman.2018.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 05/22/2018] [Accepted: 06/05/2018] [Indexed: 06/11/2023]
Abstract
Landfills are considered important sources of mercury for surrounding ecosystems. Methylmercury (MeHg) levels in waste layers have been studied extensively; however, the levels of MeHg in cover soils remain undefined. Here, total mercury (THg) and MeHg concentrations in surface cover soils and soil cores from two landfills in China and possible factors affecting Hg methylation were studied. The mean MeHg concentration in surface cover soils from both landfills was 0.048 ng g-1, suggesting that cover soil layers are not active sites of MeHg production. Soil MeHg concentrations in both landfills were affected little by closure time. In the Jiangcungou landfill, no correlations between MeHg concentration and the measured environmental factors (e.g., THg, soil pH, organic matter (OM), and S) were observed that indicated that these parameters might have indirect effects on MeHg concentration. However, in the Laogang landfill, significant correlations were found between MeHg concentration and the measured environmental factors. The results showed that MeHg concentration in the surface cover soil from area D of the Laogang landfill is regulated mainly by soil pH, OM, and S, and that its vertical distribution in areas C and D is regulated mainly by soil pH and soil OM, respectively. These findings fill a knowledge gap regarding MeHg levels in cover soils and they advance our understanding of Hg cycling in landfills, presenting positive implications for landfill management and risk assessment of MeHg.
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Affiliation(s)
- Zhengkai Tao
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, PR China
| | - Rongxing Bian
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, PR China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, PR China.
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Ci Z, Peng F, Xue X, Zhang X. Temperature sensitivity of gaseous elemental mercury in the active layer of the Qinghai-Tibet Plateau permafrost. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:508-515. [PMID: 29605610 DOI: 10.1016/j.envpol.2018.02.085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 02/21/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Soils represent the single largest mercury (Hg) reservoir in the global environment, indicating that a tiny change of Hg behavior in soil ecosystem could greatly affect the global Hg cycle. Climate warming is strongly altering the structure and functions of permafrost and then would influence the Hg cycle in permafrost soils. However, Hg biogeochemistry in climate-sensitive permafrost is poorly investigated. Here we report a data set of soil Hg (0) concentrations in four different depths of the active layer in the Qinghai-Tibet Plateau permafrost. We find that soil Hg (0) concentrations exhibited a strongly positive and exponential relationship with temperature and showed different temperature sensitivity under the frozen and unfrozen condition. We conservatively estimate that temperature increases following latest temperature scenarios of the IPCC could result in up to a 54.9% increase in Hg (0) concentrations in surface permafrost soils by 2100. Combining the simultaneous measurement of air-soil Hg (0) exchange, we find that enhanced Hg (0) concentrations in upper soils could favor Hg (0) emissions from surface soil. Our findings indicate that Hg (0) emission could be stimulated by permafrost thawing in a warmer world.
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Affiliation(s)
- Zhijia Ci
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Fei Peng
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xian Xue
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xiaoshan Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
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39
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Zhou C, Cohen MD, Crimmins BA, Zhou H, Johnson TA, Hopke PK, Holsen TM. Mercury Temporal Trends in Top Predator Fish of the Laurentian Great Lakes from 2004 to 2015: Are Concentrations Still Decreasing? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7386-7394. [PMID: 28578575 DOI: 10.1021/acs.est.7b00982] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mercury (Hg) concentration trends in top predator fish (lake trout and walleye) of the Great Lakes (GL) from 2004 to 2015 were determined by Kendall-Theil robust regression with a cluster-based age normalization method to control for the effect of changes in lake trophic status. When data from the GLs (except Lake Erie) are combined, a significant decreasing trend in the lake trout Hg concentrations was found between 2004 and 2015 with an annual decrease of 4.1% per year, consistent with the decline in regional atmospheric Hg emissions and water Hg concentrations. However, a breakpoint was detected with a significant decreasing slope (-8.1% per year) before the breakpoint (2010), and no trend after the breakpoint. When the lakes are examined individually, Lakes Superior and Huron, which are dominated by atmospheric Hg inputs and are more likely than the lower lakes to respond to declining emissions from areas surrounding the GL, have significant decreasing trends with rates between 5.2 and 7.8% per year from 2004 to 2015. These declining trends appear to be driven by decreasing regional atmospheric Hg emissions although they may be partly counterbalanced by other factors, including increasing local emissions, food web changes, eutrophication, and responses to global climate change. Lakes Michigan, Erie and Ontario may have been more impacted by these other factors and their trends changed from decreasing to non-decreasing or increasing in recent years.
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Affiliation(s)
- Chuanlong Zhou
- Department of Civil and Environmental Engineering, Clarkson University , Potsdam, New York 13676, United States
| | - Mark D Cohen
- Air Resources Laboratory, United States National Oceanic and Atmospheric Administration , College Park, Maryland 20740, United States
| | - Bernard A Crimmins
- Department of Civil and Environmental Engineering, Clarkson University , Potsdam, New York 13676, United States
| | - Hao Zhou
- Institute for a Sustainable Environment, Clarkson University , Potsdam, New York 13676, United States
| | - Timothy A Johnson
- Institute for a Sustainable Environment, Clarkson University , Potsdam, New York 13676, United States
| | - Philip K Hopke
- Institute for a Sustainable Environment, Clarkson University , Potsdam, New York 13676, United States
| | - Thomas M Holsen
- Department of Civil and Environmental Engineering, Clarkson University , Potsdam, New York 13676, United States
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40
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Paranjape AR, Hall BD. Recent advances in the study of mercury methylation in aquatic systems. Facets (Ott) 2017. [DOI: 10.1139/facets-2016-0027] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
With increasing input of neurotoxic mercury to environments as a result of anthropogenic activity, it has become imperative to examine how mercury may enter biotic systems through its methylation to bioavailable forms in aquatic environments. Recent development of stable isotope-based methods in methylation studies has enabled a better understanding of the factors controlling methylation in aquatic systems. In addition, the identification and tracking of the hgcAB gene cluster, which is necessary for methylation, has broadened the range of known methylators and methylation-conducive environments. Study of abiotic factors in methylation with new molecular methods (the use of stable isotopes and genomic methods) has helped elucidate the confounding influences of many environmental factors, as these methods enable the examination of their direct effects instead of merely correlative observations. Such developments will be helpful in the finer characterization of mercury biogeochemical cycles, which will enable better predictions of the potential effects of climate change on mercury methylation in aquatic systems and, by extension, the threat this may pose to biota.
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Affiliation(s)
- Avnee R. Paranjape
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Britt D. Hall
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
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41
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Liu YR, Dong JX, Zhang QG, Wang JT, Han LL, Zeng J, He JZ. Longitudinal occurrence of methylmercury in terrestrial ecosystems of the Tibetan Plateau. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 218:1342-1349. [PMID: 27613323 DOI: 10.1016/j.envpol.2016.08.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
Methylmercury (MeHg), a neurotoxin, is a global concern because of its potential risk to human and ecological health. Elevated mercury (Hg) concentrations were recently reported in the Tibetan Plateau (TP) due to increasing Hg input from distant regions, yet little is known about MeHg production and distribution in the terrestrial ecosystems of the TP. Here, we report longitudinal occurrence of MeHg and the factors regulating net MeHg production in 23 grassland sites from eastern to western TP. The soil MeHg content varied from 0.002 to 0.058 ng g-1, with different distribution patterns between the eastern and western TP. There was a positive correlation between the MeHg concentration and the longitude after 90 °E, which is similar to the distribution patterns of the total mercury (THg), water and organic carbon in this region. Average MeHg concentration in topsoil is generally higher than that in subsoil. Our results show that MeHg concentration in soils of the TP is directly affected by soil water, potential microbial methylators and THg, while indirectly regulated by soil organic carbon through the microbial community and the longitude-dependent precipitation through soil water. Our study suggests that soil water is the most important driver regulating net MeHg production in the grasslands of the TP. These findings have important implications for unraveling the mechanism of net production of MeHg in high-altitude environments.
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Affiliation(s)
- Yu-Rong Liu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Ji-Xin Dong
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qiang-Gong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Jun-Tao Wang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Li-Li Han
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jun Zeng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ji-Zheng He
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville 3010, Victoria, Australia
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