1
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Bento B, Hintelmann H. Assessment of mercury methylation and methylmercury demethylation potentials in water and sediments along the Wabigoon River system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175658. [PMID: 39168343 DOI: 10.1016/j.scitotenv.2024.175658] [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: 05/05/2024] [Revised: 08/15/2024] [Accepted: 08/18/2024] [Indexed: 08/23/2024]
Abstract
Monomethylmercury (MMHg) plays a crucial role in the accumulation of mercury (Hg) within aquatic food chains. Since ambient levels of methylmercury are governed by the balance of simultaneous methylation and demethylation processes, determining in situ methylation and demethylation rates is critically important to understand the dynamics of methylmercury in the environment. This is especially important in the Wabigoon River system in Ontario, Canada, which is severely contaminated with Hg by a chlor-alkali facility operating in the 1960s, and still exhibits some of the highest recorded fish mercury concentrations in Canada. This work used a simultaneous addition of isotope enriched Hg and MMHg tracers to ascertain Hg methylation and MMHg demethylation potentials. At the locations investigated for this study, the most favourable conditions for Hg methylation were found at the Hydroelectric dam, being able to transform 4.2 % and 4.4 % of added Hg in water and sediments per day, respectively, to MMHg. This could correspond to 1.9 ng/L and 29 ng/g of new MMHg being produced from current ambient Hg. Clay Lake, which is considered a sink for mercury and exhibiting a seasonal anoxic environment at its bottom waters, also demonstrated significant MMHg generation, being able to produce 2.7 ng/L and 13 ng/g of MMHg per day, respectively. Demethylation rates in sediments of riverbed and wetland locations showed an average half-life for methylmercury of 2.1 days, indicating a rapid turnover of MMHg in the Wabigoon River. However, significantly lower demethylation rates were also measured near the inflow of Clay Lake, where it took up to 144 days for MMHg to decrease by 50 %. Generally, most of the investigated locations downstream of the pollution source displayed the potential to generate methylmercury, which could be distributed throughout the Wabigoon River system and therefore require attention with respect to future remediation activities.
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Affiliation(s)
- Beatriz Bento
- Environmental and Life Sciences, Trent University, Peterborough, ON, Canada.
| | - Holger Hintelmann
- Department of Chemistry, Trent University, Peterborough, ON, Canada; Water Quality Centre, Trent University, Peterborough, ON, Canada.
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2
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Aqdam MM, Baltzer JL, Branfireun BA, Low G, Low M, Swanson HK. Can remotely sensed catchment to lake area ratios predict mercury levels in subarctic fishes? ENVIRONMENTAL RESEARCH 2024; 260:119545. [PMID: 38986798 DOI: 10.1016/j.envres.2024.119545] [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: 05/14/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/12/2024]
Abstract
Mercury concentrations ([Hg]) in fish reflect a complex array of interacting biogeochemical and ecological variables. In northern regions where fish are a critical subsistence food, understanding and predicting fish [Hg] can be particularly difficult, largely due to a paucity of comprehensive data associated with the logistical challenges of field sampling. Building on previous work where we elucidated causal relationships between fish [Hg] and a variety of catchment, water quality, and ecological variables in subarctic lakes, we investigated whether using only ratios of catchment area to lake area (CA:LA) can predict [Hg] in northern freshwater fish species. As CA:LA can be sensed remotely, they may be more feasible and practical to obtain than field data in far northern regions. Our study included thirteen remote lakes that represent a CA:LA gradient of 6.2-423.5 within an ∼66,000 km2 subarctic region of Northwest Territories, Canada. We found that size-standardized [Hg] in three widespread fish species, including Lake Whitefish (Coregonus clupeaformis), Walleye (Sander vitreus), and Northern Pike (Esox lucius), were significantly and positively related to CA:LA (p < 0.007, r2 = 67-80%), indicating higher fish [Hg] in smaller lakes surrounded by relatively larger catchments. Our findings provide compelling evidence that remotely sensed CA:LA can be used to predict [Hg] in northern fishes and aid in prioritizing understudied and subsistence fishing lakes of the Canadian subarctic for [Hg] monitoring programs.
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Affiliation(s)
- Mehdi M Aqdam
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada; Azimuth Consulting Group Inc., Vancouver, BC, Canada.
| | | | | | - George Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Mike Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Heidi K Swanson
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada.
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3
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Wang J, Zhang Y, Zhou L, Gao Y, Li K, Sun S. Multiple effects of carbon, sulfur and iron on microbial mercury methylation in black-odorous sediments. ENVIRONMENTAL RESEARCH 2024; 263:120048. [PMID: 39313174 DOI: 10.1016/j.envres.2024.120048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 09/06/2024] [Accepted: 09/20/2024] [Indexed: 09/25/2024]
Abstract
Black-odorous sediments provide ideal conditions for microbial mercury methylation. However, the multiple effects of carbon, sulfur, and iron on the microbial methylmercury of mercury in black-odorous sediments remains unclear. In this study, we conducted mercury methylation experiments using sediments collected from organically contaminated water bodies, as well as black-odorous sediments simulated in the laboratory. The results showed that black-odorous sediments exhibit a high capacity for mercury methylation. By simulating the blackening and odorization process in sediments, it was confirmed that dissolved oxygen, organic matter and sulfide were the primary factors triggering the black-odorous phenomenon in sediments. Regarding the influence of key factors in sediments on methylmercury formation, the batch tests demonstrated that high concentrations of organics additions (above 200 mg/L) may reduce bacterial activity and weaken mercury methylation in sediments. Under five different iron-sulfur ratios, the concentrations of methylmercury in the black-odorous sediments showed an increasing trend, the ratio of 5.0 Fe/S exhibited the highest MeHg accumulation. The iron-sulfur ratio in the sediment had a significant effect on the mercury methylation process, which was mainly due to the competition between Fe2+ and Hg2+ for sulfide sites and the adsorption/coprecipitation of Hg2+ by FeS. These findings offer a potential avenue for further understanding and controlling mercury methylation, contributing to the mitigation of the potential threat of mercury pollution to the environment and human health.
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Affiliation(s)
- Jinting Wang
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China.
| | - Yan Zhang
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China
| | - Lean Zhou
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China
| | - Yang Gao
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China
| | - Kai Li
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China
| | - Shiquan Sun
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, China; Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, China.
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4
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Aslam MW, Meng B, Ali W, Abrar MM, Abdelhafiz MA, Feng X. Low mercury risks in paddy soils across the Pakistan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 943:173879. [PMID: 38857798 DOI: 10.1016/j.scitotenv.2024.173879] [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: 03/28/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
Mercury (Hg) is a globally distributed heavy metal. Here, we study Hg concentration and isotopic composition to understand the status of Hg pollution and its sources in Pakistan's paddy soil. The collected paddy soils (n = 500) across the country have an average THg concentration of 22.30 ± 21.74 ng/g. This low mean concentration suggests Hg pollution in Pakistan was not as severe as previously thought. Meanwhile, samples collected near brick kilns and industrial areas were significantly higher in THg than others, suggesting the influence of Hg emitted from point sources in certain areas. Soil physicochemical properties showed typical characteristic of mineral soils due to the study area's arid to semi-arid climate. Hg stable isotopes analysis, depicted mean Δ199Hg of -0.05 ± 0.12‰ and mean δ202Hg -0.45 ± 0.35‰, respectively, for contaminated sites, depicting Hg was primarily sourced from coal combustion by local anthropogenic sources. While uncontaminated sites show mean Δ199Hg of 0.15 ± 0.08‰, mean Δ200Hg of 0.06 ± 0.07‰ and mean δ202Hg of -0.32 ± 0.28‰, implying long-range transboundry Hg transport through wet Hg(II) deposition as a dominant Hg source. This study fills a significant knowledge gap regarding the Hg pollution status in Pakistan and suggests that the Hg risk in Pakistan paddies is generally low.
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Affiliation(s)
- Muhammad Wajahat Aslam
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China.
| | - Waqar Ali
- Department of Ecological Sciences and Engineering, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Muhammad Mohsin Abrar
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, 510225 Guangzhou, China; Engineering and Technology Research Center for Agricultural Land Pollution and Integrated Prevention, Guangzhou, China
| | - Mahmoud A Abdelhafiz
- Geology Department, Faculty of Science, Al-Azhar University, Assiut 71524, Egypt
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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5
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Zhu S, Yang P, Yin Y, Zhang S, Lv J, Tian S, Jiang T, Wang D. Influences of wildfire on the soil dissolved organic matter characteristics and its electron-donating capacity. WATER RESEARCH 2024; 266:122382. [PMID: 39298894 DOI: 10.1016/j.watres.2024.122382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 08/24/2024] [Accepted: 09/02/2024] [Indexed: 09/22/2024]
Abstract
Global increases in the intensity and frequency of wildfires are driving major changes in soil organic matter (SOM) characteristics, including soil dissolved organic matter (DOM). As the most crucial component of SOM, soil DOM plays a pivotal role in the carbon cycle and regulates the environmental fate of contaminants through its versatile reactivities, including electron-donating capacity (EDC). However, it is still being determined how wildfire influences key characteristics of soil DOM and subsequent effects on EDC in forest soils. Thus, we conducted our study to fill this gap with the forest soils of Jinyun Mountain Nature Reserve of China, which experienced an unprecedented wildfire event in 2022. The results from optical characterization, high-performance size-exclusion chromatography (HPSEC), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) showed decreasing molecular weight but elevating nitrogen-containing molecular formulas of soil DOM in the burned soils. This could be attributed to the Maillard reaction and microbial re-colonies. Additionally, wildfires increased the condensed aromatics and lignin components in soil DOM. In the burned soils, we observed increasing EDC of soil DOM, which accounts for an increase in lignin-derived phenolic components. Overall, the findings of this study demonstrate that eco-disturbances, such as wildfires, induce alterations in the properties of DOM, leading to variations in its reactivity and potentially influencing the fate of environmental pollutants beyond carbon dynamics alone. Thus, incorporating the dynamic properties of soil DOM, particularly in the context of climate change, can enhance the assessment of risks associated with contaminants in soil and water, providing valuable insights.
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Affiliation(s)
- Sihua Zhu
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Peijie Yang
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yongguang Yin
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; 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
| | - Siqi Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Jitao Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Shanyi Tian
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, 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, College of Resources and Environment, Southwest University, Chongqing 400716, China
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6
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Rosati G, Solidoro C, Laurent C, Alcázar LA, Umgiesser G, Canu D. Mercury cycling in contaminated coastal environments: modeling the benthic-pelagic coupling and microbial resistance in the Venice Lagoon. WATER RESEARCH 2024; 261:121965. [PMID: 38964216 DOI: 10.1016/j.watres.2024.121965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 07/06/2024]
Abstract
Anthropogenic activities have been releasing mercury for centuries, and despite global efforts to control emissions, concentrations in environmental media remain high. Coastal sediments can be a long-term repository for mercury, but also a secondary source, and competing processes in marine ecosystems can lead to the conversion of mercury into the toxic and bioaccumulative species methylmercury, which threatens ecosystem and human health. We investigate the fate and transport of three mercury species in a coastal lagoon affected by historical pollution using a novel high-resolution finite element model that integrates mercury biogeochemistry, sediment dynamics and hydrodynamics. The model resolves mercury dynamics in the seawater and the seabed taking into account partitioning, transport driven by water and sediment, and photochemical and microbial transformations. We simulated three years (early 2000s, 2019, and 2020) to assess the spatio-temporal distribution of mercury species concentrations and performed a sensitivity analysis to account for uncertainties. The modeled mercury species concentrations show high temporal and spatial variability, with water concentrations in some areas of the lagoon exceeding those of the open Mediterranean Sea by two orders of magnitude, consistent with available observations from the early 2000s. The results support conclusions about the importance of different processes in shaping the environmental gradients of mercury species. Due to the past accumulation of mercury in the lagoon sediments, inorganic mercury in the water is closely related to the resuspension of contaminated sediments, which is significantly reduced by the presence of benthic vegetation. The gradients of methylmercury depend on the combination of several factors, of which sediment resuspension and mercury methylation are the most relevant. The results add insights into mercury dynamics at coastal sites characterized by a combination of past pollution (i.e. sediment enrichment) and erosive processes, and suggest possible nature-based mitigation strategies such as the preservation of the integrity of benthic vegetation and morphology.
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Affiliation(s)
- Ginevra Rosati
- National Institute of Oceanography and Applied Geophysics - OGS, Trieste, 34010, Italy.
| | - Cosimo Solidoro
- National Institute of Oceanography and Applied Geophysics - OGS, Trieste, 34010, Italy; International Centre for Theoretical Physic, ICTP, Trieste, 34010, Italy
| | - Célia Laurent
- National Institute of Oceanography and Applied Geophysics - OGS, Trieste, 34010, Italy
| | | | | | - Donata Canu
- National Institute of Oceanography and Applied Geophysics - OGS, Trieste, 34010, Italy
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7
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Tang Y, Liu Y, He Y, Zhang J, Guo H, Liu W. Quantifying the impact of anthropogenic emissions and aquatic environmental impacts on sedimentary mercury variations in a typical urban river. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 355:124185. [PMID: 38782160 DOI: 10.1016/j.envpol.2024.124185] [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: 01/25/2024] [Revised: 04/20/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024]
Abstract
In urban and industrial regions, sedimentary mercury (Hg) serves as the crucial indicator for Hg pollution, posing potential risks to ecology and human health. The physicochemical processes of Hg in aquatic environments are influenced by various factors such as anthropogenic emissions and aquatic environmental impacts, making it challenging to quantify the drivers of total mercury (THg) variations. Here, we analyzed the spatiotemporal variations, quantified driving factors, and assessed accumulation risks of sedimentary THg from the mainstream of a typical urban river (Haihe River). THg in the urban region (37-3237 ng g-1) was significantly higher (t-test, p < 0.01) than in suburban (71-2317 ng g-1) and developing regions (156-916 ng g-1). The sedimentary THg in suburban and developing regions increased from 2003 to 2018, indicating the elevated atmospheric deposition of Hg. Together with the temperature, grain size of sediments, total organic carbon (TOC), the pH and salinity of water, 40 components of parent and substituted polycyclic aromatic hydrocarbons (PAHs) were first introduced to quantify the driver of sedimentary THg based on generalized additive model. Results showed that anthropogenic emissions, including three PAHs components (31%) and TOC (63%), accounted for 94% of sedimentary THg variations. The aquatic environmental impacts accounted for 5% of sedimentary THg variations. The geo-accumulation index of THg indicated moderate to heavy accumulation in the urban region. This study demonstrates that homologous pollutants such as PAHs can be used to trace sources and variations of Hg pollution, supporting their co-regulation as international conventions regulate pollutants.
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Affiliation(s)
- Yi Tang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing, 100012, China
| | - Yang Liu
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, Beijing, 100083, China; Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Science, Peking University, Beijing, 100871, China.
| | - Yong He
- Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Science, Peking University, Beijing, 100871, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Jiaodi Zhang
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Huaming Guo
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Beijing, Beijing, 100083, China
| | - Wenxin Liu
- Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Science, Peking University, Beijing, 100871, China
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8
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Sanz-Sáez I, Bravo AG, Ferri M, Carreras JM, Sánchez O, Sebastian M, Ruiz-González C, Capo E, Duarte CM, Gasol JM, Sánchez P, Acinas SG. Microorganisms Involved in Methylmercury Demethylation and Mercury Reduction are Widely Distributed and Active in the Bathypelagic Deep Ocean Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:13795-13807. [PMID: 39046290 PMCID: PMC11308531 DOI: 10.1021/acs.est.4c00663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/25/2024]
Abstract
The ocean's mercury (Hg) content has tripled due to anthropogenic activities, and although the dark ocean (>200 m) has become an important Hg reservoir, concentrations of the toxic and bioaccumulative methylmercury (MeHg) are low and therefore very difficult to measure. As a consequence, the current understanding of the Hg cycle in the deep ocean is severely data-limited, and the factors controlling MeHg, as well as its transformation rates, remain largely unknown. By analyzing 52 globally distributed bathypelagic deep-ocean metagenomes and 26 new metatranscriptomes from the Malaspina Expedition, our study reveals the widespread distribution and expression of bacterial-coding genes merA and merB in the global bathypelagic ocean (∼4000 m depth). These genes, associated with HgII reduction and MeHg demethylation, respectively, are particularly prevalent within the particle-attached fraction. Moreover, our results indicate that water mass age and the organic matter composition shaped the structure of the communities harboring merA and merB genes living in different particle size fractions, their abundance, and their expression levels. Members of the orders Corynebacteriales, Rhodobacterales, Alteromonadales, Oceanospirillales, Moraxellales, and Flavobacteriales were the main taxonomic players containing merA and merB genes in the deep ocean. These findings, together with our previous results of pure culture isolates of the deep bathypelagic ocean possessing the metabolic capacity to degrade MeHg, indicated that both methylmercury demethylation and HgII reduction likely occur in the global dark ocean, the largest biome in the biosphere.
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Affiliation(s)
- Isabel Sanz-Sáez
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Andrea G. Bravo
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Marta Ferri
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Joan-Martí Carreras
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Olga Sánchez
- Departament
de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Marta Sebastian
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Clara Ruiz-González
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Eric Capo
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Carlos M. Duarte
- Red
Sea Research Center, Division of Biological and Environmental Sciences
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900,Saudi Arabia
| | - Josep M. Gasol
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Pablo Sánchez
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
| | - Silvia G. Acinas
- Departament
de Biologia Marina i Oceanografia, Institut
de Ciències del Mar, ICM-CSIC, 08003 Barcelona, Catalunya, Spain
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9
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Wang Y, Xu T, Song E, Jiang Y, Wang F, Gu C, Ju X, Bian Y, Song Y, Kengara FO, Jiang X. Ultrasensitive detection of trace Hg(Ⅱ) in acidic conditions using DMABR loaded on sepiolite: Function, application and mechanism studies. JOURNAL OF HAZARDOUS MATERIALS 2024; 474:134734. [PMID: 38850937 DOI: 10.1016/j.jhazmat.2024.134734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/14/2024] [Accepted: 05/23/2024] [Indexed: 06/10/2024]
Abstract
Fast and real-time detection of trace Hg(Ⅱ) by fluorescent probes under acidic conditions is urgently required due to the high toxicity and accessibility to creatures and human being. However, fluorescent probes for Hg(Ⅱ) detection in environmental samples are rarely reported due to the protonation potential of acidic mercury sources. In this study, the SD probe was developed by 5-(p-dimethylaminobenzylidene) rhodanine (DMABR) loaded on sepiolite by hydrothermal treatment, and showed excellent Hg(Ⅱ) detection performances for mercury sources at pH 4-10 due to buffering ability of the hyperconjugated lactam rings. Sepiolite functioned as the support skeleton to decrease intermolecular transition, and thus increased the sensitivity. At pH 4, the SD probe showed high selectivity and sensitivity for Hg(Ⅱ) among various species, with low LOD and binding constant of 4.78 × 10-9 M and 1.34 × 106 M-1, respectively. Through DFT calculations, MAS 1H NMR and 2D-COS analysis, the detection mechanism was demonstrated as SN1 substitution of the spontaneous leaving H on amino groups in the transient state during tautomeric equilibrium, rather than the expected high-affinity sulphydryl. Additionally, the SD probe exhibited promising potential in quantifying water-soluble and bioavailable Hg(Ⅱ) in acidic polluted soil and water samples. Moreover, real-time detection was realized by paper-based strips.
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Affiliation(s)
- Yuncheng Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tingyuan Xu
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA
| | - En Song
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangzhao Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenggang Gu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuehai Ju
- Key Laboratory of Soft Chemistry and Functional Materials of MOE, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yongrong Bian
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yang Song
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | | | - Xin Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China; University of Chinese Academy of Sciences, Beijing 100049, China
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10
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Boie F, Ducey TF, Xing Y, Wang J, Rinklebe J. Field-aged rice hull biochar stimulated the methylation of mercury and altered the microbial community in a paddy soil under controlled redox condition changes. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134446. [PMID: 38696958 DOI: 10.1016/j.jhazmat.2024.134446] [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: 02/05/2024] [Revised: 03/25/2024] [Accepted: 04/25/2024] [Indexed: 05/04/2024]
Abstract
Mercury (Hg) contaminated paddy soils are hot spots for methylmercury (MeHg) which can enter the food chain via rice plants causing high risks for human health. Biochar can immobilize Hg and reduce plant uptake of MeHg. However, the effects of biochar on the microbial community and Hg (de)methylation under dynamic redox conditions in paddy soils are unclear. Therefore, we determined the microbial community in an Hg contaminated paddy soil non-treated and treated with rice hull biochar under controlled redox conditions (< 0 mV to 600 mV) using a biogeochemical microcosm system. Hg methylation exceeded demethylation in the biochar-treated soil. The aromatic hydrocarbon degraders Phenylobacterium and Novosphingobium provided electron donors stimulating Hg methylation. MeHg demethylation exceeded methylation in the non-treated soil and was associated with lower available organic matter. Actinobacteria were involved in MeHg demethylation and interlinked with nitrifying bacteria and nitrogen-fixing genus Hyphomicrobium. Microbial assemblages seem more important than single species in Hg transformation. For future directions, the demethylation potential of Hyphomicrobium assemblages and other nitrogen-fixing bacteria should be elucidated. Additionally, different organic matter inputs on paddy soils under constant and dynamic redox conditions could unravel the relationship between Hg (de)methylation, microbial carbon utilization and nitrogen cycling.
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Affiliation(s)
- Felizitas Boie
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Thomas F Ducey
- US Department of Agriculture, Coastal Plains Soil, Water, Plant Research Center, 2611 West Lucas Street, Florence, SC, USA
| | - Ying Xing
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550002, PR China
| | - Jianxu Wang
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550082 Guiyang, P.R. China
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
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11
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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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12
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Wang Y, Zhang L, Chen X, Li C, Ding S, Yan J, Xiao J, Wang B, Xu L, Hang X. Algal-derived dissolved organic matter accelerates mercury methylation under cyanobacterial blooms in the sediment of eutrophic lakes. ENVIRONMENTAL RESEARCH 2024; 251:118734. [PMID: 38493854 DOI: 10.1016/j.envres.2024.118734] [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: 01/01/2024] [Revised: 02/17/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Mercury (Hg), especially in the form of methylmercury (MeHg), poses a significant threat to both organisms and the environment due to its extreme toxicity. While methylation process of Hg in sediments has been extensively studied, recognition of its associated risks and mechanisms during cyanobacterial blooms remains limited. This study investigated the distribution characteristics of Hg and MeHg in sediments of Taihu Lake, China. The concentration of Hg and MeHg varied within the range of 96.0-212.0 ng g-1 and 0.1-0.5 ng g-1, respectively. Higher ecological risks of Hg were found in algal-dominated regions compared to macrophyte areas. The significant correlations observed between Hg, MeHg, and algal-derived dissolved organic matter (ADOM) components C1 and C2 in algal-dominated regions indicate a close association between ADOM components and the Hg methylation process. These components are involved in the absorption or complexation of Hg, participate in redox reactions, and modulate microbial activity. The dsrB gene in sulfate-reducing bacteria (SRB) was found to accelerate the metabolic pathways of Hg methylation. These findings indicate that ADOM could enhance the methylation process of Hg during cyanobacterial blooms, which warrants attention.
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Affiliation(s)
- Yan Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Lan Zhang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Xiang Chen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Cai Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jiabao Yan
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Jing Xiao
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Bin Wang
- Zhongyifeng Construction Group Co., Ltd., Suzhou, 215131, China
| | - Lv Xu
- Anhui Urban Construction Design Institute Corp., Ltd, Hefei, 230051, China
| | - Xiaoshuai Hang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China.
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13
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Lawruk-Desjardins C, Storck V, Ponton DE, Amyot M, Walsh DA. A genome catalogue of mercury-methylating bacteria and archaea from sediments of a boreal river facing human disturbances. Environ Microbiol 2024; 26:e16669. [PMID: 38922750 DOI: 10.1111/1462-2920.16669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Methyl mercury, a toxic compound, is produced by anaerobic microbes and magnifies in aquatic food webs, affecting the health of animals and humans. The exploration of mercury methylators based on genomes is still limited, especially in the context of river ecosystems. To address this knowledge gap, we developed a genome catalogue of potential mercury-methylating microorganisms. This was based on the presence of hgcAB from the sediments of a river affected by two run-of-river hydroelectric dams, logging activities and a wildfire. Through the use of genome-resolved metagenomics, we discovered a unique and diverse group of mercury methylators. These were dominated by members of the metabolically versatile Bacteroidota and were particularly rich in microbes that ferment butyrate. By comparing the diversity and abundance of mercury methylators between sites subjected to different disturbances, we found that ongoing disturbances, such as the input of organic matter related to logging activities, were particularly conducive to the establishment of a mercury-methylating niche. Finally, to gain a deeper understanding of the environmental factors that shape the diversity of mercury methylators, we compared the mercury-methylating genome catalogue with the broader microbial community. The results suggest that mercury methylators respond to environmental conditions in a manner similar to the overall microbial community. Therefore, it is crucial to interpret the diversity and abundance of mercury methylators within their specific ecological context.
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Affiliation(s)
| | - Veronika Storck
- Department of Biology, Concordia University, Montreal, Quebec, Canada
- Département de sciences biologiques, Université de Montréal, Montreal, Quebec, Canada
| | - Dominic E Ponton
- Département de sciences biologiques, Université de Montréal, Montreal, Quebec, Canada
| | - Marc Amyot
- Département de sciences biologiques, Université de Montréal, Montreal, Quebec, Canada
| | - David A Walsh
- Department of Biology, Concordia University, Montreal, Quebec, Canada
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14
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Pilote M, Houle D, Gagnon C, Couture S, Dastoor A, Ryjkov A. Key factors influencing Hg levels and trends in unperturbed oligotrophic temperate and boreal lakes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 356:124232. [PMID: 38823549 DOI: 10.1016/j.envpol.2024.124232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/15/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024]
Abstract
Mercury (Hg) is a toxic metal that presents a major risk to ecosystems, biota, human health, and remains a priority concern. In temperate and boreal lakes Hg and methylmercury (MMHg) are expected to vary as a function of atmospheric Hg deposition, lake water chemistry, catchment characteristics and climate variables. The aim of this study was to quantify Hg and MMHg in unperturbed oligotrophic lakes and to identify the factors controlling their distribution. We first hypothesized that lake Hg (and MMHg to lesser extent) spatial variations are linked to atmospheric deposition, catchment characteristics, and terrestrial exportation of dissolved organic carbon (DOC). We secondly examined if lake Hg concentrations have followed the decrease in atmospheric Hg emission observed between the mid-1990s to the end-2010s. We found that overall, atmospheric Hg has little impact on lake Hg and MMHg concentrations, which are both primarily influenced by DOC input originating from the forest catchment. The relationship between DOC and Hg differed between the spring and the fall, with a Hg-to-DOC ratio twice as high in spring. This seems related to snowmelt input of Hg (with a relatively reduced input of DOC) or the internal lake build-up of Hg during the ice-covered period. Of the 10 lakes intensively visited over a 20-year period, only 3 showed significant lake Hg decreases despite significant negative trends in atmospheric Hg concentrations, suggesting a lag between atmospheric and surface water temporal trends. Overall, terrestrial catchments retain around 80% of atmospheric Hg implying that large Hg pools have been built up in soils in the last decades. As such, the reduction of atmospheric Hg alone will not necessarily result in Hg decreases in lakes, since the Hg concentrations may be modulated by DOC export trends and catchment characteristics. This stresses the need to improve our understanding of the processes governing Hg transfers from catchments into lakes.
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Affiliation(s)
- M Pilote
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada.
| | - D Houle
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - C Gagnon
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - S Couture
- Environment and Climate Change Canada, Water Science and Technology, Aquatic Contaminants Research Division, 105 McGill Street, Montreal, Qc, H2Y 2E7, Canada
| | - A Dastoor
- Environment and Climate Change Canada, Atmospheric Science and Technology, Air Quality Research Division, 2121 route Transcanadienne, Dorval, Qc, H9P 1J3, Canada
| | - A Ryjkov
- Environment and Climate Change Canada, Atmospheric Science and Technology, Air Quality Research Division, 2121 route Transcanadienne, Dorval, Qc, H9P 1J3, Canada
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15
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Zheng Z, Hu J, He T, Liu C, Zhou X, Yin D. Suppression of mercury methylation in soil and methylmercury accumulation in rice by dissolved organic matter derived from sulfur-rich rape straw. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123657. [PMID: 38428787 DOI: 10.1016/j.envpol.2024.123657] [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: 11/28/2023] [Revised: 01/09/2024] [Accepted: 02/24/2024] [Indexed: 03/03/2024]
Abstract
Straw amendment significantly enhances mercury (Hg) methylation and subsequent methylmercury (MeHg) bioaccumulation in Hg-contaminated paddy fields by releasing dissolved organic matter (DOM). This study comprehensively investigates the regulatory mechanisms of DOM and its different molecular weights derived from sulfur-rich rape straw (RaDOM) and composted rape straw (CRaDOM) applied in the rice-filling stage on soil MeHg production and subsequent bioaccumulation in rice grains. The results indicated that the amendment of RaDOM and CRaDOM significantly reduced soil MeHg content by 42.40-62.42%. This reduction can be attributed to several factors, including the suppression of Hg-methylating bacteria in soil, the supply of sulfate from RaDOM and CRaDOM, and the increase in the humification, molecular weight, and humic-like fractions of soil DOM. Additionally, adding RaDOM increased the MeHg bioaccumulation factor in roots by 27.55% while inhibiting MeHg transportation by 12.24% and ultimately reducing MeHg content in grains by 21.24% compared to the control group. Similarly, CRaDOM enhanced MeHg accumulation by 25.19%, suppressed MeHg transportation by 39.65%, and reduced MeHg levels in the grains by 27.94%. The assimilation of sulfate derived from RaDOM and CRaDOM into glutathione may be responsible for the increased retention of MeHg in the roots. Over the three days, there was a significant decrease in soil MeHg content as the molecular weight of RaDOM increased; conversely, altering the molecular weight of CRaDOM demonstrated an inverse trend. However, this pattern was not observed after 12 days. Applying sulfur-rich rape DOM can help mitigate MeHg accumulation in paddy fields by regulating the quality of soil DOM, sulfur cycling, and Hg-methylating bacteria.
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Affiliation(s)
- Zhoujuan Zheng
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Jie Hu
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Tianrong He
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Chengbin Liu
- Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China
| | - Xian Zhou
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Deliang Yin
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China.
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16
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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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17
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Wu Z, Li Z, Shao B, Chen J, Cui X, Cui X, Liu X, Zhao YX, Pu Q, Liu J, He W, Liu Y, Liu Y, Wang X, Meng B, Tong Y. Differential response of Hg-methylating and MeHg-demethylating microbiomes to dissolved organic matter components in eutrophic lake water. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133298. [PMID: 38141310 DOI: 10.1016/j.jhazmat.2023.133298] [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: 09/14/2023] [Revised: 12/01/2023] [Accepted: 12/15/2023] [Indexed: 12/25/2023]
Abstract
Methylmercury (MeHg) production in aquatic ecosystems is a global concern because of its neurotoxic effect. Dissolved organic matter (DOM) plays a crucial role in biogeochemical cycling of Hg. However, owing to its complex composition, the effects of DOM on net MeHg production have not been fully understood. Here, the Hg isotope tracer technique combined with different DOM treatments was employed to explore the influences of DOM with divergent compositions on Hg methylation/demethylation and its microbial mechanisms in eutrophic lake waters. Our results showed that algae-derived DOM treatments enhanced MeHg concentrations by 1.42-1.53 times compared with terrestrial-derived DOM. Algae-derived DOM had largely increased the methylation rate constants by approximately 1-2 orders of magnitude compared to terrestrial-derived DOM, but its effects on demethylation rate constants were less pronounced, resulting in the enhancement of net MeHg formation. The abundance of hgcA and merB genes suggested that Hg-methylating and MeHg-demethylating microbiomes responded differently to DOM treatments. Specific DOM components (e.g., aromatic proteins and soluble microbial byproducts) were positively correlated with both methylation rate constants and the abundance of Hg-methylating microbiomes. Our results highlight that the DOM composition influences the Hg methylation and MeHg demethylation differently and should be incorporated into future Hg risk assessments in aquatic ecosystems.
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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
| | - Ji Chen
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Xiaomei Cui
- School of Ecology and Environment, Tibet University, Lhasa 850000, China
| | - Xiaoyu Cui
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Xianhua Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Ying Xin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Qiang Pu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Wei He
- School of Water Resource and Environment, China University of Geoscience (Beijing), Beijing 100083, China
| | - Yiwen Liu
- 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
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; School of Ecology and Environment, Tibet University, Lhasa 850000, China.
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18
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Peng X, Yang Y, Yang S, Li L, Song L. Recent advance of microbial mercury methylation in the environment. Appl Microbiol Biotechnol 2024; 108:235. [PMID: 38407657 PMCID: PMC10896945 DOI: 10.1007/s00253-023-12967-6] [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: 09/11/2023] [Revised: 12/02/2023] [Accepted: 12/13/2023] [Indexed: 02/27/2024]
Abstract
Methylmercury formation is mainly driven by microbial-mediated process. The mechanism of microbial mercury methylation has become a crucial research topic for understanding methylation in the environment. Pioneering studies of microbial mercury methylation are focusing on functional strain isolation, microbial community composition characterization, and mechanism elucidation in various environments. Therefore, the functional genes of microbial mercury methylation, global isolations of Hg methylation strains, and their methylation potential were systematically analyzed, and methylators in typical environments were extensively reviewed. The main drivers (key physicochemical factors and microbiota) of microbial mercury methylation were summarized and discussed. Though significant progress on the mechanism of the Hg microbial methylation has been explored in recent decade, it is still limited in several aspects, including (1) molecular biology techniques for identifying methylators; (2) characterization methods for mercury methylation potential; and (3) complex environmental properties (environmental factors, complex communities, etc.). Accordingly, strategies for studying the Hg microbial methylation mechanism were proposed. These strategies include the following: (1) the development of new molecular biology methods to characterize methylation potential; (2) treating the environment as a micro-ecosystem and studying them from a holistic perspective to clearly understand mercury methylation; (3) a more reasonable and sensitive inhibition test needs to be considered. KEY POINTS: • Global Hg microbial methylation is phylogenetically and functionally discussed. • The main drivers of microbial methylation are compared in various condition. • Future study of Hg microbial methylation is proposed.
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Affiliation(s)
- Xuya Peng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shapingba Street, Chongqing, 400045, China
| | - Yan Yang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shapingba Street, Chongqing, 400045, China
| | - Shu Yang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shapingba Street, Chongqing, 400045, China.
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
| | - Lei Li
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shapingba Street, Chongqing, 400045, China
| | - Liyan Song
- School of resources and environmental engineering, Anhui University, No 111 Jiulong Road, Economic and Technology Development Zone, Hefei, 230601, People's Republic of China.
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19
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Zhou Y, Li S, Hintelmann H, Tang W, Zhong H. New insights into HgSe antagonism: Minor impact on inorganic Hg mobility while potential impacts on microorganisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169705. [PMID: 38160847 DOI: 10.1016/j.scitotenv.2023.169705] [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: 10/27/2023] [Revised: 12/13/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
Selenium (Se) is a crucial antagonistic factor of mercury (Hg) methylation in soil, with the transformation of inorganic Hg (IHg) to inert mercury selenide (HgSe) being the key mechanism. However, little evidence has been provided of the reduced Hg mobility at environmentally relevant doses of Hg and Se, and the potential impacts of Se on the activities of microbial methylators have been largely ignored. This knowledge gap hinders effective mitigation for methylmercury (MeHg) risks, considering that Hg supply and microbial methylators serve as materials and workers for MeHg production in soils. By monitoring the mobility of IHg and microbial activities after Se spike, we reported that 1) active methylation might be the premise of HgSe antagonism, as higher decreases in MeHg net production were found in soils with higher constants of Hg methylation rate; 2) IHg mobility did not significantly change upon Se addition in soils with high DOC concentrations, challenging the long-held view of Hg immobilization by Se; and 3) the activities of iron-reducing bacteria (FeRB), an important group of microbial methylators, might be potentially regulated by Se addition at a dose of 4 mg/kg. These findings provide empirical evidence that IHg mobility may not be the limiting factor under Se amendment and suggest the potential impacts of Se on microbial activities.
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Affiliation(s)
- Yang Zhou
- School of the Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, China
| | - Shouying Li
- School of the Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, China
| | - Holger Hintelmann
- Department of Chemistry, Trent University, Peterborough, ON, Canada; Water Quality Centre, Trent University, Peterborough, ON, Canada
| | - Wenli Tang
- School of the Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, China.
| | - Huan Zhong
- School of the Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, China.
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20
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Kim J, Soerensen AL, Jeong H, Jeong S, Kim E, Lee YM, Jin YK, Rhee TS, Hong JK, Han S. Cross-shelf processes of terrigenous organic matter drive mercury speciation on the east siberian shelf in the Arctic Ocean. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123270. [PMID: 38163627 DOI: 10.1016/j.envpol.2023.123270] [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: 10/21/2023] [Revised: 12/15/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
The cross-shelf distributions of total mercury (THg), methylmercury (MeHg) and organic and inorganic matter, as well as the presence of the hgcA gene were investigated on the East Siberian Shelf (ESS) to understand the processes underlying the speciation of sedimentary Hg. Samples were collected from 12 stations grouped into four zones based on water depth: inner shelf (5 stations), mid-shelf (3 stations), outer shelf (2 stations), and slope (2 stations). The THg concentration in the surface sediment increased from the inner shelf (0.25 ± 0.023 nmol g-1) toward the slope (0.52 nmol g-1), and, when normalized to total organic carbon content, the THg showed a positive correlation with the clay-to-sand ratio (r2 = 0.48, p = 0.012) and degree of chemical weathering (r2 = 0.79, p = 0.0001). The highest MeHg concentrations (3.0 ± 1.8 pmol g-1), as well as peaks in the S/C ratio (0.012 ± 0.002) of sediment-leached organic matter, were found on the mid-shelf, suggesting that the activities of sulfate reducers control the net Hg(II) methylation rates in the sediment. This was supported by results from a principal component analysis (PCA) performed with Hg species concentrations and sediment-leached organic matter compositions. The site-specific variation in MeHg showed the highest similarity with that of CHONS compounds in the PCA, where Deltaproteobacteria were projected to be putative Hg(II) methylators in the gene analysis. In summary, the hydrodynamic sorting of lithogenic particles appears to govern the cross-shelf distribution of THg, and in situ methylation is considered a major source of MeHg in the ESS sediment.
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Affiliation(s)
- Jihee Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Anne L Soerensen
- Department of Environmental Research and Monitoring, Swedish Museum of Natural History, Stockholm, Sweden
| | - Hakwon Jeong
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Seorin Jeong
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Eunsuk Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Yung Mi Lee
- Korea Polar Research Institute, Incheon, Republic of Korea
| | - Young Keun Jin
- Korea Polar Research Institute, Incheon, Republic of Korea
| | - Tae Siek Rhee
- Korea Polar Research Institute, Incheon, Republic of Korea
| | - Jong Kuk Hong
- Korea Polar Research Institute, Incheon, Republic of Korea
| | - Seunghee Han
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
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21
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Huang H, Mackereth RW, Mitchell CPJ. Impacts of forest harvesting on mercury concentrations and methylmercury production in boreal forest soils and stream sediment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:122966. [PMID: 37981183 DOI: 10.1016/j.envpol.2023.122966] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023]
Abstract
Methylmercury (MeHg) is the most neurotoxic and bioaccumulative form of mercury (Hg) present in the terrestrial and aquatic food sources of boreal ecosystems, posing potential risks to wildlife and human health. Harvesting impacts on Hg methylation and MeHg concentrations in forest soils and stream sediment are not fully understood. In this study, a field investigation was carried out in 4 harvested and 2 unharvested boreal forest watersheds, before and after harvest, to better understand impacts on Hg methylation and MeHg concentration in soils and stream sediment, including their responses to different forest management practices. Changes in total Hg (THg) and MeHg concentrations, first-order potential rate constants for Hg methylation and MeHg demethylation (Kmeth and Kdemeth) as well as total carbon content and carbon-to-nitrogen ratio post-harvest in upland, wetland and riparian soils and stream sediment were assessed and compared. Increases in MeHg production were minimal in upland, wetland or riparian soils after harvest. Sediment in streams with minor buffer protection (∼3 m), greater fractions (>75%) of harvested watershed area and more road construction had significantly increased THg and MeHg concentrations, %-MeHg, Kmeth and total carbon content post-harvest. From these patterns, we infer that inputs of carbon and inorganic Hg into harvest-impacted stream sediment are likely sourced from the harvested upland areas and stimulate in situ MeHg production in stream sediment. These findings indicate the importance of stream sediment as potential MeHg pools in harvested forest watersheds. The findings also demonstrate that forest management practices aiming to mitigate organic matter and Hg inputs to streams can effectively alleviate harvesting impacts on Hg methylation and MeHg concentrations in stream sediment.
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Affiliation(s)
- Haiyong Huang
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Robert W Mackereth
- Centre for Northern Forest Ecosystem Research, Ontario Ministry of Natural Resources and Forestry, Thunder Bay, ON, Canada
| | - Carl P J Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
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22
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Pan Y, Garg S, Fu QL, Peng J, Yang X, Waite TD. Copper Safeguards Dissolved Organic Matter from Sunlight-Driven Photooxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21178-21189. [PMID: 38064756 DOI: 10.1021/acs.est.3c07549] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Sunlight plays a crucial role in the transformation of dissolved organic matter (DOM) and the associated carbon cycle in aquatic environments. This study demonstrates that the presence of nanomolar concentrations of copper (Cu) significantly decreases the rate of photobleaching and the rate of loss of electron-donating moieties of three selected types of DOM (including both terrestrial and microbially derived DOM) under simulated sunlight irradiation. Employing Fourier transform ion cyclotron resonance mass spectrometry, we further confirm that Cu selectively inhibits the photooxidation of lignin- and tannin-like phenolic moieties present within the DOM, in agreement with the reported inhibitory impact of Cu on the photooxidation of phenolic compounds. On the basis of the inhibitory impact of Cu on the DOM photobleaching rate, we calculate the contribution of phenolic moieties to DOM photobleaching to be at least 29-55% in the wavelength range of 220-460 nm. The inhibition of loss of electrons from DOM during irradiation in the presence of Cu is also explained quantitatively by developing a mathematical model describing hydrogen peroxide (a proxy measure of loss of electrons from DOM) formation on DOM irradiation in the absence and presence of Cu. Overall, this study advances our understanding of DOM transformation in natural sunlit waters.
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Affiliation(s)
- Yanheng Pan
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Shikha Garg
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Qing-Long Fu
- School of Environmental Studies, China University of Geosciences, Wuhan 430078, China
| | - Jianglin Peng
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - T David Waite
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
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23
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Leclerc M, Ponton DE, Bilodeau F, Planas D, Amyot M. Enhanced Bioaccumulation and Transfer of Monomethylmercury through Periphytic Biofilms in Benthic Food Webs of a River Affected by Run-of-River Dams. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20792-20801. [PMID: 38016692 PMCID: PMC10720379 DOI: 10.1021/acs.est.3c05585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 11/03/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023]
Abstract
Run-of-river (ROR) power plants impound limited terrestrial areas compared to traditional hydropower plants with large reservoirs and are assumed to have reduced impacts on mercury cycling. We conducted a study on periphyton and benthic communities from different habitats of the St. Maurice River (Québec, Canada) affected by two ROR power plants and their effect on the bioaccumulation and biomagnification of monomethylmercury (MMHg). Proportion of total mercury as MMHg reached maximum values about 2.9 times higher in flooded sites compared to unflooded sites. Impoundment by ROR would therefore provide favorable environments for the growth of periphyton, which can produce and accumulate MMHg. Periphyton MMHg concentrations significantly explained concentrations in some benthic macroinvertebrates, reflecting a local transfer. Through the analysis of δ13C and δ15N signatures, we found that flooding, creating scattered lenthic habitats, led to modifications in trophic structures by the introduction of new organic matter sources. The computed trophic magnification slopes did not show significant differences in the transfer efficiency of MMHg between sectors, while intercepts of flooded sectors were higher. Increases in MMHg concentrations in flooded areas are likely due to the impoundment, combined with watershed disturbances, and the creation of small habitats favorable to periphyton should be included in future predictive models.
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Affiliation(s)
- Maxime Leclerc
- GRIL,
GEOTOP, Département de Sciences Biologiques, Université de Montréal, 1375 Thérèse-Lavoie-Roux Ave., Montréal, Québec H2V 0B3, Canada
| | - Dominic E. Ponton
- GRIL,
GEOTOP, Département de Sciences Biologiques, Université de Montréal, 1375 Thérèse-Lavoie-Roux Ave., Montréal, Québec H2V 0B3, Canada
| | - François Bilodeau
- Hydro-Québec,
Direction Environnement, 800 De Maisonneuve Est Blvd., Montréal, Québec H2Z 1A4, Canada
| | - Dolors Planas
- GRIL,
GEOTOP, Département de Sciences Biologiques, Université du Québec à Montréal, 141 Président-Kennedy Ave., Montréal, Québec H2X 1Y4, Canada
| | - Marc Amyot
- GRIL,
GEOTOP, Département de Sciences Biologiques, Université de Montréal, 1375 Thérèse-Lavoie-Roux Ave., Montréal, Québec H2V 0B3, Canada
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24
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Lei P, Zhu J, Zhang J, He H, Chen M, Zhong H. Algal organic matter inhibits methylmercury photodegradation in eutrophic lake water: A dynamic study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165661. [PMID: 37474073 DOI: 10.1016/j.scitotenv.2023.165661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
Algal organic matter (AOM) is a major component of dissolved organic matter (DOM) in eutrophic lakes and could impact the photodegradation of neurotoxic methylmercury (MeHg) in water. Predicting these effects, however, is challenging, largely due to the dynamic changes of AOM during algal decomposition. Here, we investigated the effects of AOM on MeHg photodegradation throughout the algal decomposition process and elucidated these effects by characterizing dynamic changes of AOM and exploring the respective roles of various reactive oxygen species (ROS). Our results reveal that AOM derived from algal decomposition significantly inhibits MeHg photodegradation, and the extent of this inhibition varies depending on the specific lakes (8-21 %, p < 0.05) and their eutrophication states (16-28 %, p < 0.05). The inhibitory effect gradually weakened as the decomposition progressed, which may be attributed to the dynamic changes in the quantity and quality of AOM. Moreover, hydroxyl radical (·OH) was found to be the main contributor in driving MeHg photodegradation (15-23 %) during the early stages of decomposition (day 0-3), while in the later stage (day 12-24), the role of singlet oxygen (1O2, 15-20 %) and (3DOM*, 21-30 %) gradually strengthened and these three ROS jointly drove MeHg photodegradation. Based on our findings and recent studies, we propose that AOM derived from algal decomposition plays a vital role in increasing the risk of MeHg in eutrophic lakes. It promotes MeHg formation while simultaneously inhibiting its photodegradation. Integrating AOM-MeHg interactions into Hg biogeochemical cycling models would reduce uncertainties when predicting MeHg risks.
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Affiliation(s)
- Pei Lei
- School of Environment, Nanjing Normal University, Nanjing 210023, China; State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Jinjie Zhu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing 210023, China; Suzhou Wuzhong Environmental Monitoring Station, Suzhou 215104, China
| | - Jin Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Mingying Chen
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing 210023, China; Environmental and Life Science Program (EnLS), Trent University, Peterborough, Ontario, Canada.
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25
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Ci Z, Tang X, Shen W, Chen B. Gaseous mercury exchange between air and highly dynamic tidal flats: A laboratory incubation experiment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 335:122383. [PMID: 37586689 DOI: 10.1016/j.envpol.2023.122383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/19/2023] [Accepted: 08/13/2023] [Indexed: 08/18/2023]
Abstract
Gaseous mercury (mainly elemental mercury, Hg(0)) exchange between air and Earth's surfaces is one of the most critical fluxes governing global Hg cycle. As an important and unique part of intertidal ecosystem, tidal flat is characterized by periodic inundation and exposure due to tidal cycle, generating varying hydrological, photochemical and biogeochemical processes. However, quantitative and mechanistic understanding of Hg(0) dynamics between air and exceptionally dynamic tide flats has remained limited to date. In this study, we select five representative tidal flat sediments from typical coastal habits of Chinese coastlines to perform laboratory incubation experiments for deciphering the effect of the interaction of tidal cycle and solar radiation on Hg(0) dynamics over tidal flats with different sediment compositions. We show that sediment Hg concentration, tidal cycle and solar radiation collectively modulate the air-surface Hg(0) exchange over tidal flats and highlight that the photochemistry dominates the Hg(0) production and emission over tidal flats. We find that the daytime inundation presents highest Hg(0) emission fluxes for Hg-poor sediment, but the daytime exposure is the hot moment of Hg(0) emission from Hg-rich sediments and substantially contributes to daily Hg(0) emission fluxes. In the treatment to mimic semidiurnal tide, the daily Hg(0) fluxes are positively correlated to sediment Hg concentrations. Combining our mechanistic insights on air-surface Hg(0) exchange over tidal flats and related data and knowledge reported by other studies, we discuss the implications of our study for field measurement and model development of Hg(0) dynamics over highly dynamic tidal flats. We conclude that the air-surface Hg(0) dynamics over tidal flats are extremely complex and highly variable, and a greater understanding the interactions between natural processes, human impacts and climate forcings will better constrain current and future Hg biogeochemical cycle in global tidal flats.
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Affiliation(s)
- Zhijia Ci
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Zhuhai, 519082, China.
| | - Xiong Tang
- Guangdong Eco-Engineering Polytechnic, Guangzhou, 510520, China
| | - Wenjie Shen
- School of Earth Sciences and Engineering, Sun Yat-sen University, Zhuhai, 519082, China; Guangdong Key Laboratory of Geological Process and Mineral Resources Exploration, Zhuhai, 519082, China
| | - Baowei Chen
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Zhuhai, 519082, China
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26
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Wu Q, Wang B, Hu H, Bravo AG, Bishop K, Bertilsson S, Meng B, Zhang H, Feng X. Sulfate-reduction and methanogenesis are coupled to Hg(II) and MeHg reduction in rice paddies. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132486. [PMID: 37690197 DOI: 10.1016/j.jhazmat.2023.132486] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/17/2023] [Accepted: 09/03/2023] [Indexed: 09/12/2023]
Abstract
Methylmercury (MeHg) produced in rice paddies is the main source of MeHg accumulation in rice, resulting in high risk of MeHg exposure to humans and wildlife. Net MeHg production is affected by Hg(II) reduction and MeHg demethylation, but it remains unclear to what extent these processes influence net MeHg production, as well as the role of the microbial guilds involved. We used isotopically labeled Hg species and specific microbial inhibitors in microcosm experiments to simultaneously investigate the rates of Hg(II) and MeHg transformations, as well as the key microbial guilds controlling these processes. Results showed that Hg(II) and MeHg reduction rate constants significantly decreased with addition of molybdate or BES, which inhibit sulfate-reduction and methanogenesis, respectively. This suggests that both sulfate-reduction and methanogenesis are important processes controlling Hg(II) and MeHg reduction in rice paddies. Meanwhile, up to 99% of MeHg demethylation was oxidative demethylation (OD) under the incubation conditions, suggesting that OD was the main MeHg degradative pathway in rice paddies. In addition, [202Hg(0)/Me202Hg] from the added 202Hg(NO3)2 was up to 13.9%, suggesting that Hg(II) reduction may constrain Hg(II) methylation in rice paddies at the abandoned Hg mining site. This study improves our understanding of Hg cycling pathways in rice paddies, and more specifically how reduction processes affect net MeHg production and related microbial metabolisms.
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Affiliation(s)
- Qingqing Wu
- 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
| | - Baolin Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Haiyan Hu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciencies del Mar (ICM-CSIC), Barcelona E08003, Catalunya, Spain
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala SE-75007, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala SE-75007, Sweden
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Hua Zhang
- 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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27
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Liu C, Ning Y, Liu J. Geochemical mercury pools regulate diverse communities of hgcA microbes and MeHg levels in paddy soils. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122172. [PMID: 37437760 DOI: 10.1016/j.envpol.2023.122172] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/26/2023] [Accepted: 07/09/2023] [Indexed: 07/14/2023]
Abstract
Rice paddies are unique artificial wetlands generating methylmercury (MeHg), a highly potent neurotoxin. However, the impact of diverse mercury (Hg) pools on the Hg-methylating communities during rice growth is unclear. This study investigates soil treated with five mercury forms (HgCl2, α-HgS, β-HgS, nano-HgS, and Hg-DOM) at two levels (5 mg/kg and 50 mg/kg). The results showed a varying abundance of sulphate-reducing bacteria, Geobacteraceae, methanogens, and hgcA microbes in the soils across rice grown under different mercury treatments and concentrations. Soils treated with HgCl2, nano-HgS and β-HgS had higher than average levels of hgcA-methanogen abundance, and the abundance significantly and positively correlated with MeHg concentration in all samples (p < 0.05). The shifting trends in Hg-methylating microbial structure following treatment with α-HgS, β-HgS, nano-HgS and Hg-DOM at both 5 and 50 mg/kg Hg levels were diverse compared with the control group. HgCl2 treatment showed contrasting trends in community distribution of Hg methylators at 5 and 50 mg/kg Hg levels during rice growth. Dissolved organic carbon, redox potential and sulphate levels significantly correlated with variation in the Hg-methylating microbial community structure and MeHg production in soils.
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Affiliation(s)
- Chutong Liu
- Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China; Key Laboratory of Functional Geomaterials in China Nonmetallic Minerals Industry, China University of Geosciences, Wuhan, 430074, China
| | - Yongqiang Ning
- Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China; Key Laboratory of Functional Geomaterials in China Nonmetallic Minerals Industry, China University of Geosciences, Wuhan, 430074, China
| | - Jinling Liu
- Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China; Key Laboratory of Functional Geomaterials in China Nonmetallic Minerals Industry, China University of Geosciences, Wuhan, 430074, China.
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28
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Rahman MM, Jung E, Eom S, Lee W, Han S. Mercury concentrations in sediments and oysters in a temperate coastal zone: a comparison of farmed and wild varieties. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:109810-109824. [PMID: 37777705 DOI: 10.1007/s11356-023-29992-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/16/2023] [Indexed: 10/02/2023]
Abstract
Oyster aquaculture has progressively increased to meet growing demands for seafood worldwide; however, its effects on methylmercury (MeHg) production in sediment and accumulation in oysters are largely unknown. In this study, total Hg (THg) and MeHg in sediments collected from aquaculture and reference sites and in farmed and wild oysters were measured and compared to explore potential factors that regulate MeHg production and bioaccumulation at the aquaculture sites. The results showed that the mean concentrations of THg and MeHg in varying sediment depths at the aquaculture site were 34 ± 4.1 ng g-1 and 16 ± 12 pg g-1, respectively. In comparison, the mean concentrations of THg and MeHg in sediments at the reference site were 25 ± 2.5 ng g-1 and 63 ± 28 pg g-1, respectively. While the MeHg/THg in the aquaculture sediments increased with organic carbon content, the slope of MeHg/THg versus organic carbon content was suppressed by high concentrations of dissolved sulfide in the pore water. Multiple parameters (total sulfur, total nitrogen and acid volatile sulfide in sediment, and dissolved sulfide in pore water) showed significant negative relationships with MeHg/THg in the sediment, and the total sulfur content in the sediment showed the highest inverse correlation factor with MeHg/THg (r = - 0.83). The mean concentrations of THg and MeHg in farmed oysters (mean weight 3.2 ± 1.5 g) were 36 ± 10 ng g-1 and 15 ± 6.7 ng g-1, respectively, while those in wild oysters (mean weight 0.92 ± 0.32 g) were 47 ± 9.9 ng g-1 and 15 ± 6.7 ng g-1, respectively. Concerning oysters of the same size range, THg and MeHg levels were higher in farmed oysters than in wild oysters despite the faster growth rate of farmed oysters, suggesting that the Hg content of food sources is more important than growth dilution rates in the control of Hg levels. The mean hazardous quotient for MeHg in farmed oyster was calculated as 0.044 ± 0.020, suggesting no expected health risk from farmed oyster consumption.
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Affiliation(s)
- Md Moklesur Rahman
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Eunji Jung
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Sangwoo Eom
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Woojin Lee
- Department of Civil and Environmental Engineering, National Lab. Astana, Nazarbayev University, 53 Kabanbay Batyr Ave., Nur-Sultan, 010000, Republic of Kazakhstan
| | - Seunghee Han
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
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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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30
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Kwasigroch U, Łukawska-Matuszewska K, Jędruch A, Brocławik O, Bełdowska M. Mobility and bioavailability of mercury in sediments of the southern Baltic sea in relation to the chemical fractions of iron: Spatial and temporal patterns. MARINE ENVIRONMENTAL RESEARCH 2023; 191:106132. [PMID: 37579704 DOI: 10.1016/j.marenvres.2023.106132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 07/29/2023] [Accepted: 08/09/2023] [Indexed: 08/16/2023]
Abstract
Marine sediments play a significant role as reservoirs for mercury (Hg), a bioaccumulative toxic pollutant that poses risks to human and ecosystem health. Iron (Fe) has been recognized as an influential factor in the complexation and bioavailability of Hg in sediments. However, limited studies have investigated the interactions between the chemical fractions of these elements in natural settings. This study aims to examine the fractions of Hg and Fe in sediments of the Baltic Sea, a region historically impacted by Hg pollution. The Hg fractions were determined using the thermodesorption technique, while sequential extraction was employed to identify the Fe fractions. The findings confirm the crucial role of Fe in the formation, as well as the horizontal and vertical distribution of labile and stable Hg in marine sediments. Factors such as the contribution of organic matter, the presence of reactive Fe, and Fe associated with sheet silicates emerged as significant drivers that positively influenced the content of the most labile Hg fractions, potentially affecting the mobility and bioavailability of Hg in the marine environment.
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Affiliation(s)
- Urszula Kwasigroch
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland
| | - Katarzyna Łukawska-Matuszewska
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland
| | - Agnieszka Jędruch
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland; Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry and Biochemistry, Powstańców Warszawy 55, 81-712, Sopot, Poland.
| | - Olga Brocławik
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland
| | - Magdalena Bełdowska
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland
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31
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Bartz KK, Hannam MP, Wilson TL, Lepak RF, Ogorek JM, Young DB, Eagles-Smith CA, Krabbenhoft DP. Understanding drivers of mercury in lake trout (Salvelinus namaycush), a top-predator fish in southwest Alaska's parklands. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 330:121678. [PMID: 37119998 PMCID: PMC10716799 DOI: 10.1016/j.envpol.2023.121678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/10/2023] [Accepted: 04/19/2023] [Indexed: 05/13/2023]
Abstract
Mercury (Hg) is a widespread element and persistent pollutant, harmful to fish, wildlife, and humans in its organic, methylated form. The risk of Hg contamination is driven by factors that regulate Hg loading, methylation, bioaccumulation, and biomagnification. In remote locations, with infrequent access and limited data, understanding the relative importance of these factors can pose a challenge. Here, we assessed Hg concentrations in an apex predator fish species, lake trout (Salvelinus namaycush), collected from 14 lakes spanning two National Parks in southwest Alaska, U.S.A. We then examined factors associated with the variation in fish Hg concentrations using a Bayesian hierarchical model. We found that total Hg concentrations in water were consistently low among lakes (0.11-0.50 ng L-1). Conversely, total Hg concentrations in lake trout spanned a thirty-fold range (101-3046 ng g-1 dry weight), with median values at 7 lakes exceeding Alaska's human consumption threshold. Model results showed that fish age and, to a lesser extent, body condition best explained variation in Hg concentration among fish within a lake, with Hg elevated in older, thinner lake trout. Other factors, including plankton methyl Hg content, fish species richness, volcano proximity, and glacier loss, best explained variation in lake trout Hg concentration among lakes. Collectively, these results provide evidence that multiple, hierarchically nested factors control fish Hg levels in these lakes.
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Affiliation(s)
- Krista K Bartz
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA.
| | - Michael P Hannam
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Tammy L Wilson
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Ryan F Lepak
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, 53706, USA; U.S. Environmental Protection Agency Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, 6201 Congdon Blvd, Duluth, MN, 55804, USA
| | - Jacob M Ogorek
- U.S. Geological Survey, Upper Midwest Water Science Center, Mercury Research Laboratory, 1 Gifford Pinchot Dr, Madison, WI, 53726, USA
| | - Daniel B Young
- National Park Service, Lake Clark National Park and Preserve, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97330, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Upper Midwest Water Science Center, Mercury Research Laboratory, 1 Gifford Pinchot Dr, Madison, WI, 53726, USA
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32
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Liu E, Xue J, Zhang G, Wang Y, Wang D, Yin D, He T. Distribution and Release of Mercury Regulated by the Decomposition of a Pioneer Habitat-Adapted Plant in the Water-Level-Fluctuating Zone of the Three Gorges Reservoir. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2023; 111:1. [PMID: 37335383 DOI: 10.1007/s00128-023-03760-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Pioneer habitat-adapted bermudagrass is prevalent in the water-level-fluctuating zone of the Three Gorges Reservoir area. This study was performed to explore the response characteristics of dissolved organic matter (DOM) qualities to bermudagrass decomposition and their regulation in the distribution and release of mercury (Hg) and methylmercury (MeHg) in the soil-water system. Compared to the control, the bermudagrass decomposition resulted in a great increase in the protein-like components in the water in the initial stages (p < 0.01), but it also greatly reduced the humification degree of water DOM (p < 0.01). However, it accelerated the consumption of protein-like components, the humification rate, and the synthesis of humic-like DOM in the water over time. This changing pattern of the DOM qualities resulted in an initial elevation and a subsequent great decrease in the dissolved Hg and MeHg concentrations in the pore water, which ultimately reduced their release levels into the overlying water by 26.50% and 54.42%, respectively, compared to the control. Our results indicate the potential inhibitory effects of short-term bermudagrass decomposition caused by flooding and how decomposition affects the release of total Hg and MeHg by shaping the DOM qualities, and they have implications for similar aquatic systems in which herbaceous plants are frequently decomposed after submergence.
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Affiliation(s)
- Enxin Liu
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China
| | - Jinping Xue
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Ge Zhang
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China
| | - Yongmin Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Deliang Yin
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China.
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China.
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China.
| | - Tianrong He
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China
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Liu J, Chen J, Poulain AJ, Pu Q, Hao Z, Meng B, Feng X. Mercury and Sulfur Redox Cycling Affect Methylmercury Levels in Rice Paddy Soils across a Contamination Gradient. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:8149-8160. [PMID: 37194595 PMCID: PMC10234277 DOI: 10.1021/acs.est.3c02676] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 05/18/2023]
Abstract
Methylmercury (MeHg) contamination in rice via paddy soils is an emerging global environmental issue. An understanding of mercury (Hg) transformation processes in paddy soils is urgently needed in order to control Hg contamination of human food and related health impacts. Sulfur (S)-regulated Hg transformation is one important process that controls Hg cycling in agricultural fields. In this study, Hg transformation processes, such as methylation, demethylation, oxidation, and reduction, and their responses to S input (sulfate and thiosulfate) in paddy soils with a Hg contamination gradient were elucidated simultaneously using a multi-compound-specific isotope labeling technique (200HgII, Me198Hg, and 202Hg0). In addition to HgII methylation and MeHg demethylation, this study revealed that microbially mediated reduction of HgII, methylation of Hg0, and oxidative demethylation-reduction of MeHg occurred under dark conditions; these processes served to transform Hg between different species (Hg0, HgII, and MeHg) in flooded paddy soils. Rapid redox recycling of Hg species contributed to Hg speciation resetting, which promoted the transformation between Hg0 and MeHg by generating bioavailable HgII for fuel methylation. Sulfur input also likely affected the microbial community structure and functional profile of HgII methylators and, therefore, influenced HgII methylation. The findings of this study contribute to our understanding of Hg transformation processes in paddy soils and provide much-needed knowledge for assessing Hg risks in hydrological fluctuation-regulated ecosystems.
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Affiliation(s)
- Jiang Liu
- State
Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
| | - Ji Chen
- State
Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
- College
of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Alexandre J. Poulain
- Biology
Department, University of Ottawa, 30 Marie Curie, Ottawa ON K1N 6N5, Canada
| | - Qiang Pu
- State
Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
| | - Zhengdong Hao
- State
Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, 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 550002, China
| | - Xinbin Feng
- State
Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
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34
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Yang N, Hu J, Yin D, He T, Tian X, Ran S, Zhou X. Mercury and methylmercury in Hg-contaminated paddy soil and their uptake in rice as regulated by DOM from different agricultural sources. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27712-9. [PMID: 37249779 DOI: 10.1007/s11356-023-27712-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 05/13/2023] [Indexed: 05/31/2023]
Abstract
In this study, from the perspectives of structural and compositional variations of soil-dissolved organic matter (DOM), we explored the effects of agricultural DOM inputs on methylmercury (MeHg) accumulation in the soil and mercury (Hg) bioaccumulation in rice grains. Pot experiments with the addition of DOMs from maize straw (MaS), rape straw (RaS), rice straw (RiS), composted rice straw (CRiS), cow dung (CD), and composted cow dung (CCD) were then conducted. Results showed that, relative to the control, the DOM amendment from each agricultural source elevated MeHg concentrations in the soil, with an increase of 18-227%, but only parts of DOMs elevated total dissolved Hg (DHg) and MeHg (DMeHg) concentrations in pore water. Among all DOM species, RiS, CRiS, and CCD significantly increased total Hg (THg) and MeHg contents in rice grains by 34-64% and 32-118%, respectively. Compared with RiS, THg and MeHg contents in rice grains in the CRiS treatment decreased slightly, which was consistent with the distributions of DHg and DMeHg concentrations in pore water and the aromaticity variation of soil DOM. In contrast, the CCD input significantly enhanced the enrichment of THg and MeHg in rice grains relative to CD because it significantly reduced the humification of soil DOM at all rice-growing stages while increasing the low-molecular-weight fractions in soil DOM. The THg and MeHg contents in the rice grains were significantly lower treated by RaS than those by MaS and RiS, which may be related to the higher sulfur-containing compounds such as sulfate and cysteine in rape straw or its DOM solution. Overall, DOM amendment from different agricultural sources resulted in significantly discriminative effects on the MeHg accumulation in soil and Hg enrichment in rice in the Hg-contaminated paddy field by shaping soil DOM properties.
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Affiliation(s)
- Ningla Yang
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environment, Guizhou University, Guiyang, 550025, China
| | - Jie Hu
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environment, Guizhou University, Guiyang, 550025, China
| | - Deliang Yin
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
- College of Resources and Environment, Guizhou University, Guiyang, 550025, China
| | - Tianrong He
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China.
- College of Resources and Environment, Guizhou University, Guiyang, 550025, China.
| | - Xiang Tian
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
| | - Shu Ran
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
| | - Xian Zhou
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China
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Wang T, Yang X, Li Z, Chen W, Wen X, He Y, Ma C, Yang Z, Zhang C. MeHg production in eutrophic lakes: Focusing on the roles of algal organic matter and iron-sulfur-phosphorus dynamics. JOURNAL OF HAZARDOUS MATERIALS 2023; 457:131682. [PMID: 37270963 DOI: 10.1016/j.jhazmat.2023.131682] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/06/2023]
Abstract
The mechanisms by which eutrophication affects methylmercury (MeHg) production have not been comprehensively summarized, which hinders accurately predicting the MeHg risk in eutrophic lakes. In this review, we first discussed the effects of eutrophication on biogeochemical cycle of mercury (Hg). Special attentions were paid to the roles of algal organic matter (AOM) and iron (Fe)-sulfur (S)-phosphorus (P) dynamics in MeHg production. Finally, the suggestions for risk control of MeHg in eutrophic lakes were proposed. AOM can affect in situ Hg methylation by stimulating the abundance and activities of Hg methylating microorganisms and regulating Hg bioavailability, which are dependent on bacteria-strain and algae species, the molecular weight and composition of AOM as well as environmental conditions (e.g., light). Fe-S-P dynamics under eutrophication including sulfate reduction, FeS formation and P release could also play crucial but complicated roles in MeHg production, in which AOM may participate through influencing the dissolution and aggregation processes, structural order and surface properties of HgS nanoparticles (HgSNP). Future studies should pay more attention to the dynamics of AOM in responses to the changing environmental conditions (e.g., light penetration and redox fluctuations) and how such variations will subsequently affect MeHg production. The effects of Fe-S-P dynamics on MeHg production under eutrophication also deserve further investigations, especially the interactions between AOM and HgSNP. Remediation strategies with lower disturbance, greater stability and less cost like the technology of interfacial O2 nanobubbles are urgent to be explored. This review will deepen our understanding of the mechanisms of MeHg production in eutrophic lakes and provide theoretical guidance for its risk control.
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Affiliation(s)
- Tantan Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xu Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Zihao Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Wenhao Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xin Wen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Yubo He
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Chi Ma
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Zhongzhu Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Chang Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
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36
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Gutensohn M, Schaefer JK, Yunda E, Skyllberg U, Björn E. The Combined Effect of Hg(II) Speciation, Thiol Metabolism, and Cell Physiology on Methylmercury Formation by Geobacter sulfurreducens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7185-7195. [PMID: 37098211 PMCID: PMC10173453 DOI: 10.1021/acs.est.3c00226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The chemical and biological factors controlling microbial formation of methylmercury (MeHg) are widely studied separately, but the combined effects of these factors are largely unknown. We examined how the chemical speciation of divalent, inorganic mercury (Hg(II)), as controlled by low-molecular-mass thiols, and cell physiology govern MeHg formation by Geobacter sulfurreducens. We compared MeHg formation with and without addition of exogenous cysteine (Cys) to experimental assays with varying nutrient and bacterial metabolite concentrations. Cysteine additions initially (0-2 h) enhanced MeHg formation by two mechanisms: (i) altering the Hg(II) partitioning from the cellular to the dissolved phase and/or (ii) shifting the chemical speciation of dissolved Hg(II) in favor of the Hg(Cys)2 complex. Nutrient additions increased MeHg formation by enhancing cell metabolism. These two effects were, however, not additive since cysteine was largely metabolized to penicillamine (PEN) over time at a rate that increased with nutrient addition. These processes shifted the speciation of dissolved Hg(II) from complexes with relatively high availability, Hg(Cys)2, to complexes with lower availability, Hg(PEN)2, for methylation. This thiol conversion by the cells thereby contributed to stalled MeHg formation after 2-6 h Hg(II) exposure. Overall, our results showed a complex influence of thiol metabolism on microbial MeHg formation and suggest that the conversion of cysteine to penicillamine may partly suppress MeHg formation in cysteine-rich environments like natural biofilms.
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Affiliation(s)
| | - Jeffra K Schaefer
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Elena Yunda
- Department of Chemistry, Umeå University, SE- 90187 Umeå, Sweden
| | - Ulf Skyllberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Erik Björn
- Department of Chemistry, Umeå University, SE- 90187 Umeå, Sweden
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37
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Hu J, Yang N, He T, Zhou X, Yin D, Wang Y, Zhou L. Elevated methylmercury production in mercury-contaminated paddy soil resulted from the favorable dissolved organic matter variation created by algal decomposition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 324:121415. [PMID: 36893976 DOI: 10.1016/j.envpol.2023.121415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/18/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
Algae-derived organic matter (AOM) may considerably regulate methylmercury (MeHg) production and accumulation in the paddy fields by changing the soil-dissolved OM (SDOM) properties. In this study, a 25-day microcosm experiment was performed to compare the responding mechanisms of MeHg production in the Hg-contaminated paddy soil-water system to the input of algae-, rice-, and rape-derived OMs. Results showed that algal decomposition could release much more cysteine and sulfate than crop straws. Compared with crop straw-derived OMs, AOM input greatly increased the dissolved organic carbon concentrations in soil but resulted in a greater decrease in tryptophan-like fractions while accelerated the formation of high-molecular-weight fractions in soil DOM. Moreover, AOM input significantly increased MeHg concentrations in the pore water by 19.43%-3427.66% and 52.81%-5846.57% compared to rape- and rice-derived OMs, respectively (P < 0.05). And, a similar MeHg changing pattern was also observed in the overlying water (10-25 d) and the soil solid-phase particles (15-25 d) (P < 0.05). Correlation analysis revealed that MeHg concentrations in the AOM-added soil-water system had significantly negative and positive relationships with the tryptophan-like C4 fraction and molecular weight (E2/E3 ratio) of soil DOM, respectively (P < 0.01). These findings suggest that AOM has a higher capacity than crop straw-derived OMs to promote MeHg production and accumulation in the Hg-contaminated paddy soils by creating a favorable soil DOM variation and providing more microbial electron donors and receptors.
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Affiliation(s)
- Jie Hu
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Ningla Yang
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Tianrong He
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Xian Zhou
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Deliang Yin
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China.
| | - Yan Wang
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, 550025, China; College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Litao Zhou
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
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Zhang Y, Yang K, Chen H, Dong Y, Li W. Origin, composition, and accumulation of dissolved organic matter in a hypersaline lake of the Qinghai-Tibet Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161612. [PMID: 36642270 DOI: 10.1016/j.scitotenv.2023.161612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/21/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Inland saline lakes are widely distributed and commonly exist in arid and semi-arid regions. Dissolved organic matter (DOM) in saline lakes plays an important role in the global carbon cycle and is a key regulator of saline lake ecosystem functions through biotic and abiotic processes. However, the origin, composition, and cycling of DOM in saline lakes, especially hypersaline lakes, remain largely unknown. In this study, two lake brine DOM samples and three input river DOM samples from a hypersaline lake, Da Qaidam Lake (DQL) in the Qaidam Basin of the Qinghai-Tibet Plateau (QTP), were isolated and analyzed using a multi-analytical approach. The results indicated that, although terrestrial in origin, the DOM composition and features of DQL were dominated by indigenous in-lake processes owing to the very long water residence time of the lake brine. Lake DOM contained more aliphatic compounds but fewer aromatic compounds than DOM from the rivers. Lake DOM also exhibited more chemodiversity and contained highly saturated and oxidized components that were incorporated with heteroatoms. Despite the limited contributions from riverine DOM, some special features of lake DOM, such as the high content of sulfur-bearing components, may be partly related to the long-term accumulation of hotspring riverine input. Flocculation, photodegradation, microbial degradation, evapo-concentration, and primary production processes were considered synergistic factors in the persistence and features of the hypersaline lake DOM. The results of this study can further our knowledge of the transformation and long-term turnover of DOM in hypersaline lakes and how DOM chemodiversity changes across wide aquatic ecosystems.
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Affiliation(s)
- Yaoling Zhang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, PR China; Qinghai Provincial Key Laboratory of Resources and Chemistry of Salt Lakes, Xining 810008, PR China.
| | - Keli Yang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, PR China; Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lake Resources, Xining 810008, PR China
| | - Hongmei Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, PR China
| | - Yaping Dong
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, PR China; Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lake Resources, Xining 810008, PR China
| | - Wu Li
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, PR China; Qinghai Provincial Key Laboratory of Resources and Chemistry of Salt Lakes, Xining 810008, PR China.
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Abdelhafiz MA, Liu J, Jiang T, Pu Q, Aslam MW, Zhang K, Meng B, Feng X. DOM influences Hg methylation in paddy soils across a Hg contamination gradient. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121237. [PMID: 36758923 DOI: 10.1016/j.envpol.2023.121237] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/05/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Rice paddies provide optimum conditions for Hg methylation, and paddy soil is a hot spot for Hg methylation and the predominant source of methylmercury (MeHg) accumulated in rice grains. The role of dissolved organic matter (DOM) in controlling Hg bioavailability and methylation in rice paddy systems remains unclear. Paddy soils from eight various cultivation sites in China were chosen to investigate the variations in soil DOM and the influence of DOM concentration and optical characteristics on Hg methylation in rice paddy systems. In the present study, 151 rhizosphere soil samples were collected, and UV-Vis absorption and fluorescent spectroscopy were used to identify the optical properties of DOM. The relationship between MeHg and DOM's optical property indices revealed the production of MeHg consumes lower molecular weight DOM. Moreover, the correlation between DOM concentration and its optical characteristics highlighted the significant role of humic components on MeHg variability in paddy soil. Variation and correlation results demonstrated the allochthonous origin of DOM in the Hg-contaminated soil, with a higher molecular weight and humic character of DOM, as well as the dominant role of autochthonous DOM in promoting Hg methylation in uncontaminated soil. The current study indicated that soil organic matter and its dissolved fractions tend to limit Hg bioavailability and subsequently diminish MeHg production in contaminated paddy soils. Furthermore, the leading roles of allochthonous DOM in protecting MeHg from degradation and autochthonous DOM signatures in enhancing MeHg production in paddy soils. Overall, these findings provide insight into the correlative distributions of DOM and Hg along a Hg concentration gradient in paddy soil, thereby highlighting their potential role in controlling Hg bioavailability and regulating Hg methylation in the soil ecosystems.
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Affiliation(s)
- Mahmoud A Abdelhafiz
- 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; Geology Department, Faculty of Science, Al-Azhar University, Assiut, 71524, Egypt
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Tao Jiang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China
| | - Qiang Pu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Muhammad Wajahat Aslam
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Kun Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, 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
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Zhang S, Yin Y, Yang P, Yao C, Tian S, Lei P, Jiang T, Wang D. Using the end-member mixing model to evaluate biogeochemical reactivities of dissolved organic matter (DOM): autochthonous versus allochthonous origins. WATER RESEARCH 2023; 232:119644. [PMID: 36736245 DOI: 10.1016/j.watres.2023.119644] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 01/02/2023] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
Dissolved organic matter (DOM) is an essential component of environmental systems. It usually originates from two end-members, including allochthonous and autochthonous sources. Previously, links have been established between DOM origins/sources and its biogeochemical reactivities. However, the influence of changes in DOM characteristics driven by end-member mixing on DOM biogeochemical reactivities has not been clarified. In this study, we investigated variations of DOM reactivities responding to the dynamics of DOM characteristics induced by different mixing ratios of two DOM end-members derived from humic acid (HA) and algae, respectively. Four biogeochemical reactivities of DOM were evaluated, including biodegradation, ·OH production, photodegradation, and redox capacity. Results showed that the variations of DOM characteristics due to the two end-members mixing significantly impact its biogeochemical reactivities. However, not all spectral parameters and reactivities followed the conservative mixing behavior. In contrast to reactivities of ·OH production and redox capacity, mixed samples showed apparent deviations from conservative linear relationships in biodegradation and photodegradation due to the interaction between the two end-members. Regarding the role of DOM properties influencing reactivity changes, peak A and M were recognized as the most stable parameters. However, peak C and SUVA254 were identified as the most vital contributors for explaining DOM reactivity variations. These findings suggest that a general model for describing the dynamic relationship between DOM source and reactivity cannot be proposed. Thus, the dynamics of DOM reactivity in diverse ecosystems cannot be estimated simply by the "plus or minus" of the reactivity from individual end-member. The effect of end-member mixing should be evaluated in a given reactivity instead of generalization. This study provides important insights for further understanding the dynamics of DOM's environmental role in different ecosystems influenced by variations of source inputs. In future, more field investigations are needed to further verify our findings in this study, especially in the scenario of end-member mixing.
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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
| | - Yongguang Yin
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Peijie Yang
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Cong Yao
- 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
| | - Shanyi Tian
- 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
| | - Pei Lei
- School of Environment, Nanjing Normal University, Nanjing 210023, 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; Institute 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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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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42
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Laske SM, Burke SM, Carey MP, Swanson HK, Zimmerman CE. Investigating effects of climate-induced changes in water temperature and diet on mercury concentrations in an Arctic freshwater forage fish. ENVIRONMENTAL RESEARCH 2023; 218:114851. [PMID: 36414108 DOI: 10.1016/j.envres.2022.114851] [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: 08/19/2022] [Revised: 10/28/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
The amount of mercury (Hg) in Arctic lake food webs is, and will continue to be, affected by rapid, ongoing climate change. At warmer temperatures, fish require more energy to sustain growth; changes in their metabolic rates and consuming prey with potentially higher Hg concentrations could result in increased Hg accumulation. To examine the potential implications of climate warming on forage fish Hg accumulation in Arctic lakes, we quantified growth and Hg accumulation in Ninespine Stickleback Pungitius pungitius under different temperature and diet scenarios using bioenergetics models. Four scenarios were considered that examined the role of climate, diet, climate × diet, and climate × diet × elevated prey Hg. As expected, annual fish growth increased with warmer temperatures, but growth rates and Hg accumulation were largely diet dependent. Compared to current growth rates of 0.3 g⋅y-1, fish growth increased at least 200% for fish consuming energy-dense benthic prey and decreased at least 40% for fish consuming pelagic prey. Compared to baseline levels, the Hg burden per kilocalorie of Ninespine Stickleback declined up to 43% with benthic consumption - indicating strong somatic growth dilution - but no more than 4% with pelagic consumption; elevated prey Hg concentrations led to moderate Hg declines in benthic-foraging fish and Hg increases in pelagic-foraging fish. Bioenergetics models demonstrated the complex interaction of water temperature, growth, prey proportions, and prey Hg concentrations that respond to climate change. Further work is needed to resolve mechanisms and rates linking climate change to Hg availability and uptake in Arctic freshwater systems.
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Affiliation(s)
- Sarah M Laske
- U. S. Geological Survey, Alaska Science Center, Anchorage, AK, USA.
| | - Samantha M Burke
- Department of Biology and Water Institute, University of Waterloo, Waterloo, Ontario, Canada
| | - Michael P Carey
- U. S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Heidi K Swanson
- Department of Biology and Water Institute, University of Waterloo, Waterloo, Ontario, Canada
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43
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Capo E, Cosio C, Gascón Díez E, Loizeau JL, Mendes E, Adatte T, Franzenburg S, Bravo AG. Anaerobic mercury methylators inhabit sinking particles of oxic water columns. WATER RESEARCH 2023; 229:119368. [PMID: 36459894 DOI: 10.1016/j.watres.2022.119368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/27/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Increased concentration of mercury, particularly methylmercury, in the environment is a worldwide concern because of its toxicity in severely exposed humans. Although the formation of methylmercury in oxic water columns has been previously suggested, there is no evidence of the presence of microorganisms able to perform this process, using the hgcAB gene pair (hgc+ microorganisms), in such environments. Here we show the prevalence of hgc+ microorganisms in sinking particles of the oxic water column of Lake Geneva (Switzerland and France) and its anoxic bottom sediments. Compared to anoxic sediments, sinking particles found in oxic waters exhibited relatively high proportion of hgc+genes taxonomically assigned to Firmicutes. In contrast hgc+members from Nitrospirae, Chloroflexota and PVC superphylum were prevalent in anoxic sediment while hgc+ Desulfobacterota were found in both environments. Altogether, the description of the diversity of putative mercury methylators in the oxic water column expand our understanding on MeHg formation in aquatic environments and at a global scale.
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Affiliation(s)
- Eric Capo
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Pg Marítim de la Barceloneta 37-49, 08003, Spain
| | - Claudia Cosio
- Université de Reims Champagne-Ardenne, UMR-I 02 INERIS-URCA-ULH SEBIO, Reims, France.
| | - Elena Gascón Díez
- Department F.-A. Forel for Environmental and Aquatic Sciences, and Institute for Environmental Sciences, University of Geneva, Geneva 1205, Switzerland; Direction générale de la santé, Secteur des produits chimiques, République et Canton de Genève, Switzerland
| | - Jean-Luc Loizeau
- Department F.-A. Forel for Environmental and Aquatic Sciences, and Institute for Environmental Sciences, University of Geneva, Geneva 1205, Switzerland
| | - Elsa Mendes
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Pg Marítim de la Barceloneta 37-49, 08003, Spain
| | - Thierry Adatte
- ISTE, Institut des Sciences de la Terre, Université de Lausanne, GEOPOLIS, 1015, Lausanne, Switzerland
| | - Sören Franzenburg
- Institute of Clinical Molecular Biology, Kiel University and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Andrea G Bravo
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Pg Marítim de la Barceloneta 37-49, 08003, Spain.
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Osafo NOA, Jan J, Porcal P, Borovec J. Contrasting catchment soil pH and Fe concentrations influence DOM distribution and nutrient dynamics in freshwater systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159988. [PMID: 36356733 DOI: 10.1016/j.scitotenv.2022.159988] [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: 07/15/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
Organic matter (OM) quantity, quality, and nutrient dynamics within twelve shallow lakes in the Czech Republic were assessed in the context of catchment soil pH and iron (Fe) concentration. The catchments of the lakes were classified into two categories: (i) slightly acidic (soil pH = 5.1-6.3) with Fe-rich soils (H_Fe; Fe = 315-344 mg kg-1 in Mehlich 3 extract); and (ii) neutral (soil pH = 6.8-7.6) with Fe-poor soils (L_Fe; Fe = 126-259 mg kg-1 in Mehlich 3 extract). The quality of OM in the two lake types was characterized using a combination of spectroscopic techniques (UV-Vis, fluorescence, and Fourier Transform Infrared spectroscopy). We show that dissolved nutrient and dissolved organic carbon (DOC) concentrations, as well as the amount of aromatic and protein-like compounds in the water column and sediment porewater were significantly (p < 0.01) lower in the H_Fe lakes compared to the waterbodies located within L_Fe catchments. The FTIR analyses of the H_Fe sediments contained higher relative concentrations of aromatic compounds with hydroxyl-containing functional groups and carbohydrates, while more aliphatic and oxidised OM was found in the L_Fe lake sediments. These results suggest that the pH value of catchment soils and, particularly, their Fe content have profound geochemical effects on the mobility of OM and nutrients in the sediments of recipient waters. Because the OM-Fe association stabilises OM in sediments, waterbodies within L_Fe catchments are likely more vulnerable to increasing eutrophication and oxygen depletion compared to those in H_Fe catchments and this has important implications for water quality management, risk assessment, and predictions of aquatic ecosystem vulnerability under conditions of accelerating climate change.
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Affiliation(s)
- Nana O-A Osafo
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, České Budějovice 370 05. Czech Republic.
| | - Jiří Jan
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czech Republic
| | - Petr Porcal
- Faculty of Science, University of South Bohemia, České Budějovice 370 05. Czech Republic; Institute of Hydrobiology, Biology Centre CAS, České Budějovice 370 05, Czech Republic
| | - Jakub Borovec
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, České Budějovice 370 05. Czech Republic
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Moslemi-Aqdam M, Low G, Low M, Laird BD, Branfireun BA, Swanson HK. Estimates, spatial variability, and environmental drivers of mercury biomagnification rates through lake food webs in the Canadian subarctic. ENVIRONMENTAL RESEARCH 2023; 217:114835. [PMID: 36400218 DOI: 10.1016/j.envres.2022.114835] [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: 08/12/2022] [Revised: 10/27/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Biomagnification of mercury (Hg) through lake food webs is understudied in rapidly changing northern regions, where wild-caught subsistence fish are critical to food security. We investigated estimates and among-lake variability of Hg biomagnification rates (BMR), relationships between Hg BMR and Hg levels in subsistence fish, and environmental drivers of Hg BMR in ten remote subarctic lakes in Northwest Territories, Canada. Lake-specific linear regressions between Hg concentrations (total Hg ([THg]) in fish and methyl Hg ([MeHg]) in primary consumers) and baseline-adjusted δ15N ratios were significant (p < 0.001, r2 = 0.58-0.88), indicating biomagnification of Hg through food webs of all studied lakes. Quantified using the slope of Hg-δ15N regressions, Hg BMR ranged from 0.16 to 0.25, with mean ± standard deviation of 0.20 ± 0.03). Using fish [MeHg] rather than [THg] lowered estimates of Hg BMR by ∼10%, suggesting that the use of [THg] as a proxy for [MeHg] in fish can influence estimates of Hg BMR. Among-lake variability of size-standardized [THg] in resident fish species from different trophic guilds, namely Lake Whitefish (Coregonus clupeaformis) and Northern Pike (Esox lucius), was not significantly explained by among-lake variability in Hg BMR. Stepwise multiple regressions indicated that among-lake variability of Hg BMR was best explained by a positive relationship with catchment forest cover (p = 0.009, r2 = 0.59), likely reflecting effects of forest cover on water chemistry of downstream lakes and ultimately, concentrations of biomagnifying MeHg (and percent MeHg of total Hg) in resident biota. These findings improve our understanding of Hg biomagnification in remote subarctic lakes.
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Affiliation(s)
| | - George Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Mike Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Brian D Laird
- School of Public Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | | | - Heidi K Swanson
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
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Duval B, Tessier E, Kortazar L, Fernandez LA, de Diego A, Amouroux D. Dynamics, distribution, and transformations of mercury species from pyrenean high-altitude lakes. ENVIRONMENTAL RESEARCH 2023; 216:114611. [PMID: 36283441 DOI: 10.1016/j.envres.2022.114611] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/03/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
While mercury (Hg) is a major concern in all aquatic environments because of its methylation and biomagnification pathways, very few studies consider Hg cycling in remote alpine lakes which are sensitive ecosystems. Nineteen high-altitude pristine lakes from Western/Central Pyrenees were investigated on both northern (France) and southern (Spain) slopes (1620-2600 m asl.). Subsurface water samples were collected in June 2017/2018/2019 and October 2017/2018 for Hg speciation analysis of inorganic mercury (iHg(II)), monomethylmercury (MMHg), and dissolved gaseous mercury (DGM) to investigate spatial and seasonal variations. In June 2018/2019 and October 2018, more comprehensive studies were performed in four lakes by taking water column depth profiles. Besides, in-situ incubation experiments using isotopically enriched Hg species (199iHg(II), 201MMHg) were conducted to investigate Hg transformation mechanisms in the water column. While iHg(II) (0.08-1.10 ng L-1 in filtered samples; 0.11-1.19 ng L-1 in unfiltered samples) did not show significant seasonal variations in the subsurface water samples, MMHg (<0.03-0.035 ng L-1 in filtered samples; <0.03-0.062 ng L-1 in unfiltered samples) was significantly higher in October 2018, mainly because of in-situ methylation. DGM (0.02-0.68 ng L-1) varies strongly and can exhibit higher levels in comparison with other pristine areas. Depth profiles and incubation experiments highlighted the importance of in-situ biotic methylation triggered by anoxic conditions in bottom waters. In-situ incubations confirm that significant methylation, demethylation and photoreduction extents are taking place in the water columns. Overall, drastic environmental changes occurring daily and seasonally in alpine lakes are providing conditions that can both promote Hg methylation (stratified anoxic waters) and MMHg photodemethylation (intense UV light). In addition, light induced photoreduction is a major pathway controlling significant gaseous Hg evasion. Global warming and potential eutrophication may thus have direct implications on Hg turnover and MMHg burden in those remote ecosystems.
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Affiliation(s)
- Bastien Duval
- Universite de Pau et des Pays de L'Adour / E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et Les Materiaux, UMR5254, Helioparc, 64053 Pau, France; Kimika Analitikoa Saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa Z/g, 48940 Leioa (Basque Country).
| | - Emmanuel Tessier
- Universite de Pau et des Pays de L'Adour / E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et Les Materiaux, UMR5254, Helioparc, 64053 Pau, France
| | - Leire Kortazar
- Kimika Analitikoa Saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa Z/g, 48940 Leioa (Basque Country)
| | - Luis Angel Fernandez
- Kimika Analitikoa Saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa Z/g, 48940 Leioa (Basque Country)
| | - Alberto de Diego
- Kimika Analitikoa Saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa Z/g, 48940 Leioa (Basque Country)
| | - David Amouroux
- Universite de Pau et des Pays de L'Adour / E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour L'Environnement et Les Materiaux, UMR5254, Helioparc, 64053 Pau, France.
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Bradford MA, Mallory ML, O'Driscoll NJ. The Complex Interactions Between Sediment Geochemistry, Methylmercury Production, and Bioaccumulation in Intertidal Estuarine Ecosystems: A Focused Review. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 110:26. [PMID: 36571620 DOI: 10.1007/s00128-022-03653-w] [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: 07/20/2022] [Accepted: 11/20/2022] [Indexed: 06/17/2023]
Abstract
Due to their natural geochemistry, intertidal estuarine ecosystems are vulnerable to bioaccumulation of methylmercury (MeHg), a neurotoxin that readily bioaccumulates in organisms. Determining MeHg concentrations in intertidal invertebrates at the base of the food web is crucial in determining MeHg exposure in higher trophic level organisms like fish and birds. The processes that govern the production of MeHg in coastal ecosystems are influenced by many geochemical factors including sulfur species, organic matter, and salinity. The interactions of these factors with mercury are complex, and a wide variety of results have been reported in the literature. This paper reviews conceptual models to better clarify the various geochemical and physical factors that impact MeHg production and bioavailability in intertidal ecosystems.
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Affiliation(s)
| | - Mark L Mallory
- Biology Department, Acadia University, Wolfville, NS, Canada
| | - Nelson J O'Driscoll
- Earth and Environmental Science Department, Acadia University, Wolfville, NS, Canada
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Li P, Wang R, Kainz MJ, Yin D. Algal Density Controls the Spatial Variations in Hg Bioconcentration and Bioaccumulation at the Base of the Pelagic Food Web of Lake Taihu, China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14528-14538. [PMID: 36194456 DOI: 10.1021/acs.est.2c05625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Algal density can significantly impact mercury (Hg) bioaccumulation and biomagnification in aquatic food webs, but the underlying mechanisms remain controversial especially in subtropical and tropical regions. We conducted a comprehensive field study on Hg bioconcentration in phytoplankton and bioaccumulation in size-fractionated zooplankton across 17 sampling sites in Lake Taihu, a large shallow lake in eastern China with large spatial differences in algal density. The higher algal density in the northern sites is highly associated with the lower THg bioconcentration factor (BCF) in phytoplankton and lower THg bioaccumulation factor (BAF) in zooplankton. The low Hg BCFs or BAFs at productive sites could not be explained by algal bloom dilution but attributed to the low Hg bioavailability, which is highly associated with the elevated pH levels at productive sites. The smaller body size of the dominant zooplankton species at higher algal density sites also contributed to their lower Hg bioaccumulation. Importantly, we provide evidence that high algal density is associated with a low proportion of methylmercury (MeHg) in total Hg (% MeHg) in phytoplankton, which is further transferred to zooplankton. Such a low THg BCF or BAF and low % MeHg in plankton at high algal density sites hamper the entry of Hg into the pelagic food webs, which are important but yet underestimated driving forces for the low Hg contents in pelagic fish that are commonly observed in anthropogenic-impacted eutrophic lakes in subtropical regions.
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Affiliation(s)
- Pengwei Li
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai200092, China
| | - Rui Wang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai200092, China
| | - Martin J Kainz
- WasserCluster Lunz - Biologische Station, Inter-University Center for Aquatic Ecosystem Research, A-3293Lunz am See, Austria
- Department of Biomedical Research, Danube University Krems, A-3500Krems, Austria
| | - Daqiang Yin
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai200092, China
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Seelos M, Beutel M, McCord S, Kim S, Vigil K. Plankton population dynamics and methylmercury bioaccumulation in the pelagic food web of mine-impacted surface water reservoirs. HYDROBIOLOGIA 2022; 849:4803-4822. [PMID: 36213552 PMCID: PMC9526464 DOI: 10.1007/s10750-022-05018-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/02/2022] [Accepted: 09/16/2022] [Indexed: 05/28/2023]
Abstract
UNLABELLED Thermal stratification of reservoirs can lead to anaerobic conditions that facilitate the microbial conversion of mercury (Hg) to neurotoxic and bioaccumulative methylmercury (MeHg). But MeHg production is just the first step in a complex set of processes that affect MeHg in fish. Of particular relevance is uptake into suspended particulate matter (SPM) and zooplankton at the base of the pelagic food web. We assessed plankton dynamics and Hg uptake into the pelagic food web of four Hg-impaired California water reservoirs. Combining water chemistry, plankton taxonomy, and stable carbon (C) and nitrogen (N) isotope values of SPM and zooplankton samples, we investigated differences among the reservoirs that may contribute to differing patterns in MeHg bioaccumulation. Methylmercury accumulated in SPM during the spring and summer seasons. Percent MeHg (MeHg/Hg*100%) in SPM was negatively associated with δ15N values, suggesting that "fresh" algal biomass could support the production and bioaccumulation of MeHg. Zooplankton δ13C values were correlated with SPM δ13C values in the epilimnion, suggesting that zooplankton primarily feed in surface waters. However, zooplankton MeHg was poorly associated with MeHg in SPM. Our results demonstrate seasonal patterns in biological MeHg uptake and how multiple data sources can help constrain the drivers of MeHg bioaccumulation. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10750-022-05018-0.
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Affiliation(s)
- Mark Seelos
- Environmental Systems Graduate Program, University of California Merced, Merced, CA 95343 USA
- Valley Water, San Jose, CA 95118 USA
| | - Marc Beutel
- Environmental Systems Graduate Program, University of California Merced, Merced, CA 95343 USA
| | | | - Sora Kim
- Department of Life and Environmental Sciences, University of California Merced, Merced, CA 95343 USA
| | - Katie Vigil
- Department of Global Environmental Health, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112 USA
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50
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Xing Y, Wang J, Kinder CES, Yang X, Slaný M, Wang B, Song H, Shaheen SM, Leinweber P, Rinklebe J. Rice hull biochar enhances the mobilization and methylation of mercury in a soil under changing redox conditions: Implication for Hg risks management in paddy fields. ENVIRONMENT INTERNATIONAL 2022; 168:107484. [PMID: 36049376 DOI: 10.1016/j.envint.2022.107484] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Biochar amendment to paddy soils was promising to mitigate mercury (Hg) accumulation in rice; thus, it was applied to reduce human Hg exposure via rice consumption. However, how biochar affects Hg mobilization and MeHg formation in soil under changed redox potential (Eh) conditions remained unknown. Here, we explored the change of dissolved total Hg (DTHg) and dissolved MeHg (DMeHg), and their controlling biogeochemical factors in a soil with(out) biochar amendment under changing Eh conditions using biogeochemical microcosm. Biochar amendment resulted in a widen Eh range (-300 to 400 mV) compared to the control (-250 to 350 mV), demonstrating that biochar promoted reduction-oxidization reactions in soil. Biochar amendment enhanced Hg mobilization by mediating reductive dissolution of Fe/Mn (hydr)oxides. Thus, the increased Hg availability promoted MeHg formation in the soils. Biochar amendment changed the soil organic matter (SOM) composition. Positive correlations between the relative abundance of LIPID (lipids, alkanes/alkenes), ALKYL (alkylaromatics), and suberin and MeHg concentrations indicate that these SOM groups might be related to MeHg formation. Biochar enhanced the releasing and methylation of Hg by promoting the mobilization of Fe(oxyhydr)oxides and alternation of carbon chemistry under dynamic Eh conditions. There is an unexpected environmental risk associated with biochar application to paddy soils under dynamic Eh condition, and one should be aware this risk when applying biochar aiming to minimize human Hg exposure health risks via rice consumption.
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Affiliation(s)
- Ying Xing
- School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550002, PR China; University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Jianxu Wang
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550082, PR China.
| | - Christoph E S Kinder
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Xing Yang
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Michal Slaný
- Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava, Slovakia
| | - Bing Wang
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, PR China
| | - Hocheol Song
- University of Sejong, Department of Environment, Energy and Geoinformatics, 98 Gunja-Dong, Guangjin-Gu, Seoul, South Korea
| | - Sabry M Shaheen
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; King Abdulaziz University, Faculty of Meteorology, Environment and Arid Land Agriculture, Department of Arid Land Agriculture, Jeddah 21589, Saudi Arabia; University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33516 Kafr El-Sheikh, Egypt
| | - Peter Leinweber
- University of Rostock, Department Light, Life and Matter (LLM), Albert-Einstein-Strasse 25, D-18059 Rostock, Germany; Soil Science, University of Rostock, Justus-von-Liebig-Weg 6, 18051 Rostock, Germany
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Sejong, Department of Environment, Energy and Geoinformatics, 98 Gunja-Dong, Guangjin-Gu, Seoul, South Korea.
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