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Li Z, Zhou C, Wang Y, He D, Liu M, Yin Y, Liu G, Wang X, Cai Y, Li Y. Total mercury, methylmercury, and their possible controlling factors in soils of typical coastal wetlands in China. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134711. [PMID: 38795491 DOI: 10.1016/j.jhazmat.2024.134711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/16/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
Coastal wetland soils play a critical role in the global mercury (Hg) cycle, serving as both an important repository for total mercury (THg) and a hotspot for methylmercury (MeHg) production. This study investigated Hg pollution in soils dominated by Phragmites australis (PA) and Spartina alterniflora (SA) across five representative China's coastal wetlands (Yellow River (YR), Linhong River (LHR), Yangtze River (CJR), Min River (MR), and Nanliu River (NLR)). The THg concentrations ranged from 16.7 to 446.0 (96.3 ± 59.3 ng g-1, dw), while MeHg concentrations varied from 0.01 to 0.81 (0.12 ± 0.12 ng g-1, dw). We further evaluated Hg risk in these wetlands using potential ecological risk index (Er) and geographical enrichment factor (Igeo). Most wetlands exhibited low to moderate ecological risk, except the PA habitat in the YR wetland, showing moderate to high risk. Soil organic matter significantly influenced THg and MeHg distribution, while MeHg% correlated well with soil salinity and pH. These findings highlight the importance of organic-rich coastal wetland soils in THg and MeHg accumulation, with the soil properties influencing net MeHg production. Furthermore, SA habitat generally exhibited higher MeHg%, suggesting its invasion elevates the ecological risk of MeHg in coastal wetlands. ENVIRONMENTAL IMPLICATION: Mercury (Hg), a global pollutant, poses great risks to wildlife and humans. Since industrialization, anthropogenic Hg release surpassed natural sources. Long-term exposure leads to biomagnification of Hg. This study assessed Hg and methylmercury pollution and risks in soils of five China's coastal wetlands dominated by Phragmites australis and Spartina alterniflora. Environmental factors (total carbon, total organic carbon, total nitrogen, salinity, pH) were analyzed to reveal key variables influencing Hg pollution and methylation. Essential for quantifying Hg pollution in coastal wetlands, the findings provide a scientific basis for effective wetland conservation policies and addressing environmental health in these regions.
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Affiliation(s)
- Zheng Li
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Chengzhen Zhou
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yingjun Wang
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Ding He
- Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong 999077, China.
| | - Maodian Liu
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yongguang Yin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Guangliang Liu
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Xuejun Wang
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yong Cai
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Yanbin Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
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Gosnell KJ, Mazrui N, Mason RP. Properties influencing flux and diatom uptake of mercury and methylmercury from estuarine sediments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123604. [PMID: 38423275 DOI: 10.1016/j.envpol.2024.123604] [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: 11/10/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024]
Abstract
Mercury (Hg) is a conspicuous and persistent global pollutant. Ionic Hg can be methylated into noxious methylmercury (CH3Hg), which biomagnifies in marine tropic webs and poses a health risk to humans and organisms. Sediment Hg methylation rates are variable, and the output flux of created CH3Hg are dependent on sediment characteristics and environmental factors. Thus, uncertainties remain about the formation and flux of CH3Hg from sediment, and how this could contribute to the bioaccumulative burden for coastal organisms in shallow ecosystems. Cores were collected from 3 estuarine locations along the Eastern USA to examine how sediments characteristics influence the introduction of Hg and CH3Hg into the base of the food chain. Stable isotopes of inorganic 200Hg and CH3199Hg were injected into sediments of individual cores, with cultured diatoms constrained to overlying waters. Five different treatments were done on duplicate cores, spiked with: (1) no Hg isotopes (control); (2) inorganic 200Hg; (3) CH3199Hg; (4) both 200Hg and CH3199Hg isotopes, (5) both 200Hg and CH3199Hg into overlying waters (not sediment). Experimental cores were incubated for 3 days under temperature and light controlled conditions. These results demonstrate that upper sediments characteristics lead to high variability in Hg cycling. Notably, sediments which contained abundant and peaty organic material (∼28 %LOI), had the highest pore water DOC (3206 μM) and displayed bands of sulfur reducing bacteria yielded the greatest methylation rate (1.97 % day-1) and subsequent diatom uptake of CH3200Hg (cell quota 0.18 amol/cell) in the overlying water.
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Affiliation(s)
- Kathleen J Gosnell
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Department of Marine Sciences, University of Connecticut, Groton, CT, USA.
| | - Nashaat Mazrui
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA; Okavango Research Institute, University of Botswana, Manu, Botswana
| | - Robert P Mason
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
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Ma T, Perrot V, Baeyens W, Li G, Lievens S, Ngo HTT, Nguyen TTT, Leermakers M, Gao Y. Mercury distribution, mobilization and bioavailability in polluted sediments of Scheldt Estuary and Belgian Coastal Zone. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133209. [PMID: 38101023 DOI: 10.1016/j.jhazmat.2023.133209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/03/2023] [Accepted: 12/07/2023] [Indexed: 12/17/2023]
Abstract
In this study, the vertical distribution of mercury (Hg) in estuarine and marine sediment porewaters and solid phases was assessed by conventional and passive sampling techniques in the historically polluted Scheldt Estuary and Belgian Coastal Zone (BCZ). The Diffusive Gradients in Thin-films (DGT) measured labile Hg concentrations (HgLA) were mostly lower than the porewater Hg concentrations (HgPW), and they also presented different vertical distribution patterns. Still high Hg concentrations in the sediment solid phases, comparable to the historical ones, were observed. Even though pH, redox potential and dissolved sulfide concentration could influence the Hg biogeochemical behaviour, organic matter (OM) played a key role in governing Hg mobilization from sediment solid phase to porewater and in its partitioning between porewater and solid phase over depth. In the marine sediments, where OM had a marine signature, higher labile Hg concentrations in the porewater and faster resupply from the solid phase were observed. The DGT technique showed significant potential not only for the measurement of bioavailable Hg fractions in porewater, but also for the assessment of kinetic parameters governing the release of labile Hg species from the solid phase with the assistance of the DGT Induced Fluxes in Sediments (DIFS) model.
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Affiliation(s)
- Tianhui Ma
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Vincent Perrot
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Willy Baeyens
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Guanlei Li
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Sybrien Lievens
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Huong Thi Thuy Ngo
- Environmental Chemistry and Ecotoxicology Lab, Faculty of Biotechnology, Chemistry and Environmental Engineering, Phenikaa University, Yen Nghia Ward - Ha Dong District, 12116 Hanoi, Vietnam
| | - Thao Thi Thanh Nguyen
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium; Vietnam Institute of Geosciences and Mineral Resources, 67 Chien Thang, Van Quan, Ha Dong District, 12109 Hanoi, Vietnam
| | - Martine Leermakers
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Yue Gao
- Analytical, Environmental and Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
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Herring G, Tennant LB, Willacker JJ, Johnson M, Siegel RB, Polasik JS, Eagles-Smith CA. Wildfire burn severity and stream chemistry influence aquatic invertebrate and riparian avian mercury exposure in forested ecosystems. ECOTOXICOLOGY (LONDON, ENGLAND) 2024; 33:131-141. [PMID: 38381206 DOI: 10.1007/s10646-024-02730-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/08/2024] [Indexed: 02/22/2024]
Abstract
Terrestrial soils in forested landscapes represent some of the largest mercury (Hg) reserves globally. Wildfire can alter the storage and distribution of terrestrial-bound Hg via reemission to the atmosphere or mobilization in watersheds where it may become available for methylation and uptake into food webs. Using data associated with the 2007 Moonlight and Antelope Fires in California, we examined the long-term direct effects of wildfire burn severity on the distribution and magnitude of Hg concentrations in riparian food webs. Additionally, we quantified the cross-ecosystem transfer of Hg from aquatic invertebrate to riparian bird communities; and assessed the influence of biogeochemical, landscape variables, and ecological factors on Hg concentrations in aquatic and terrestrial food webs. Benthic macroinvertebrate methylmercury (MeHg) and riparian bird blood total mercury (THg) concentrations varied by 710- and 760-fold, respectively, and Hg concentrations were highest in predators. We found inconsistent relationships between Hg concentrations across and within taxa and guilds in response to stream chemical parameters and burn severity. Macroinvertebrate scraper MeHg concentrations were influenced by dissolved organic carbon (DOC); however, that relationship was moderated by burn severity (as burn severity increased the effect of DOC declined). Omnivorous bird Hg concentrations declined with increasing burn severity. Overall, taxa more linked to in situ energetic pathways may be more responsive to the biogeochemical processes that influence MeHg cycling. Remarkably, 8 years post-fire, we still observed evidence of burn severity influencing Hg concentrations within riparian food webs, illustrating its overarching role in altering the storage and redistribution of Hg and influencing biogeochemical processes.
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Affiliation(s)
- Garth Herring
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA.
| | - Lora B Tennant
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
- Nez Perce Tribe, Department of Fisheries Resource Management, Joseph, OR, 97846, USA
| | - James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| | - Matthew Johnson
- National Park Service, Inventory & Monitoring Division, Southern Colorado Plateau Network, Flagstaff, AZ, 86001, USA
| | - Rodney B Siegel
- The Institute for Bird Populations, Petaluma, CA, 94953, USA
| | - Julia S Polasik
- The Institute for Bird Populations, Petaluma, CA, 94953, USA
- Teton Raptor Center, Wilson, WY, 83014, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
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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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Liu X, Wang Y, Li Z, Song Y, Li Y, Yin Y, Cai Y. Riverine input of suspended particulate matter controls distribution, partitioning and transport of mercury and methylmercury in the Yellow River Estuary. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131597. [PMID: 37182462 DOI: 10.1016/j.jhazmat.2023.131597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/10/2023] [Accepted: 05/07/2023] [Indexed: 05/16/2023]
Abstract
Riverine mercury (Hg) is the largest global source of Hg in coastal oceans. The Yellow River delivers the majority of Hg to the semi-enclosed Bohai Sea, where Hg contamination adversely affects the surrounding heavily populated provinces in northern China. Mercury distribution patterns in the river-estuary interacting area provides essential information to understand the riverine Hg transport and biogeochemical cycling of Hg in the estuary. Analyzing the spatial distributions of total- (THg) and methyl-Hg (MeHg) in the lower end of Yellow River (∼105 km) and adjacent estuary, we found the dominant role of suspended particulate matter (SPM) in Hg transport, with 99.1% and 86.3% of THg and MeHg being in particulate phase. The SPM dynamics, such as transport, retention, sorting and sedimentation, governs Hg transport with water flow and particle-water partition of Hg. While THg decreased along the water flow to the river mouth with the settlement of particulate THg (about 27.5% onto the riverbed and the rest entering the sea), MeHg and particulate MeHg increased by 110% and 117%, respectively. This study highlights the distinct patterns in THg and MeHg distribution and transport and suggests potential Hg methylation and external MeHg input in the river-estuary mixed zone.
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Affiliation(s)
- Xiaoquan Liu
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Yingjun Wang
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
| | - Zheng Li
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Yue Song
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Yanbin Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Yongguang Yin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yong Cai
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China; Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, United States.
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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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Yao C, He T. Effect of peat and thiol-modified peat application on mercury (im)mobilization in mercury-polluted paddy soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 254:114743. [PMID: 36905846 DOI: 10.1016/j.ecoenv.2023.114743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/26/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
Mercury (Hg) pollution in paddy soil has gained special attention because methylmercury (MeHg) can accumulate in rice grains. Therefore, there is an urgent need to explore the remediation materials of mercury-polluted paddy soil. In this study, herbaceous peat (HP), peat moss (PM), and thiol-modified HP/PM (MHP/MPM) were selected to investigate the effects and probable mechanism of their application on Hg (im)mobilization in mercury-polluted paddy soil through pot experiments. The results showed that HP, PM, MHP and MPM addition increased MeHg concentrations in the soil, indicating that the addition of peat and thiol-modified peat might increase the exposure risk of MeHg in soil. The addition of HP could significantly decrease the total mercury (THg) and MeHg concentrations in rice, with average reduction efficiencies of 27.44% and 45.97%, respectively, while adding PM slightly increased the THg and MeHg concentrations in rice. In addition, the addition of MHP and MPM significantly decreased the bioavailable Hg concentrations in the soil and THg and MeHg concentrations in rice, with reduction efficiencies of rice THg and MeHg of 79.14∼93.14% and 82.72∼93.87%, respectively, indicating that thiol-modified peat had good remediation potential. The possible mechanism is that Hg can bind with thiols in MHP/MPM and form steady compounds in the soil, reducing Hg mobility in the soil and inhibiting its uptake by rice. Our study showed the potential value of HP, MHP and MPM addition for Hg remediation. Additionally, we must weigh the pros and cons when adding organic materials as remediation agents to mercury-polluted paddy soil.
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Affiliation(s)
- Cong Yao
- College of Resources and Environment, Southwest University, Chongqing 400715, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, 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.
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Park J, Cho H, Han S, An SU, Choi A, Lee H, Hyun JH. Impacts of the invasive Spartina anglica on C-S-Hg cycles and Hg(II) methylating microbial communities revealed by hgcA gene analysis in intertidal sediment of the Han River estuary, Yellow Sea. MARINE POLLUTION BULLETIN 2023; 187:114498. [PMID: 36603235 DOI: 10.1016/j.marpolbul.2022.114498] [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: 09/23/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
We investigated the impact of invasive vegetation on mercury cycles, and identified microorganisms directly related to Hg(II) methylation using hgcA gene in vegetated mud flats (VMF) inhabited by native Suaeda japonica (SJ) and invasive Spartina anglica (SA), and unvegetated mud flats (UMF) in Ganghwa intertidal sediments. Sulfate reduction rate (SRR) and rate constants of Hg(II) methylation (Km) and methyl-Hg demethylation (Kd) were consistently greater in VMF than in UMF, specifically 1.5, 2 and 11.7 times higher, respectively, for SA. Both Km and Kd were significantly correlated with SRR and the abundance of sulfate-reducing bacteria. These results indicate that the rhizosphere of invasive SA provides a hotspot for Hg dynamics coupled with sulfate reduction. HgcA gene analysis revealed that Hg(II)-methylators were dominated by Deltaproteobacteria, Chloroflexi and Euryarchaeota, comprising 37.9%, 35.8%, and 6.5% of total hgcA gene sequences, respectively, which implies that coastal sediments harbor diverse Hg(II)-methylating microorganisms that previously underrepresented.
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Affiliation(s)
- Jisu Park
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea
| | - Hyeyoun Cho
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea
| | - Seunghee Han
- School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, South Korea
| | - Sung-Uk An
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea; Korean Institute of Ocean Science & Technology (KIOST), 385 Haeyang-ro, Yeongdo-gu, Busan Metropolitan City 49111, South Korea
| | - Ayeon Choi
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea; Korean Institute of Ocean Science & Technology (KIOST), 385 Haeyang-ro, Yeongdo-gu, Busan Metropolitan City 49111, South Korea
| | - Hyeonji Lee
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea
| | - Jung-Ho Hyun
- Department of Marine Sciences and Convergent Technology, Hanyang University (ERICA Campus), 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, South Korea.
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Hillyer KE, Raes E, Bissett A, Beale DJ. Multi-omics eco-surveillance of bacterial community function in legacy contaminated estuary sediments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 318:120857. [PMID: 36513173 DOI: 10.1016/j.envpol.2022.120857] [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: 08/09/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Complex legacy contamination is a major issue for many estuaries, with toxicity affecting change in bacterial communities, and their provision of associated goods and services. Sequencing surveys of bacterial community composition provide inferred function; however, additional insights may be generated by measurement of realised metabolic phenotypes. We apply multi-omics (genomics, lipidomics, and metabolomics), with traditional sediment quality analyses, to characterise sediment-associated bacterial communities in an estuary subject to legacy metal contamination (Zn, Hg, As, Cd, Cu and Pb). Analyses of bacterial composition and inferred function (genomics) are coupled with measurements of realised bacterial phenotype (metabolomics and lipidomics) at multiple industrialised and reference sites. At sites with the highest sediment metal concentrations (NTB), we also observed increased abundances of hydrocarbon and sulphuric acid metabolites, indicating additional sediment contamination. Bacterial phyla across sampled sites were dominated by Proteobacteria and Desulfobacteria. NTB sites were enriched with metabolically versatile, cooperative and biofilm forming phyla including, Zixibacteria, Spirochaetota, SAR324 clade, Proteobacteria, Latescibacterota, Desulfobacterota, Deferrisomtota and Acidobateriota; with inferred functions characterised by sulphur metabolism, pathways associated with the degradation of complex organic molecules, and fermentation. Reference sites were characterised by enhanced vitamin biosynthesis, cell wall, cofactor and carbohydrate biosynthesis, and CO2 fixation. Measured metabolic phenotypes at NTB sites supported predicted functions, with most consistent change observed to naphthalene and aminobenzoate degradation pathways and carbohydrate metabolism (galactose, amino and nucleotide sugar). Change in NTB metabolite profiles was most highly correlated with sediment Hg concentrations, indicative of toxic exposure and potential for Hg methylation. Lipid profiles generated further insight into potential functional (hydroxy fatty acids) and community level change (ceramide phosphoethanolamines, unsaturated glycerides). Multi-omics outputs provided insights into bacterial community functions, modes of contaminant toxicity and expressed mechanisms of adaptation, necessary to better inform management decisions and predictive models in increasingly human-influenced environments.
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Affiliation(s)
- Katie E Hillyer
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Ecosciences Precinct, Dutton Park, QLD, Australia
| | - Eric Raes
- Oceans and Atmosphere, CSIRO, Battery Point, Hobart, TAS, Australia; Flourishing Oceans, Minderoo Foundation, Broadway, Nedlands, WA, Australia
| | - Andrew Bissett
- Oceans and Atmosphere, CSIRO, Battery Point, Hobart, TAS, Australia
| | - David J Beale
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Ecosciences Precinct, Dutton Park, QLD, Australia.
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11
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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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12
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Cugler de Pontes G, Vicente MDC, Kasper D, Machado WT, Wasserman JC. Spatial distribution of total mercury and methylmercury in the sediment of a tropical coastal environment subjected to heavy urban inputs. CHEMOSPHERE 2023; 312:137067. [PMID: 36397303 DOI: 10.1016/j.chemosphere.2022.137067] [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: 05/28/2020] [Revised: 07/26/2020] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Jurujuba Cove is located in Guanabara Bay (adjacent to highly populated city of Rio de Janeiro, Brazil), which receives diffuse sources of contaminants along with two main freshwater inputs (the Cachoeira and Icaraí rivers), and hosts mussel farms. The main goal of this work was to evaluate the total mercury (THg) and methylmercury (MeHg) concentrations distributions in the sediments of the cove and their associations with physical and chemical parameters, thereby assessing their geochemical behavior. Twenty samples of surface sediments were collected and characterized for grain size, pH, redox potential, organic carbon, total phosphorus, THg and MeHg. Spatial distribution maps were produced for each parameter and a principal components analysis was carried out, to assess THg and MeHg behavior and their relationships with other parameters. The principal components analysis showed that grain size functions as the main diluting agent. The highest THg concentrations were observed in the mussel-farm area (656.1 ng g-1), and were related to fine grain size and elevated organic carbon values. High MeHg concentrations also occurred in the center of the cove, probably favored by high organic carbon content (low-energy environment). Total phosphorus concentrations indicate that Cachoeira River is a possible source of sewage, but little mercury seems to come from it. The results showed that although total mercury concentrations are elevated, with exception of a few locations, small methylmercury convertion rates were recorded in the sediments.
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Affiliation(s)
- Gabriela Cugler de Pontes
- Post-Graduation Program in Geochemistry, University Federal Fluminense, Outeiro São João Baptista s/n - Centro - Niterói, RJ. CEP, 24020-141. Brazil.
| | - Murilo de Carvalho Vicente
- Post-Graduation Program in Geochemistry, University Federal Fluminense, Outeiro São João Baptista s/n - Centro - Niterói, RJ. CEP, 24020-141. Brazil.
| | - Daniele Kasper
- Laboratory of Tracers Applied to Environmental Science Wolfgang Christian Pfeiffer; Institute of Biophysics Carlos Chagas Filho, University Federal of Rio de Janeiro, Avenida Carlos Chagas Filho, 373, Bloco G - Cidade Universitária - Ilha do Fundão, CEP: 21941-902, Rio de Janeiro - RJ, Brazil.
| | - Wilson Thadeu Machado
- Post-Graduation Program in Geochemistry, University Federal Fluminense, Outeiro São João Baptista s/n - Centro - Niterói, RJ. CEP, 24020-141. Brazil.
| | - Julio Cesar Wasserman
- Post-Graduation Program in Geochemistry, University Federal Fluminense, Outeiro São João Baptista s/n - Centro - Niterói, RJ. CEP, 24020-141. Brazil.
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13
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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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14
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Ulus Y, Tsui MTK, Sakar A, Nyarko P, Aitmbarek NB, Ardón M, Chow AT. Declines of methylmercury along a salinity gradient in a low-lying coastal wetland ecosystem at South Carolina, USA. CHEMOSPHERE 2022; 308:136310. [PMID: 36088973 DOI: 10.1016/j.chemosphere.2022.136310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Wetlands are widely regarded as biogeochemical hotspots of highly toxic methylmercury (MeHg), mainly mediated by sulfate-reducing bacteria. In low-lying coastal wetlands, sea level rise, a phenomenon caused by global climate change, is slowly degrading numerous healthy freshwater forested wetlands into salt-degraded counterparts with a nickname "ghost forests", and eventually converting them to saltmarshes. However, little is known about the changes of mercury (Hg) methylation, bioaccumulation, and biomagnification along the forest-to-saltmarsh gradient. Here, we conducted extensive field sampling in three wetland states (healthy forested wetlands, salt-degraded forested wetlands, and saltmarsh) along a salinity gradient (from 0 to 9.4 ppt) in Winyah Bay, South Carolina, USA. We found that in our study wetland systems the saltmarshes had the lowest levels of both total Hg and MeHg in sediments and biota, as compared to healthy forested wetlands and saltwater-degraded ghost forests. Our results suggest that the slow conversion of forested wetland to saltmarsh could reduce net MeHg production in our study wetland systems, which we hypothesized that could be attributed to increased sulfate reduction and excessive buildup of sulfide in sediment that inhibits microbial Hg methylation, and/or reduced canopy density and increased photodegradation of MeHg. However, it should be noted that biogeochemical MeHg responses to salinity changes may be site-specific and we urge more similar studies in other wetland systems along a salinity gradient. Therefore, long-term salinization of coastal wetlands and the slow conversion of forests to marshes could decrease long-term exposure of toxic MeHg levels in coastal food webs that are similar to our system, and ultimately reduce human exposure to this neurotoxin.
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Affiliation(s)
- Yener Ulus
- Department of Environmental Studies, Davidson College, Davidson, NC, 28035, USA; Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Martin Tsz-Ki Tsui
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA; School of Life Sciences, Earth and Environmental Sciences Programme, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
| | - Aslihan Sakar
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Paul Nyarko
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Nadia B Aitmbarek
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Marcelo Ardón
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA
| | - Alex T Chow
- Biogeochemistry and Environmental Quality Research Group, Clemson University, Georgetown, SC, 29442, USA
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15
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Kho F, Koppel DJ, von Hellfeld R, Hastings A, Gissi F, Cresswell T, Higgins S. Current understanding of the ecological risk of mercury from subsea oil and gas infrastructure to marine ecosystems. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129348. [PMID: 35797785 DOI: 10.1016/j.jhazmat.2022.129348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/31/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Many oil and gas fields are nearing production cessation and will require decommissioning, with the preferred method being complete infrastructure removal in most jurisdictions. However, decommissioning in situ, leaving some disused components in place, is an option that may be agreed to by the regulators and reservoir titleholders in some circumstances. To understand this option's viability, the environmental impacts and risks of any residual contaminants assessed. Mercury, a contaminant of concern, is naturally present in hydrocarbon reservoirs, may contaminate offshore processing and transmission infrastructure, and can biomagnify in marine ecosystems. Mercury's impact is dependent on its speciation, concentration, and the exposure duration. However, research characterising and quantifying the amount of mercury in offshore infrastructure and the efficacy of decontamination is limited. This review describes the formation of mercury-contaminated products within oil and gas infrastructure, expected exposure pathways after environmental release, possible impacts, and key research gaps regarding the ecological risk of in situ decommissioned contaminated infrastructure. Suggestions are made to overcome these gaps, improving the in situ mercury quantification in infrastructure, understanding environmental controls on, and forecasting of, mercury methylation and bioaccumulation, and the cumulative impacts of multiple stressors within decommissioned infrastructures.
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Affiliation(s)
- Fenny Kho
- Faculty of Science and Engineering, Curtin University, Perth, WA, Australia; Curtin Corrosion Centre, Curtin University, Perth, WA, Australia
| | - Darren J Koppel
- Faculty of Science and Engineering, Curtin University, Perth, WA, Australia; Australian Institute of Marine Science, Perth, WA, Australia
| | - Rebecca von Hellfeld
- National Decommissioning Centre, University of Aberdeen, Aberdeen, Scotland, UK.
| | - Astley Hastings
- National Decommissioning Centre, University of Aberdeen, Aberdeen, Scotland, UK
| | - Francesca Gissi
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Tom Cresswell
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Stuart Higgins
- Faculty of Science and Engineering, Curtin University, Perth, WA, Australia
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16
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Mercury Accumulation in a Stream Ecosystem: Linking Labile Mercury in Sediment Porewaters to Bioaccumulative Mercury in Trophic Webs. WATER 2022. [DOI: 10.3390/w14132003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mercury (Hg) deposition and accumulation in the abiotic and biotic environments of a stream ecosystem were studied. This study aimed to link labile Hg in porewater to bioaccumulative Hg in biota. Sediment cores, porewaters, and biota were sampled from four sites along the Fourmile Branch (SC, USA) and measured for total Hg (THg) and methyl-Hg (MHg) concentrations. Water quality parameters were also measured at the sediment–water interface (SWI) to model the Hg speciation. In general, Hg concentrations in porewaters and bulk sediment were relatively high, and most of the sediment Hg was in the solid phase as non-labile species. Surface sediment presented higher Hg concentrations than the medium and bottom layers. Mercury methylation and MHg production in the sediment was primarily influenced by sulfate levels, since positive correlations were observed between sulfate and Hg in the porewaters. The majority of Hg species at the SWI were in non-labile form, and the dominant labile Hg species was complexed with dissolved organic carbon. MHg concentrations in the aquatic food web biomagnified with trophic levels (biofilm, invertebrates, and fish), increasing by 3.31 times per trophic level. Based on the derived data, a modified MHg magnification model was established to estimate the Hg bioaccumulation at any trophic level using Hg concentrations in the abiotic environment (i.e., porewater).
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17
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Liu J, Li Y, Duan D, Peng G, Li P, Lei P, Zhong H, Tsui MTK, Pan K. Effects and mechanisms of organic matter regulating the methylmercury dynamics in mangrove sediments. JOURNAL OF HAZARDOUS MATERIALS 2022; 432:128690. [PMID: 35325865 DOI: 10.1016/j.jhazmat.2022.128690] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/09/2022] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
Mangrove ecosystems serve as an important carbon sink but also could be a hotspot that produces neurotoxic methylmercury (MeHg). Although many studies have focused on mercury (Hg) contamination in this carbon-rich ecosystem, our understanding of the effects and mechanisms of the organic matter (OM) regulation of MeHg production in mangrove sediments is still limited. Here, we examined the effects of Hg contamination and OM enrichment on MeHg production in anoxic mangrove sediments and identified the major microbial guilds attending this process. The mangrove sediments possessed a high potential for producing MeHg, but this was counterbalanced by its rapid degradation. Sulfate-reducing bacteria (SRB) such as Desulfobacterales, Desulfovibrionales, and Syntrophobacterales were the major methylators. OM diagenesis significantly changed the biogeochemical conditions, accelerating MeHg degradation in the sediments. The enhanced MeHg degradation could be attributed to the abundant sulfide produced during OM decomposition, which could potentially inhibit the Hg methylation by immobilization of inorganic Hg, abiotically degrade MeHg, and favor the non-mer-mediated degradation of MeHg by SRB. Our study provides both geochemical and microbial clues that can partly explain the low MeHg levels widely observed in mangrove sediments.
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Affiliation(s)
- Jingli Liu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Yanping Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Dandan Duan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Guogan Peng
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Ping Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Pei Lei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Martin Tsz-Ki Tsui
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Ke Pan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
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18
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Moslemi-Aqdam M, Baker LF, Baltzer JL, Branfireun BA, Evans MS, Laird BD, Low G, Low M, Swanson HK. Understanding among-lake variability of mercury concentrations in Northern Pike (Esox lucius): A whole-ecosystem study in subarctic lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153430. [PMID: 35090925 DOI: 10.1016/j.scitotenv.2022.153430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Mercury concentrations ([Hg]) in fish reflect complex biogeochemical and ecological interactions that occur at a range of spatial and biological scales. Elucidating these interactions is crucial to understanding and predicting fish [Hg], particularly at northern latitudes, where environmental perturbations are having profound effects on land-water-animal interactions, and where fish are a critical subsistence food source. Using data from eleven subarctic lakes that span an area of ~60,000 km2 in the Dehcho Region of Northwest Territories (Canada), we investigated how trophic ecology and growth rates of fish, lake water chemistry, and catchment characteristics interact to affect [Hg] in Northern Pike (Esox lucius), a predatory fish of widespread subsistence and commercial importance. Results from linear regression and piecewise structural equation models showed that 83% of among-lake variability in Northern Pike [Hg] was explained by fish growth rates (negative) and concentrations of methyl Hg ([MeHg]) in benthic invertebrates (positive). These variables were in turn influenced by concentrations of dissolved organic carbon, MeHg (water), and total Hg (sediment) in lakes, which were ultimately driven by catchment characteristics. Lakes in relatively larger catchments and with more temperate/subpolar needleleaf and mixed forests had higher [Hg] in Northern Pike. Our results provide a plausible mechanistic understanding of how interacting processes at scales ranging from whole catchments to individual organisms influence fish [Hg], and give insight into factors that could be considered for prioritizing lakes for monitoring in subarctic regions.
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Affiliation(s)
| | - Leanne F Baker
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | | | | | - Marlene S Evans
- Water Science and Technology Directorate, Environment and Climate Change Canada, Saskatoon, SK, Canada
| | - Brian D Laird
- School of Public Health Sciences, University of Waterloo, Waterloo, ON, 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, University of Waterloo, Waterloo, ON, Canada; Water Institute, University of Waterloo, Waterloo, ON, Canada
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19
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An Y, Zhang R, Yang S, Wang Y, Lei Y, Peng S, Song L. Microbial mercury methylation potential in a large-scale municipal solid waste landfill, China. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 145:102-111. [PMID: 35526502 DOI: 10.1016/j.wasman.2022.04.038] [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: 01/26/2022] [Revised: 04/23/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Landfills harbor ideal conditions for microbial mercury methylation. However, the levels and distribution of mercury (Hg) and methylmercury (MeHg), potential microbial Hg methylation, and their linkage within landfills are largely unknown. In the present study, total mercury (THg), MeHg, the Hg methylation gene (hgcA) and mer operon were quantified in 30 waste samples from different depths (0-30 m) at 5 locations within a large-scale landfill in China. The average concentrations of THg and MeHg in the solid waste samples were 1422.91 ng/g and 3.15 ng/g, respectively. THg (up to 14405.29 ng/g) and MeHg (up to 10.42 ng/g) have high concentrations in the middle part (10-15 m) along the depth profiles. The concentration of THg was strongly positively (both p < 0.05) correlated with the MeHg concentration and the relative abundance of hgcA, indicating that the THg concentration can play an important role in microbial Hg methylation. The hgcA genes were detected in most samples and mer operon were detected in all samples. Combined hgcA qPCR and metagenomics data showed that Archaea Methanofollis may mainly account for Hg methylation within landfills. These findings provide fundamental knowledge on Hg cycles in landfills.
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Affiliation(s)
- Yuwei An
- Chongqing Jiaotong University, Chongqing 400074, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, China
| | - Rui Zhang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Shu Yang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
| | - Yangqing Wang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Yu Lei
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Shaohong Peng
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming 525000, China
| | - Liyan Song
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China.
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20
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Chaudhary DK, Kim KH, Lee M, Kim H, Hong Y. Insights into Bacterial Community Structure and Metabolic Diversity of Mercury-Contaminated Sediments from Hyeongsan River, Pohang, South Korea. Curr Microbiol 2022; 79:156. [PMID: 35397046 DOI: 10.1007/s00284-022-02847-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 03/16/2022] [Indexed: 11/30/2022]
Abstract
This study investigated the bacterial community structure and metabolic diversity and their relationship with Hg and other environmental variables in sediments collected from different locations (HSR-1-HSR-6) in the Hyeongsan River estuary in South Korea. The results showed that the highest total mercury (THg) and methylmercury (MeHg) concentrations were in HSR-2, with values of 4585.3 µg/kg and 13.4 µg/kg, respectively. The lowest THg (31.9 µg/kg) and MeHg (0.1 µg/kg) concentrations were found in HSR-1. Sulfate and organic matter (OM) were more influential environmental variables, revealing a positive association with THg and MeHg and negatively affecting bacterial and metabolic diversities. Bacterial and metabolic diversities were also negatively impacted by the THg and MeHg concentrations. Proteobacteria and Bacteroidetes were abundantly distributed in all the sediments. The dominance of Proteobacteria was upscaled in all the heavily Hg-contaminated sites (HSR-2-HSR-6), and it was the only phylum that showed a significant positive correlation with THg, MeHg, and OM. The genera Sulfurovum and Sulfurimonas were abundantly observed in sites with high Hg contamination, whereas Congregibacter, Gaetbulibacter, Ilumatobacter, Methylotenera, Nevskia, and Sediminibacter were only detected in low Hg-contaminated sites (HSR-1). The community-level physiological profile data showed the highest (1.0) average well color development (AWCD) value in HSR-1 and the lowest (0.45) AWCD value in HSR-2. Overall, these results demonstrated the inhibitory effects of THg, MeHg, and other environmental variables on microbial communities and metabolic diversity. These findings broaden the current knowledge on the dynamics of bacterial and metabolic diversities in Hg-contaminated sediments and might be useful in the management of Hg pollution.
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Affiliation(s)
- Dhiraj Kumar Chaudhary
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong, 30019, Republic of Korea
| | - Kyung Hee Kim
- Water Environmental Engineering Research Division, National Institute of Environmental Research, Hwangyong-ro 42, Seogu, Incheon, 22689, Republic of Korea
| | - Mikyung Lee
- Water Environmental Engineering Research Division, National Institute of Environmental Research, Hwangyong-ro 42, Seogu, Incheon, 22689, Republic of Korea
| | - Hwansuk Kim
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong, 30019, Republic of Korea
| | - Yongseok Hong
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong, 30019, Republic of Korea.
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21
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Bailon MX, Park M, Solis KL, Na Y, Chaudhary DK, Kim S, Hong Y. Reduction in mercury bioavailability to Asian clams (Corbicula fluminea) and changes in bacterial communities in sediments with activated carbon amendment. CHEMOSPHERE 2022; 291:132700. [PMID: 34710454 DOI: 10.1016/j.chemosphere.2021.132700] [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: 05/21/2021] [Revised: 08/23/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Activated carbon (AC) amendment is considered as one of the alternatives for managing and remediating mercury (Hg) contaminated sediments because of its high sorptive capacity and potential to immobilize the contaminant. For this study, the underlying mechanisms that control the reduction of Hg bioavailability in AC-amended estuarine sediments were investigated in box microcosm set-ups with 28-day Asian clam bioassay experiments. The application of diffusive gradients in thin film technique (DGT) revealed that the total mercury and methylmercury levels in sediment pore water decreased by 60%-75% in 1%-3% AC-amended sediments. This decrease subsequently led to a linear reduction in the Hg body burden in Asian clams, even at 1% sorbent mixing. These observations implied that AC amendment reduced the net flux of Hg into the pore water and overlying water, resulting in reduced Hg bioaccumulation in benthic organisms. The addition of AC to sediment also led to reduced dissolved organic carbon and several biogeochemical indicators (HS-, Mn, and Fe) in the pore water. Furthermore, the 16 S rRNA gene amplicon sequencing analysis revealed noticeable alterations in the microbial communities after AC amendment. The predominant phylum was Firmicutes in control sediment, Bacteroidetes in 1% AC-amended sediment, and Proteobacteria in both 2% and 3% AC-amended sediment samples. The genera-level analysis showed that the relative abundance of the Hg-methylators decreased as the level of AC amendment increased. These observations suggested that AC amendment decreased Hg bioavailability not only by physicochemical sorption but also by changing geochemical species and shifting the microbial community composition.
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Affiliation(s)
- Mark Xavier Bailon
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea; Department of Science and Technology, Philippine Science High School - Central Luzon Campus, Lily Hill, Clark Freeport Zone, Mabalacat City, Pampanga, 2010, Philippines
| | - Minoh Park
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea
| | - Kurt Louis Solis
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea
| | - Yeong Na
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea
| | - Dhiraj Kumar Chaudhary
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea
| | - Sungpyo Kim
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea
| | - Yongseok Hong
- Department of Environmental Engineering, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City, 30019, South Korea.
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22
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Wang J, Dai J, Chen G, Jiang F. Role of sulfur biogeochemical cycle in mercury methylation in estuarine sediments: A review. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:126964. [PMID: 34523493 DOI: 10.1016/j.jhazmat.2021.126964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 07/26/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Estuaries are sinks for mercury, in which the most toxic mercury form, neurotoxic methylmercury (MeHg), is produced by mercury methylators and accumulates in estuarine sediments. In the same area, the microbial sulfur cycle is triggered by sulfate-reducing bacteria (SRB), which is considered as the main mercury methylator. In this review, we analyzed the sulfur and mercury speciation in sediments from 70 estuaries globally. Abundant mercury and sulfur species were found in the global estuarine sediments. Up to 727 μg THg/g dw and 880 ng MeHg/g dw were found in estuarine sediments, showing the serious risk of mercury to aquatic ecological systems. Significant correlations between sulfur and MeHg concentrations were discovered. Especially, the porewater sulfate concentration positively correlated to MeHg production. The sulfur cycle affects MeHg formation via activating mercury methylator activities and limiting mercury bioavailability, leading to promote or inhibit MeHg formation at different sulfur speciation concentrations. These results suggest that sulfur biogeochemical cycle plays an important role in mercury methylation in estuarine sediments, and the effect of the sulfur cycle on mercury methylation deserves to be further explored in future research.
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Affiliation(s)
- Jinting Wang
- Department of Civil and Environmental Engineering, Water Technology Lab, Hong Kong Branch of Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ji Dai
- Department of Civil and Environmental Engineering, Water Technology Lab, Hong Kong Branch of Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Lab, Hong Kong Branch of Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Feng Jiang
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, School of Environmental Science & Engineering, Sun Yat-sen University, Guangzhou, China.
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23
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Valsecchi L, Roscioli C, Schiavon A, Marziali L. Methylmercury determination in freshwater biota and sediments: Static headspace GC-MS compared to direct mercury analyzer. MethodsX 2022; 8:101581. [PMID: 35004215 PMCID: PMC8720905 DOI: 10.1016/j.mex.2021.101581] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022] Open
Abstract
We developed and compared two analytical methods for determination of MeHg in freshwater biota and sediments, by: I) simplified static headspace GC-MS using internal standard (IS) isotope dilution quantification, after microwave acid digestion and aqueous phase NaBEt4 ethylation; II) Automated Mercury Analyzer, after double toluene extraction followed by back-extraction with L-cystein. The performance was evaluated by analysis of certified reference materials. For biota, mean recovery was 100 ± 2% and relative standard deviation (RSD) ≤ 6.8% for method I, and mean recovery was 98 ± 7% and RSD ≤13% for method II. For sediments, recovery of 94.5% and RSD of 8.8% were obtained with method I, and recovery of 90.3% and RSD of 9.4% with method II. Limits of detection (LOD) were 0.7 µg kg−1 and 6 µg kg−1, respectively. Both techniques were tested for MeHg analysis in freshwater invertebrates, fish and sediments, covering a large range of MeHg values (1.9–670 µg kg−1 d.w.). • Both protocols proved to be suitable for MeHg analysis in complex environmental matrices, even if, for method II, interferences in the extraction phase and limited sensitivity may hinder sediment analysis. • Passing-Bablock regression revealed a slight disproportion between methods, with line slope = 1.058 (95% CI ranging from 1.001 to 1.090).
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Affiliation(s)
- Lucia Valsecchi
- CNR-IRSA National Research Council, Water Research Institute, Via del Mulino 19, Brugherio (MB) I-20861, Italy
| | - Claudio Roscioli
- CNR-IRSA National Research Council, Water Research Institute, Via del Mulino 19, Brugherio (MB) I-20861, Italy
| | - Alfredo Schiavon
- CNR-IRSA National Research Council, Water Research Institute, Via del Mulino 19, Brugherio (MB) I-20861, Italy.,Department of Ecohydrology, IGB Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin 12587, Germany
| | - Laura Marziali
- CNR-IRSA National Research Council, Water Research Institute, Via del Mulino 19, Brugherio (MB) I-20861, Italy
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24
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Aslam MW, Meng B, Abdelhafiz MA, Liu J, Feng X. Unravelling the interactive effect of soil and atmospheric mercury influencing mercury distribution and accumulation in the soil-rice system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:149967. [PMID: 34482140 DOI: 10.1016/j.scitotenv.2021.149967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) accumulation in rice is an emerging health concern worldwide. However, sources and interactions responsible for Hg species accumulation in different rice tissues are still uncertain. Four experimental plots were carefully designed at an artisanal Hg mining site and a control site to evaluate the effect of atmospheric and soil Hg contents on Hg accumulation in rice. We showed that inorganic Hg (IHg) contents in rice tissues grown either in contaminated or control site soil (non-contaminated soil) were higher at Hg artisanal mining site than those at the control site. Elevated total gaseous mercury (TGM) levels in ambient air were the predominant source of IHg to rice at the Hg mining area. Methylmercury (MeHg) concentrations in rice plant tissues increased in proportionality with MeHg contents in paddy soil. Our results suggest that both atmosphere and soil Hg sources have been impacted the IHg accumulation in rice. Above ground rice tissues, grains, leaves, and stalk accumulated IHg from both atmosphere and soil to varying degrees. Nonetheless, the study also provides the first direct evidence that atmospheric Hg accumulated by above-ground rice tissues could be translocated to below-ground tissues (roots). However, the extent to which atmosphere or soil Hg contributes to IHg in rice tissues may vary with each source's concentration gradient at the given site. No evidence of in planta Hg methylation was found during the current study. Hence, paddy fields are potential MeHg production sites, whereas paddy soil is a unique MeHg accumulation source in rice plants. This study expands and clarifies the contribution of various sources involved in Hg accumulation in the soil rice system. The findings here provide the basis for future research strategies to deal with the global issue of Hg contaminated rice.
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Affiliation(s)
- Muhammad Wajahat Aslam
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China.
| | - Mahmoud A Abdelhafiz
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR 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 550002, PR China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China; Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian 710061, PR China.
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25
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Du J, Liu F, Zhao L, Liu C, Fu Z, Teng Y. Mercury horizontal spatial distribution in paddy field and accumulation of mercury in rice as well as their influencing factors in a typical mining area of Tongren City, Guizhou, China. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2021; 19:1555-1567. [PMID: 34900288 PMCID: PMC8617142 DOI: 10.1007/s40201-021-00711-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/12/2021] [Indexed: 06/01/2023]
Abstract
PURPOSE To make up for the deficiency of the distribution characteristics of mercury (Hg) pollution in soil and rice in a specific area, the relationship between more than ten soil indices and Hg in soil-rice system was analysed, and the main factors affecting mercury accumulation in rice were screened out. So as to provide reliable theoretical and scientific basis for the regulation and safe utilization of Hg-contaminated soil. METHODS The Hg-polluted area of Siqian Dam, with a paddy field area of 1.34 million square meters, was selected as the research unit. Soil and corresponding rice samples were collected and analysed. Then, common Kriging interpolation was used to explore the spatial distribution differences of mercury content between soil and rice, Pearson correlation analysis and stepwise linear regression were used to analyse the relationship between mercury content and 14 soil indices. RESULTS In the study area, the total mercury(THg) content in soil and rice was as high as 30.60 mg/kg and 160.19 µg/kg, respectively, and the methyl mercury(MeHg) content was as high as 14.56 µg/kg and 40.32 µg/kg, respectively, indicating that mercury pollution in soil and rice was serious. The horizontal spatial distribution of soil THg and MeHg was different. Flood with its sediment and topography were the main reasons for the uneven distribution of Hg content in the region. The spatial distribution of Hg was different between rice and soil. There was no significant correlation between rice and soil THg, but there was a significant correlation between rice and soil MeHg content. Among the 14 soil indices, available potassium was a vital index affecting the accumulation of Hg in rice, followed by pH, Zn, Mn and Fe. CONCLUSIONS The results showed that in weakly acidic and fertile soil, the appropriate reduction of soil pH, OM and available Se and Cr contents could inhibit soil Hg methylation, the reduction of potassium fertilizer application could further reduce rice Hg accumulation. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s40201-021-00711-z.
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Affiliation(s)
- Jingjing Du
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025 China
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Fang Liu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025 China
| | - Ling Zhao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Chong Liu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025 China
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhaocong Fu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ying Teng
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China
- University of Chinese Academy of Sciences, Beijing, 100049 China
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26
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Chen L, Zhang X, Cao M, Pan Y, Xiao C, Wang P, Liang Y, Liu G, Cai Y. Release of legacy mercury and effect of aquaculture on mercury biogeochemical cycling in highly polluted Ya-Er Lake, China. CHEMOSPHERE 2021; 275:130011. [PMID: 33667774 DOI: 10.1016/j.chemosphere.2021.130011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Although global mercury (Hg) emission from chlor-alkali industry is decreasing, the legacy Hg may still have potential risks due to its environmental persistence. The objective of this work is to study the biogeochemical cycling and potential risk of Hg in the Ya-Er Lake, which was heavily contaminated by historical chlor-alkali production. Higher concentrations of total Hg (THg) in Ya-Er Lake water (16.8 ± 8.4 ng L-1) and sediment (547 ± 489 ng g-1) than other lake systems were observed, reflecting serious Hg pollution in this system. Diffusion rates of Hg at sediment-water interface and budget of Hg showed that release of legacy Hg in sediment (accounting for ∼80%) dominated THg in water, and about 80% methylmercury (MeHg) of total was diffused from sediment. Significant correlations between total organic carbon (TOC) derived from aquaculture and THg diffusion and MeHg concentrations in sediment suggest that TOC plays important roles in controlling legacy Hg release and MeHg production. The actual weekly intakes of Hg via consumption of cultured catfish and wild topmouth culter were higher than the established provisional tolerable weekly intake (PTWI) of MeHg. These results indicated that although the nearby chlor-alkali plant has been shut down for three decades, the release of legacy Hg stored in the sediment still adversely affects this ecosystem. Moreover, aquaculture could enhance MeHg production and control MeHg distribution in the polluted aquatic ecosystem, potentially posing a health risk to surrounding inhabitants through consumption of fish.
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Affiliation(s)
- Lufeng Chen
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xing Zhang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Mengxi Cao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Yu Pan
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Cailing Xiao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Pu Wang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Yong Liang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Guangliang Liu
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Yong Cai
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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27
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Duan D, Lei P, Lan W, Li T, Zhang H, Zhong H, Pan K. Litterfall-derived organic matter enhances mercury methylation in mangrove sediments of South China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:142763. [PMID: 33069467 DOI: 10.1016/j.scitotenv.2020.142763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Mercury (Hg) contamination in mangrove ecosystems has received increasing attention in recent years. Although many studies have investigated methylmercury (MeHg) contamination and its relationship to a number of environmental factors in mangrove sediments, the production of MeHg in this carbon-rich ecosystem has not been fully evaluated. In this study, we measured the total mercury (THg) and MeHg concentrations in the sediments collected from seven mangrove forests in China. In addition, we examined the origin and quality of sedimentary organic matter (OM), trying to evaluate their influence on the MeHg accumulation in mangrove sediments. We found that litterfall played an important role in regulating THg and MeHg contents in mangrove sediments. THg and MeHg concentrations in the mangrove sediments were positively correlated to OM content and the labile fraction of the OM. Multiple evidence (stable carbon isotopes, monosaccharide compositions, and biogenic silica) suggested that OM in mangrove sediments was dominated by input from litterfall. THg and MeHg concentrations were elevated at the sediments with higher input of mangrove OM. We observed that addition of mangrove litter stimulated the production of MeHg under anaerobic conditions. Overall, our results suggested that litterfall acted as a source of inorganic Hg, labile carbon, and low-molecular-weight OM which greatly favor the Hg methylation. Our study provides new insights into the MeHg production in mangrove sediments.
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Affiliation(s)
- Dandan Duan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Pei Lei
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
| | - Wenlu Lan
- Marine Environmental Monitoring Center of Guangxi, Beihai 536000, China; Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, China
| | - Tianshen Li
- Marine Environmental Monitoring Center of Guangxi, Beihai 536000, China; Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, China
| | - Hao Zhang
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
| | - Ke Pan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
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28
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Khan EA, Abbas Z. A scoping review of sources of mercury and its health effects among Pakistan's most vulnerable population. REVIEWS ON ENVIRONMENTAL HEALTH 2021; 36:39-45. [PMID: 32822319 DOI: 10.1515/reveh-2019-0099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Mercury and methyl mercury are poisonous to human body. In the recent times, exposure to mercury has been anthropogenic in nature. Within the past several decades, many incidences of mercury poisoning have been documented in several countries including Pakistan. Mercury has been ingested where it has been used to preserve crops, through the point and non-point source discharge into the surface water, and consequently entering the food chain. We conducted this scoping review of mercury and its health effects in Pakistan in order to raise the flag to a silent ongoing Minamata disease in the country. We conducted a systematic search of the available literature in Google Scholar, PubMed, and grey literature of unpublished theses and reports of various universities across the country. We found that in the northern Pakistan, suspended sediments were the major pathway of the riverine mercury transport. Sediments of Hunza and Gilgit River were found high in mercury concentrations. Gold mining leads to an increase in mercury concentration in soil and river waters flowing in this region. High concentrations up to 108 ng/L were found in Shimsal River. It is suspected that that high level of mercury transport may be leading to accumulation of mercury in major water bodies and lakes downstream. Occupational exposure to mercury and other heavy metals is common in an unregulated private sector of the country. Goldsmiths burn the amalgamated gold without personal protective measures. Direct exposure to the fumes of mercury leads to respiratory, dermatological, systemic and neurological ailments specific to mercury poisoning. We found good evidence of bioaccumulation of mercury in fish and fish products in Pakistan. The untreated waste water discharge is responsible to not only afflicted the fish but also the birds which feed on this fish. Further, the same untreated waste water from factories and agriculture runoffs affect vegetables grown in it. Studies looking at the biomarkers for mercury in humans have shown increased and even toxic levels of mercury among the most vulnerable populations of the country. Other sources of mercury exposure included mercury in traditional medicines and cigarette products. Though no evidence was found for its presence in drinking water, its existence in the food chain and occupational exposure pose great threat to the humans as well as animals.
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Affiliation(s)
| | - Zaigham Abbas
- Deputy Director Chemical, Ministry of Climate Change, Islamabad, Pakistan
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29
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Seelen EA, Chen CY, Balcom PH, Buckman KL, Taylor VF, Mason RP. Historic contamination alters mercury sources and cycling in temperate estuaries relative to uncontaminated sites. WATER RESEARCH 2021; 190:116684. [PMID: 33310435 PMCID: PMC7855490 DOI: 10.1016/j.watres.2020.116684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 05/16/2023]
Abstract
Mercury (Hg) is a global and persistent pollutant which can be methylated to more toxic forms (methylmercury; MeHg) in natural systems. Both forms pose a health risk to humans and wildlife, and exposure often begins in aquatic environments. Therefore, quantifying aquatic concentrations and identifying source pathways is important for understanding biotic exposure. In this study, data from estuaries in the Northeast United States were combined to evaluate how point source contamination impacts the concentration and source dynamics of water column total and MeHg with an emphasis on sediment versus non-sediment sources. Partial least squares regression models were implemented to identify a set of variables most related to water column MeHg and total Hg (HgT) across the estuaries. The main findings suggest that contaminated sites have strong internal recycling of HgT that dominates over external inputs, and this leads to elevated concentrations of HgT and MeHg in the local water columns. However, HgT sources in uncontaminated estuarine systems have a strong connection to the local watershed with dissolved HgT linked to dissolved organic carbon, and particulate HgT linked to watershed land use and estuarine mixing. There was little correlative evidence that water column MeHg concentrations were linked to sediment in such systems, but unlike HgT, the concentrations were also not clearly linked to the watershed. Instead, in situ methylation of dissolved water column HgT appeared to dominate the MeHg source pathway. The results suggest that Hg point-source contaminated sites should be considered independently from non-contaminated sites in terms of management, and that land use plays an important indirect role in coastal MeHg dynamics.
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Affiliation(s)
- Emily A Seelen
- University of Connecticut, Department of Marine Sciences, 1084 Shennecossett Road, Groton, CT, 06340 USA.
| | - Celia Y Chen
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755 USA.
| | - Prentiss H Balcom
- University of Connecticut, Department of Marine Sciences, 1084 Shennecossett Road, Groton, CT, 06340 USA; Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), 29 Oxford Street, Cambridge, MA 02138 USA.
| | - Kate L Buckman
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755 USA.
| | - Vivien F Taylor
- Dartmouth College, Department of Earth Science, Hanover, NH 03755 USA.
| | - Robert P Mason
- University of Connecticut, Department of Marine Sciences, 1084 Shennecossett Road, Groton, CT, 06340 USA.
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30
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Janssen SE, Tate MT, Krabbenhoft DP, DeWild JF, Ogorek JM, Babiarz CL, Sowers AD, Tuttle PL. The influence of legacy contamination on the transport and bioaccumulation of mercury within the Mobile River Basin. JOURNAL OF HAZARDOUS MATERIALS 2021; 404:124097. [PMID: 33022526 DOI: 10.1016/j.jhazmat.2020.124097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/28/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
Past industrial use and subsequent release of mercury (Hg) into the environment have resulted in severe cases of legacy contamination that still influence contemporary Hg levels in biota. While the bioaccumulation of legacy Hg is commonly assessed via concentration measurements within fish tissue, this practice becomes difficult in regions of high productivity and methylmercury (MeHg) production, like the Mobile River Basin, Alabama in the southeastern United States. This study applied Hg stable isotope tracers to distinguish legacy Hg from regional deposition sources in sediments, waters, and fish within the Mobile River. Sediments and waters displayed differences in δ202Hg between industrial and background sites, which corresponded to drastic differences in Hg concentration. Sites that were affected by legacy Hg, as defined by δ202Hg, produced largemouth bass with lower MeHg content (59-70%) than those captured in the main rivers (>85%). Direct measurements of Hg isotopes and mathematical estimates of MeHg isotope pools in fish displayed similar distinctions between legacy and watershed sources as observed in other matrices. These results indicate that legacy Hg can accumulate directly into fish tissue as the inorganic species and may also be available for methylation within contaminated zones decades after the initial release.
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Affiliation(s)
- Sarah E Janssen
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA.
| | - Michael T Tate
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - David P Krabbenhoft
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - John F DeWild
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Jacob M Ogorek
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Christopher L Babiarz
- U.S. Geological Survey Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Anthony D Sowers
- U.S. Fish and Wildlife Service, Georgia Ecological Services Office, 4980 Wildlife Dr., Townsend, GA 31331, USA
| | - Peter L Tuttle
- U.S. Fish and Wildlife Service, Deepwater Horizon Gulf Restoration Office, 341 Greeno Road, Fairhope, AL 36532, USA
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31
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Azad AM, Frantzen S, Bank MS, Madsen L, Maage A. Mercury bioaccumulation pathways in tusk (Brosme brosme) from Sognefjord, Norway: Insights from C and N isotopes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:115997. [PMID: 33218771 DOI: 10.1016/j.envpol.2020.115997] [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: 05/11/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
Seafood is the main source of methylmercury (MeHg) exposure for humans and elevated total mercury (Hg) concentrations have been reported in marine fish from Norwegian fjords compared with offshore areas. Hg in tusk fillets (n = 201) and liver samples (n = 177) were measured in individuals from different habitats including offshore, coastal area, outer and inner Sognefjord. Specifically, the effects of habitat, energy sources and trophic complexity on Hg bioaccumulation pathways in tusk (Brosme brosme) were investigated using stable isotopes of carbon (δ13C) and nitrogen (δ15N). The concentrations of Hg in tusk increased from offshore towards inner Sognefjord. While Hg concentrations in sediment were at background levels, tusk fillet samples from 7 of 8 sites in Sognefjord had higher Hg levels than the maximum level set by European Union. Based on these findings, human consumption advice for tusk from Sognefjord was issued by the Norwegian Food Safety Authority. δ13C values in tusk successfully discriminated individuals from different habitats and were positively correlated to Hg concentrations in tusk across individuals, sites and habitats, outlining the potential importance of terrestrial carbon and most likely the atmospheric deposition of Hg from the catchment to the overall Hg bioaccumulation and exposure regime in tusk. Additionally, we postulate that the effects of terrestrial carbon sources increased towards inner Sognefjord and likely influenced Hg bioavailability throughout the food web. In contrast, δ15N values were patchy throughout the fjord system and although trophic position explained some of the Hg variation between individual fish, it was not correlated with Hg variation across sites and habitats. Our results suggest that tusk can accumulate high levels of Hg in fjord ecosystems and that catchment runoff is likely an important driver of Hg bioaccumulation in this species.
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Affiliation(s)
- A M Azad
- Institute of Marine Research, Bergen, Norway; Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen, Norway.
| | - S Frantzen
- Institute of Marine Research, Bergen, Norway
| | - M S Bank
- Institute of Marine Research, Bergen, Norway; Department of Environmental Conservation, University of Massachusetts, Amherst, Amherst, MA, USA
| | - L Madsen
- Institute of Marine Research, Bergen, Norway; Department of Biology, University of Copenhagen, Denmark
| | - A Maage
- Institute of Marine Research, Bergen, Norway; Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen, Norway
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32
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Wu Q, Hu H, Meng B, Wang B, Poulain AJ, Zhang H, Liu J, Bravo AG, Bishop K, Bertilsson S, Feng X. Methanogenesis Is an Important Process in Controlling MeHg Concentration in Rice Paddy Soils Affected by Mining Activities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13517-13526. [PMID: 33084323 DOI: 10.1021/acs.est.0c00268] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rice paddies are agricultural sites of special concern because the potent toxin methylmercury (MeHg), produced in rice paddy soils, accumulates in rice grains. MeHg cycling is mostly controlled by microbes but their importance in MeHg production and degradation in paddy soils and across a Hg concentration gradient remains unclear. Here we used surface and rhizosphere soil samples in a series of incubation experiments in combination with stable isotope tracers to investigate the relative importance of different microbial groups on MeHg production and degradation across a Hg contamination gradient. We showed that sulfate reduction was the main driver of MeHg formation and concentration at control sites, and that methanogenesis had an important and complex role in MeHg cycling as Hg concentrations increased. The inhibition of methanogenesis at the mining sites led to an increase in MeHg production up to 16.6-fold and a decrease in MeHg degradation by up to 77%, suggesting that methanogenesis is associated with MeHg degradation as Hg concentrations increased. This study broadens our understanding of the roles of microbes in MeHg cycling and highlights methanogenesis as a key control of MeHg concentrations in rice paddies, offering the potential for mitigation of Hg contamination and for the safe production of rice in Hg-contaminated areas.
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Affiliation(s)
- Qingqing Wu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Haiyan Hu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, P. R. China
- 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, P. R. China
| | - Baolin Wang
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala SE-75007, Sweden
| | - Alexandre J Poulain
- Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Hua Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, P. R. China
| | - Jinling Liu
- School of Earth Sciences, China University of Geosciences, Wuhan 430074, P. R. China
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Pg Marítim de la Barceloneta 37-49, 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
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, P. R. China
- Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian 710061, P. R. China
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Pathak A, Jaswal R, Xu X, White JR, Edwards B, Hunt J, Brooks S, Rathore RS, Agarwal M, Chauhan A. Characterization of Bacterial and Fungal Assemblages From Historically Contaminated Metalliferous Soils Using Metagenomics Coupled With Diffusion Chambers and Microbial Traps. Front Microbiol 2020; 11:1024. [PMID: 32655505 PMCID: PMC7325934 DOI: 10.3389/fmicb.2020.01024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/27/2020] [Indexed: 01/05/2023] Open
Abstract
The majority of environmental microbiomes are not amenable to cultivation under standard laboratory growth conditions and hence remain uncharacterized. For environmental applications, such as bioremediation, it is necessary to isolate microbes performing the desired function, which may not necessarily be the fast growing or the copiotroph microbiota. Toward this end, cultivation and isolation of microbial strains using diffusion chambers (DC) and/or microbial traps (MT) have both been recently demonstrated to be effective strategies because microbial enrichment is facilitated by soil nutrients and not by synthetically defined media, thus simulating their native habitat. In this study, DC/MT chambers were established using soils collected from two US Department of Energy (DOE) sites with long-term history of heavy metal contamination, including mercury (Hg). To characterize the contamination levels and nutrient status, soils were first analyzed for total mercury (THg), methylmercury (MeHg), total carbon (TC), total nitrogen (TN), and total phosphorus (TP). Multivariate statistical analysis on these measurements facilitated binning of soils under high, medium and low levels of contamination. Bacterial and fungal microbiomes that developed within the DC and MT chambers were evaluated using comparative metagenomics, revealing Chthoniobacter, Burkholderia and Bradyrhizobium spp., as the predominant bacteria while Penicillium, Thielavia, and Trichoderma predominated among fungi. Many of these core microbiomes were also retrieved as axenic isolates. Furthermore, canonical correspondence analysis (CCA) of biogeochemical measurements, metal concentrations and bacterial communities revealed a positive correlation of Chthoniobacter/Bradyrhizobium spp., to THg whereas Burkholderia spp., correlated with MeHg. Penicillium spp., correlated with THg whereas Trichoderma spp., and Aspergillus spp., correlated with MeHg, from the MT approach. This is the first metagenomics-based assessment, isolation and characterization of soil-borne bacterial and fungal communities colonizing the diffusion chambers (DC) and microbial traps (MT) established with long-term metal contaminated soils. Overall, this study provides proof-of-concept for the successful application of DC/MT based assessment of mercury resistant (HgR) microbiomes in legacy metal-contaminated soils, having complex contamination issues. Overall, this study brings out the significance of microbial communities and their relevance in context to heavy metal cycling for better stewardship and restoration of such historically contaminated systems.
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Affiliation(s)
- Ashish Pathak
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Rajneesh Jaswal
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Xiaoyu Xu
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, United States
| | - John R White
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Bobby Edwards
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Jaden Hunt
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Scott Brooks
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Rajesh Singh Rathore
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Meenakshi Agarwal
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
| | - Ashvini Chauhan
- School of the Environment, Florida A&M University, Tallahassee, FL, United States
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Luo H, Cheng Q, Pan X. Photochemical behaviors of mercury (Hg) species in aquatic systems: A systematic review on reaction process, mechanism, and influencing factor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137540. [PMID: 32143045 DOI: 10.1016/j.scitotenv.2020.137540] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/23/2020] [Accepted: 02/23/2020] [Indexed: 06/10/2023]
Abstract
The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg0, Hg2+, and MeHg. Migration of Hg is determined by its complexation with organic and inorganic ligands that are widely present in the water. The presence of dissolved organic matter (DOM) is closely related to photochemical reactions of Hg. DOM can strongly bind to mercury (e.g., Hg2+ and MeHg), thus affecting its speciation, mobility and toxicity, eventually dominating its bioavailability. This review summarizes extensive studies on photochemical behaviors of Hg including: (1) photo-oxidation; (2) photo-reduction; (3) photochemical methylation; and (4) MeHg photo-degradation. Photo-oxidation of Hg0 is mostly caused by oxidative free radicals (e.g., •OH, CO3•-, O3, and 1O2), while photo-reduction of Hg2+ is more complicated and it involves two pathways: (1) primary processes (direct photolysis of Hg2+ or ligand-metal charge transfer of Hg2+-DOM complex); and (2) secondary processes (reduction of Hg2+-DOM complex induced by free radicals derived from DOM photolysis). Photochemical methylation of inorganic Hg occurs as follows: (1) Hg2+ complexes with methyl donors (e.g., acetic acid, tert-butyl, alcohols, etc.) to form intermediates, followed by (2) an intramolecular methyl transfer. MeHg photo-degradation is the leading pathway for MeHg demethylation and it primarily proceeds via four different pathways. The information on DOM was also mentioned, but DOM is not the only factor that affects the photochemical behaviors of Hg. Other influencing factors such as: (1) pH value; (2) dissolved oxygen; (3) cations (Fe3+, K+) and anions (NO3-, HCO3-, CO32-, Cl-); and (4) suspended substance cannot be ignored.
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Affiliation(s)
- Hongwei Luo
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Qianqian Cheng
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xiangliang Pan
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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35
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Ji X, Liu C, Zhang M, Yin Y, Pan G. Mitigation of methylmercury production in eutrophic waters by interfacial oxygen nanobubbles. WATER RESEARCH 2020; 173:115563. [PMID: 32059129 DOI: 10.1016/j.watres.2020.115563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/17/2020] [Accepted: 01/28/2020] [Indexed: 06/10/2023]
Abstract
In mercury (Hg)-polluted eutrophic waters, algal blooms are likely to aggravate methylmercury (MeHg) production by causing intensified hypoxia and enriching organic matter at the sediment-water interface. The technology of interfacial oxygen (O2) nanobubbles is proven to alleviate hypoxia and may have potential to mitigate the risks of MeHg formation. In this study, incubation column experiments were performed using sediment and overlying water samples collected from the Baihua Reservoir (China), which is currently suffering from co-contamination of Hg and eutrophication. The results indicated that after the application of O2 nanobubbles, the %MeHg (ratio of MeHg to total Hg) in the overlying water and surface sediment decreased by up to 76% and 56% respectively. In addition, the MeHg concentrations decreased from 0.54 ± 0.15 to 0.17 ± 0.01 ng L-1 in the overlying water and from 56.61 ± 9.23 to 25.48 ± 4.08 ng g-1 in the surface sediment. The decline could be attributed to the alleviation of anoxia and the decrease of labile organic matter and bioavailable Hg. In addition, hgcA gene abundances in the overlying water and surface sediment decreased by up to 69% and 44% after the addition of O2 nanobubbles, as is consistent with MeHg occurrence in such areas. Accordingly, this work proposed a promising strategy of using interfacial oxygen nanobubbles to alleviate the potentially enhanced MeHg production during algal bloom outbreaks in Hg-polluted eutrophic waters.
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Affiliation(s)
- Xiaonan Ji
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chengbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China
| | - Meiyi Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
| | - Yongguang Yin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Beijing Advanced Science and Innovation Center, Chinese Academy of Sciences, Beijing, 101407, PR China; Center of Integrated Water-Energy-Food Studies (iWEF), School of Animal, Rural, and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, NG25 0QF, UK.
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36
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Hu H, Wang B, Bravo AG, Björn E, Skyllberg U, Amouroux D, Tessier E, Zopfi J, Feng X, Bishop K, Nilsson MB, Bertilsson S. Shifts in mercury methylation across a peatland chronosequence: From sulfate reduction to methanogenesis and syntrophy. JOURNAL OF HAZARDOUS MATERIALS 2020; 387:121967. [PMID: 31901845 DOI: 10.1016/j.jhazmat.2019.121967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/07/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
Peatlands are globally important ecosystems where inorganic mercury is converted to bioaccumulating and highly toxic methylmercury, resulting in high risks of methylmercury exposure in adjacent aquatic ecosystems. Although biological mercury methylation has been known for decades, there is still a lack of knowledge about the organisms involved in mercury methylation and the drivers controlling their methylating capacity. In order to investigate the metabolisms responsible for mercury methylation and methylmercury degradation as well as the controls of both processes, we studied a chronosequence of boreal peatlands covering fundamentally different biogeochemical conditions. Potential mercury methylation rates decreased with peatland age, being up to 53 times higher in the youngest peatland compared to the oldest. Methylation in young mires was driven by sulfate reduction, while methanogenic and syntrophic metabolisms became more important in older systems. Demethylation rates were also highest in young wetlands, with a gradual shift from biotic to abiotic methylmercury degradation along the chronosequence. Our findings reveal how metabolic shifts drive mercury methylation and its ratio to demethylation as peatlands age.
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Affiliation(s)
- Haiyan Hu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China; Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, SE-75236 Uppsala, Sweden.
| | - Baolin Wang
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain
| | - Erik Björn
- Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Ulf Skyllberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden
| | - David Amouroux
- CNRS/Univ Pau & Pays Adour/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Materiaux-mira, UMR5254, 64000, Pau, France
| | - Emmanuel Tessier
- CNRS/Univ Pau & Pays Adour/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Materiaux-mira, UMR5254, 64000, Pau, France
| | - Jakob Zopfi
- Department of Environmental Sciences, Biogeochemistry, University of Basel, CH-4056 Basel, Switzerland
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Mats B Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden
| | - Stefan Bertilsson
- Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, SE-75236 Uppsala, Sweden; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
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37
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Du S, Wang X, Zhang T, Ding C. Kinetic characteristics and predictive models of methylmercury production in paddy soils. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:424-428. [PMID: 31325887 DOI: 10.1016/j.envpol.2019.07.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/25/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Understanding the mercury (Hg) methylation process is important for the management of paddy soils contaminated by Hg. In this work, samples of eighteen paddy soils with varying soil properties were spiked with inorganic Hg and subjected to a 90 d flooding period. Soil pH and redox potential (Eh) were measured in situ at intervals, and soils were sampled for the analysis of methylmercury (MeHg). The Hg methylation efficiency increased with flooding time and reached a relatively steady state at 30 d of incubation, ranging from 0.08% to 2.52%, and was significantly correlated with the in situ soil pH and Eh. The Elovich equation could adequately describe the kinetic production of MeHg. MeHg production was well predicted by the in situ soil pH and Eh of flooded soils, in addition to the organic matter content of air-dried soil samples and flooding time. The two predictive models explained 78% and 68% of the variability of the Hg methylation efficiency. The results suggested that the methylation of inorganic Hg in paddy soils after flooding can be predicted as a function of routinely measured soil properties and flooding time, a correlation that can be utilized to improve understanding of the extent of Hg methylation and the management of Hg-contaminated paddy soils.
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Affiliation(s)
- Shuyang Du
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingxiang Wang
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Ecological Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan 335211, China
| | - Taolin Zhang
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Changfeng Ding
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
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38
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Ackerman JT, Fleck JA, Eagles-Smith CA, Marvin-DiPasquale M, Windham-Myers L, Herzog MP, McQuillen HL. Wetland Management Strategy to Reduce Mercury in Water and Bioaccumulation in Fish. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:2178-2196. [PMID: 31343757 DOI: 10.1002/etc.4535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 06/10/2023]
Abstract
Wetland environments provide numerous ecosystem services but also facilitate methylmercury (MeHg) production and bioaccumulation. We developed a wetland-management technique to reduce MeHg concentrations in wetland fish and water. We physically modified seasonal wetlands by constructing open- and deep-water treatment cells at the downstream end of seasonal wetlands to promote naturally occurring MeHg-removal processes. We assessed the effectiveness of reducing mercury (Hg) concentrations in surface water and western mosquitofish that were caged at specific locations within 4 control and 4 treatment wetlands. Methylmercury concentrations in wetland water were successfully decreased within treatment cells during only the third year of study; however, treatment cells were not effective for reducing total Hg concentrations. Furthermore, treatment cells were not effective for reducing total Hg concentrations in wetland fish. Mercury concentrations in fish were not correlated with total Hg concentrations in filtered, particulate, or whole water; and the slope of the correlation with water MeHg concentrations differed between months. Fish total Hg concentrations were weakly correlated with water MeHg concentrations in April when fish were introduced into cages but were not correlated in May when fish were retrieved from cages. Fish total Hg concentrations were greater in treatment wetlands than in control wetlands the year after the treatment wetlands' construction but declined by the second year. During the third year, fish total Hg concentrations increased in both control and treatment wetlands after an unexpected regional flooding event. Overall, we found limited support for the use of open- and deep-water treatment cells at the downstream end of wetlands to reduce MeHg concentrations in water but not fish. We suggest that additional evaluation over a longer period of time is necessary. Environ Toxicol Chem 2019;38:2178-2196. Published 2019 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work, and as such, is in the public domain in the United States of America..
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Affiliation(s)
- Joshua T Ackerman
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, California
| | - Jacob A Fleck
- US Geological Survey, California Water Science Center, Sacramento, California
| | - Collin A Eagles-Smith
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon
| | | | | | - Mark P Herzog
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, California
| | - Harry L McQuillen
- US Bureau of Land Management, Cosumnes River Preserve, Galt, California
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39
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Lei P, Zhong H, Duan D, Pan K. A review on mercury biogeochemistry in mangrove sediments: Hotspots of methylmercury production? THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 680:140-150. [PMID: 31112813 DOI: 10.1016/j.scitotenv.2019.04.451] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
Wetlands are highly productive and biologically diverse environments that provide numerous ecosystem services, but can also be sources of methylmercury (MeHg) production and export. Mangrove wetlands contribute up to 15% of the coastal sediment carbon storage and ~10% of the particulate terrestrial carbon exported to the ocean. Thus, mercury (Hg) methylation in mangrove sediments and subsequent MeHg output to adjacent waters could have a great impact on global Hg cycling. In this review, we provide a comprehensive analysis of the literature on worldwide Hg concentrations in mangrove ecosystems, and the results reveal that a large range of total Hg (THg) and MeHg concentrations is detected in mangrove systems. Then, we discuss the potential roles of organic matter (OM) in controlling the Hg biogeochemistry in mangrove sediments. The intense OM decomposition by anoxic reduction (e.g., sulfate reduction) drastically affects sediment chemistries, such as redox potential, pH, and sulfur speciation, all of which may have a great impact on MeHg production. While the outwelling of carbon from mangroves has been extensively examined, little is known about their roles in exporting MeHg to adjacent waters. Our understanding of Hg biogeochemical processes in mangrove systems is constrained by the limited MeHg data and a lack of in-depth studies on the Hg methylation potential in this ecologically important environment. More efforts are needed to gain better insights into the contributions mangrove wetlands to the global Hg cycle.
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Affiliation(s)
- Pei Lei
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China; Environmental and Life Science Program (EnLS), Trent University, Peterborough, Ontario, Canada
| | - Dandan Duan
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Ke Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
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Azaroff A, Tessier E, Deborde J, Guyoneaud R, Monperrus M. Mercury and methylmercury concentrations, sources and distribution in submarine canyon sediments (Capbreton, SW France): Implications for the net methylmercury production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 673:511-521. [PMID: 30995585 DOI: 10.1016/j.scitotenv.2019.04.111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/08/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Submarine canyons are important stocks of commercial interest fish, whose consumption is one of the main monomethymercury (MeHg) exposure to humans. Currently, biogeochemistry of mercury in those biologically productive system is unknown. In this work, inorganic mercury (Hg(II)) and organic mercury (MeHg) distributions were measured in sedimentary accumulative zones (slopes and terraces) against adjacent continental shelf sediments. Hg compound concentrations in these sediments show a huge range of concentrations (Hg(II) ranging from 18 to 973 ng g-1 and MeHg ranging from 0.07 to 2.03 ng g-1) exhibiting factors 50 and 20 fold, respectively. Higher values of mercury compounds were observed in canyon locations suggesting a high accumulation of mercury associated with higher values of clay fraction and organic matter content. The reactivity of mercury was investigated in sediment of three locations along Capbreton submarine canyon axis using slurry incubations experiments and isotopic tracers. Specific methylation and demethylation rate constants (kM and kD) were calculated. Results clearly showed that MeHg concentrations in these sediments are controlled by competing and simultaneous methylation and demethylation reactions mainly mediated by biotic process. Mercury reactivity was found higher in coastal stations compared to the offshore station due to more labile organic matter which may stimulate microbial activities. However, higher net MeHg production was estimated for the offshore station due to high Hg(II) concentrations suggesting a potential MeHg source for such marine environments.
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Affiliation(s)
- Alyssa Azaroff
- CNRS/ UNIV PAU & PAYS ADOUR/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR 5254, 64600 Anglet, France
| | - Emmanuel Tessier
- CNRS/ UNIV PAU & PAYS ADOUR/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR 5254, 64000 Pau, France
| | - Jonathan Deborde
- CNRS/ UNIV PAU & PAYS ADOUR/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR 5254, 64600 Anglet, France
| | - Rémy Guyoneaud
- CNRS/ UNIV PAU & PAYS ADOUR/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR 5254, 64000 Pau, France
| | - Mathilde Monperrus
- CNRS/ UNIV PAU & PAYS ADOUR/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR 5254, 64600 Anglet, France.
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Beckers F, Mothes S, Abrigata J, Zhao J, Gao Y, Rinklebe J. Mobilization of mercury species under dynamic laboratory redox conditions in a contaminated floodplain soil as affected by biochar and sugar beet factory lime. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 672:604-617. [PMID: 30970288 DOI: 10.1016/j.scitotenv.2019.03.401] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 03/21/2019] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
Mercury and its species are toxic and therefore strategies to immobilize them or to impede the formation of bioaccumulative MeHg are a hot topic of ongoing research. Biochar (BC) and sugar beet factory lime (SBFL) are suggested to have the potential to meet these goals. However, their ability to restrain the mobilization of total Hg (Hgt), methylmercury (MeHg), and ethylmercury (EtHg) or the formation of MeHg and EtHg has not been examined to date. Moreover, the effect of systematically altered redox conditions on the release dynamics of Hgt, MeHg, and EtHg in a contaminated floodplain soil as affected by these soil amendments has not been studied. Therefore, we investigated the impact of pre-defined redox conditions on the release dynamics of Hgt, MeHg, and EtHg in a contaminated floodplain soil (CS) and the soil amended with either BC (CS+BC) or SBFL (CS+SBFL). The mobilization of Hgt, MeHg, and EtHg was generally higher at low redox potential (EH) and decreased with increasing EH, irrespective of soil treatment. Both BC and SBFL diminished the release of Hgt from soil but not the methylation and ethylation of Hg. In CS+SBFL approximately half of Hgt was found in solution compared to CS. However, higher methylation efficiency (MeHg/Hgt ratio) was found in CS+SBFL counterbalancing this benefit. Abundances of specific phospholipid fatty acids suggest the presence of sulfate-reducing bacteria, which are considered as primary Hg methylators. The results indicate that both BC and SBFL have the potential to curtail the release of Hgt from inundated soils, while SBFL was more efficient. However, these amendments had no marked effect on the MeHg and EtHg concentrations. Therefore, further research should be conducted to identify soil additives that are capable to reduce the release and formation of these Hg species.
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Affiliation(s)
- Felix Beckers
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Sibylle Mothes
- UFZ Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstraße 15, 04318 Leipzig, Germany
| | - Jens Abrigata
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Jiating Zhao
- CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yuxi Gao
- CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy & Geoinformatics, Sejong University, 98 Gunja-Dong, Guangjin-Gu, Seoul, South Korea.
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Lázaro WL, Díez S, Bravo AG, da Silva CJ, Ignácio ÁRA, Guimaraes JRD. Cyanobacteria as regulators of methylmercury production in periphyton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:723-729. [PMID: 30861408 DOI: 10.1016/j.scitotenv.2019.02.233] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/18/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Biotic mercury (Hg) methylation appears to depend on factors such as microbial activity and the concentration and bioavailability of Hg2+ to the Hg-methylating organisms. Recently, the presence of cyanobacteria has been linked with high methylmercury (MeHg) concentrations. The aim of this work was to test MeHg production in microcosms, in relation to the amount of periphytic cyanobacteria, dissolved organic matter (DOM) and phosphorus concentrations, as well as periphytic primary production rates. Water and periphyton samples were collected for cultivation and isolation of cyanobacteria from the Guaporé River floodplain, Brazil. We cultivated the periphyton in microcosms with different concentrations of cyanobacteria, total phosphorus and DOM. The highest net MeHg production (6.8 to 24.6% of added Hg d-1) occurred in the microcosm with added cyanobacteria, followed by microcosms with added phosphorus (6.1 to 11.4%) and added DOM (6.4 to 9.1%). Positive correlations were found between MeHg production, addition of cyanobacteria, phosphorus and DOM and periphytic primary productivity. Our results bring the first direct experimental evidence of the relevance of cyanobacteria and primary production as regulators of MeHg production in periphyton. These findings have numerous implications for the management of natural and engineered wetlands.
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Affiliation(s)
- Wilkinson L Lázaro
- Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brasil. Avenida Santos Dummont, Cidade Universitária, 78200-000 Cáceres, MT, Brazil.
| | - Sergi Díez
- Environmental Chemistry Department, Institute of Environmental Assessment and Water Research (IDAEA-CSIC). C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
| | - Andrea G Bravo
- Environmental Chemistry Department, Institute of Environmental Assessment and Water Research (IDAEA-CSIC). C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
| | - Carolina J da Silva
- Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brasil. Avenida Santos Dummont, Cidade Universitária, 78200-000 Cáceres, MT, Brazil; Rede Bionorte, Doutorado em Biodiversidade e Biotecnologia da Amazônia Legal. Avenida Fernando Correa da Costa, 2.367, Boa Esperança, 78060-900, Cuiabá, Brazil.
| | - Áurea R A Ignácio
- Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brasil. Avenida Santos Dummont, Cidade Universitária, 78200-000 Cáceres, MT, Brazil.
| | - Jean R D Guimaraes
- Laboratório de Traçadores, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ). Av. Carlos Chagas Filho 373 Bloco G, CCS, Cidade Universitária, 21941-902, Rio de Janeiro, RJ, Brazil.
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Beckers F, Awad YM, Beiyuan J, Abrigata J, Mothes S, Tsang DCW, Ok YS, Rinklebe J. Impact of biochar on mobilization, methylation, and ethylation of mercury under dynamic redox conditions in a contaminated floodplain soil. ENVIRONMENT INTERNATIONAL 2019; 127:276-290. [PMID: 30951944 DOI: 10.1016/j.envint.2019.03.040] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/14/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
Mercury (Hg) is a highly toxic element, which is frequently enriched in flooded soils due to its anthropogenic release. The mobilization of Hg and its species is of ultimate importance since it controls the transfer into the groundwater and plants and finally ends in the food chain, which has large implications on human health. Therefore, the remediation of those contaminated sites is an urgent need to protect humans and the environment. Often, the stabilization of Hg using amendments is a reliable option and biochar is considered a candidate to fulfill this purpose. We tested two different pine cone biochars pyrolyzed at 200 °C or 500 °C, respectively, with a view to decrease the mobilization of total Hg (Hgt), methylmercury (MeHg), and ethylmercury (EtHg) and/or the formation of MeHg and EtHg in a contaminated floodplain soil (Hgt: 41 mg/kg). We used a highly sophisticated automated biogeochemical microcosm setup to systematically alter the redox conditions from ~-150 to 300 mV. We continuously monitored the redox potential (EH) along with pH and determined dissolved organic carbon (DOC), SUVA254, chloride (Cl-), sulfate (SO42-), iron (Fe), and manganese (Mn) to be able to explain the mobilization of Hg and its species. However, the impact of biochar addition on Hg mobilization was limited. We did not observe a significant decrease of Hgt, MeHg, and EtHg concentrations after treating the soil with the different biochars, presumably because potential binding sites for Hg were occupied by other ions and/or blocked by biofilm. Solubilization of Hg bound to DOC upon flooding of the soils might have occurred which could be an indirect impact of EH on Hg mobilization. Nevertheless, Hgt, MeHg, and EtHg in the slurry fluctuated between 0.9 and 52.0 μg/l, 11.1 to 406.0 ng/l, and 2.3 to 20.8 ng/l, respectively, under dynamic redox conditions. Total Hg concentrations were inversely related to the EH; however, ethylation of Hg was favored at an EH around 0 mV while methylation was enhanced between -50 and 100 mV. Phospholipid fatty acid profiles suggest that sulfate-reducing bacteria may have been the principal methylators in our experiment. In future, various biochars should be tested to evaluate their potential in decreasing the mobilization of Hg and to impede the formation of MeHg and EtHg under dynamic redox conditions in frequently flooded soils.
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Affiliation(s)
- Felix Beckers
- University of Wuppertal, Institute of Foundation Engineering, Waste and Water Management, School of Architecture and Civil Engineering, Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Yasser Mahmoud Awad
- University of Wuppertal, Institute of Foundation Engineering, Waste and Water Management, School of Architecture and Civil Engineering, Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Korea Biochar Research Center, O-Jeong Eco-Resilience Institute (OJERI) & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea; Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt
| | - Jingzi Beiyuan
- University of Wuppertal, Institute of Foundation Engineering, Waste and Water Management, School of Architecture and Civil Engineering, Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; School of Environment and Chemical Engineering, Foshan University, Foshan, Guangdong, China; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Jens Abrigata
- University of Wuppertal, Institute of Foundation Engineering, Waste and Water Management, School of Architecture and Civil Engineering, Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Sibylle Mothes
- UFZ Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstraße 15, 04318 Leipzig, Germany
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Yong Sik Ok
- Korea Biochar Research Center, O-Jeong Eco-Resilience Institute (OJERI) & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea.
| | - Jörg Rinklebe
- University of Wuppertal, Institute of Foundation Engineering, Waste and Water Management, School of Architecture and Civil Engineering, Soil and Groundwater Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy & Geoinformatics, Sejong University, 98 Gunja-Dong, Guangjin-Gu, Seoul, Republic of Korea.
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Ji X, Liu C, Shi J, Pan G. Optimization of pretreatment procedure for MeHg determination in sediments and its applications. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:17707-17718. [PMID: 31028624 DOI: 10.1007/s11356-019-05179-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
Methylmercury (MeHg) in sediment is difficult to be determined due to its low concentration and binding compounds like sulfide and organic matter. Moreover, wet sediment samples have been suggested to behave differently from certified reference materials in MeHg analysis. Optimal pretreatment procedure for MeHg determination in sediments has not been ascertained and whether the procedure could apply to sediment samples with complex matrix merits further research. This work firstly compared recovery results of five pretreatment procedures for MeHg determination using ERM-CC580. Using the optimal pretreatment procedure, recovery results were analyzed in different sediment samples after manipulation of moisture content, organic matter, and acid volatile sulfide. The procedure using CuSO4/HNO3 as leaching solutions and mechanical shaking as extraction method was proved to produce the most satisfactory recovery results (100.67 ± 6.75%, mean ± standard deviation). And when moisture content varied from 20 to 80%, average recovery results in sediment samples ranged from 100 to 125%. Furthermore, before and after the manipulation of organic matter or acid volatile sulfide, spiking recovery results varied little and were all within acceptable limit (85~105%). Therefore, the procedure of CuSO4/HNO3-mechanical is proposed as a universal pretreatment method for MeHg determination in sediment samples with various characteristics.
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Affiliation(s)
- Xiaonan Ji
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Chengbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Jianbo Shi
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
- Beijing Advanced Science and Innovation Center, Chinese Academy of Sciences, Beijing, 101407, People's Republic of China.
- Center of Integrated Water-Energy-Food studies (iWEF), School of Animal, Rural, and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, NG25 0QF, UK.
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Azad AM, Frantzen S, Bank MS, Johnsen IA, Tessier E, Amouroux D, Madsen L, Maage A. Spatial distribution of mercury in seawater, sediment, and seafood from the Hardangerfjord ecosystem, Norway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 667:622-637. [PMID: 30833261 DOI: 10.1016/j.scitotenv.2019.02.352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 02/22/2019] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Hardangerfjord is one of the longest fjords in the world and has historical mercury (Hg) contamination from a zinc plant in its inner sector. In order to investigate the extent of Hg transferred to abiotic and biotic ecosystem compartments, Hg and monomethylmercury (MeHg) concentrations were measured in seawater, sediment, and seafood commonly consumed by humans. Although total mercury in seawater has been described previously, this investigation reports novel MeHg data for seawater from Norwegian fjords. Total Hg and MeHg concentrations in seawater, sediment, and biota increased towards the point source of pollution (PSP) and multiple lines of evidence show a clear PSP effect in seawater and sediment concentrations. In fish, however, similar high concentrations were found in the inner part of another branch adjacent to the PSP. We postulate that, in addition to PSP, atmospheric Hg, terrestrial run-off and hydroelectric power stations are also important sources of Hg in this fjord ecosystem. Hg contamination gradually increased towards the inner part of the fjord for most fish species and crustaceans. Since the PSP and the atmospheric Hg pools were greater towards the inner part of the fjord, it is not entirely possible to discriminate the full extent of the PSP and the atmospheric Hg contribution to the fjord food web. The European Union (EU) Hg maximum level for consumption was exceeded in demersal fish species including tusk (Brosme brosme), blue ling (Molva dypterygia) and common ling (Molva molva) from the inner fjord (1.08 to 1.89 mg kg-1 ww) and from the outer fjord (0.49 to 1.07 mg kg-1 ww). Crustaceans were less contaminated and only European lobster (Homarus gammarus) from inner fjord exceeded the EU limit (0.62 mg kg-1 ww). Selenium (Se) concentrations were also measured in seafood species and Se-Hg co-exposure dynamics are also discussed.
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Affiliation(s)
- Atabak M Azad
- Institute of Marine Research, Bergen, Norway; Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen, Norway.
| | | | - Michael S Bank
- Institute of Marine Research, Bergen, Norway; Department of Environmental Conservation, University of Massachusetts, Amherst, USA.
| | | | - Emmanuel Tessier
- CNRS/ Univ Pau & Pays Adour/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR5254, 64000 Pau, France
| | - David Amouroux
- CNRS/ Univ Pau & Pays Adour/ E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux - MIRA, UMR5254, 64000 Pau, France
| | - Lise Madsen
- Institute of Marine Research, Bergen, Norway; Department of Biology, University of Copenhagen, Denmark
| | - Amund Maage
- Institute of Marine Research, Bergen, Norway; Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen, Norway
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Buckman KL, Seelen EA, Mason RP, Balcom P, Taylor VF, Ward JE, Chen CY. Sediment organic carbon and temperature effects on methylmercury concentration: A mesocosm experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:1316-1326. [PMID: 30970496 PMCID: PMC6461384 DOI: 10.1016/j.scitotenv.2019.02.302] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/01/2019] [Accepted: 02/19/2019] [Indexed: 05/21/2023]
Abstract
The fate and mobility of mercury, and its bioaccumulation primarily as methylmercury (MeHg), in marine ecosystems are influenced by climate related environmental factors, including increased temperature and carbon loading. To investigate the interactions between sediment organic carbon and temperature MeHg bioaccumulation, mesocosm experiments were conducted examining relationships between sediment, water column and biota (sediment-dwelling amphipod and juvenile oyster) MeHg concentration. Experimental treatments consisted of a two by two design of high and low temperature (15 & 25 °C) and high and low sediment organic carbon (4-5% and 13% LOI, pre-experiment). Sediment organic carbon had significant individual effects on MeHg concentration in water and biota, with higher carbon associated with lower MeHg. Temperature individual effects were significant for sediment, water, and only amphipod MeHg concentration, with higher temperature treatments indicating higher MeHg concentration. There were significant temperature × carbon interactions observed for sediment, dissolved, and oyster MeHg concentration. Sediment carbon reduction had greater influence than temperature on increasing MeHg concentrations in both the water column and biota. MeHg concentrations in the bulk sediment were not correlated with MeHg in the water column or in the biota, indicating that even when sediments are the only source of MeHg, bulk sediment measurements do not provide a good proxy for bioaccumulation and that the concentration in bulk sediments is not the primary determinant of MeHg entry into the food web.
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Affiliation(s)
- K L Buckman
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States of America.
| | - E A Seelen
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - R P Mason
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - P Balcom
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America; Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, United States of America
| | - V F Taylor
- Department of Earth Science, Dartmouth College, Hanover, NH, United States of America
| | - J E Ward
- Department of Marine Science, University of Connecticut, Groton, CT, United States of America
| | - C Y Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States of America
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Hassan H, Elezz AA, Abuasali M, AlSaadi H. Baseline concentrations of mercury species within sediments from Qatar's coastal marine zone. MARINE POLLUTION BULLETIN 2019; 142:595-602. [PMID: 31232346 DOI: 10.1016/j.marpolbul.2019.04.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Baseline concentration of total mercury (THg), organic extractable mercury and methylmercury (CH3Hg) concentrations in sediments from the northeastern, eastern and southeastern parts of the Arabian Gulf were assessed. Surface sediments were collected from eleven stations from the coastal waters of Qatar. All analyses were performed on homogenised samples. Total mercury analysis was performed by Cold Vapour Atomic Absorption Spectrometry (CVAAS), and methylmercury was analysed by Cold Vapour Atomic Fluorescence spectrometry (CVAFS) after aqueous phase ethylation of the extracted samples. Total mercury (THg) in sediments varied from 8.0 μg/kg to 34.3 μg/kg. Methylmercury was detected in all stations and ranged from 1.46 μg/kg to 3.10 μg/kg accounting for 5.4% to 18.4% of total mercury. Total organic carbon (TOC) ranged from 0.16 to 0.72%, while Organic extractable mercury ranged from 1.55 μg/kg to 13.3 μg/kg. Analysis, the grain size within these sediments, was carried out previously paving the way for studying the influence of these parameters on the sedimentary mercury concentration. Speciation was also assessed, as were relations between the measured mercury fractions.
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Affiliation(s)
- Hassan Hassan
- Environmental Science Center (ESC), Qatar University, Qatar.
| | | | - Mazen Abuasali
- Environmental Science Center (ESC), Qatar University, Qatar
| | - Hamood AlSaadi
- Environmental Science Center (ESC), Qatar University, Qatar
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Shetaya WH, Huang JH, Osterwalder S, Mestrot A, Bigalke M, Alewell C. Sorption kinetics of isotopically labelled divalent mercury ( 196Hg 2+) in soil. CHEMOSPHERE 2019; 221:193-202. [PMID: 30639815 DOI: 10.1016/j.chemosphere.2019.01.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/03/2019] [Accepted: 01/05/2019] [Indexed: 06/09/2023]
Abstract
Understanding the sorption kinetics of Hg2+ is the key to predicting its reactivity in soils which is indispensable for environmental risk assessment. The temporal change in the solubility of 196Hg2+ spikes (6 mg kg-1) added to a range of soils with different properties was investigated and modelled. The sorption of 196Hg2+ displayed a biphasic pattern with a rapid initial (short-term) phase followed by a slower (time-dependent) one. The overall reaction rate constants ranged from 0.003 to 4.9 h-1 and were significantly correlated (r = 0.94) to soil organic carbon (SOC). Elovich and Spherical Diffusion expressions compellingly fitted the observed 196Hg2+ sorption kinetics highlighting their flexibility to describe reactions occurring over multiple phases and wide timeframes. A parameterized Elovich model from soil variables indicated that the short-term sorption is solely controlled by SOC while the time-dependent sorption appeared independent of SOC and decreased at higher pH values and Al(OH)3 and MnO2 concentrations. This is consistent with a rapid chemical reaction of Hg2+ with soil organic matter (SOM) which is followed by a noticeably slower phase likely occurring through physical pathways e.g. pore diffusion of Hg2+ into spherical soil aggregates and progressive incorporation of soluble organic-Hg into solid phase. The model lines predicted that in soils with >4% SOC, Hg2+ is removed from soil solution over seconds to minutes; however, in soils with <2% SOC and higher pH values, Hg2+ may remain soluble for months and beyond with a considerable associated risk of re-emission or migration to the surrounding environments.
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Affiliation(s)
- Waleed H Shetaya
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland; Air Pollution Research Department, Environmental Research Division, National Research Centre, 33 El-Bohouth St., Dokki, Giza 12622, Egypt.
| | - Jen-How Huang
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Stefan Osterwalder
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Adrien Mestrot
- Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland
| | - Moritz Bigalke
- Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland
| | - Christine Alewell
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
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Ackerman JT, Hartman CA, Herzog MP. Mercury contamination in resident and migrant songbirds and potential effects on body condition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 246:797-810. [PMID: 30623836 DOI: 10.1016/j.envpol.2018.11.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
Methlymercury is a significant risk to environmental health globally. We examined the ecological drivers of methylmercury bioaccumulation in songbirds and its effect on body condition while experimentally removing the potentially confounding and predominant effects of site and habitat. We measured blood and feather mercury concentrations and body condition in nearly 1200 individuals representing resident or migrant songbirds of 52 species and 5 foraging guilds. Songbird mercury concentrations differed among species, foraging guilds, residency status, dates, and ages, but not sexes. Blood mercury concentrations 1) ranged from 0.003 in house finch to 0.85 μg/g ww in American robin, 2) were 125 times greater in insectivores than granivores and 3.6 times greater in insectivores than omnivores, 3) were 3.3 times greater in summer residents than in migrating songbirds, 4) increased by 25% throughout spring and summer, and 5) were 45% higher in adults than juveniles. Songbird mercury concentrations were negatively correlated with body condition, with blood mercury concentrations decreasing by 44% and 34% over the range of standardized body masses and fat scores, respectively. Our results highlight the importance of foraging and migration ecology in determining methylmercury contamination in birds, and the potential for reduced body condition with methylmercury exposure in songbirds.
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Affiliation(s)
- Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA.
| | - C Alex Hartman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | - Mark P Herzog
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
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Le Croizier G, Schaal G, Point D, Le Loc'h F, Machu E, Fall M, Munaron JM, Boyé A, Walter P, Laë R, Tito De Morais L. Stable isotope analyses revealed the influence of foraging habitat on mercury accumulation in tropical coastal marine fish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:2129-2140. [PMID: 30290354 DOI: 10.1016/j.scitotenv.2018.09.330] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/25/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
Bioaccumulation of toxic metal elements including mercury (Hg) can be highly variable in marine fish species. Metal concentration is influenced by various species-specific physiological and ecological traits, including individual diet composition and foraging habitat. The impact of trophic ecology and habitat preference on Hg accumulation was analyzed through total Hg concentration and stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in the muscle of 132 fish belonging to 23 different species from the Senegalese coast (West Africa), where the marine ecosystem is submitted to nutrient inputs from various sources such as upwelling or rivers. Species-specific ecological traits were first investigated and results showed that vertical (i.e. water column distribution) and horizontal habitat (i.e. distance from the coast) led to differential Hg accumulation among species. Coastal and demersal fish were more contaminated than offshore and pelagic species. Individual characteristics therefore revealed an increase of Hg concentration in muscle that paralleled trophic level for some locations. Considering all individuals, the main carbon source was significantly correlated with Hg concentration, again revealing a higher accumulation for fish foraging in nearshore and benthic habitats. The large intraspecific variability observed in stable isotope signatures highlights the need to conduct ecotoxicological studies at the individual level to ensure a thorough understanding of mechanisms driving metal accumulation in marine fish. For individuals from a same species and site, Hg variation was mainly explained by fish length, in accordance with the bioaccumulation of Hg over time. Finally, Hg concentrations in fish muscle are discussed regarding their human health impact. No individual exceeded the current maximum acceptable limit for seafood consumption set by both the European Union and the Food and Agriculture Organization of the United Nations. However, overconsumption of some coastal demersal species analyzed here could be of concern regarding human exposure to mercury.
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Affiliation(s)
- Gaël Le Croizier
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France; Géosciences Environnement Toulouse (GET), UMR 5563 CNRS, IRD, UPS, CNES, Observatoire Midi Pyrénées (OMP), 14 avenue Edouard Belin, 31400 Toulouse, France.
| | - Gauthier Schaal
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
| | - David Point
- Géosciences Environnement Toulouse (GET), UMR 5563 CNRS, IRD, UPS, CNES, Observatoire Midi Pyrénées (OMP), 14 avenue Edouard Belin, 31400 Toulouse, France
| | - François Le Loc'h
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
| | - Eric Machu
- Laboratoire d'Océanographie Physique et Spatiale (LOPS), UMR 6523 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, 29280 Plouzané, France; Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang, Université Cheikh Anta DIOP de Dakar, Ecole Supérieure Polytechnique, BP 5085, Dakar Fann, Sénégal
| | - Massal Fall
- Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang, Université Cheikh Anta DIOP de Dakar, Ecole Supérieure Polytechnique, BP 5085, Dakar Fann, Sénégal; Centre de Recherches Océanographiques de Dakar-Thiaroye (CRODT/ISRA), BP 2241, Dakar, Sénégal
| | - Jean-Marie Munaron
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
| | - Aurélien Boyé
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
| | - Pierre Walter
- Géosciences Environnement Toulouse (GET), UMR 5563 CNRS, IRD, UPS, CNES, Observatoire Midi Pyrénées (OMP), 14 avenue Edouard Belin, 31400 Toulouse, France
| | - Raymond Laë
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
| | - Luis Tito De Morais
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS, UBO, IRD, IFREMER, Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, BP 70, 29280 Plouzané, France
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