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Li X, Hu D, Du J, He L. Understanding mercury accumulation in mosses of two subalpine forests in China. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134266. [PMID: 38626682 DOI: 10.1016/j.jhazmat.2024.134266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/10/2024] [Accepted: 04/08/2024] [Indexed: 04/18/2024]
Abstract
The role of forest ecosystems in the global mercury (Hg) biogeochemical cycle is widely recognized; however, using litterfall as a surrogate to assess the Hg sink function of forests encounters limitations. We investigated the accumulation characteristics and influencing factors of Hg in mosses from two remote subalpine forests in southwestern China. The results indicated that there was high Hg accumulation in subalpine forest mosses, with average concentrations of 82 ± 49 ng g-1 for total mercury (THg) and 1.3 ± 0.8 ng g-1 for methylmercury (MeHg). We demonstrated that the accumulation capacity of Hg in mosses was significantly dependent on species and substrates (micro-habitats), the mosses on tree trunks exhibited significantly elevated Hg accumulation levels (THg 132 ± 56 ng g-1, MeHg 1.6 ± 0.2 ng g-1) compared to mosses in other substrates. The surface morphologies and biochemical components of leaf (phyllidia), such as cation exchange capacity (CEC), pectin, uronic acid, and metallothionein, play a crucial role in the accumulation of Hg by mosses. These findings provide valuable insights into Hg accumulation in forest mosses. Suggesting that the contribution of mosses Hg accumulation should be considered when assessing atmospheric Hg sinks of forests.
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Affiliation(s)
- Xiaohui Li
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Dan Hu
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Jie Du
- Jiuzhaigou Scenic Area Administration, Zhangzha, Jiuzhaigou, Sichuan 623402, China.
| | - Lei He
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
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2
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Evers DC, Ackerman JT, Åkerblom S, Bally D, Basu N, Bishop K, Bodin N, Braaten HFV, Burton MEH, Bustamante P, Chen C, Chételat J, Christian L, Dietz R, Drevnick P, Eagles-Smith C, Fernandez LE, Hammerschlag N, Harmelin-Vivien M, Harte A, Krümmel EM, Brito JL, Medina G, Barrios Rodriguez CA, Stenhouse I, Sunderland E, Takeuchi A, Tear T, Vega C, Wilson S, Wu P. Global mercury concentrations in biota: their use as a basis for a global biomonitoring framework. ECOTOXICOLOGY (LONDON, ENGLAND) 2024:10.1007/s10646-024-02747-x. [PMID: 38683471 DOI: 10.1007/s10646-024-02747-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/06/2024] [Indexed: 05/01/2024]
Abstract
An important provision of the Minamata Convention on Mercury is to monitor and evaluate the effectiveness of the adopted measures and its implementation. Here, we describe for the first time currently available biotic mercury (Hg) data on a global scale to improve the understanding of global efforts to reduce the impact of Hg pollution on people and the environment. Data from the peer-reviewed literature were compiled in the Global Biotic Mercury Synthesis (GBMS) database (>550,000 data points). These data provide a foundation for establishing a biomonitoring framework needed to track Hg concentrations in biota globally. We describe Hg exposure in the taxa identified by the Minamata Convention: fish, sea turtles, birds, and marine mammals. Based on the GBMS database, Hg concentrations are presented at relevant geographic scales for continents and oceanic basins. We identify some effective regional templates for monitoring methylmercury (MeHg) availability in the environment, but overall illustrate that there is a general lack of regional biomonitoring initiatives around the world, especially in Africa, Australia, Indo-Pacific, Middle East, and South Atlantic and Pacific Oceans. Temporal trend data for Hg in biota are generally limited. Ecologically sensitive sites (where biota have above average MeHg tissue concentrations) have been identified throughout the world. Efforts to model and quantify ecosystem sensitivity locally, regionally, and globally could help establish effective and efficient biomonitoring programs. We present a framework for a global Hg biomonitoring network that includes a three-step continental and oceanic approach to integrate existing biomonitoring efforts and prioritize filling regional data gaps linked with key Hg sources. We describe a standardized approach that builds on an evidence-based evaluation to assess the Minamata Convention's progress to reduce the impact of global Hg pollution on people and the environment.
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Affiliation(s)
- David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | | | - Dominique Bally
- African Center for Environmental Health, BP 826 Cidex 03, Abidjan, Côte d'Ivoire
| | - Nil Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC, Canada
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Upsalla, Sweden
| | - Nathalie Bodin
- Research Institute for Sustainable Development Seychelles Fishing Authority, Victoria, Seychelles
| | | | - Mark E H Burton
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Paco Bustamante
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Celia Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - John Chételat
- Environment and Cliamte Change Canada, National Wildlife Research Centre, Ottawa, ON, K1S 5B6, Canada
| | - Linroy Christian
- Department of Analytical Services, Dunbars, Friars Hill, St John, Antigua and Barbuda
| | - Rune Dietz
- Department of Ecoscience, Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000, Roskilde, Denmark
| | - Paul Drevnick
- Teck American Incorporated, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Collin Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Luis E Fernandez
- Sabin Center for Environment and Sustainability and Department of Biology, Wake Forest University, Winston-Salem, NC, 29106, USA
- Centro de Innovación Científica Amazonica (CINCIA), Puerto Maldonado, Madre de Dios, Peru
| | - Neil Hammerschlag
- Shark Research Foundation Inc, 29 Wideview Lane, Boutiliers Point, NS, B3Z 0M9, Canada
| | - Mireille Harmelin-Vivien
- Aix-Marseille Université, Université de Toulon, CNRS/INSU/IRD, Institut Méditerranéen d'Océanologie (MIO), UM 110, Campus de Luminy, case 901, 13288, Marseille, cedex 09, France
| | - Agustin Harte
- Basel, Rotterdam and Stockholm Conventions Secretariat, United Nations Environment Programme (UNEP), Chem. des Anémones 15, 1219, Vernier, Geneva, Switzerland
| | - Eva M Krümmel
- Inuit Circumpolar Council-Canada, Ottawa, Canada and ScienTissiME Inc, Barry's Bay, ON, Canada
| | - José Lailson Brito
- Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier, 524, Sala 4002, CEP 20550-013, Maracana, Rio de Janeiro, RJ, Brazil
| | - Gabriela Medina
- Director of Basel Convention Coordinating Centre, Stockholm Convention Regional Centre for Latin America and the Caribbean, Hosted by the Ministry of Environment, Montevideo, Uruguay
| | | | - Iain Stenhouse
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Elsie Sunderland
- Harvard University, Pierce Hall 127, 29 Oxford Street, Cambridge, MA, 02138, USA
| | - Akinori Takeuchi
- National Institute for Environmental Studies, Health and Environmental Risk Division, 16-2 Onogawa Tsukuba, Ibaraki, 305-8506, Japan
| | - Tim Tear
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Claudia Vega
- Centro de Innovaccion Cientifica Amazonica (CINCIA), Jiron Ucayali 750, Puerto Maldonado, Madre de Dios, 17001, Peru
| | - Simon Wilson
- Arctic Monitoring and Assessment Programme (AMAP) Secretariat, N-9296, Tromsø, Norway
| | - Pianpian Wu
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
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3
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Yu C, Peng M, Wang X, Pan X. Photochemical demethylation of methylmercury (MeHg) in aquatic systems: A review of MeHg species, mechanisms, and influencing factors. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123297. [PMID: 38195023 DOI: 10.1016/j.envpol.2024.123297] [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: 09/12/2023] [Revised: 12/01/2023] [Accepted: 01/02/2024] [Indexed: 01/11/2024]
Abstract
Photodemethylation is the major pathway of methylmercury (MeHg) demethylation in surface water before uptake by the food chain, whose mechanisms and influence factors are still not completely understood. Here, we review the current knowledge on photodemethylation of MeHg and divide MeHg photolysis into three pathways: (1) direct photodemethylation, (2) free radical attack, and (3) intramolecular electron or energy transfer. In aquatic environments, dissolved organic matter is involved into all above pathways, and due to its complex compositions, properties and concentrations, DOM poses multiple functions during the PD of MeHg. DOM-MeHg complex (mainly by sulfur-containing molecules) might weaken the C-Hg bond and enhance PD through both direct and indirect pathways. In special, synergistic effects of both strong binding sites and chromophoric moieties in DOM might lead to intramolecular electron or energy transfer. Moreover, DOM might play a role of radical scavenger; while triplet state DOM, which is generated by chromophoric DOM under light, might become a source of free radicals. Apart from DOMs, transition metals, halides, NO3-, NO2-, and carbonates also act as radical initialaters or scavengers, and significantly pose effects on radical demethylation, which is generally mediated by hydroxyl radicals and singlet oxygen. Environmental factors such as pH, light wavelength, light intensity, dissolved oxygen, salinity, and suspended particles also affect the PD of MeHg. This study assessed previously published works on three major mechanisms, with the goal of providing general estimates for photodemethylation under various environment factors according to know effects, and highlighting the current uncertainties for future research directions.
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Affiliation(s)
- Chenghao Yu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Mao Peng
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Xiaonan Wang
- 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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Huang H, Mackereth RW, Mitchell CPJ. Impacts of forest harvesting on mercury concentrations and methylmercury production in boreal forest soils and stream sediment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:122966. [PMID: 37981183 DOI: 10.1016/j.envpol.2023.122966] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023]
Abstract
Methylmercury (MeHg) is the most neurotoxic and bioaccumulative form of mercury (Hg) present in the terrestrial and aquatic food sources of boreal ecosystems, posing potential risks to wildlife and human health. Harvesting impacts on Hg methylation and MeHg concentrations in forest soils and stream sediment are not fully understood. In this study, a field investigation was carried out in 4 harvested and 2 unharvested boreal forest watersheds, before and after harvest, to better understand impacts on Hg methylation and MeHg concentration in soils and stream sediment, including their responses to different forest management practices. Changes in total Hg (THg) and MeHg concentrations, first-order potential rate constants for Hg methylation and MeHg demethylation (Kmeth and Kdemeth) as well as total carbon content and carbon-to-nitrogen ratio post-harvest in upland, wetland and riparian soils and stream sediment were assessed and compared. Increases in MeHg production were minimal in upland, wetland or riparian soils after harvest. Sediment in streams with minor buffer protection (∼3 m), greater fractions (>75%) of harvested watershed area and more road construction had significantly increased THg and MeHg concentrations, %-MeHg, Kmeth and total carbon content post-harvest. From these patterns, we infer that inputs of carbon and inorganic Hg into harvest-impacted stream sediment are likely sourced from the harvested upland areas and stimulate in situ MeHg production in stream sediment. These findings indicate the importance of stream sediment as potential MeHg pools in harvested forest watersheds. The findings also demonstrate that forest management practices aiming to mitigate organic matter and Hg inputs to streams can effectively alleviate harvesting impacts on Hg methylation and MeHg concentrations in stream sediment.
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Affiliation(s)
- Haiyong Huang
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Robert W Mackereth
- Centre for Northern Forest Ecosystem Research, Ontario Ministry of Natural Resources and Forestry, Thunder Bay, ON, Canada
| | - Carl P J Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
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5
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Harrow-Lyle TJ, Lam WY, Emilson EJS, Mackereth RW, Mitchell CPJ, Melles SJ. Watershed characteristics and chemical properties govern methyl mercury concentrations within headwater streams of boreal forests in Ontario, Canada. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 345:118526. [PMID: 37418824 DOI: 10.1016/j.jenvman.2023.118526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/21/2023] [Accepted: 06/25/2023] [Indexed: 07/09/2023]
Abstract
Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest as there are legacy MeHg concerns. However, models accounting for the complexity of underlying processes have not yet been developed. We assessed how catchment characteristics and stream water chemistry influence MeHg concentrations within 19 watersheds of the Dryden - Wabigoon Forest in Ontario, Canada, using a structural equation modelling (SEM) approach. Despite the study area encompassing a large variation of boreal forest watersheds in the Canadian Shield, our SEM had substantial explanatory power across the region (χ251 = 45.37, p-value = 0.70, R2 = 0.75). Nitrate concentrations (p-value <0.001), water temperature (p-value = 0.002), and the latent watershed characteristic (p-value <0.001) had a positive influence on MeHg concentrations once variable interactions were accounted. Due to the inherent strengths of applying an SEM approach, we describe two plausible pathways driving MeHg concentrations: 1) indirect effect of forest-derived nutrients increases in-situ MeHg production in Dryden - Wabigoon Forest streams, and 2) direct supply of MeHg from inundated soils following consistent precipitation and inundation events (i.e., fill, sit, and spill).
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Affiliation(s)
- Tyler J Harrow-Lyle
- Department of Chemistry and Biology, Toronto Metropolitan University, 43 Gerrard St, Toronto, Ontario, M5B 2K, Canada.
| | - Wai Ying Lam
- University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Erik J S Emilson
- Natural Resources Canada, Canadian Forest Service, 1219 Queen Street E., Sault Ste. Marie, Ontario, P6A 2E5, Canada.
| | - Robert W Mackereth
- Ministry Natural Resources and Forestry, 421 James St., Thunder Bay, Ontario, P7E 2V6, Canada.
| | - Carl P J Mitchell
- University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Stephanie J Melles
- Department of Chemistry and Biology, Toronto Metropolitan University, 43 Gerrard St, Toronto, Ontario, M5B 2K, Canada.
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Li Z, Wang T, Yang X, Wen X, Chen W, He Y, Yu Z, Zhang C. Microbial community function and methylmercury production in oxygen-limited paddy soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 266:115585. [PMID: 37856980 DOI: 10.1016/j.ecoenv.2023.115585] [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: 05/01/2023] [Revised: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023]
Abstract
Methylmercury is a neurotoxic compound that can enter rice fields through rainfall or irrigation with contaminated wastewater, and then contaminate the human food chain through the consumption of rice. Flooded paddy soil has a porous structure that facilitates air exchange with the atmosphere, but the presence of trace amounts of oxygen in flooded rice field soil and its impact on microbial-mediated formation of methylmercury is still unclear. We compared the microbial communities and their functions in oxygen-depleted and oxygen-limited paddy soil. We discovered that oxygen-limited paddy soil had higher methylmercury concentration, which was strongly correlated with soil properties and methylation potential. Compared with oxygen-depleted soil, oxygen-limited soil altered the microbial composition based on 16 S rRNA sequences, but not based on hgcA sequences. Moreover, oxygen-limited soil enhanced microbial activity significantly, increasing the abundance of more than half of the KEGG pathways, especially the metabolic pathways that might be involved in methylation. Our study unveils how microbial communities influence methylmercury formation in oxygen-limited paddy soil. ENVIRONMENTAL IMPLICATIONS: This study examined how low oxygen input affects microbial-induced MeHg formation in anaerobic paddy soil. We found that oxygen-limited soil produced more MeHg than oxygen-depleted soil. Oxygen input altered the microbial community structure of 16 S rRNA sequencing in anaerobic paddy soil, but had little impact on the hgcA sequencing community structure. Microbial activity and metabolic functions related to MeHg formation were also higher in oxygen-limited paddy soil. We suggest that oxygen may not be a limiting factor for Hg methylators, and that insufficient oxygen input in flooded paddy soil increases the risk of human exposure to MeHg from rice consumption.
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Affiliation(s)
- Zihao Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Tantan Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xu Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xin Wen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Wenhao Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Yubo He
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Zhigang Yu
- Australian Center for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Chang Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
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Keva O, Kiljunen M, Hämäläinen H, Jones RI, Kahilainen KK, Kankaala P, Laine MB, Schilder J, Strandberg U, Vesterinen J, Taipale SJ. Allochthony, fatty acid and mercury trends in muscle of Eurasian perch (Perca fluviatilis) along boreal environmental gradients. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155982. [PMID: 35588838 DOI: 10.1016/j.scitotenv.2022.155982] [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: 02/15/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Environmental change, including joint effects of increasing dissolved organic carbon (DOC) and total phosphorus (TP) in boreal northern lakes may affect food web energy sources and the biochemical composition of organisms. These environmental stressors are enhanced by anthropogenic land-use and can decrease the quality of polyunsaturated fatty acids (PUFAs) in seston and zooplankton, and therefore, possibly cascading up to fish. In contrast, the content of mercury in fish increases with lake browning potentially amplified by intensive forestry practises. However, there is little evidence on how these environmental stressors simultaneously impact beneficial omega-3 fatty acid (n3-FA) and total mercury (THg) content of fish muscle for human consumption. A space-for-time substitution study was conducted to assess whether environmental stressors affect Eurasian perch (Perca fluviatilis) allochthony and muscle nutritional quality [PUFA, THg, and their derivative, the hazard quotient (HQ)]. Perch samples were collected from 31 Finnish lakes along pronounced lake size (0.03-107.5 km2), DOC (5.0-24.3 mg L-1), TP (5-118 μg L-1) and land-use gradients (forest: 50.7-96.4%, agriculture: 0-32.6%). These environmental gradients were combined using principal component analysis (PCA). Allochthony for individual perch was modelled using source and consumer δ2H values. Perch allochthony increased with decreasing lake pH and increasing forest coverage (PC1), but no correlation between lake DOC and perch allochthony was found. Perch muscle THg and omega-6 fatty acid (n6-FA) content increased with PC1 parallel with allochthony. Perch muscle DHA (22:6n3) content decreased, and ALA (18:3n3) increased towards shallower murkier lakes (PC2). Perch allochthony was positively correlated with muscle THg and n6-FA content, but did not correlate with n3-FA content. Hence, the quality of perch muscle for human consumption decreases (increase in HQ) with increasing forest coverage and decreasing pH, potentially mediated by increasing fish allochthony.
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Affiliation(s)
- Ossi Keva
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland.
| | - Mikko Kiljunen
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
| | - Heikki Hämäläinen
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
| | - Roger I Jones
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, FI-16900 Lammi, Finland
| | - Paula Kankaala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Miikka B Laine
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
| | - Jos Schilder
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
| | - Ursula Strandberg
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Jussi Vesterinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland; Association for Water and Environment of Western Uusimaa, Lohja, Finland
| | - Sami J Taipale
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), FI-40014 Jyväskylä, Finland
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Yu Y, Li Z, Liu Y, Wang F, Liu Y, Zhao J, Li Y, Gao Y, Zhu N. Roles of plant-associated microorganisms in regulating the fate of Hg in croplands: A perspective on potential pathways in maintaining sustainable agriculture. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155204. [PMID: 35421489 DOI: 10.1016/j.scitotenv.2022.155204] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
In heavy metal-contaminated croplands, plant-associated microorganisms play important roles in the adaptation of crops to heavy metals. Plant-associated microbes can interact with Hg and stimulate plant resistance to Hg toxicity, which is crucial for impeding Hg accumulation along the food chain. The roles of rhizosphere microorganisms for the improvement of plant growth and Hg resistance have drawn great research attention. However, the interactions among plant-endophyte-Hg have been neglected although they might be important for in vivo Hg detoxification. In this study, we systematically summarized 1) the roles of plant-associated microorganisms in Hg detoxification and plant growth, 2) Hg methylation and demethylation driven by plant-associated microbes, 3) the relationships between plant-associated microbes and Hg biogeochemical cycling. The possible mechanisms underlying crop-endophyte-Hg interactions were discussed, although limited studies on this aspect are available to date. The challenges and perspectives of plant-endophytes in dampening Hg phytotoxicity and controlling Hg accumulation in croplands were proposed on the basis of the present knowledge. Taken together, this work provides evidence for further understanding the interactions between soil-plant-endophyte-Hg systems and as well as new interpretations and perspectives into regulating the fate of Hg in croplands.
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Affiliation(s)
- Yue Yu
- School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang 212100, Jiangsu, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China
| | - Zhanming Li
- School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang 212100, Jiangsu, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
| | - Yonghua Liu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, & CAS-HKU Joint Laboratory of Metallomics on Health and Environment, & Beijing Metallomics Facility, & National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; School of Chemical and Biological Engineering, Taiyuan University of Science and Technology, Taiyuan 030000, Shanxi, China
| | - Fang Wang
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China
| | - Yurong Liu
- State Key Laboratory of Agricultural Microbiology and College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiating Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, & CAS-HKU Joint Laboratory of Metallomics on Health and Environment, & Beijing Metallomics Facility, & National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yufeng Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, & CAS-HKU Joint Laboratory of Metallomics on Health and Environment, & Beijing Metallomics Facility, & National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yuxi Gao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, & CAS-HKU Joint Laboratory of Metallomics on Health and Environment, & Beijing Metallomics Facility, & National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Nali Zhu
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
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Méndez-López M, Gómez-Armesto A, Alonso-Vega F, Pontevedra-Pombal X, Fonseca F, de Figueiredo T, Arias-Estévez M, Nóvoa-Muñoz JC. The role of afforestation species as a driver of Hg accumulation in organic horizons of forest soils from a Mediterranean mountain area in SW Europe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154345. [PMID: 35257764 DOI: 10.1016/j.scitotenv.2022.154345] [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: 12/15/2021] [Revised: 02/10/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Forest areas are a primary sink of atmospheric mercury (Hg) within terrestrial ecosystems, whereas forest vegetation plays a key role in atmospheric Hg transfer to soil horizons. This study assessed variations in total Hg contents (HgT) and accumulation (HgRes) in the soil organic horizons of a forest area in NE Portugal, where post-wildfire afforestation led to the substitution of the native deciduous species (Quercus pyrenaica) by fast-growing coniferous species (Pseudotsuga menziesii and Pinus nigra). The study also evaluated, for each species, the links between Hg contents and other biophilic elements of soil organic matter (C, N, S) present in organic subhorizons (OL, OF, OH). Mean HgT in the organic horizons of the different tree species follow the sequence: P. nigra (88 μg kg-1) < Q.pyrenaica (101 μg kg-1) <P. menziesii (141 μg kg-1). The highest HgRes for the entire organic horizon was found under P. menziesii (471 μg m-2), followed by P. nigra (253 μg m-2) and Q. pyrenaica (189 μg m-2). Among the organic subhorizons, values of HgT and HgRes follow the sequence OL < OF < OH, which is consistent with the degree of organic matter humification. Indeed, HgT and HgRes correlated significantly with the C/N and C/S ratios for all species and organic subhorizons, suggesting that the quality of organic matter may influence strongly the Hg fate in these forest soils. Soils from P. menziesii plots have shown an HgRes 2.5 times higher than in plots dominated by the native Q. pyrenaica. Hg accumulation in the organic horizons, promoted in the coniferous species, may increase the risk of Hg mobilization due to wildfires and forest management practices. Therefore, forest management plans should select cautiously the tree species for afforestation in order to minimize adverse environmental effects caused by changes in the biogeochemical cycle of contaminants such as Hg.
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Affiliation(s)
- M Méndez-López
- Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencia do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain; Campus da Auga, Universidade de Vigo, Laboratorio de Tecnoloxía e Diagnose Ambiental, Rúa Canella da Costa da Vela 12, 32004 Ourense, Spain.
| | - A Gómez-Armesto
- Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencia do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain; Campus da Auga, Universidade de Vigo, Laboratorio de Tecnoloxía e Diagnose Ambiental, Rúa Canella da Costa da Vela 12, 32004 Ourense, Spain
| | - F Alonso-Vega
- Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencia do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain; Campus da Auga, Universidade de Vigo, Laboratorio de Tecnoloxía e Diagnose Ambiental, Rúa Canella da Costa da Vela 12, 32004 Ourense, Spain
| | - X Pontevedra-Pombal
- Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, 15786 Santiago de Compostela, Spain
| | - F Fonseca
- Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Sta Apolónia, 5300-253 Bragança, Portugal
| | - T de Figueiredo
- Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Sta Apolónia, 5300-253 Bragança, Portugal
| | - M Arias-Estévez
- Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencia do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain; Campus da Auga, Universidade de Vigo, Laboratorio de Tecnoloxía e Diagnose Ambiental, Rúa Canella da Costa da Vela 12, 32004 Ourense, Spain
| | - J C Nóvoa-Muñoz
- Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencia do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, As Lagoas s/n, 32004 Ourense, Spain; Campus da Auga, Universidade de Vigo, Laboratorio de Tecnoloxía e Diagnose Ambiental, Rúa Canella da Costa da Vela 12, 32004 Ourense, Spain
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10
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Reclaimed Water Reuse for Groundwater Recharge: A Review of Hot Spots and Hot Moments in the Hyporheic Zone. WATER 2022. [DOI: 10.3390/w14121936] [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
As an alternative resource, reclaimed water is rich in the various nutrients and organic matter that may irreparably endanger groundwater quality through the recharging process. During groundwater recharge with reclaimed water, hot spots and hot moments (HSHMs) in the hyporheic zones, located at the groundwater–reclaimed water interface, play vital roles in cycling and processing energy, carbon, and nutrients, drawing increasing concern in the fields of biogeochemistry, environmental chemistry, and pollution treatment and prevention engineering. This paper aims to review these recent advances and the current state of knowledge of HSHMs in the hyporheic zone with regard to groundwater recharge using reclaimed water, including the generation mechanisms, temporal and spatial characteristics, influencing factors, and identification indicators and methods of HSHMs in the materials cycle. Finally, the development prospects of HSHMs are discussed. It is hoped that this review will lead to a clearer understanding of the processes controlling water flow and pollutant flux, and that further management and control of HSHMs can be achieved, resulting in the development of a more accurate and safer approach to groundwater recharge with reclaimed water.
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11
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Millera Ferriz L, Ponton DE, Storck V, Leclerc M, Bilodeau F, Walsh DA, Amyot M. Role of organic matter and microbial communities in mercury retention and methylation in sediments near run-of-river hydroelectric dams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145686. [PMID: 33609815 DOI: 10.1016/j.scitotenv.2021.145686] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/08/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
Run-of-river power plants (RoRs) are expected to triple in number over the next decades in Canada. These structures are not anticipated to considerably promote the mobilization and transport of mercury (Hg) and its subsequent microbial transformation to methylmercury (MeHg), a neurotoxin able to biomagnify in food webs up to humans. To test whether construction of RoRs had an effect on Hg transport and transformation, we studied Hg and MeHg concentrations, organic matter contents and methylating microbial community abundance and composition in the sediments of a section of the St. Maurice River (Quebec, Canada). This river section has been affected by the construction of two RoR dams and its watershed has been disturbed by a forest fire, logging, and the construction of wetlands. Higher total Hg (THg) and MeHg concentrations were observed in the surface sediments of the flooded sites upstream of the RoRs. These peaks in THg and MeHg were correlated with organic matter proportions in the sediments (r2 = 0.87 and 0.82, respectively). In contrast, the proportion of MeHg, a proxy for methylation potential, was best explained by the carbon to nitrogen ratio suggesting the importance of terrigenous organic matter as labile substrate for Hg methylation in this system. Metagenomic analysis of Hg-methylating communities based on the hgcA functional gene marker indicated an abundance of methanogens, sulfate reducers and fermenters, suggesting that these metabolic guilds may be primary Hg methylators in these surface sediments. We propose that RoR pondages act as traps for sediments, organic matter and Hg, and that this retention can be amplified by other disturbances of the watershed such as forest fire and logging. RoR flooded sites can be conducive to Hg methylation in sediments and may act as gateways for bioaccumulation and biomagnification of MeHg along food webs, particularly in disturbed watersheds.
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Affiliation(s)
- L Millera Ferriz
- Département de sciences biologiques, Université de Montréal, Montreal H2V 2S9, QC, Canada; Biology Department, Concordia University, Montreal H4B 1R6, QC, Canada; GRIL, Groupe de Recherche Interuniversitaire en Limnologie, Département de sciences biologiques, Université de Montréal, Campus MIL, Montreal H3C 3J7, QC, Canada
| | - D E Ponton
- Département de sciences biologiques, Université de Montréal, Montreal H2V 2S9, QC, Canada; GRIL, Groupe de Recherche Interuniversitaire en Limnologie, Département de sciences biologiques, Université de Montréal, Campus MIL, Montreal H3C 3J7, QC, Canada
| | - V Storck
- Département de sciences biologiques, Université de Montréal, Montreal H2V 2S9, QC, Canada; Biology Department, Concordia University, Montreal H4B 1R6, QC, Canada
| | - M Leclerc
- Département de sciences biologiques, Université de Montréal, Montreal H2V 2S9, QC, Canada; GRIL, Groupe de Recherche Interuniversitaire en Limnologie, Département de sciences biologiques, Université de Montréal, Campus MIL, Montreal H3C 3J7, QC, Canada
| | - F Bilodeau
- Hydro-Québec Production, Environment Department, Montreal, QC, Canada
| | - D A Walsh
- Biology Department, Concordia University, Montreal H4B 1R6, QC, Canada; GRIL, Groupe de Recherche Interuniversitaire en Limnologie, Département de sciences biologiques, Université de Montréal, Campus MIL, Montreal H3C 3J7, QC, Canada
| | - M Amyot
- Département de sciences biologiques, Université de Montréal, Montreal H2V 2S9, QC, Canada; GRIL, Groupe de Recherche Interuniversitaire en Limnologie, Département de sciences biologiques, Université de Montréal, Campus MIL, Montreal H3C 3J7, QC, Canada.
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12
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Yin M, Wan Y, Li S, Zhao X, Zhang W, Zhang Y, Wang H. Carbon nitride-doped melamine-silver adsorbents with peroxidase-like catalysis and visible-light photocatalysis: Colorimetric detection and detoxification removal of total mercury. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124978. [PMID: 33385729 DOI: 10.1016/j.jhazmat.2020.124978] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/04/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
Mesoporous melamine-silver (MA-Ag) nanocomposites doped with carbon nitride quantum dots (CNQDs) were fabricated simply by the controlled supramolecular self-assembly. It was discovered that the resulting nanoflower-like CNQDs@MA-Ag nanocomposites could exhibit the peroxidase-like catalysis, which could be specifically enhanced by Hg2+ by forming Ag@Hg alloys. A double catalysis-based colorimetric method was thereby developed for the fast detecting of Hg2+ and Hg0 in wastewater samples, with the levels down to 0.050 nM and 18.3 nM, respectively. Moreover, strong visible-light-driven photocatalysis of the nanocomposites was demonstrated for oxidizing Hg0 into Hg2+ through photocatalytic H2O2 production so as to realize the detoxification of Hg0 in the environmental wastewater. Besides, the fabricated mesoporous CNQDs@MA-Ag nanocomposites with large specific surface areas might facilitate the high Hg adsorption through the powerful MA-Hg chelate interaction, showing the efficient adsorption and/or removal of total Hg. The catalysis-selective colorimetric analysis and photocatalysis-based detoxification removal of total mercury may promise for wide applications in the environmental monitoring and wastewater treatment of toxic heavy metals of mercury.
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Affiliation(s)
- Mengyuan Yin
- Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China
| | - Yuqi Wan
- Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China
| | - Shuai Li
- Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China
| | - Xiaoting Zhao
- Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China
| | - Wenwen Zhang
- Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China
| | - Yun Zhang
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, Guilin University of Technology, Guilin, 541004 Guangxi, PR China
| | - Hua Wang
- School of Life Sciences, Huzhou University, Huzhou, 313000 Zhejiang, PR China; Rizhao Key Laboratory of Marine Medicine and Materials Application Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165 Shandong, PR China.
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13
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Kuglerová L, Hasselquist EM, Sponseller RA, Muotka T, Hallsby G, Laudon H. Multiple stressors in small streams in the forestry context of Fennoscandia: The effects in time and space. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 756:143521. [PMID: 33243494 DOI: 10.1016/j.scitotenv.2020.143521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/29/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
In this paper we describe how forest management practices in Fennoscandian countries, namely Sweden and Finland, expose streams to multiple stressors over space and time. In this region, forestry includes several different management actions and we explore how these may successively disturb the same location over 60-100 year long rotation periods. Of these actions, final harvest and associated road construction, soil scarification, and/or ditch network maintenance are the most obvious sources of stressors to aquatic ecosystems. Yet, more subtle actions such as planting, thinning of competing saplings and trees, and removing logging residues also represent disturbances around waterways in these landscapes. We review literature about how these different forestry practices may introduce a combination of physicochemical stressors, including hydrological change, increased sediment transport, altered thermal and light regimes, and water quality deterioration. We further elaborate on how the single stressors may combine and interact and we consequently hypothesise how these interactions may affect aquatic communities and processes. Because production forestry is practiced on a large area in both countries, the various stressors appear multiple times during the rotation cycles and potentially affect the majority of the stream network length within most catchments. We concluded that forestry practices have traditionally not been the focus of multiple stressor studies and should be investigated further in both observational and experimental fashion. Stressors accumulate across time and space in forestry dominated landscapes, and may interact in unpredictable ways, limiting our current understanding of what forested stream networks are exposed to and how we can design and apply best management practices.
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Affiliation(s)
- Lenka Kuglerová
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
| | - Eliza Maher Hasselquist
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden; Water Quality Impacts Unit, Natural Resources Institute Finland, Helsinki, Finland
| | | | - Timo Muotka
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland; Finnish Environment Institute, Freshwater Centre, Oulu, Finland
| | - Göran Hallsby
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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14
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Thomas SM, Melles SJ, Mackereth RW, Tunney TD, Chu C, Oswald CJ, Bhavsar SP, Johnston TA. Climate and landscape conditions indirectly affect fish mercury levels by altering lake water chemistry and fish size. ENVIRONMENTAL RESEARCH 2020; 188:109750. [PMID: 32526497 DOI: 10.1016/j.envres.2020.109750] [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: 11/18/2019] [Revised: 05/15/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as individual fish biology and water chemistry at the lake-scale, whereas, climate, and land-use/land-cover conditions within lake catchments can be influential at relatively larger scales. Nevertheless, unravelling the intricate network of pathways that govern how lake-scale and large-scale factors interact to affect mercury levels in fish remains an important scientific challenge. Using structural equation models (SEMs) and multiple long-term databases we identified direct and indirect effects of lake-scale and larger-scale factors on mercury levels in Walleye and Northern Pike - two species that are valued in inland fisheries. At the lake-level, the most parsimonious path models contained direct effects of fish weight, DOC, and pH, as well as an indirect effect of DOC on fish mercury levels via fish weight. Interestingly, lakeshed-, climate-, and full-path models that combine the effects of both lakeshed and climate revealed indirect effects of surrounding landscape conditions and latitude via DOC, pH, and fish weight but no direct effects on fish mercury levels. These results are generally consistent across species and lakes, except for some differences between stratified and non-stratified lakes. Our findings imply that understanding climate and land-use driven alterations of water chemistry and fish biology will be critical to predicting and mitigating fish mercury bioaccumulation in the future.
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Affiliation(s)
- Shyam M Thomas
- Department of Chemistry & Biology, Ryerson University, Toronto, ON M5B 2K3, Canada.
| | - Stephanie J Melles
- Department of Chemistry & Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Robert W Mackereth
- Ontario Ministry of Natural Resources & Forestry, Centre for Northern Forest Ecosystem Research, Thunder Bay, ON P7E 2V6, Canada
| | - Tyler D Tunney
- Fisheries and Oceans Canada, Freshwater Habitat Section, Gulf Fisheries Centre, Moncton, NB E1C 9B6, Canada
| | - Cindy Chu
- Ontario Ministry of Natural Resources & Forestry, Aquatic Research and Monitoring Section, Peterborough, ON K9L 0G2, Canada
| | - Claire J Oswald
- Department of Geography and Environmental Studies, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Satyendra P Bhavsar
- Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, Conservation and Parks, Toronto, ON M9P 3V6, Canada
| | - Thomas A Johnston
- Ontario Ministry of Natural Resources and Forestry, Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University, Sudbury, ON P3E 2C6, Canada
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15
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Bishop K, Shanley JB, Riscassi A, de Wit HA, Eklöf K, Meng B, Mitchell C, Osterwalder S, Schuster PF, Webster J, Zhu W. Recent advances in understanding and measurement of mercury in the environment: Terrestrial Hg cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137647. [PMID: 32197286 DOI: 10.1016/j.scitotenv.2020.137647] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/23/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
This review documents recent advances in terrestrial mercury cycling. Terrestrial mercury (Hg) research has matured in some areas, and is developing rapidly in others. We summarize the state of the science circa 2010 as a starting point, and then present the advances during the last decade in three areas: land use, sulfate deposition, and climate change. The advances are presented in the framework of three Hg "gateways" to the terrestrial environment: inputs from the atmosphere, uptake in food, and runoff with surface water. Among the most notable advances: These and other advances reported here are of value in evaluating the effectiveness of the Minamata Convention on reducing environmental Hg exposure to humans and wildlife.
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Affiliation(s)
- Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | | | - Ami Riscassi
- Department of Environmental Sciences, University of Virginia, P.O. Box 400123, Charlottesville, VA 22904-4123, USA.
| | - Heleen A de Wit
- Norwegian Institute for Water Research, Gaustadalléen 21, NO-0349, Norway.
| | - Karin Eklöf
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 75007 Uppsala, Sweden.
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
| | - Carl Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
| | - Stefan Osterwalder
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, CNRS, IRD, Grenoble 18 INP, 38000 Grenoble, France.
| | - Paul F Schuster
- U.S. Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303-1066, USA.
| | - Jackson Webster
- Department of Civil Engineering, California State University, 400 W. 1st Street, 21 95929-0930 Chico, CA, USA.
| | - Wei Zhu
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden.
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16
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Bravo AG, Cosio C. Biotic formation of methylmercury: A bio-physico-chemical conundrum. LIMNOLOGY AND OCEANOGRAPHY 2020; 65:1010-1027. [PMID: 32612306 PMCID: PMC7319479 DOI: 10.1002/lno.11366] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/17/2019] [Accepted: 10/02/2019] [Indexed: 05/11/2023]
Abstract
Mercury (Hg) is a natural and widespread trace metal, but is considered a priority pollutant, particularly its organic form methylmercury (MMHg), because of human's exposure to MMHg through fish consumption. Pioneering studies showed the methylation of divalent Hg (HgII) to MMHg to occur under oxygen-limited conditions and to depend on the activity of anaerobic microorganisms. Recent studies identified the hgcAB gene cluster in microorganisms with the capacity to methylate HgII and unveiled a much wider range of species and environmental conditions producing MMHg than previously expected. Here, we review the recent knowledge and approaches used to understand HgII-methylation, microbial biodiversity and activity involved in these processes, and we highlight the current limits for predicting MMHg concentrations in the environment. The available data unveil the fact that HgII methylation is a bio-physico-chemical conundrum in which the efficiency of biological HgII methylation appears to depend chiefly on HgII and nutrients availability, the abundance of electron acceptors such as sulfate or iron, the abundance and composition of organic matter as well as the activity and structure of the microbial community. An increased knowledge of the relationship between microbial community composition, physico-chemical conditions, MMHg production, and demethylation is necessary to predict variability in MMHg concentrations across environments.
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Affiliation(s)
- Andrea G. Bravo
- Department of Marine Biology and Oceanography, Institute of Marine SciencesSpanish National Research Council (CSIC)BarcelonaSpain
| | - Claudia Cosio
- Université de Reims Champagne Ardennes, UMR‐I 02 INERIS‐URCA‐ULH SEBIO, Unité Stress Environnementaux et BIOsurveillance des milieux aquatiquesReimsFrance
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17
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Xie M, Zhang C, Liao X, Huang C. The influence of wetting-drying alternation on methylmercury degradation in Guangzhou soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 259:113866. [PMID: 31891907 DOI: 10.1016/j.envpol.2019.113866] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
In one of our previous studies, the mechanisms of radical-initiated methylmercury (MeHg) degradation in soil with coexisting Fe and Cu have been reported. In this work, various environmental factors, including water table fluctuation, pH and major ions, are discussed to clarify the behavior of MeHg in subsurface environments. Soil column experiments were set up to simulate the degradation of MeHg in the soil with an iron-bearing mineral (annite), which has often undergone repeating wetting-drying cycles, resulting from the local climate. The results indicate that wetting-drying alternation can initiate MeHg degradation in the soil with the annite mineral. Additionally, the majority of the major ions (K+, Na+, Mg2+, Fe3+, Cl-, SO42-, NO3-) in the interstitial soil had little effect in the degradation of MeHg with the exception of Cu, which improved the degradation depending on the pH. At acidic pHs Cu increased the production of hydroxyl radical while at more alkaline pHs there was oxidation to Cu(III). The products including Hg(II) and Hg(0) of MeHg degradation were also identified in this work. This study reveals that the geochemical cycle of MeHg is closely linked to local climate and pedosphere processes.
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Affiliation(s)
- Mengying Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
| | - Caixiang Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China.
| | - Xiaoping Liao
- School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan, 430074, PR China
| | - Changsheng Huang
- Wuhan Center of China Geological Survey, Wuhan, 430205, Hubei, China
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18
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Lavoie NC, Grégoire DS, Stenzler BR, Poulain AJ. Reduced sulphur sources favour Hg II reduction during anoxygenic photosynthesis by Heliobacteria. GEOBIOLOGY 2020; 18:70-79. [PMID: 31536173 DOI: 10.1111/gbi.12364] [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: 05/27/2019] [Revised: 08/16/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
The consumption of rice has become a global food safety issue because rice paddies support the production of high levels of the potent neurotoxin, methylmercury. The production of methylmercury is carried out by chemotrophic anaerobes that rely on a diversity of terminal electron acceptors, namely sulphate. Sulphur can be a limiting nutrient in rice paddies, and sulphate amendments are often used to stimulate crop production, which can increase methylmercury production. Mercury (Hg) redox cycling can affect Hg methylation by controlling the delivery of inorganic Hg substrates to methylators in anoxic habitats. Whereas sulphur is recognized as a key substrate controlling methylmercury production, the controls sulphur exerts on other microbe-mediated Hg transformations remain poorly understood. To explore the potential coupling between sulphur assimilation and anaerobic HgII reduction to Hg0 , we studied Heliobacillus mobilis, a mesophilic anoxygenic phototroph representative from the Heliobacteriacea family originally isolated from a rice paddy. Here, we tested whether the redox state of the sulphur sources available to H. mobilis would affect its ability to reduce HgII . By comparing Hg0 production over a redox gradient of sulphur sources, we demonstrate that phototrophic HgII reduction is favoured in the presence of reduced sulphur sources such as thiosulphate and cysteine. We also show that cysteine exerts dynamic control on Hg cycling by affecting not only Hg's bioavailability but also its abiotic photoreduction under low light conditions. Specifically, in the absence of cells we show that organic matter (as yeast extract) and cysteine are both required for photoreduction to occur. This study offers insights into how one of the most primitive forms of photosynthesis affects Hg redox transformations and frames Heliobacteria as key players in Hg cycling within paddy soils, forming a basis for management strategies to mitigate Hg accumulation in rice.
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Affiliation(s)
- Noémie C Lavoie
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Daniel S Grégoire
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Bejamin R Stenzler
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Alexandre J Poulain
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
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Gygax S, Gfeller L, Wilcke W, Mestrot A. Emerging investigator series: mercury mobility and methylmercury formation in a contaminated agricultural flood plain: influence of flooding and manure addition. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:2008-2019. [PMID: 31617529 DOI: 10.1039/c9em00257j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The fate and the methylation of mercury (Hg) in the terrestrial environment are still poorly understood and although the main drivers of release and methylation of mercury in soils are known (low redox potential and microbial carbon availability) their interactions are not well understood. This is of concern since many agriculturally used floodplains, where the recurring flooding and agricultural practices (e.g. manure amendments) may have an impact on the fate and the biomethylation of Hg, are at the same time Hg-contaminated. In this study, we modified and validated existing methods to extract and analyze methylmercury (MeHg) by HPLC-ICP-MS in soils and we assessed the Hg and MeHg concentrations in three fields situated in a Hg polluted agricultural floodplain. Further, we incubated the top soil from the three studied fields for 11 days under flooded conditions in presence or absence of 2 mass% of cow manure, a common agricultural amendment in the area. Total Hg and MeHg concentrations ranged from <limit of detection (LOD, 0.012 mg kg-1) to 28.2 mg kg-1 and from 1.2 to 7.8 μg kg-1 respectively. Hg was released to the soil solution after 12 hours with a maximum between day 2 and day 7. MeHg levels in the soil solution were <LOD although it was found in the soil before and after the incubation. The addition of cow manure to saturated soils led to an increase in the MeHg concentrations of the soil solid phase by up to fivefold to a maximum of 26.4 ± 1.1 μg kg-1 (n = 3). Our study demonstrates that the combination of low redox potential because of flooding with common agricultural practices such as the amendment of manures enhances the formation of toxic MeHg.
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Affiliation(s)
- Sebastian Gygax
- Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland
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20
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Sun T, Ma M, Wang X, Wang Y, Du H, Xiang Y, Xu Q, Xie Q, Wang D. Mercury transport, transformation and mass balance on a perspective of hydrological processes in a subtropical forest of China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:113065. [PMID: 31465902 DOI: 10.1016/j.envpol.2019.113065] [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: 05/14/2019] [Revised: 08/15/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
Forest ecosystem has long been suggested as a vital component in the global mercury (Hg) biogeochemical cycling. However, there remains large uncertainties in understanding total Hg (THg) and methylmercury (MeHg) variations and their controlling factors during the whole hydrological processes in forest ecosystems. Here, we quantified Hg mass flow along hydrological processes of wet deposition, throughfall, stemflow, litter leachate, soil leachate, surface runoff, and stream, and litterfall Hg deposition, and air-forest floor elemental Hg (Hg0) exchange flux to set up a Hg mass balance in a subtropical forest of China. Results showed that THg concentration in stream was lower than that in wet deposition, while an opposite characteristic for MeHg concentration, and both THg and MeHg fluxes of stream were lower than those of wet deposition. Variations of THg and MeHg in throughfall and litter leachate had strong direct and indirect effects on controlling variations of THg and MeHg in surface runoff, soil leachate and stream, respectively. Especially, the net Hg methylation was suggested in the forest canopy and forest floor layers, and significant particulate bound Hg (PBM) filtration was observed in soil layers. The Hg mass balance showed that the litterfall Hg deposition was the main Hg input for forest floor Hg, and the elemental Hg vapor (Hg0) re-emission from forest floor was the dominant Hg output. Overall, we estimated the net THg input flux of 13.8 μg m-2 yr-1 and net MeHg input flux of 0.6 μg m-2 yr-1 within the forest ecosystem. Our results highlighted the important roles of forest canopy and forest floor to shape Hg in output flow, and the forest floor is a distinct sink of MeHg.
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Affiliation(s)
- Tao Sun
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Ming Ma
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Xun Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Yongmin Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Hongxia Du
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Yuping Xiang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Qinqin Xu
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Qing Xie
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400715, China.
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21
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Willacker JJ, Eagles-Smith CA, Kowalski BM, Danehy RJ, Jackson AK, Adams EM, Evers DC, Eckley CS, Tate MT, Krabbenhoft DP. Timber harvest alters mercury bioaccumulation and food web structure in headwater streams. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:636-645. [PMID: 31330355 PMCID: PMC6799996 DOI: 10.1016/j.envpol.2019.07.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/02/2019] [Accepted: 07/05/2019] [Indexed: 05/15/2023]
Abstract
Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest's influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in 10 paired catchments that were either clear-cut in their entirety, clear-cut except for an 8-m wide riparian buffer, or left unharvested. Average mercury concentrations in aquatic biota from clear-cut catchments were 50% higher than in reference catchments and 165% higher than in catchments with a riparian buffer. Mercury concentrations in aquatic invertebrates and salamanders were not correlated with aqueous THg or MeHg concentrations, but rather treatment effects appeared to correspond with differences in the utilization of terrestrial and aquatic basal resources in the stream food webs. Carbon and nitrogen isotope data suggest that a diminished shredder niche in the clear-cut catchments contributed to lower basal resource diversity compared with the reference of buffered treatments, and that elevated Hg concentrations in the clear-cut catchments reflect an increased reliance on aquatic resources in clear-cut catchments. In contrast, catchments with riparian buffers had higher basal resource diversity than the reference catchments, indicative of more balanced utilization of terrestrial and aquatic resources. Further, following timber harvest THg concentrations in riparian songbirds were elevated, suggesting an influence of timber harvest on Hg export to riparian food webs. These data, coupled with comparisons of individual feeding guilds, indicate that changes in organic matter sources and associated effects on stream food web structure are important mechanisms by which timber harvest modifies Hg bioaccumulation in headwater streams and riparian consumers.
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Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
| | - Brandon M Kowalski
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Robert J Danehy
- Catchment Aquatic Ecology, 5335 Saratoga St., Eugene, OR, 97405, USA
| | - Allyson K Jackson
- Oregon State University, Department of Fisheries and Wildlife, 104 Nash Hall, Corvallis, OR, 97331, USA
| | - Evan M Adams
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA, 98101, USA
| | - Michael T Tate
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
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Rodenhouse NL, Lowe WH, Gebauer RLE, McFarland KP, Bank MS. Mercury bioaccumulation in temperate forest food webs associated with headwater streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 665:1125-1134. [PMID: 30893744 DOI: 10.1016/j.scitotenv.2019.02.151] [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: 11/28/2018] [Revised: 01/25/2019] [Accepted: 02/09/2019] [Indexed: 06/09/2023]
Abstract
The soils and food webs associated with mid to high elevation, forested, headwater streams in northeastern North America are potential hotspots for mercury (Hg) methylation and bioaccumulation, but are not well studied. Our goals were to quantify total Hg (THg) and methyl Hg (MeHg) concentrations in soils and terrestrial food webs associated with headwater streams of northern hardwood forests to identify predictors of small-scale spatial variation in Hg bioaccumulation. We sampled soil characteristics that promote Hg methylation including pH, sulfur and calcium content, and organic matter. To assess spatial variation, we sampled at high (~700 m asl) and mid elevations (~500 m asl), both adjacent to (<1 m) and away from (>75 m) three replicate headwater streams in each of two watersheds of the White Mountains region, New Hampshire, USA. Soils of these forested watersheds differed significantly in pH and the content of calcium, sulfur, organic matter and THg. Conditions for methylation were more favorable in the upland forest sites compared to streamside sites. Significant bioaccumulation of THg occurred in all measured components of the food web, including insects, spiders, salamanders, and birds. Trophic position, as determined by δ15N, was the best predictor of both THg and MeHg bioaccumulation across the sampled taxa and was also a better predictor than spatial location. However, the degree of bioaccumulation at which MeHg significantly affects animal behavior, reproduction or survival is unknown for most taxa in terrestrial habitats, particularly for invertebrates. These findings show that Hg methylation and bioaccumulation is not limited to areas traditionally classified as wetlands or to areas with exceptionally high THg inputs, but that it is a widespread and important phenomenon in the moist deciduous forests of eastern North America.
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Affiliation(s)
| | - Winsor H Lowe
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | | | | | - Michael S Bank
- Department of Environmental Conservation, University of Massachusetts, Amherst, MA, USA; Institute of Marine Research, Postboks 1870, Nordnes 5817, Bergen, Norway
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23
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He M, Tian L, Braaten HFV, Wu Q, Luo J, Cai LM, Meng JH, Lin Y. Mercury-Organic Matter Interactions in Soils and Sediments: Angel or Devil? BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 102:621-627. [PMID: 30600387 DOI: 10.1007/s00128-018-2523-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
Many studies have suggested that organic matter (OM) substantially reduces the bioavailability and risks of mercury (Hg) in soils and sediments; however, recent reports have supported that OM greatly accelerates Hg methylation and increases the risks of Hg exposure. This study aims to summarize the interactions between Hg and OM in soils and sediments and improve our understanding of the effects of OM on Hg methylation. The results show that OM characteristics, promotion of the activity of Hg-methylating microbial communities, and the microbial availability of Hg accounted for the acceleration of Hg methylation which increases the risk of Hg exposure. These three key aspects were driven by multiple factors, including the types and content of OM, Hg speciation, desorption and dissolution kinetics and environmental conditions.
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Affiliation(s)
- Mei He
- School of Resources and Environment, Yangtze University, Wuhan, 430100, People's Republic of China
| | - Lei Tian
- School of Petroleum Engineering, Yangtze University, Wuhan, 430100, People's Republic of China
| | | | - Qingru Wu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Jie Luo
- School of Resources and Environment, Yangtze University, Wuhan, 430100, People's Republic of China
| | - Li-Mei Cai
- School of Resources and Environment, Yangtze University, Wuhan, 430100, People's Republic of China
| | - Jiang-Hui Meng
- Hubei Cooperative Innovation Center of Unconventional Oil and Gas, Yangtze University, Wuhan, 430100, People's Republic of China
| | - Yan Lin
- School of Resources and Environment, Yangtze University, Wuhan, 430100, People's Republic of China.
- Norwegian Institute for Water Research, 0349, Oslo, Norway.
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24
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Han D, Fu Q, Gao S, Hu Z, Zhang X, Chen X, Feng J, Cheng J, Wang W. Two-year monitoring of gaseous elementary mercury in a typical iron-steel plant in Yangtze River Delta, China: Characterization and estimation of its dynamic oxidation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 657:1217-1226. [PMID: 30677888 DOI: 10.1016/j.scitotenv.2018.12.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 12/09/2018] [Accepted: 12/09/2018] [Indexed: 06/09/2023]
Abstract
A two-year gaseous elementary mercury (GEM) measurement was implemented at an iron-steel plant in Yangtze River Delta, China, which provided an excellent opportunity to investigate their dynamic cycling. The hourly GEM concentrations ranged between 0.78 and 113.8 ng m-3, with a mean value of 3.83 ± 2.53 ng m-3. Temporally, seasonal GEM contents decreased as winter ≈ spring > summer > autumn, while diurnal cycling was observed with a steady decrease at 14:00-17:00. GEM variations were found to be related to source emissions, meteorology and regional transportation. Three major oxidants (O3, Br and OH radicals) were used to evaluate GEM oxidation in the daytime, and the estimated GEM depletion rate was 70.8 ± 52.5 molecule cm-3 s-1 (0.09 ± 0.06 ng m-3 h-1). The GEM oxidized by Br radicals accounted for 83.4% of the total GEM oxidation rate, followed by O3 (13.8%). The estimated atmospheric lifetime of GEM was 22.9 to 345.2 days, which implies a major contribution of Br radicals to the GEM sink. These findings highlight the ability of iron-steel industry emissions and in-situ oxidation to affect daily local GEM cycling significantly.
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Affiliation(s)
- Deming Han
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qingyan Fu
- Shanghai Environmental Monitor Center, Shanghai 200235, China
| | - Song Gao
- Shanghai Environmental Monitor Center, Shanghai 200235, China; Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Zihao Hu
- School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
| | - Xufeng Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaolin Chen
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jingjing Feng
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jinping Cheng
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Wenhua Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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25
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Mercury methylating microbial communities of boreal forest soils. Sci Rep 2019; 9:518. [PMID: 30679728 PMCID: PMC6345997 DOI: 10.1038/s41598-018-37383-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/29/2018] [Indexed: 02/05/2023] Open
Abstract
The formation of the potent neurotoxic methylmercury (MeHg) is a microbially mediated process that has raised much concern because MeHg poses threats to wildlife and human health. Since boreal forest soils can be a source of MeHg in aquatic networks, it is crucial to understand the biogeochemical processes involved in the formation of this pollutant. High-throughput sequencing of 16S rRNA and the mercury methyltransferase, hgcA, combined with geochemical characterisation of soils, were used to determine the microbial populations contributing to MeHg formation in forest soils across Sweden. The hgcA sequences obtained were distributed among diverse clades, including Proteobacteria, Firmicutes, and Methanomicrobia, with Deltaproteobacteria, particularly Geobacteraceae, dominating the libraries across all soils examined. Our results also suggest that MeHg formation is also linked to the composition of non-mercury methylating bacterial communities, likely providing growth substrate (e.g. acetate) for the hgcA-carrying microorganisms responsible for the actual methylation process. While previous research focused on mercury methylating microbial communities of wetlands, this study provides some first insights into the diversity of mercury methylating microorganisms in boreal forest soils.
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Ranius T, Hämäläinen A, Egnell G, Olsson B, Eklöf K, Stendahl J, Rudolphi J, Sténs A, Felton A. The effects of logging residue extraction for energy on ecosystem services and biodiversity: A synthesis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 209:409-425. [PMID: 29309965 DOI: 10.1016/j.jenvman.2017.12.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/26/2017] [Accepted: 12/19/2017] [Indexed: 06/07/2023]
Abstract
We review the consequences for biodiversity and ecosystem services from the industrial-scale extraction of logging residues (tops, branches and stumps from harvested trees and small-diameter trees from thinnings) in managed forests. Logging residue extraction can replace fossil fuels, and thus contribute to climate change mitigation. The additional biomass and nutrients removed, and soils and other structures disturbed, have several potential environmental impacts. To evaluate potential impacts on ecosystem services and biodiversity we reviewed 279 scientific papers that compared logging residue extraction with non-extraction, the majority of which were conducted in Northern Europe and North America. The weight of available evidence indicates that logging residue extraction can have significant negative effects on biodiversity, especially for species naturally adapted to sun-exposed conditions and the large amounts of dead wood that are created by large-scaled forest disturbances. Slash extraction may also pose risks for future biomass production itself, due to the associated loss of nutrients. For water quality, reindeer herding, mammalian game species, berries, and natural heritage the results were complicated by primarily negative but some positive effects, while for recreation and pest control positive effects were more consistent. Further, there are initial negative effects on carbon storage, but these effects are transient and carbon stocks are mostly restored over decadal time perspectives. We summarize ways of decreasing some of the negative effects of logging residue extraction on specific ecosystem services, by changing the categories of residue extracted, and site or forest type targeted for extraction. However, we found that suggested pathways for minimizing adverse outcomes were often in conflict among the ecosystem services assessed. Compensatory measures for logging residue extraction may also be used (e.g. ash recycling, liming, fertilization), though these may also be associated with adverse environmental impacts.
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Affiliation(s)
- Thomas Ranius
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden.
| | - Aino Hämäläinen
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden
| | - Gustaf Egnell
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
| | - Bengt Olsson
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden
| | - Karin Eklöf
- Department of Water and Environment, Swedish University of Agricultural Sciences, Box 7050, 750 07 Uppsala, Sweden
| | - Johan Stendahl
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, 750 07 Uppsala, Sweden
| | - Jörgen Rudolphi
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
| | - Anna Sténs
- Department of Historical, Philosophical and Religious Studies, Umeå University, 901 87 Umeå, Sweden
| | - Adam Felton
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 49, 230 53 Alnarp, Sweden
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Eckley CS, Eagles-Smith C, Tate MT, Kowalski B, Danehy R, Johnson SL, Krabbenhoft DP. Stream Mercury Export in Response to Contemporary Timber Harvesting Methods (Pacific Coastal Mountains, Oregon, USA). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1971-1980. [PMID: 29366328 PMCID: PMC6690352 DOI: 10.1021/acs.est.7b05197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Land-use activities can alter hydrological and biogeochemical processes that can affect the fate, transformation, and transport of mercury (Hg). Previous studies in boreal forests have shown that forestry operations can have profound but variable effects on Hg export and methylmercury (MeHg) formation. The Pacific Northwest is an important timber producing region that receives large atmospheric Hg loads, but the impact of forest harvesting on Hg mobilization has not been directly studied and was the focus of our investigation. Stream discharge was measured continuously, and Hg and MeHg concentrations were measured monthly for 1.5 years following logging in three paired harvested and unharvested (control) catchments. There was no significant difference in particulate-bound Hg concentrations or loads in the harvested and unharvested catchments which may have resulted from forestry practices aimed at minimizing erosion. However, the harvested catchments had significantly higher discharge (32%), filtered Hg concentrations (28%), filtered Hg loads (80%), and dissolved organic carbon (DOC) loads (40%) compared to forested catchments. MeHg concentrations were low (mostly <0.05 ng L-1) in harvested, unharvested, and downstream samples due to well-drained/unsaturated soil conditions and steep slopes with high energy eroding stream channels that were not conducive to the development of anoxic conditions that support methylation. These results have important implications for the role forestry operations have in affecting catchment retention and export of Hg pollution.
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Affiliation(s)
- Chris S. Eckley
- United States Environmental Protection Agency Region-10, Seattle, Washington 98101, United States
| | - Collin Eagles-Smith
- United States Geological Survey, Forest & Rangeland Ecosystem Science Center, Corvallis, Oregon 97331, United States
| | - Michael T. Tate
- United States Geological Survey, Wisconsin Water Science Center, Middleton, Wisconsin 53562, United States
| | - Brandon Kowalski
- United States Geological Survey, Forest & Rangeland Ecosystem Science Center, Corvallis, Oregon 97331, United States
| | - Robert Danehy
- Catchment Aquatic Ecology, Eugene, Oregon 97405, United States
| | - Sherri L. Johnson
- United States Forest Service, Pacific Northwest Research Station, Corvallis, Oregon 97331-8550, United States
| | - David P. Krabbenhoft
- United States Geological Survey, Wisconsin Water Science Center, Middleton, Wisconsin 53562, United States
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