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Willacker J, Eagles-Smith CA, Chandler JA, Naymik J, Myers R, Krabbenhoft DP. Reservoir Stratification Modulates the Influence of Impoundments on Fish Mercury Concentrations along an Arid Land River System. Environ Sci Technol 2023; 57:21313-21326. [PMID: 38051342 PMCID: PMC10734268 DOI: 10.1021/acs.est.3c04646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 12/07/2023]
Abstract
Impoundment is among the most common hydrologic alterations with impacts on aquatic ecosystems that can include effects on mercury (Hg) cycling. However, landscape-scale differences in Hg bioaccumulation between reservoirs and other habitats are not well characterized nor are the processes driving these differences. We examined total Hg (THg) concentrations of Smallmouth Bass (Micropterus dolomieu) collected from reservoir, tailrace, and free-flowing reaches along an 863 km segment of the Snake River, USA, a semiarid river with 22 impoundments along its course. Across three size-classes (putative 1-year-old, first reproductive, and harvestable sized fish), THg concentrations in reservoirs and tailraces averaged 76% higher than those in free-flowing segments. Among reservoirs, THg concentrations were highest in reservoirs with inconsistent stratification patterns, 47% higher than annually stratified, and 144% higher than unstratified reservoirs. Fish THg concentrations in tailraces immediately downstream of stratified reservoirs were higher than those below unstratified (38-130%) or inconsistently stratified (32-79%) reservoirs. Stratification regimes influenced the exceedance of fish and human health benchmarks, with 52-80% of fish from stratifying reservoirs and downstream tailraces exceeding a human consumption benchmark, compared to 6-17% where stratification did not occur. These findings suggest that impoundment and stratification play important roles in determining the patterns of Hg exposure risk across the landscape.
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Affiliation(s)
- James
J. Willacker
- U.S.
Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, Oregon 97331, United States
| | - Collin A. Eagles-Smith
- U.S.
Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, Oregon 97331, United States
| | - James A. Chandler
- Idaho
Power Company, 1221 West Idaho Street, Boise, Idaho 83702, United States
| | - Jesse Naymik
- Idaho
Power Company, 1221 West Idaho Street, Boise, Idaho 83702, United States
| | - Ralph Myers
- Idaho
Power Company, 1221 West Idaho Street, Boise, Idaho 83702, United States
| | - David P. Krabbenhoft
- U.S.
Geological Survey, Upper Midwest Water Science Center, 8505 Research Way, Middleton, Wisconsin 53562, United States
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2
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Zhang K, Zheng W, Sun R, He S, Shuai W, Fan X, Yuan S, Fu P, Deng J, Li X, Wang S, Chen J. Stable Isotopes Reveal Photoreduction of Particle-Bound Mercury Driven by Water-Soluble Organic Carbon during Severe Haze. Environ Sci Technol 2022; 56:10619-10628. [PMID: 35853134 DOI: 10.1021/acs.est.2c01933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Haze with high loading of particles may result in significant enrichment of particle-bound Hg (PBM), potentially impacting the atmospheric Hg transformation and transport. However, the dynamics of Hg transformation and the relative environmental effect during severe haze episodes remain unclear. Here, we report Hg isotopic compositions of atmospheric particles (PM2.5, PM10, and TSP) collected during a severe haze episode in Tianjin, China, to investigate the transformation and fate of Hg during haze events. All severe haze samples display significantly higher Δ199Hg (up to 1.50‰) than global urban PBM, which cannot be explained by primary anthropogenic emissions. The high Δ199Hg is likely caused by photoreduction of PBM promoted by water-soluble organic carbon (WSOC) during the particle accumulation period, as demonstrated by the positive correlations of Δ199Hg with WSOC and relative humidity and confirmed by our laboratory-controlled photoreduction experiment. The results show that, on average, 21% of PBM are likely photoreduced and re-emitted back to the atmosphere as Hg(0), potentially requiring revision of atmospheric Hg budgeting and modeling. This study highlights the release of large portions of PBM back to the gas phase through photoreduction, which needs to be taken into account while evaluating the atmospheric Hg cycle and the relative ecological effects.
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Affiliation(s)
- Ke Zhang
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wang Zheng
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Ruoyu Sun
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Sheng He
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wangcai Shuai
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xiongfei Fan
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shengliu Yuan
- School of Earth System Science, Tianjin University, Tianjin 300072, China
- Chemistry Department, Trent University, Ontario K9J7B8, Canada
| | - Pingqing Fu
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Junjun Deng
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xiaodong Li
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shuxiao Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiubin Chen
- School of Earth System Science, Tianjin University, Tianjin 300072, China
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3
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Živković I, Gačnik J, Jozić S, Kotnik J, Šolić M, Horvat M. A Simplified Approach to Modeling the Dispersion of Mercury from Precipitation to Surface Waters—The Bay of Kaštela Case Study. JMSE 2022; 10:539. [DOI: 10.3390/jmse10040539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Wet deposition is the main source of mercury (Hg) from the atmosphere to the Earth’s surface. However, the processes that govern the dispersion of deposited Hg in seawater are currently not well understood. To address this issue, total mercury (THg) concentrations in surface seawaters and precipitation were determined on a monthly basis in the Bay of Kaštela (Central Adriatic Sea). Following the assumption that deposited THg is diluted in the seawater bulk due to mixing processes, an exponential decay-like model was developed and the wet deposition of THg was normalized based on periods between precipitation events and seawater sampling. Normalized wet deposition of THg showed significant correlation with the THg gradient in surface seawater after removal of an outlier. To explain the observed outlier, further data normalization included wind data to account for enhanced seawater mixing due to strong winds. Wind-normalized THg deposition of all datapoints showed significant correlation with the THg gradient in surface seawater. The correlation showed that the THg gradient in surface seawater of 0.378 pg L−1 m−1 corresponds to THg wet deposition of 1 ng m−2 after including the influence of wind speed on seawater mixing.
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4
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Wang T, Obrist D. Inorganic and methylated mercury dynamics in estuarine water of a salt marsh in Massachusetts, USA. Environ Pollut 2022; 294:118657. [PMID: 34890749 DOI: 10.1016/j.envpol.2021.118657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 11/06/2021] [Accepted: 12/06/2021] [Indexed: 05/26/2023]
Abstract
Salt marsh estuaries serve as sources and sinks for nutrients and elements to and from estuarine water, which enhances and alleviates watershed fluxes to the coastal ocean. We assessed sources and sinks of mercury in the intertidal Plum Island Sound estuary in Massachusetts, the largest salt marsh estuary of New England, using 25-km spatial water sampling transects. Across all seasons, dissolved (FHg) and total (THg) mercury concentrations in estuarine water were highest and strongly enhanced in upper marshes (1.31 ± 0.20 ng L-1 and 6.56 ± 3.70 ng L-1, respectively), compared to riverine Hg concentrations (0.86 ± 0.17 ng L-1 and 0.88 ± 0.34 ng L-1, respectively). Mercury concentrations declined from upper to lower marshes and were lowest in ocean water (0.38 ± 0.10 ng L-1 and 0.56 ± 0.25 ng L-1, respectively). Conservative mixing models using river and ocean water as endmembers indicated that internal estuarine Hg sources strongly enhanced estuarine water Hg concentrations. For FHg, internal estuarine Hg contributions were estimated at 26 g yr-1 which enhanced Hg loads from riverine sources to the ocean by 44%. For THg, internal sources amounted to 251 g yr-1 and exceeded riverine sources six-fold. Proposed sources for internal estuarine mercury contributions include atmospheric deposition to the large estuarine surface area and sediment re-mobilization, although sediment Hg concentrations were low (average 23 ± 2 μg kg-1) typical of uncontaminated sediments. Soil mercury concentrations under vegetation, however, were ten times higher (average 200 ± 225 μg kg-1) than in intertidal sediments suggesting that high soil Hg accumulation might drive lateral export of Hg to the ocean. Spatial transects of methylated Hg (MeHg) showed no concentration enhancements in estuarine water and no indication of internal MeHg sources or formation. Initial mass balance considerations suggest that atmospheric deposition may either be in similar magnitude, or possibly exceed lateral tidal export which would be consistent with strong Hg accumulation observed in salt marsh soils sequestering Hg from current and past atmospheric deposition.
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Affiliation(s)
- Ting Wang
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts Lowell, Lowell, MA, 01854, USA.
| | - Daniel Obrist
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts Lowell, Lowell, MA, 01854, USA.
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Angot H, Rutkowski E, Sargent M, Wofsy SC, Hutyra LR, Howard D, Obrist D, Selin NE. Atmospheric mercury sources in a coastal-urban environment: a case study in Boston, Massachusetts, USA. Environ Sci Process Impacts 2021; 23:1914-1929. [PMID: 34739015 DOI: 10.1039/d1em00253h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) is an environmental toxicant dangerous to human health and the environment. Its anthropogenic emissions are regulated by global, regional, and local policies. Here, we investigate Hg sources in the coastal city of Boston, the third largest metropolitan area in the Northeastern United States. With a median of 1.37 ng m-3, atmospheric Hg concentrations measured from August 2017 to April 2019 were at the low end of the range reported in the Northern Hemisphere and in the range reported at North American rural sites. Despite relatively low ambient Hg concentrations, we estimate anthropogenic emissions to be 3-7 times higher than in current emission inventories using a measurement-model framework, suggesting an underestimation of small point and/or nonpoint emissions. We also test the hypothesis that a legacy Hg source from the ocean contributes to atmospheric Hg concentrations in the study area; legacy emissions (recycling of previously deposited Hg) account for ∼60% of Hg emitted annually worldwide (and much of this recycling takes place through the oceans). We find that elevated concentrations observed during easterly oceanic winds can be fully explained by low wind speeds and recirculating air allowing for accumulation of land-based emissions. This study suggests that the influence of nonpoint land-based emissions may be comparable in size to point sources in some regions and highlights the benefits of further top-down studies in other areas.
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Affiliation(s)
- Hélène Angot
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais, Wallis, Sion, Switzerland
| | - Emma Rutkowski
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Maryann Sargent
- School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Steven C Wofsy
- School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Lucy R Hutyra
- Department of Earth and Environment, Boston University, Boston, MA, USA
| | - Dean Howard
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts-Lowell, MA, USA
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Daniel Obrist
- Department of Environmental, Earth, and Atmospheric Sciences, University of Massachusetts-Lowell, MA, USA
| | - Noelle E Selin
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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6
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Willacker JJ, Eagles-Smith CA, Blazer VS. Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed. Ecotoxicology 2020; 29:459-484. [PMID: 32239332 DOI: 10.1007/s10646-020-02193-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and recent research efforts to address this knowledge gap and provide a comprehensive assessment of fish Hg concentrations in the watershed's freshwater habitats. The resulting dataset consisted of nearly 8000 total Hg (THg) concentrations from 600 locations. Across the watershed, fish THg concentrations spanned a 44-fold range, with mean concentrations varying by 2.6- and 8.8-fold among major sub-watersheds and individual 8-digit hydrological units, respectively. Although, mean THg concentrations tended to be moderate, fish frequently exceeded benchmarks for potential adverse health effects, with 45, 48, and 36% of all samples exceeding benchmarks for human, avian piscivore, and fish risk, respectively. Importantly, the percentage of fish exceeding these benchmarks was not uniform among species or locations. The variation in fish THg concentrations among species and sites highlights the roles of waterbody, landscape, and ecological processes in shaping broad patterns in Hg risk across the watershed. We outline an integrated Hg monitoring program that could identify key factors influencing Hg concentrations across the watershed and facilitate the implementation of management strategies to mitigate the risks posed by Hg.
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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.
| | - Vicki S Blazer
- U.S. Geological Survey, Leetown Science Center, National Fish Health Research Laboratory, 11649 Leetown Road, Kearneysville, WV, 25430, USA
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7
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Lyman SN, Cheng I, Gratz LE, Weiss-Penzias P, Zhang L. An updated review of atmospheric mercury. Sci Total Environ 2020; 707:135575. [PMID: 31784172 DOI: 10.1016/j.scitotenv.2019.135575] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
The atmosphere is a key component of the biogeochemical cycle of mercury, acting as a reservoir, transport mechanism, and facilitator of chemical reactions. The chemical and physical behavior of atmospheric mercury determines how, when, and where emitted mercury pollution impacts ecosystems. In this review, we provide current information about what is known and what remains uncertain regarding mercury in the atmosphere. We discuss new ambient, laboratory, and theoretical information about the chemistry of mercury in various atmospheric media. We review what is known about mercury in and on solid- and liquid-phase aerosols. We present recent findings related to wet and dry deposition and spatial and temporal trends in atmospheric mercury concentrations. We also review atmospheric measurement methods that are in wide use and those that are currently under development.
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Affiliation(s)
- Seth N Lyman
- Bingham Research Center, Utah State University, 320 N Aggie Blvd., Vernal, UT, USA; Department of Chemistry and Biochemistry, Utah State University, 4820 Old Main Hill, Logan, UT, USA.
| | - Irene Cheng
- Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin St., Toronto, Ontario, Canada
| | - Lynne E Gratz
- Environmental Studies Program, Colorado College, 14 East Cache la Poudre St., Colorado Springs, CO, USA
| | - Peter Weiss-Penzias
- Chemistry and Biochemistry Department, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA; Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
| | - Leiming Zhang
- Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin St., Toronto, Ontario, Canada
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Griggs T, Liu L, Talbot RW, Torres A, Lan X. Comparison of Atmospheric Mercury Speciation at a Coastal and an Urban Site in Southeastern Texas, USA. Atmosphere 2020; 11:73. [DOI: 10.3390/atmos11010073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sixteen months of continuous measurements and the analysis of atmospheric mercury (gaseous elemental mercury GEM, gaseous oxidized mercury GOM, and particulate bound mercury PBM) under urban and coastal settings were conducted in Southeastern Texas. At the urban site, the GEM mean mixing ratio was 185 ppqv, 5%–10% higher than the Northern Hemisphere GEM background level. GOM and PBM mixing ratios were as much as six times higher than their background level. The coastal site GEM mean mixing ratio was 165 ppqv, higher than other coastal sites located in the Northern Hemisphere. GOM and PBM mean mixing ratios at the coastal site were 0.75 ppqv and 0.58 ppqv. The urban site had a higher frequency of high mercury events (>300 ppqv) compared to the coastal site. The diurnal patterns were found for both sites: In the urban environment, GEM accumulated to the maximum mixing ratio just after sunrise and decreased to the minimum mixing ratio in late afternoon. In the coastal environment, GEM decreased at night reaching its minimum mixing ratio before sunrise. The relationship between atmospheric mercury species and meteorological parameters was investigated. An examination of the relationship between atmospheric mercury species and key trace gases was conducted as well, showing that the concurrence of GEM, CO2, CO, CH4, and SO2 maximum mixing ratios was notable and provided evidence they may originate from the same emission source. The coastal site was at times influenced by polluted air from urban Houston and the cleaner Gulf of Mexico marine air at other times.
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Tripathee L, Guo J, Kang S, Paudyal R, Huang J, Sharma CM, Zhang Q, Chen P, Ghimire PS, Sigdel M. Spatial and temporal distribution of total mercury in atmospheric wet precipitation at four sites from the Nepal-Himalayas. Sci Total Environ 2019; 655:1207-1217. [PMID: 30577113 DOI: 10.1016/j.scitotenv.2018.11.338] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
The studies on global pollutant mercury (Hg), which is of public concern due to its high toxicity and capacity to long-range transport via atmospheric circulation, is poorly characterized in wet deposition over the Nepal-Himalayas region. Therefore, in order to understand the concentration levels, spatial distribution and seasonal variation of total Hg, 333 precipitation samples were collected from south to north: Kathmandu (1314 m a.s.l.), Dhunche (2065 m a.s.l.), Dimsa (3078 m a.s.l.) and Gosainkunda (4417 m a.s.l.) characterized as urban, rural, remote forest and remote alpine sites, respectively, for over one-year period. The highest Hg concentration was found in Kathmandu comparable to the urban sites worldwide, and significantly lower concentrations at other three sites demonstrated similar levels as in rural and remote alpine sites worldwide. Higher wet deposition fluxes of 34.91 and 15.89 μg m-2 year-1 were found in Kathmandu and Dhunche respectively, due to higher precipitation amount. Clear and distinct seasonal differences were observed with higher concentrations in non-monsoon and lower values in monsoon periods due to less scavenging and high pollutant concentration loadings during the dry period. The positive correlation of Hg flux and precipitation amount with Hg concentration suggested that both precipitation amount and Hg concentration plays a vital role in Hg deposition in the central Himalayan region. Enrichment factor (EFHg) indicated that the anthropogenic emission sources play a significant role for Hg enrichment and a high ratio of EFmonsoon to EFnon-monsoon (>2.18) suggested that the anthropogenic atmospheric mercury could likely be long-range transported from south Asian regions to the Himalayas during the monsoon season. In addition, our results showed that the major ionic compositions (e.g., SO42-, NO3-, NH4+, K+, Ca2+) could influence Hg concentration in wet precipitation. The anthropogenic sources of Hg such as biomass and fossil fuel combustion, crustal aerosols may contribute to the Hg concentration in wet precipitation over the central Himalayas.
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Affiliation(s)
- Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rukumesh Paudyal
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Huang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Chhatra Mani Sharma
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Prakriti Sharma Ghimire
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Madan Sigdel
- Central Department of Hydrology and Meteorology, Tribhuvan University, Kathmandu, Nepal
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Fitzgerald WF, Engstrom DR, Hammerschmidt CR, Lamborg CH, Balcom PH, Lima-Braun AL, Bothner MH, Reddy CM. Global and Local Sources of Mercury Deposition in Coastal New England Reconstructed from a Multiproxy, High-Resolution, Estuarine Sediment Record. Environ Sci Technol 2018; 52:7614-7620. [PMID: 29897241 DOI: 10.1021/acs.est.7b06122] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Historical reconstruction of mercury (Hg) accumulation in natural archives, especially lake sediments, has been essential to understanding human perturbation of the global Hg cycle. Here we present a high-resolution chronology of Hg accumulation between 1727 and 1996 in a varved sediment core from the Pettaquamscutt River Estuary (PRE), Rhode Island. Mercury accumulation is examined relative to (1) historic deposition of polycyclic aromatic hydrocarbons (PAHs) and lead (Pb) and its isotopes (206Pb/207Pb) in the same core, and (2) other reconstructions of Hg deposition in urban and remote settings. Mercury deposition in PRE parallels the temporal patterns of PAHs, and both track industrialization and regional coal use between 1850 and 1950 as well as rising petroleum use after 1950. There is little indication of increased Hg deposition from late 19th-century silver and gold mining in the western U.S. A broad maximum of Hg deposition during 1930-1980, and not found in remote sites, is consistent with the predicted influence of additional industrial sources and commercial products. Our results imply that a significant portion of global anthropogenic Hg emissions during the 20th century was deposited locally, near urban and industrial centers of Hg use and release.
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Affiliation(s)
- William F Fitzgerald
- Department of Marine Sciences , University of Connecticut , Groton , Connecticut 06340 , United States
| | - Daniel R Engstrom
- St. Croix Watershed Research Station, Science Museum of Minnesota , Marine on St. Croix , Minnesota 55047 , United States
| | - Chad R Hammerschmidt
- Department of Earth & Environmental Sciences , Wright State University , Dayton , Ohio 45435 , United States
| | - Carl H Lamborg
- Department of Ocean Sciences , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Prentiss H Balcom
- Department of Marine Sciences , University of Connecticut , Groton , Connecticut 06340 , United States
| | - Ana L Lima-Braun
- Department of Marine Chemistry and Geochemistry , Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Michael H Bothner
- United States Geological Survey, Woods Hole Science Center , Woods Hole , Massachusetts 02543 , United States
| | - Christopher M Reddy
- Department of Marine Chemistry and Geochemistry , Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
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11
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Risch M, Kenski D. Spatial Patterns and Temporal Changes in Atmospheric-Mercury Deposition for the Midwestern USA, 2001–2016. Atmosphere 2018; 9:29. [DOI: 10.3390/atmos9010029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Risch MR, DeWild JF, Gay DA, Zhang L, Boyer EW, Krabbenhoft DP. Atmospheric mercury deposition to forests in the eastern USA. Environ Pollut 2017; 228:8-18. [PMID: 28501633 DOI: 10.1016/j.envpol.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 06/07/2023]
Abstract
Atmospheric mercury (Hg) deposition to forests is important because half of the land cover in the eastern USA is forest. Mercury was measured in autumn litterfall and weekly precipitation samples at a total of 27 National Atmospheric Deposition Program (NADP) monitoring sites in deciduous and mixed deciduous-coniferous forests in 16 states in the eastern USA during 2007-2014. These simultaneous, uniform, repeated, annual measurements of forest Hg include the broadest area and longest time frame to date. The autumn litterfall-Hg concentrations and litterfall mass at the study sites each year were combined with annual precipitation-Hg data. Rates of litterfall-Hg deposition were higher than or equal to precipitation-Hg deposition rates in 70% of the annual data, which indicates a substantial contribution from litterfall to total atmospheric-Hg deposition. Annual litterfall-Hg deposition in this study had a median of 11.7 μg per square meter per year (μg/m2/yr) and ranged from 2.2 to 23.4 μg/m2/yr. It closely matched modeled dry-Hg deposition, based on land cover at selected NADP Hg-monitoring sites. Mean annual atmospheric-Hg deposition at forest study sites exhibited a spatial pattern partly explained by statistical differences among five forest-cover types and related to the mapped density of Hg emissions. Forest canopies apparently recorded changes in atmospheric-Hg concentrations over time because litterfall-Hg concentrations decreased year to year and litterfall-Hg concentrations were significantly higher in 2007-2009 than in 2012-2014. These findings reinforce reported decreases in Hg emissions and atmospheric elemental-Hg concentrations during this same time period. Methylmercury (MeHg) was detected in all litterfall samples at all sites, compared with MeHg detections in less than half the precipitation samples at selected sites during the study. These results indicate MeHg in litterfall is a pathway into the terrestrial food web where it can accumulate in the prey of songbirds, bats, and raptors.
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Affiliation(s)
- Martin R Risch
- U.S. Geological Survey, 5957 Lakeside Blvd., Indianapolis, IN 46278, United States.
| | - John F DeWild
- U.S. Geological Survey, 8505 Research Way, Middleton, WI, 53562, United States
| | - David A Gay
- Illinois State Water Survey, University of Illinois, 2204 Griffith Drive, Champaign, IL, 61820, United States
| | - Leiming Zhang
- Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Ontario, Canada
| | - Elizabeth W Boyer
- The Pennsylvania State University, Department of Ecosystem Science & Management, 304 Forest Resources Building, University Park, PA 16802, United States
| | - David P Krabbenhoft
- U.S. Geological Survey, 8505 Research Way, Middleton, WI, 53562, United States
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13
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Holmes CD, Krishnamurthy NP, Caffrey JM, Landing WM, Edgerton ES, Knapp KR, Nair US. Thunderstorms Increase Mercury Wet Deposition. Environ Sci Technol 2016; 50:9343-50. [PMID: 27464305 DOI: 10.1021/acs.est.6b02586] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Mercury (Hg) wet deposition, transfer from the atmosphere to Earth's surface by precipitation, in the United States is highest in locations and seasons with frequent deep convective thunderstorms, but it has never been demonstrated whether the connection is causal or simple coincidence. We use rainwater samples from over 800 individual precipitation events to show that thunderstorms increase Hg concentrations by 50% relative to weak convective or stratiform events of equal precipitation depth. Radar and satellite observations reveal that strong convection reaching the upper troposphere (where high atmospheric concentrations of soluble, oxidized mercury species (Hg(II)) are known to reside) produces the highest Hg concentrations in rain. As a result, precipitation meteorology, especially thunderstorm frequency and total rainfall, explains differences in Hg deposition between study sites located in the eastern United States. Assessing the fate of atmospheric mercury thus requires bridging the scales of global transport and convective precipitation.
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Affiliation(s)
- Christopher D Holmes
- Department of Earth, Ocean, and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Nishanth P Krishnamurthy
- Department of Earth, Ocean, and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Jane M Caffrey
- Center for Environmental Diagnostics and Bioremediation, University of West Florida , Pensacola, Florida 32514, United States
| | - William M Landing
- Department of Earth, Ocean, and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Eric S Edgerton
- Atmospheric Research & Analysis, Inc. , Cary, North Carolina 27513, United States
| | - Kenneth R Knapp
- National Centers for Environmental Information, National Oceanic and Atmospheric Administration , Asheville, North Carolina 28801, United States
| | - Udaysankar S Nair
- Department of Atmospheric Science, University of Alabama , Huntsville, Alabama 35805, United States
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14
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15
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Shanley JB, Engle MA, Scholl M, Krabbenhoft DP, Brunette R, Olson ML, Conroy ME. High Mercury Wet Deposition at a "Clean Air" Site in Puerto Rico. Environ Sci Technol 2015; 49:12474-12482. [PMID: 26368125 DOI: 10.1021/acs.est.5b02430] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Atmospheric mercury deposition measurements are rare in tropical latitudes. Here we report on seven years (April 2005 to April 2012, with gaps) of wet Hg deposition measurements at a tropical wet forest in the Luquillo Mountains, northeastern Puerto Rico, U.S. Despite receiving unpolluted air off the Atlantic Ocean from northeasterly trade winds, during two complete years the site averaged 27.9 μg m(-2) yr(-1) wet Hg deposition, or about 30% more than Florida and the Gulf Coast, the highest deposition areas within the U.S. These high Hg deposition rates are driven in part by high rainfall, which averaged 2855 mm yr(-1). The volume-weighted mean Hg concentration was 9.8 ng L(-1), and was highest during summer and lowest during the winter dry season. Rainout of Hg (decreasing concentration with increasing rainfall depth) was minimal. The high Hg deposition was not supported by gaseous oxidized mercury (GOM) at ground level, which remained near global background concentrations (<10 pg m(-3)). Rather, a strong positive correlation between Hg concentrations and the maximum height of rain detected within clouds (echo tops) suggests that droplets in high convective cloud tops scavenge GOM from above the mixing layer. The high wet Hg deposition at this "clean air" site suggests that other tropical areas may be hotspots for Hg deposition as well.
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Affiliation(s)
- James B Shanley
- U.S. Geological Survey, P.O. Box 628, Montpelier, Vermont 05601, United States
| | - Mark A Engle
- U.S. Geological Survey, El Paso, Texas 79968, United States
| | - Martha Scholl
- U.S. Geological Survey, Reston, Virginia 20192, United States
| | | | - Robert Brunette
- Eurofins Frontier Global Sciences Inc., Bothell, Washington 98011, United States
| | - Mark L Olson
- University of Illinois , Champaign, Illinois 61820, United States
| | - Mary E Conroy
- University of Vermont , Burlington, Vermont 05405, United States
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16
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Deeds DA, Ghoshdastidar A, Raofie F, Guérette ÉA, Tessier A, Ariya PA. Development of a Particle-Trap Preconcentration-Soft Ionization Mass Spectrometric Technique for the Quantification of Mercury Halides in Air. Anal Chem 2015; 87:5109-16. [DOI: 10.1021/ac504545w] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel A. Deeds
- Department
of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec H3A 2K6, Canada
| | - Avik Ghoshdastidar
- Department
of Chemistry, McGill University, Montreal, Quebec H3A 2K6, Canada
| | - Farhad Raofie
- Department
of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec H3A 2K6, Canada
| | | | - Alain Tessier
- Centre
for Biological Applications of Mass Spectrometry, Concordia University, Montreal, Quebec, Canada
| | - Parisa A. Ariya
- Department
of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec H3A 2K6, Canada
- Department
of Chemistry, McGill University, Montreal, Quebec H3A 2K6, Canada
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17
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Cole A, Steffen A, Eckley C, Narayan J, Pilote M, Tordon R, Graydon J, St. Louis V, Xu X, Branfireun B. A Survey of Mercury in Air and Precipitation across Canada: Patterns and Trends. Atmosphere 2014; 5:635-68. [DOI: 10.3390/atmos5030635] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Kwon SY, Blum JD, Chen C, Meattey DE, Mason RP. Mercury isotope study of sources and exposure pathways of methylmercury in estuarine food webs in the Northeastern U.S. Environ Sci Technol 2014; 48:10089-97. [PMID: 25116221 PMCID: PMC4151785 DOI: 10.1021/es5020554] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 08/06/2014] [Accepted: 08/12/2014] [Indexed: 05/20/2023]
Abstract
We measured mercury (Hg) isotope ratios in sediments and various estuarine organisms (green crab, blue mussel, killifish, eider) to investigate methylmercury (MMHg) sources and exposure pathways in five Northeast coast (U.S.) estuaries. The mass independent Hg isotopic compositions (MIF; Δ(199)Hg) of the sediments were linearly correlated with the sediment 1/Hg concentrations (Δ(199)Hg: r(2) = 0.77, p < 0.05), but the mass dependent isotope compositions (MDF; δ(202)Hg) were not (r(2) = 0.26, p = 0.16), reflecting inputs of anthropogenic Hg sources with varying δ(202)Hg. The estuarine organisms all display positive Δ(199)Hg values (0.21 to 0.98 ‰) indicating that MMHg is photodegraded to varying degrees (5-12%) prior to entry into the food web. The δ(202)Hg and Δ(199)Hg values of most organisms can be explained by a mixture of MMHg and inorganic Hg from sediments. At one contaminated site mussels have anomalously high δ(202)Hg, indicating exposure to a second pool of MMHg, compared to sediment, crabs and fish. Eiders have similar Δ(199)Hg as killifish but much higher δ(202)Hg, suggesting that there is an internal fractionation of δ(202)Hg in birds. Our study shows that Hg isotopes can be used to identify multiple anthropogenic inorganic Hg and MMHg sources and determine the degree of photodegradation of MMHg in estuarine food webs.
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Affiliation(s)
- Sae Yun Kwon
- Department
of Earth and Environmental Sciences, University
of Michigan, 1100 N.
University Avenue, Ann Arbor, Michigan 48109, United
States
- Phone: 1.734.615.7209; fax: 1.734.763.4690; e-mail:
| | - Joel D. Blum
- Department
of Earth and Environmental Sciences, University
of Michigan, 1100 N.
University Avenue, Ann Arbor, Michigan 48109, United
States
| | - Celia
Y. Chen
- Department
of Biological Sciences, Dartmouth College, 78 College Street, Hanover, New Hampshire 03755-3576, United States
| | - Dustin E. Meattey
- Biodiversity
Research Institute, 652
Main Street, Gorham, Maine 04038, United States
| | - Robert P. Mason
- Department
of Marine Science, University of Connecticut, 1080 Shennecossett Road, Groton, Connecticut 06340, United States
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19
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Chalmers AT, Krabbenhoft DP, Van Metre PC, Nilles MA. Effects of urbanization on mercury deposition and accumulation in New England. Environ Pollut 2014; 192:104-112. [PMID: 24907856 DOI: 10.1016/j.envpol.2014.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 05/01/2014] [Accepted: 05/03/2014] [Indexed: 06/03/2023]
Abstract
We compare total mercury (HgT) loading and methylmercury (MeHg) accumulation in streams and lakes from an urbanized area (Boston, Massachusetts) to rural regions of southern New Hampshire and Maine. The maximum HgT loading, as indicated by HgT atmospheric deposition, HgT emissions, and sediment HgT concentrations, did not coincide with maximum MeHg concentrations in fish. Urbanized ecosystems were areas of high HgT loading but had low MeHg concentrations in fish. Controls on MeHg production and accumulation appeared to be related primarily to HgT loading in undeveloped areas, while ecosystem sensitivity to MeHg formation appeared to be more important in regulating accumulation of MeHg in the urban area.
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Affiliation(s)
- Ann T Chalmers
- U.S. Geological Survey, 87 State St., Montpelier, VT, USA.
| | | | | | - Mark A Nilles
- U.S. Geological Survey, P.O. Box 25046, MS 401, Bldg 95, Lakewood, CO 80225-0046, USA.
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20
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Lan X, Talbot R, Laine P, Lefer B, Flynn J, Torres A. Seasonal and Diurnal Variations of Total Gaseous Mercury in Urban Houston, TX, USA. Atmosphere 2014; 5:399-419. [DOI: 10.3390/atmos5020399] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Bergman BG, Bump JK. Mercury in aquatic forage of large herbivores: impact of environmental conditions, assessment of health threats, and implications for transfer across ecosystem compartments. Sci Total Environ 2014; 479-480:66-76. [PMID: 24534700 DOI: 10.1016/j.scitotenv.2014.01.102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 06/03/2023]
Abstract
Mercury (Hg) is a leading contaminant across U.S. water bodies, warranting concern for wildlife species that depend upon food from aquatic systems. The risk of Hg toxicity to large herbivores is little understood, even though some large herbivores consume aquatic vascular plants (macrophytes) that may hyper-accumulate Hg. We investigated whether total Hg and methylmercury (MeHg) in aquatic forage may be of concern to moose (Alces alces) and beaver (Castor canadensis) by measuring total Hg and MeHg concentrations, calculating sediment-water bioconcentration factors for macrophyte species these herbivores consume, and estimating herbivore daily Hg consumption. Abiotic factors impacting macrophyte Hg were assessed, as was the difference in Hg concentrations of macrophytes from glacial lakes and those created or expanded by beaver damming. The amount of aquatic-derived Hg that moose move from aquatic to terrestrial systems was calculated, in order to investigate the potential for movement of Hg across ecosystem compartments by large herbivores. Results indicate that the Hg exposure of generalist herbivores may be affected by macrophyte community composition more so than by many abiotic factors in the aquatic environment. Mercury concentrations varied greatly between macrophyte species, with relatively high concentrations in Utricularia vulgaris (>80 ng g(-1) in some sites), and negligible concentrations in Nuphar variegata (~6 ng g(-1)). Macrophyte total Hg concentration was correlated with water pH in predictable ways, but not with other variables generally associated with aquatic Hg concentrations, such as dissolved organic carbon. Moose estimated daily consumption of MeHg is equivalent to or below human reference levels, and far below wildlife reference levels. However, estimated beaver Hg consumption exceeds reference doses for humans, indicating the potential for sub-lethal nervous impairment. In regions of high moose density, moose may be ecologically important vectors that transfer Hg from aquatic to surrounding terrestrial systems.
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Affiliation(s)
- Brenda Gail Bergman
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
| | - Joseph K Bump
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA
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22
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Huang J, Lyman SN, Hartman JS, Gustin MS. A review of passive sampling systems for ambient air mercury measurements. Environ Sci Process Impacts 2014; 16:374-392. [PMID: 24362622 DOI: 10.1039/c3em00501a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Atmospheric mercury (Hg) temporal and spatial patterns must be measured accurately in order to adequately understand the role of this pathway as it relates to Hg toxicity and exposure of humans and wildlife to Hg. It is also important to understand the distribution of the different chemical forms (elemental, oxidized, or particle bound) and specific compounds in air (e.g., HgCl2, HgBr2, HgO, Hg(NO3)2, and HgSO4). However, the current automated and passive sampling methods of measurement have limitations and artifacts impacting our ability to achieve this task. Both abiotic and biotic systems have been developed to measure the total gaseous Hg and oxidized Hg compounds (concentration and deposition). This study reviews and compares the performance of previously and currently applied passive sampling systems. Computable fluid dynamic modeling was conducted to gain additional understanding of a gaseous oxidized Hg (GOM) passive sampler. Case studies during which passive samplers were used are also presented to demonstrate the ability of passive samplers to capture atmospheric Hg variation. A network using passive samplers would be useful for monitoring global Hg trends due to the limits of the current automated method.
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Affiliation(s)
- Jiaoyan Huang
- Department of Natural Resources and Environmental Sciences, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
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23
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Wright G, Gustin MS, Weiss-Penzias P, Miller MB. Investigation of mercury deposition and potential sources at six sites from the Pacific Coast to the Great Basin, USA. Sci Total Environ 2014; 470-471:1099-1113. [PMID: 24252197 DOI: 10.1016/j.scitotenv.2013.10.071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 06/02/2023]
Abstract
The Western Airborne Contaminants Assessment Project showed that USA National Parks had fish mercury (Hg) concentrations above threshold concentrations set for wildlife. Since significant areas of the Western USA are arid, we hypothesized that dry deposition would be important. The primary question was whether sources of Hg were local and thus, easily addressed, or regional (from within the United States), or global (long range transport), and more difficult to address. To investigate this, surrogate surfaces and passive samplers for the measurement of GOM deposition and concentration, respectively, were deployed from the coast of California to the eastern edge of Nevada. Meteorological data, back trajectory modeling, and ozone concentrations were applied to better understand potential sources of Hg. Lowest seasonal mean Hg deposition (0.2 to 0.4 ng m(-2)h(-1)) was observed at low elevation (<100 m) Pacific Coast sites. Highest values were recorded at Lick Observatory, a high elevation coastal site (1,279 m), and Great Basin National Park (2,062 m) in rural eastern Nevada (1.5 to 2.4 ng m(-2)h(-1)). Intermediate values were recorded in Yosemite and Sequoia National Parks (0.9 to 1.2 ng m(-2)h(-1)). Results indicate that local, regional and global sources of air pollution, specifically oxidants, are contributing to observed deposition. At Great Basin National Park air chemistry was influenced by regional urban and agricultural emissions and free troposphere inputs. Dry deposition contributed ~2 times less Hg than wet deposition at the coastal locations, but 3 to 4 times more at the higher elevation sites. Based on the spatial trends, oxidation in the marine boundary layer or ocean sources contributed ~0.4 ng m(-2)h(-1) at the coastal locations. Regional pollution and long range transport contributed 1 to 2 ng m(-2)h(-1) to other locations, and the source of Hg is global and as such, all sources are important to consider.
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Affiliation(s)
- Genine Wright
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, MS186, Reno, NV 89557, United States
| | - Mae Sexauer Gustin
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, MS186, Reno, NV 89557, United States.
| | - Peter Weiss-Penzias
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, United States
| | - Matthieu B Miller
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, MS186, Reno, NV 89557, United States
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Huang J, Chang FC, Wang S, Han YJ, Castro M, Miller E, Holsen TM. Mercury wet deposition in the eastern United States: characteristics and scavenging ratios. Environ Sci Process Impacts 2013; 15:2321-2328. [PMID: 24190422 DOI: 10.1039/c3em00454f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Wet deposition is an important atmospheric mercury (Hg) pathway between air and terrestrial ecosystems. It is measured at numerous locations in the United States (U. S.) as part of the Mercury Deposition Network (MDN). The annual Hg wet deposition flux in 2009 at four locations in the northeastern U. S. (MDN sites MD08, VT99, NY20, and NY43) ranged from 6.4 to 13.4 μg per m(2) year which is higher than modeled reactive Hg (RM) dry deposition for this region. The highest ambient RM concentrations were seen at MD08, which is closest to significant anthropogenic sources; however, the volume-weighted mean Hg concentrations in precipitation were similar at these four sites. Mass based scavenging ratios (SC) of RM ranged from 1700 to 4500. Differences in SCs were likely a result of differences in meteorological conditions, the forms of RM in the atmosphere, vertical concentration variations, and measurement uncertainties, including precipitation depth and RM concentrations. RM SCs were higher than those reported for other soluble species. Multiple linear regression suggests that gaseous oxidized Hg is responsible for the majority of the scavenged RM.
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Affiliation(s)
- Jiaoyan Huang
- Department of Natural Resources and Environmental Sciences, University of Nevada, Reno, NV 89557, USA
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25
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Lamborg CH, Kent DB, Swarr GJ, Munson KM, Kading T, O'Connor AE, Fairchild GM, Leblanc DR, Wiatrowski HA. Mercury speciation and mobilization in a wastewater-contaminated groundwater plume. Environ Sci Technol 2013; 47:13239-49. [PMID: 24187956 DOI: 10.1021/es402441d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We measured the concentration and speciation of mercury (Hg) in groundwater down-gradient from the site of wastewater infiltration beds operated by the Massachusetts Military Reservation, western Cape Cod, Massachusetts. Total mercury concentrations in oxic, mildly acidic, uncontaminated groundwater are 0.5-1 pM, and aquifer sediments have 0.5-1 ppb mercury. The plume of impacted groundwater created by the wastewater disposal is still evident, although inputs ceased in 1995, as indicated by anoxia extending at least 3 km down-gradient from the disposal site. Solutes indicative of a progression of anaerobic metabolisms are observed vertically and horizontally within the plume, with elevated nitrate concentrations and nitrate reduction surrounding a region with elevated iron concentrations indicating iron reduction. Mercury concentrations up to 800 pM were observed in shallow groundwater directly under the former infiltration beds, but concentrations decreased with depth and with distance down-gradient. Mercury speciation showed significant connections to the redox and metabolic state of the groundwater, with relatively little methylated Hg within the iron reducing sector of the plume, and dominance of this form within the higher nitrate/ammonium zone. Furthermore, substantial reduction of Hg(II) to Hg(0) within the core of the anoxic zone was observed when iron reduction was evident. These trends not only provide insight into the biogeochemical factors controlling the interplay of Hg species in natural waters, but also support hypotheses that anoxia and eutrophication in groundwater facilitate the mobilization of natural and anthropogenic Hg from watersheds/aquifers, which can be transported down-gradient to freshwaters and the coastal zone.
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Affiliation(s)
- Carl H Lamborg
- Woods Hole Oceanographic Institution , Department of Marine Chemistry and Geochemistry, Woods Hole, Massachusetts 02543, United States
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26
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Sen IS, Peucker-Ehrenbrink B, Geboy N. Complex anthropogenic sources of platinum group elements in aerosols on Cape Cod, USA. Environ Sci Technol 2013; 47:10188-10196. [PMID: 23915354 DOI: 10.1021/es4016348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Platinum group elements (PGE) of anthropogenic origin have been reported in rainwater, snow, roadside soil and vegetation, industrial waste, and urban airborne particles around the world. As recent studies have shown that PGE are bioavailable in the environment and pose health risks at chronic levels, the extent of PGE pollution is of global concern. In this study, we report PGE concentrations and osmium isotope ((187)Os/(188)Os) ratios of airborne particles (particulate matter, PM10) collected in Woods Hole, a small coastal village on Cape Cod, Massachusetts, U.S.A. The sampling site is more than 100 km away from the nearest urban centers (Boston, Providence) and has no large industrial emission center within a 30 km radius. The study reveals that, although PGE concentrations in rural airborne particulate matter are orders of magnitude lower than in urban aerosols, 69% of the total osmium is of anthropogenic origin. Anthropogenic PGE signatures in airborne particles are thus not restricted to large cities with high traffic flows and substantial industries; they can also be found in rural environments. We further conclude that the combination of Pt/Rh concentration ratios and (187)Os/(188)Os composition can be used to trace PGE sources. The Pt/Rh and (187)Os/(188)Os composition of Woods Hole aerosols indicate that the anthropogenic PGE fraction is primarily sourced from ore smelting processes, with possible minor contributions from fossil fuel burning and automobile catalyst-derived materials. Our results further substantiate the use of (187)Os/(188)Os in source apportionment studies on continental scales.
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Affiliation(s)
- Indra S Sen
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts 02543, United States
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27
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Choi HD, Huang J, Mondal S, Holsen TM. Variation in concentrations of three mercury (Hg) forms at a rural and a suburban site in New York State. Sci Total Environ 2013; 448:96-106. [PMID: 22959656 DOI: 10.1016/j.scitotenv.2012.08.052] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 07/27/2012] [Accepted: 08/14/2012] [Indexed: 06/01/2023]
Abstract
Tekran® Hg speciation systems were used at a rural site (Huntington Forest, NY; HF) and a suburban site (Rochester, NY; ROC) to measure gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and fine particulate-bound mercury (PBM2.5) concentrations for two years (December 2007 to November 2009). Ancillary data were also available from the New York State Department of Environmental Conservation and the United States Environmental Protection Agency Clean Air Status and Trends Network. Seasonal GEM concentrations were similar at both sites and influenced by factors such as the planet boundary layer (PBL) height and mercury emissions from snow, soil, and point sources. In some seasons, O3 was negatively correlated with GEM at ROC and positively correlated with GEM at HF. At HF, O3 was correlated with GOM and was typically higher in the afternoon. The cause of this pattern may be photochemical reactions during the day, and the GOM diel pattern may also be due to deposition which is enhanced by dew formation during the night and early morning. PBM2.5 concentrations were higher in winter at both sites. This is indicative of local wood combustion for space heating in winter, increased sorption to particles at lower temperatures, and lower PBL in the winter. At the suburban site, 2 of 12 events with enhanced GEM/CO ratios were poorly correlated with SO2/GOM, implying that these two events were due either to long range transport or regional metallurgical industries in Canada.
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Affiliation(s)
- Hyun-Deok Choi
- Department of Civil and Environmental Engineering, Clarkson University, 8 Clarkson Ave., Potsdam, NY 13699-5710, USA
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28
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Fu X, Feng X, Sommar J, Wang S. A review of studies on atmospheric mercury in China. Sci Total Environ 2012; 421-422:73-81. [PMID: 22134034 DOI: 10.1016/j.scitotenv.2011.09.089] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 09/22/2011] [Accepted: 09/23/2011] [Indexed: 05/31/2023]
Abstract
Due to the fast developing economy, mercury (Hg) emissions to the atmosphere from Chinese mainland have increased rapidly in recent years. Consequently, this issue has received a considerable attention internationally. This paper reviews the current understanding of and knowledge on atmospheric Hg emissions, distribution and transport in China. The magnitude of Hg emissions to the atmosphere from Chinese anthropogenic sources has been estimated to be in the range of 500-700 tons per year, whereby comprising a significant proportion of the globe total anthropogenic emissions. Emissions of Hg from natural surfaces including bare soil, water, and vegetation covered soil tend in a comparison to be higher in China than in Europe and North America, indicating the importance of this source category. Atmospheric Hg exhibits a significant concentration variability among urban, semi-remote, and remote areas. Total Gaseous Mercury (TGM) concentrations in urban areas of China were often 1.5 - 5 folds higher compared to the corresponding settings in North America and Europe. In turn, particulate mercury (PHg) concentrations in urban areas of China were up to two orders of magnitude higher compared to North America and Europe. Atmospheric observations made at strictly remote sites in China also include the presence of occasional high concentrations of TGM, and the more short-lived fractions PHg and Reactive Gaseous Mercury (RGM). Accordingly, Hg deposition fluxes tended to be higher in China, with remote areas and urban areas being 1-2 times and 1-2 magnitude higher than those in North America and Europe, respectively.
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Affiliation(s)
- Xuewu Fu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China
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Huang J, Liu CK, Huang CS, Fang GC. Atmospheric mercury pollution at an urban site in central Taiwan: mercury emission sources at ground level. Chemosphere 2012; 87:579-85. [PMID: 22316589 DOI: 10.1016/j.chemosphere.2012.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/08/2012] [Accepted: 01/09/2012] [Indexed: 05/24/2023]
Abstract
Total gaseous mercury (Hg) (TGM), gaseous oxidized Hg (GOM), and particulate-bound Hg (PBM) concentrations and dry depositions were measured at an urban site in central Taiwan. The concentrations were 6.14±3.91 ng m(-3), 332±153, and 71.1±46.1 pg m(-3), respectively. These results demonstrate high Hg pollution at the ground level in Taiwan. A back trajectory plot shows the sources of the high TGM concentration were in the low atmosphere (<500 m) and approximately 50% of the air masses coming from upper troposphere (>500 m) were associated with low TGM concentrations. This finding implies that Hg is trapped in the low atmosphere and comes from local Hg emission sources. The conditional probability function (CPF) reveals that the plumes of high TGM concentrations come from the south and northwest of the site. The plume from the south comes from two municipal solid waste incinerators (MSWIs). However, no significant Hg point source is located to the northwest of the site; therefore, the plumes from the northwest are hypothesized to be related to the combustion of agricultural waste. Dry deposition fluxes of Hg measured at this site considerably exceeded those measured in North America. Overall, this area is regarded as a highly Hg contaminated area because of local Hg emission sources.
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Affiliation(s)
- Jiaoyan Huang
- Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY 13699, USA
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30
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Castro MS, Moore C, Sherwell J, Brooks SB. Dry deposition of gaseous oxidized mercury in Western Maryland. Sci Total Environ 2012; 417-418:232-240. [PMID: 22264922 DOI: 10.1016/j.scitotenv.2011.12.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to directly measure the dry deposition of gaseous oxidized mercury (GOM) in western Maryland. Annual estimates were made using passive ion-exchange surrogate surfaces and a resistance model. Surrogate surfaces were deployed for seventeen weekly sampling periods between September 2009 and October 2010. Dry deposition rates from surrogate surfaces ranged from 80 to 1512 pgm(-2)h(-1). GOM dry deposition rates were strongly correlated (r(2)=0.75) with the weekly average atmospheric GOM concentrations, which ranged from 2.3 to 34.1 pgm(-3). Dry deposition of GOM could be predicted from the ambient air concentrations of GOM using this equation: GOM dry deposition (pgm(-2)h(-1))=43.2 × GOM concentration-80.3. Dry deposition velocities computed using GOM concentrations and surrogate surface GOM dry deposition rates, ranged from 0.2 to 1.7 cms(-1). Modeled dry deposition rates were highly correlated (r(2)=0.80) with surrogate surface dry deposition rates. Using the overall weekly average surrogate surface dry deposition rate (369 ± 340 pg m(-2)h(-1)), we estimated an annual GOM dry deposition rate of 3.2 μg m(-2)year(-1). Using the resistance model, we estimated an annual GOM dry deposition rate of 3.5 μg m(-2)year(-1). Our annual GOM dry deposition rates were similar to the dry deposition (3.3 μg m(-2)h(-1)) of gaseous elemental mercury (GEM) at our site. In addition, annual GOM dry deposition was approximately 1/2 of the average annual wet deposition of total mercury (7.7 ± 1.9 μg m(-2)year(-1)) at our site. Total annual mercury deposition from dry deposition of GOM and GEM and wet deposition was approximately 14.4 μg m(-2)year(-1), which was similar to the average annual litterfall deposition (15 ± 2.1 μg m(-2)year(-1)) of mercury, which was also measured at our site.
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Affiliation(s)
- Mark S Castro
- Appalachian Laboratory, University of Maryland Center for Environmental Science, 301 Braddock Road, Frostburg, MD 21532, United States.
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31
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Risch MR, Dewild JF, Krabbenhoft DP, Kolka RK, Zhang L. Litterfall mercury dry deposition in the eastern USA. Environ Pollut 2012; 161:284-90. [PMID: 21715069 DOI: 10.1016/j.envpol.2011.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 06/04/2011] [Indexed: 05/04/2023]
Abstract
Mercury (Hg) in autumn litterfall from predominately deciduous forests was measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry deposition was significantly higher (median 12.3 micrograms per square meter (μg/m(2)), range 3.5-23.4 μg/m(2)) than annual Hg wet deposition (median 9.6 μg/m(2), range 4.4-19.7 μg/m(2)). The mean ratio of dry to wet Hg deposition was 1.3-1. The sum of dry and wet Hg deposition averaged 21 μg/m(2) per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated how annual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes.
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Affiliation(s)
- Martin R Risch
- U.S. Geological Survey, 5957 Lakeside Boulevard, Indianapolis, IN 46278, USA.
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Zhang L, Blanchard P, Johnson D, Dastoor A, Ryzhkov A, Lin CJ, Vijayaraghavan K, Gay D, Holsen TM, Huang J, Graydon JA, St Louis VL, Castro MS, Miller EK, Marsik F, Lu J, Poissant L, Pilote M, Zhang KM. Assessment of modeled mercury dry deposition over the Great Lakes region. Environ Pollut 2012; 161:272-283. [PMID: 21705119 DOI: 10.1016/j.envpol.2011.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 06/03/2011] [Indexed: 05/31/2023]
Abstract
Three sets of model predicted values for speciated mercury concentrations and dry deposition fluxes over the Great Lakes region were assessed using field measurements and model intercomparisons. The model predicted values were produced by the Community Multiscale Air Quality Modeling System for the year 2002 (CMAQ2002) and for the year 2005 (CMAQ2005) and by the Global/Regional Atmospheric Heavy Metals Model for the year 2005 (GRAHM2005). Median values of the surface layer ambient concentration of gaseous elemental mercury (GEM) from all three models were generally within 30% of measurements. However, all three models overpredicted surface-layer concentrations of gaseous oxidized mercury (GOM) and particulate bound mercury (PBM) by a factor of 2-10 at the majority of the 15 monitoring locations. For dry deposition of GOM plus PBM, CMAQ2005 showed a clear gradient with the highest deposition in Pennsylvania and its surrounding areas while GRAHM2005 showed no such gradient in this region; however, GRAHM2005 had more hot spots than those of CMAQ2005. Predicted dry deposition of GOM plus PBM from these models should be treated as upper-end estimates over some land surfaces in this region based on the tendencies of all the models to overpredict GOM and PBM concentrations when compared to field measurements. Model predicted GEM dry deposition was found to be as important as GOM plus PBM dry deposition as a contributor to total dry deposition. Predicted total annual mercury dry deposition were mostly lower than 5 μg m(-2) to the surface of the Great lakes, between 5 and 15 μg m(-2) to the land surface north of the US/Canada border, and between 5 and 40 μg m(-2) to the land surface south of the US/Canada border. Predicted dry deposition from different models differed from each other by as much as a factor of 2 at regional scales and by a greater extent at local scales.
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Affiliation(s)
- L Zhang
- Science and Technology Branch, Environment Canada, Canada.
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