1
|
Osborne C, Gilbert-Parkes S, Spiers G, Lamit LJ, Lilleskov EA, Basiliko N, Watmough S. Global Patterns of Metal and Other Element Enrichment in Bog and Fen Peatlands. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2024; 86:125-139. [PMID: 38340164 DOI: 10.1007/s00244-024-01051-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/02/2024] [Indexed: 02/12/2024]
Abstract
Peatlands are found on all continents, covering 3% of the global land area. However, the spatial extent and causes of metal enrichment in peatlands is understudied and no attempt has been made to evaluate global patterns of metal enrichment in bog and fen peatlands, despite that certain metals and rare earth elements (REE) arise from anthropogenic sources. We analyzed 368 peat cores sampled in 16 countries across five continents and measured metal and other element concentrations at three depths down to 70 cm as well as estimated cumulative atmospheric S deposition (1850-2009) for each site. Sites were assigned to one of three distinct broadly recognized peatland categories (bog, poor fen, and intermediate-to-moderately rich fen) that varied primarily along a pH gradient. Metal concentrations differed among peatland types, with intermediate-to-moderately rich fens demonstrating the highest concentrations of most metals. Median enrichment factors (EFs; a metric comparing natural and anthropogenic metal deposition) for individual metals were similar among bogs and fens (all groups), with metals likely to be influenced by anthropogenic sources (As, Cd, Co, Cu, Hg, Pb, and Sb) demonstrating median enrichment factors (EFs) > 1.5. Additionally, mean EFs were substantially higher than median values, and the positive correlation (< 0.40) with estimated cumulative atmospheric S deposition, confirmed some level of anthropogenic influence of all pollutant metals except for Hg that was unrelated to S deposition. Contrary to expectations, high EFs were not restricted to pollutant metals, with Mn, K and Rb all exhibiting elevated median EFs that were in the same range as pollutant metals likely due to peatland biogeochemical processes leading to enrichment of these nutrients in surface soil horizons. The global patterns of metal enrichment in bogs and fens identified in this study underscore the importance of these peatlands as environmental archives of metal deposition, but also illustrates that biogeochemical processes can enrich metals in surface peat and EFs alone do not necessarily indicate atmospheric contamination.
Collapse
Affiliation(s)
- Chetwynd Osborne
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, K9L 0G2, Canada
| | - Spencer Gilbert-Parkes
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, K9L 0G2, Canada
| | | | | | - Erik A Lilleskov
- USDA Forest Service, Northern Research Station, Houghton, MI, USA
| | - Nathan Basiliko
- Natural Resources Management, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada
| | - Shaun Watmough
- School of the Environment, Trent University, Peterborough, ON, K9L 0G2, Canada.
| |
Collapse
|
2
|
Wiklund JA, Kirk JL, Muir DCG, Gleason A, Carrier J, Yang F. Atmospheric trace metal deposition to remote Northwest Ontario, Canada: Anthropogenic fluxes and inventories from 1860 to 2010. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:142276. [PMID: 33370897 DOI: 10.1016/j.scitotenv.2020.142276] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/03/2020] [Accepted: 09/06/2020] [Indexed: 06/12/2023]
Abstract
National and global inventories of anthropogenic trace element emissions to air is a comparatively recent phenomenon (post-1993 in Canada) as is the monitoring of atmospheric metal deposition, the latter being also very spatially limited. Paleo-reconstructive methods offer a contiguous record of environmental contamination providing a needed framework to establish locally relevant "pre-industrial" (~natural) conditions which can be compare with relative and quantitative deviations away from reference conditions. In this study, we reconstruct the history of the long-range, anthropogenic sourced atmospheric trace element deposition to the remote region of Northwestern Ontario Canada (Experimental Lakes Area (ELA)) using dated sediment records from five lakes. Several elements are shown to be highly enriched in lake sediments relative to pre-1860 sediments (Antimony, Lead, Tellurium, Tin, Arsenic, Bismuth, Cadmium and Mercury) and moderately (Zinc, Tungsten, Thallium, Copper, Silver, Selenium, Nickel and Vanadium). Mean decadal anthropogenic atmospheric fluxes (mg m-2 yr-1) are reconstructed for 1860-2010 and compare well with available local (ELA), regional (NW Ontario Canada, N Michigan USA) monitoring data, as well as global assessments of anthropogenic contribution to atmospheric trace metal burdens. Quantitative paleo reconstructions of atmospheric contamination history using the collective signal from multiple lakes provide a rigorous methodology to assess trends, uncertainties, evaluation with monitoring data and, provide an opportunity to explore landscape processes of contaminant transport and storage. Further study of the latter is recommended to understand the latency of legacy anthropogenic contamination of the environment.
Collapse
Affiliation(s)
- Johan A Wiklund
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada, L7R 4A6.
| | - Jane L Kirk
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada, L7R 4A6.
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada, L7R 4A6
| | - Amber Gleason
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada, L7R 4A6
| | - Jacques Carrier
- National Laboratory of Environmental Testing, Environment Canada, Burlington, Ontario, Canada L7R 4A6
| | - Fan Yang
- Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada, L7R 4A6
| |
Collapse
|
3
|
Cooke CA, Martínez-Cortizas A, Bindler R, Sexauer Gustin M. Environmental archives of atmospheric Hg deposition - A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 709:134800. [PMID: 31887515 DOI: 10.1016/j.scitotenv.2019.134800] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
Environmental archives offer an opportunity to reconstruct temporal trends in atmospheric Hg deposition at various timescales. Lake sediment and peat have been the most widely used archives; however, new records from ice, tree rings, and the measurement of Hg stable isotopes, are offering new insights into past Hg cycling. Preindustrial Hg deposition has been studied over decadal to millennial timescales extending as far back as the late Pleistocene. Exploitation of mercury deposits (mainly cinnabar) first began during the mid to late Holocene in South America, Europe, and Asia, but increased dramatically during the Colonial era (1532-1900) for silver production. However, evidence for preindustrial Hg pollution is restricted to regions directly downwind or downstream of cinnabar or precious metal mining centers. Excluding these areas, there has been an approximately four-fold increase in atmospheric deposition globally over the industrial era (i.e., since 1800-1850), though regional differences exist, especially during the early 20th Century. Lake sediments, peat, ice, and tree rings are all influenced by (and integrate) a range of processes. For example, lake sediments are influenced by atmospheric deposition, sediment focusing, and the input of allochthonous material from the watershed, peat records reflect atmospheric deposition and biotic uptake, ice cores are a record of Hg scrubbed during precipitation, and tree rings record atmospheric concentrations. No archive represents an absolute record of past Hg deposition or concentrations, and post-depositional transformation of Hg profiles remains an important topic of research. However, natural archives continue to provide important insight into atmospheric Hg cycling over various timescales.
Collapse
Affiliation(s)
- Colin A Cooke
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada; Environmental Monitoring and Science Division, Alberta Environment and Parks, Government of Alberta, Edmonton, Alberta T5J 5C6 Canada.
| | - Antonio Martínez-Cortizas
- EcoPast (GI-1553), Facultade de Bioloxía, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Richard Bindler
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Mae Sexauer Gustin
- Department of Natural Resources and Environmental Science, University of Nevada-Reno Reno, Nevada 89557, United States
| |
Collapse
|
4
|
Haynes KM, Kane ES, Potvin L, Lilleskov EA, Kolka RK, Mitchell CPJ. Impacts of experimental alteration of water table regime and vascular plant community composition on peat mercury profiles and methylmercury production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 682:611-622. [PMID: 31129544 DOI: 10.1016/j.scitotenv.2019.05.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Climate change is expected to alter the hydrology and vascular plant communities in peatland ecosystems. These changes may have as yet unexplored impacts on peat mercury (Hg) concentrations and net methylmercury (MeHg) production. In this study, peat was collected from PEATcosm, an outdoor, controlled mesocosm experiment where peatland water table regimes and vascular plant functional groups were manipulated over several years to simulate potential climate change effects. Potential Hg(II) methylation and MeHg demethylation rate constants were assessed using enriched stable isotope incubations at the end of the study in 2015, and ambient peat total Hg (THg) and MeHg concentration depth profiles were tracked annually from 2011 to 2014. Peat THg and MeHg concentrations and the proportion of THg methylated (%MeHg) increased significantly within the zone of water table fluctuation when water tables were lowered, but potential Hg(II) methylation rate constants were similar regardless of water table treatment. When sedges dominate over ericaceous shrubs, MeHg concentrations and %MeHg became significantly elevated within the sedge rooting zone. Increased desorption of Hg(II) and MeHg from the solid phase peat into pore water occurred with a lowered water table and predominant sedge cover, likely due to greater aerobic peat decomposition. Deeper, more variable water tables and a transition to sedge-dominated communities coincided with increased MeHg accumulation within the zone of water table fluctuation. Sustained high water tables promoted the net downward migration of Hg(II) and MeHg. The simultaneous decrease in Hg(II) and MeHg concentrations in the near-surface peat and accumulation deeper in the peat profile, combined with the trends in Hg(II) and MeHg partitioning to mobile pore waters, suggest that changes to peatland hydrology and vascular plant functional groups redistribute peat Hg(II) and MeHg via vertical hydrochemical transport mechanisms.
Collapse
Affiliation(s)
- Kristine M Haynes
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada.
| | - Evan S Kane
- Michigan Technological University, School of Forest Resources and Environmental Science, Houghton, MI 49931, USA; USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Lynette Potvin
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Erik A Lilleskov
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Randall K Kolka
- USDA Forest Service Northern Research Station, Grand Rapids, MN 55744, USA
| | - Carl P J Mitchell
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada
| |
Collapse
|
5
|
Smieja-Król B, Fiałkiewicz-Kozieł B, Michalska A, Krzykawski T, Smołka-Danielowska D. Deposition of mullite in peatlands of southern Poland: Implications for recording large-scale industrial processes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 250:717-727. [PMID: 31035154 DOI: 10.1016/j.envpol.2019.04.077] [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: 12/18/2018] [Revised: 03/29/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
Mullite, a pure aluminosilicate (Al6Si2O13), is a rare natural rock component, known for centuries as a very resistant ceramic material. It is also a common waste product of high-temperature coal combustion that is emitted in quantity from coal-based power stations. The occurrence of mullite in two Sphagnum-dominated peatlands located near the Upper Silesia industrial region in southern Poland is described. For the first time, a complete record of mullite deposition in the peat profiles has been obtained by XRD analyses of ashed peat samples. The mullite distribution is compared with records of Hg, Pb and Cu. While mullite is supplied during high temperature processes only, Cu, Pb and Hg show more complex pattern of distribution. Both peat profiles contain elevated amounts of mullite in the time span between ca 1950-1990 with a maximum content in ca 1980. The first appearance (∼1900) of mullite is indicative of the beginning of energy production in coal-based power plants in the region. Mullite is proposed here as an indicator of industrialization in geological records. It is resistant to post-depositional processes, emitted globally, and restricted to large-scale industry.
Collapse
Affiliation(s)
- Beata Smieja-Król
- Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200, Sosnowiec, Poland.
| | - Barbara Fiałkiewicz-Kozieł
- Institute of Geoinformation and Geoecology, Adam Mickiewicz University, Krygowskiego 10, 61-680, Poznań, Poland
| | - Anna Michalska
- Department of Environmental Monitoring, Central Mining Institute, Plac Gwarków 1, 40-166, Katowice, Poland
| | - Tomasz Krzykawski
- Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200, Sosnowiec, Poland
| | | |
Collapse
|