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Garvin MC, Schijf J, Kaufman SR, Konow C, Liang D, Nigra AE, Stracker NH, Whelan RJ, Wiles GC. A survey of trace metal burdens in increment cores from eastern cottonwood (Populus deltoides) across a childhood cancer cluster, Sandusky County, OH, USA. Chemosphere 2020; 238:124528. [PMID: 31425869 DOI: 10.1016/j.chemosphere.2019.124528] [Citation(s) in RCA: 1] [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: 04/29/2019] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 06/10/2023]
Abstract
A dendrochemical study of cottonwood trees (Populus deltoides) was conducted across a childhood cancer cluster in eastern Sandusky County (Ohio, USA). The justification for this study was that no satisfactory explanation has yet been put forward, despite extensive local surveys of aerosols, groundwater, and soil. Concentrations of eight trace metals were measured by ICP-MS in microwave-digested 5-year sections of increment cores, collected during 2012 and 2013. To determine whether the onset of the first cancer cases could be connected to an emergence of any of these contaminants, cores spanning the period 1970-2009 were taken from 51 trees of similar age, inside the cluster and in a control area to the west. The abundance of metals in cottonwood tree annual rings served as a proxy for their long-term, low-level accumulation from the same sources whereby exposure of the children may have occurred. A spatial analysis of cumulative metal burdens (lifetime accumulation in the tree) was performed to search for significant 'hotspots', employing a scan statistic with a mask of variable radius and center. For Cd, Cr, and Ni, circular hotspots were found that nearly coincide with the cancer cluster and are similar in size. No hotspots were found for Co, Cu, and Pb, while As and V were largely below method detection limits. Whereas our results do not implicate exposure to metals as a causative factor, we conclude that, after 1970, cottonwood trees have accumulated more Cd, Cr, and Ni, inside the childhood cancer cluster than elsewhere in Sandusky County.
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Affiliation(s)
- Mary C Garvin
- Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
| | - Johan Schijf
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, P.O. Box 38, Solomons, MD, 20688, USA.
| | - Sonya R Kaufman
- Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
| | - Courtney Konow
- Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
| | - Dong Liang
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, P.O. Box 38, Solomons, MD, 20688, USA
| | - Anne E Nigra
- Columbia University Mailman School of Public Health, Department of Environmental Health Sciences, 722 West 168th St., New York, NY, 10032, USA
| | - Norberth H Stracker
- Johns Hopkins University School of Medicine, Division of Infectious Diseases, 1830 East Monument St., Room 442, Baltimore, MD, 21287, USA
| | - Rebecca J Whelan
- University of Notre Dame, Department of Chemistry and Biochemistry, 140D McCourtney Hall, Notre Dame, IN, 46556, USA
| | - Gregory C Wiles
- The College of Wooster, Department of Earth Sciences, 944 College Hall, Wooster, OH, 44691, USA
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McHugh KC, Widom E, Spitz HB, Wiles GC, Glover SE. Uranium mobility across annual growth rings in three deciduous tree species. J Environ Radioact 2018; 182:183-189. [PMID: 29150189 DOI: 10.1016/j.jenvrad.2017.10.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 05/25/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
Black walnut (Juglans nigra), slippery elm (Ulmus rubra), and white ash (Fraxinus americana) trees were evaluated as potential archives of past uranium (U) contamination. Like other metals, U mobility in annual growth rings of trees is dependent on the tree species. Uranium concentrations and isotopic compositions (masses 234, 235, 236, and 238) were analyzed by thermal ionization mass spectrometry to test the efficacy of using tree rings to retroactively monitor U pollution from the FFMPC, a U purification facility operating from 1951 to 1989. This study found non-natural U (depleted U and detectable 236U) in growth rings of all three tree species that pre-dated the start of operations at FFMPC and compositional trends that did not correspond with known contamination events. Therefore, the annual growth rings of these tree species cannot be used to reliably monitor the chronology of U contamination.
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Affiliation(s)
- Kelly C McHugh
- Department of Geology and Environmental Earth Science, Miami University, 118 Shideler Hall, 250 S. Patterson Ave., Oxford, OH 45056, USA.
| | - Elisabeth Widom
- Department of Geology and Environmental Earth Science, Miami University, 118 Shideler Hall, 250 S. Patterson Ave., Oxford, OH 45056, USA
| | - Henry B Spitz
- Department of Mechanical and Materials Engineering, University of Cincinnati, 598 Rhodes Hall, P.O. Box 210072, Cincinnati, OH 45221, USA
| | - Gregory C Wiles
- Department of Geology, The College of Wooster, Scovel Hall, 944 College Mall, Wooster, OH 44691, USA
| | - Sam E Glover
- Department of Mechanical and Materials Engineering, University of Cincinnati, 598 Rhodes Hall, P.O. Box 210072, Cincinnati, OH 45221, USA
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