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Cooke MW, Trudel M, Gurney-Smith HJ, Kellogg JP, Cullen JT, Francisco BBA, Mercier JF, Chen J. Radioactivity concentration measurements in fish and shellfish samples from the west coast of Canada after the Fukushima nuclear accident (2011-2018). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106934. [PMID: 35696881 DOI: 10.1016/j.jenvrad.2022.106934] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Radioactive contamination of the Pacific Ocean following the Fukushima nuclear accident has raised public concern about seafood safety, particularly in coastal Indigenous communities. To address this, Health Canada and partners have collected and analyzed a total of 621 samples of commonly consumed salmon, ground fish, and shellfish from the Canadian west coast from 2011 to 2018. While the vast majority of the 137Cs and 134Cs levels were below the Minimum Detectable Concentration (MDC, typically 0.7-1.0 Bq kg-1 fw for a 6 h counting), further examination of 19 fish samples revealed 137Cs concentrations of 0.17-0.53 Bq kg-1 fw with an average value and uncertainty (k = 1) of 0.29 ± 0.02 Bq kg-1 fw. Of these, only two samples were found to have trace levels of 134Cs likely derived from the Fukushima accident. The global fallout contribution from atmospheric nuclear weapons testing to the observed 137Cs in these two samples was determined to be 0.26 ± 0.08 Bq kg-1 fw (49 ± 14%) and 0.12 ± 0.02 Bq kg-1 fw (24 ± 4%) for collection years 2015 and 2016, respectively. The annual average level of 137Cs in fish and shellfish was also determined by spectral summation for collection years 2014-2018. In fish, 137Cs levels determined through spectral summation were relatively constant (0.18-0.25 Bq kg-1 fw) with an average value and uncertainty of 0.21 ± 0.02 Bq kg-1 fw. By contrast, 38 shellfish samples (bivalves) were measured and revealed no radiocesium or other anomalies in either tissue or shell. In all, measurements over eight years showed that the radioactivity in fish and shellfish was dominated by natural radionuclides and that the level of anthropogenic radionuclides, as indicated by the radioactive cesium content, remained small. An upper bound for ingested dose from 137Cs was determined to be approximately 0.26 μSv per year, far below the worldwide average annual effective dose of 2400 μSv from exposure to natural background radiation. We can therefore conclude that fish, such as salmon, ground fish, and shellfish from the Canadian west coast are of no radiological health concern despite the Fukushima Dai-ichi nuclear accident of 2011.
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Affiliation(s)
- M W Cooke
- Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa, K1A 1C1, Canada.
| | - M Trudel
- St. Andrews Biological Station, Fisheries and Oceans Canada, 125 Marine Science Dr, St. Andrews, E5B 0E4, Canada
| | - H J Gurney-Smith
- St. Andrews Biological Station, Fisheries and Oceans Canada, 125 Marine Science Dr, St. Andrews, E5B 0E4, Canada
| | - J P Kellogg
- School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Victoria, V8P 5C2, Canada
| | - J T Cullen
- School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Victoria, V8P 5C2, Canada
| | - B B A Francisco
- A. E. Lalonde AMS Laboratory, University of Ottawa, 25 Templeton St, Ottawa, Ontario, K1N 6N5, Canada
| | - J F Mercier
- Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa, K1A 1C1, Canada
| | - J Chen
- Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa, K1A 1C1, Canada
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Eslinger PW, Miley HS, Schrom BT. Investigations of association among atmospheric radionuclide measurements. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 241:106777. [PMID: 34826775 DOI: 10.1016/j.jenvrad.2021.106777] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 06/13/2023]
Abstract
Large networks producing frequent atmospheric radionuclide measurements have additional power in characterizing and localizing radionuclide release events over the analysis performed with four or fewer radionuclide measurements. However, adding unrelated measurements to an analysis dilutes that advantage, unless source-term models are extended to account for this complexity. A key steppingstone to obtaining network power is to select a group of related sample measurements that are associated with a release event. Such collections of measurements can be assembled by an analyst, or perhaps they can be selected by algorithm. The authors explore, using a year of atmospheric transport calculations and realistic sensor sensitivities, the potential for a computed radionuclide association tool.
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Affiliation(s)
- Paul W Eslinger
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA.
| | - Harry S Miley
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA.
| | - Brian T Schrom
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA.
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Jelin BA, Sun W, Kravets A, Naboka M, Stepanova EI, Vdovenko VY, Karmaus WJ, Lichosherstov A, Svendsen ER. Quantifying annual internal effective 137Cesium dose utilizing direct body-burden measurement and ecological dose modeling. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2016; 26:546-553. [PMID: 25757885 DOI: 10.1038/jes.2015.6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 12/19/2014] [Accepted: 12/27/2014] [Indexed: 06/04/2023]
Abstract
The Chernobyl Nuclear Power Plant (CNPP) accident represents one of the most significant civilian releases of 137Cesium (137Cs, radiocesium) in human history. In the Chernobyl-affected region, radiocesium is considered to be the greatest on-going environmental hazard to human health by radiobiologists and public health scientists. The goal of this study was to characterize dosimetric patterns and predictive factors for whole-body count (WBC)-derived radiocesium internal dose estimations in a CNPP-affected children's cohort, and cross-validate these estimations with a soil-based ecological dose estimation model. WBC data were used to estimate the internal effective dose using the International Commission on Radiological Protection (ICRP) 67 dose conversion coefficient for 137Cs and MONDAL Version 3.01 software. Geometric mean dose estimates from each model were compared utilizing paired t-tests and intra-class correlation coefficients. Additionally, we developed predictive models for WBC-derived dose estimation in order to determine the appropriateness of EMARC to estimate dose for this population. The two WBC-derived dose predictive models identified 137Cs soil concentration (P<0.0001) as the strongest predictor of annual internal effective dose from radiocesium validating the use of the soil-based EMARC model. The geometric mean internal effective dose estimate of the EMARC model (0.183 mSv/y) was the highest followed by the ICRP 67 dose estimates (0.165 mSv/y) and the MONDAL model estimates (0.149 mSv/y). All three models yielded significantly different geometric mean dose (P<0.05) estimates for this cohort when stratified by sex, age at time of exam and season of exam, except for the mean MONDAL and EMARC estimates for 15- and 16-year olds and mean ICRP and MONDAL estimates for children examined in Winter. Further prospective and retrospective radio-epidemiological studies utilizing refined WBC measurements and ecological model dose estimations, in conjunction with findings from animal toxicological studies, should help elucidate possible deterministic radiogenic health effects associated with chronic low-dose internal exposure to 137Cs.
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Affiliation(s)
- Benjamin A Jelin
- Department of Global Environmental Health Sciences: Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
| | - Wenjie Sun
- Department of Global Environmental Health Sciences: Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
| | - Alexandra Kravets
- Institue of Cell Biology and Genetic Engineering, National Academy of Sciences, Kyiv, Ukraine
| | - Maryna Naboka
- Radioecological Center, Ukrainian National Academy of Sciences, Kyiv, Ukraine
| | - Eugenia I Stepanova
- Research Center for Radiation Medicine, Academy of Medical Sciences of Ukraine, Kyiv, Ukraine
| | - Vitaliy Y Vdovenko
- Research Center for Radiation Medicine, Academy of Medical Sciences of Ukraine, Kyiv, Ukraine
| | - Wilfried J Karmaus
- Division of Epidemiology, Biostatistics and Environmental Health, School of Public Health, University of Memphis, Memphis, Tennessee, USA
| | - Alex Lichosherstov
- Radioecological Center, Ukrainian National Academy of Sciences, Kyiv, Ukraine
| | - Erik R Svendsen
- Department of Global Environmental Health Sciences: Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
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Stocki TJ, Gamberg M, Loseto L, Pellerin E, Bergman L, Mercier JF, Genovesi L, Cooke M, Todd B, Sandles D, Whyte J, Wang X. Measurements of cesium in Arctic beluga and caribou before and after the Fukushima accident of 2011. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 162-163:379-387. [PMID: 27359098 DOI: 10.1016/j.jenvrad.2016.05.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/19/2015] [Accepted: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Concern from northern communities following the Fukushima Daiichi nuclear accident of March 2011 has prompted a reassessment of the safety of their traditional foods with respect to radioactivity levels. To this end, a study was conducted to measure the levels of radionuclides in Arctic caribou (Rangifer tarandus) and beluga (Delphinapterus leucas). The main radionuclide of concern is cesium-137, which is easily transferred through the lichen-caribou food chain. Previous studies have been conducted on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl nuclear accident in 1986. In this study, samples of lichens, mushrooms, caribou, beluga and beluga prey collected before and after the Fukushima accident were analyzed for radioactivity levels. Samples were processed and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration. Both calibration standards and Monte Carlo simulations were used to determine the efficiency of the detectors for the samples, taking into account differences in individual sample sizes as well as matrices. In particular, a careful analysis of the atomic composition of lichens and mushrooms was performed to ensure the efficiencies for these sample types were correct. A comparison of the concentrations from before and after the accident indicated that there was no increase in radioactivity as a result of the atmospheric plume from the Fukushima accident. Some cesium-137, likely attributable to fallout from atmospheric weapons testing of the 1950s and 1960s (since there was no cesium-134 measured in the samples), was measured in the post Fukushima caribou and beluga whale samples; however, this amount was determined to be insignificant for any radiological concern (9.1 ± 1.8 and 0.63 ± 0.23 Bq kg-1 ww respectively). The activity concentrations of cesium-137 was about 200 times smaller than that of natural radioactive potassium in the beluga samples. Both the caribou and beluga results showed that these foods continue to be a healthy food choice for northern Canadians with respect to radioactivity, and this result has been communicated to the nearby northern communities and stakeholders.
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Affiliation(s)
- T J Stocki
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
| | - M Gamberg
- Gamberg Consulting, 708 Jarvis St. Whitehorse, YT, Y1A 2J2, Canada
| | - L Loseto
- Freshwater Institute Fisheries and Oceans Canada, 501 University Cres, Winnipeg, MB, R3T 2N6, Canada
| | - E Pellerin
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - L Bergman
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - J-F Mercier
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - L Genovesi
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - M Cooke
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - B Todd
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - D Sandles
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - J Whyte
- Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada
| | - X Wang
- Environment Canada, 867 Lakeshore Road, Burlington, ON, L7S 1A1, Canada
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Cook MC, Stukel MJ, Zhang W, Mercier JF, Cooke MW. The determination of Fukushima-derived cesium-134 and cesium-137 in Japanese green tea samples and their distribution subsequent to simulated beverage preparation. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 153:23-30. [PMID: 26714059 DOI: 10.1016/j.jenvrad.2015.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 11/27/2015] [Accepted: 12/08/2015] [Indexed: 06/05/2023]
Abstract
Health Canada's Radiation Protection Bureau has identified trace quantities of (134)Cs and (137)Cs in commercially available green tea products of Japanese origin. Referenced to March 11, 2011, the activity ratio ((134)Cs/(137)Cs) has been determined to be 1:1, which supports an origin from the Fukushima Dai-ichi Nuclear Power Plant accident. The upper limits of typical tea beverage preparation conditions were applied to the most contaminated of these green tea samples to determine the proportion of radiocesium contamination that would be available for human consumption. The distribution of radiocesium among the components of the extraction experiments (water, residual tea solid, and filter media) was determined by both conventional and Compton-suppressed gamma spectroscopy. The latter aided tremendously in providing a more complete radiocesium distribution profile, particularly for the shorter-lived (134)Cs. Cesium extraction efficiencies of 64 ± 7% and 64 ± 5% were determined based on (134)Cs and (137)Cs, respectively. Annual, effective dose estimates from ingestion of (137)Cs and (134)Cs (1.8-3.7 μSv), arising from the consumption of tea beverages prepared from the most contaminated of these samples, are insignificant relative to both total (∼ 2.4 mSv) and ingested (∼ 0.28 mSv) annual effective doses received from naturally occurring radioactive sources. As such, there is no health concern arising from the consumption of green tea beverages contaminated with radiocesium at the levels encountered in this study.
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Affiliation(s)
- Matthew C Cook
- Radiation Surveillance Division, Radiation Protection Bureau of Health Canada, 775 Brookfield Road, Ottawa, ON K1A 1C1, Canada
| | - Matthew J Stukel
- Radiation Surveillance Division, Radiation Protection Bureau of Health Canada, 775 Brookfield Road, Ottawa, ON K1A 1C1, Canada
| | - Weihua Zhang
- Radiation Surveillance Division, Radiation Protection Bureau of Health Canada, 775 Brookfield Road, Ottawa, ON K1A 1C1, Canada
| | - Jean-Francois Mercier
- Radiation Surveillance Division, Radiation Protection Bureau of Health Canada, 775 Brookfield Road, Ottawa, ON K1A 1C1, Canada
| | - Michael W Cooke
- Radiation Surveillance Division, Radiation Protection Bureau of Health Canada, 775 Brookfield Road, Ottawa, ON K1A 1C1, Canada.
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Spatiotemporal modeling and simulation of chernobyl radioactive fallout in northern Turkey. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-014-3517-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zhang R, Zhang H, Hou X, Chai Z, Chen Y, Fan Y. 129I assessment reveals the impact of Fukushima incident on Dapeng Peninsula, Shenzhen, China. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3137-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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