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Ren H, Ma X, Zhou L, Wang P, Chen T, Zou X, Zou H, Yu S, Cao Y, Lai Z, Lou X, Cao Y. Toward an efficient determination of tissue-free water tritium in food. Front Public Health 2023; 11:1185938. [PMID: 37492142 PMCID: PMC10363726 DOI: 10.3389/fpubh.2023.1185938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/26/2023] [Indexed: 07/27/2023] Open
Abstract
Introduction Tritium in the environment constitutes a radiological concern because it can become part of the hydrogen pool in environmental and biological reservoirs and thereby expose people to radiation. Methods Tissue-free water tritium (TFWT) analysis in food is an important subject of environmental radiation monitoring which plays an important role in the estimation of health risks from environmental tritium exposure. At present, tritium content in food is generally determined by liquid scintillation counter (LSC). To improve the analytical efficiency in tritium determination, we developed a novel method to treat TFWT in food using microporous membranes. Results The microporous membrane treatment method developed in this study has the following characteristics: It has a wide range of application and can process TFWT samples with conductivity below 5 μS/cm. Sample loss for the microporous membrane treatment is approximately 5%. The average treatment time is only 5 min, significantly shortened compared with the currently used atmospheric distillation treatment method (1.5 h). The results of the comparison and spike experiment show that the samples prepared by microporous membrane treatment provides equally satisfactory tritium measurement results as classic distillation method. Discussion The developed microporous membrane method is simple to operate, efficient, and environmentally friendly, and effectively improves the analysis efficiency of TFWT in food.
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Affiliation(s)
- Hong Ren
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Xiaoxiang Ma
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
- School of Public Health, Suzhou Medical College, Soochow University, Suzhou, China
| | - Lei Zhou
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Peng Wang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Ting Chen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Xiao Zou
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Hua Zou
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Shunfei Yu
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Yi Cao
- School of Public Health, Suzhou Medical College, Soochow University, Suzhou, China
| | - Zhongjun Lai
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Xiaoming Lou
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
| | - Yiyao Cao
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China
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Antonova EV, Antonov KL, Vasyanovich ME, Panchenko SV. Tritium from the Molecule to the Biosphere. 1. Patterns of Its Behavior in the Environment. RUSS J ECOL+ 2022. [DOI: 10.1134/s1067413622040038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Investigation on the chemical recovery and stability of a newly developed method for 137Cs measurement in marine biota Scomber Japonicus. Appl Radiat Isot 2022; 188:110381. [PMID: 35872558 DOI: 10.1016/j.apradiso.2022.110381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 03/30/2022] [Accepted: 07/08/2022] [Indexed: 02/08/2023]
Abstract
Seven sets of experiments based on a newly developed Mincing-Digesting method for 137Cs measuring in marine biota Scomber Japonicus were conducted to investigate the method's stability and chemical recovery. The results show the chemical recovery of radiocesium for aqueous parts is 68.77 ± 11.2%, which is relatively stable with R2 = 0.97, means this value could be used when measuring the Scomber Japonicus or other marine biota belonging to the same category and having similar muscular tissue and cellular structure. Meanwhile, the Minimum Detectable Activity (MDA) of the method is 0.013Bq/kg-ww which is comparable with that of the conventional method, means that the method could be further developed as a reliable and efficient way to measure other radionuclides in other marine biotas in the future if more experiments were conducted.
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Kim SB, Bredlaw M, Rousselle H, Bond M, Stuart M. Determination of the baseline tritium concentrations (HTO, TFWT and OBT) in soil and plants in Ontario, Canada. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 243:106810. [PMID: 34990898 DOI: 10.1016/j.jenvrad.2021.106810] [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: 08/10/2021] [Revised: 10/27/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Tritiated water (HTO), tissue free water tritium (TFWT) and organically bound tritium (OBT) activity concentrations in soil and plant leaves, collected at background areas in Ontario, were measured to quantify the current tritium baseline. Five representative background sites, based on their geological characteristics and residential populations, have been selected for this study. Undisturbed soils, plant leaves and surface water samples were collected at 5 sites (London, Kapuskasing, Thunder Bay, Elliot Lake and Cornwall areas) in 2015. Water sample HTO activity concentrations were measured using Liquid Scintillation Counting (LSC, ALOKA), and HTO activity concentrations for soil and TFWT for plant leaves were measured by LSC (Quantulus 1220) on water extracted from frozen samples using a freeze-drying vacuum system equipped with a liquid nitrogen trap. Plant leaf OBT levels were obtained by combustion of rinsed freeze-dried samples using a Parr combustion system, while soil OBT values were obtained using a tube furnace combustion system. Combustion water was distilled before being counted by LSC (Quantulus 1220). HTO activity concentrations were found to range between 1.4 and 2.0 Bq/L (MDA = 0.5 Bq/L) in surface water and soil samples. TFWT values were less than the minimum detectable activity (MDA = 3.5 Bq/L) in plant leaves. In contrast, OBT activity concentrations (MDA = 5 Bq/L) ranged from 5.7 to 17.1 Bq/L in plant leaves and 8.3-20.7 Bq/L in surface soil (0-5 cm depth). The overall OBT activity concentrations were higher in the London and the Cornwall areas. Lower levels were measured near Thunder Bay, Kapuskasing and Elliot Lake. There was no obvious relationship between soil OBT activity concentrations and soil types. The results provide the current tritium (HTO, TFWT and OBT) baseline values in Ontario. These values will be helpful for use as background locations for the evaluation of past and future environmental tritium inputs associated with nuclear facilities, and will be taken into account when evaluating the environmental impact of nuclear facilities in Ontario. Since samples in this study were primarily taken in wooded areas, some questions remain regarding the possibility that soil samples in open, non-wooded areas could show different HTO and OBT contents than those presented in this study.
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Affiliation(s)
- S B Kim
- Environment & Waste Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada.
| | - M Bredlaw
- Environment & Waste Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
| | - H Rousselle
- Environment & Waste Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
| | - M Bond
- Environment & Waste Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
| | - M Stuart
- Environment & Waste Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
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Meng D, Wang W, Du Y, Xiao C, Wen W, Dan G, Chen Z. Tritium distribution in typical plants around tritium laboratory in south-west of China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 227:106504. [PMID: 33307328 DOI: 10.1016/j.jenvrad.2020.106504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
A low-temperature desorption method was developed to remove the tissue free water tritium (TFWT) in plants, which dramatically reduces the sample-preparation time from several days to only 2-3 h. Two factors, including spatial distribution and seasonal variation, that influence the tritium distribution and the organic bound tritium (OBT)/TFWT ratios in plants were investigated based on three different kinds of subtropical-basin plants located near the decommissioned nuclear facility in south-west of China. Under the same environmental condition, higher tritium concentration was seen in pine needle (PN) compared with flat bamboo-root (FBT) and wild cotton (WC), while these three plants show similar location- and season-dependent trend of tritium distribution. The location-dependent investigation shows that OBT and TFWT concentration are significantly higher in plants growing in the downwind direction of the tritium laboratory than that in plants growing in the upwind and cross direction. In different seasons, the TFWT in plants reached peak in winter and valley in summer, while the OBT increased continuously with the season changing from spring to winter. The ratios of OBT/TFWT were investigated to evaluate the ability of plants to concentrate tritium into organic matter, which were 0.97-2.72 for PN, 0.89-1.64 for FBR, and 0.80-1.62 for WC.
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Affiliation(s)
- Dan Meng
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Weijuan Wang
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Yang Du
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Chao Xiao
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Wei Wen
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Guiping Dan
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China
| | - Zhilin Chen
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, PR China.
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Rashmi NS, D'Souza RS, Kamath SS, Mohan MP, Bharath S, Narayana B, Ravi PM, Karunakara N. Experimental database on water equivalent factor (WEQ p) and organically bound tritium activity for tropical monsoonal climate region of South West Coast of India. Appl Radiat Isot 2020; 166:109390. [PMID: 33091858 DOI: 10.1016/j.apradiso.2020.109390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/31/2020] [Accepted: 08/18/2020] [Indexed: 10/23/2022]
Abstract
Tritium in the form of tritiated water is easily incorporated into terrestrial biota as tissue free water tritium (TFWT). A part of TFWT is converted into organically bound tritium (OBT) through metabolic processes. For the computation of NE-OBT activity (expressed as Bq L-1 of combustion water) in terrestrial plants, knowledge on 'water equivalent factor (WEQp)', defined as the volume of water produced from the combustion of 1 kg of the dry sample, is essential. On a global scenario, experimental data are not available on this parameter. This paper presents (i) a method for determination of WEQp by combustion method using a tube furnace system, (ii) a large database (N = 294) on WEQp parameter for samples of tropical monsoonal climate region of the Indian subcontinent, and (iii) NE-OBT activity in terrestrial biota samples (N = 186) collected from the vicinity of a PHWR nuclear power plant of India. The data generated in this study on WEQp serves for the validation of the data compiled in IAEA (2009 and 2010), which are estimated based on the hydrogen content of protein, fat and carbohydrates, and the fractions of protein, fat and carbohydrates. The WEQp varied in the ranges of 0.492-0.678 L kg-1 (GM = 0.569 Bq L-1, GSD = 1.06), 0.520-0.630 L kg-1 (GM = 0.557 Bq L-1, GSD = 1.02) 0.473-0.633 L kg-1 (GM = 0.562 Bq L-1, GSD = 1.02) for non-leafy vegetables, leafy vegetables, and fruits, respectively. A comparison between the experimental WEQp data with those compiled in the IAEA report revealed that the maximum deviation between the two data sets is <10%. The NE-OBT activity in the food samples collected from 2.3 to 20 km zone around NPP had a geometric mean (GM) value of 25.4 Bq L-1 (GSD = 1.6, N = 186). Variations in NE-OBT activity with different seasons of the year are discussed.
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Affiliation(s)
- Nayak S Rashmi
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - Renita Shiny D'Souza
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - Srinivas S Kamath
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - M P Mohan
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - S Bharath
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - B Narayana
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - P M Ravi
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - N Karunakara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India.
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Nayak SR, D’Souza RS, Kamath SS, Mohan MP, Bharath S, Shetty T, Kumara KS, Narayana B, Dileep BN, Ravi PM, Karunakara N. Organically bound tritium: optimization of measurements in environmental matrices by combustion method and liquid scintillation spectrometry. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-018-6395-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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8
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Varlam C, Bucur C, Vagner I, Constantinescu M, Bogdan D, Faurescu I. Homogeneity assessment for grass samples used for organically bound tritium proficiency test. Appl Radiat Isot 2018; 132:147-150. [DOI: 10.1016/j.apradiso.2017.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 11/28/2017] [Accepted: 11/28/2017] [Indexed: 11/30/2022]
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Ota M, Kwamena NOA, Mihok S, Korolevych V. Role of soil-to-leaf tritium transfer in controlling leaf tritium dynamics: Comparison of experimental garden and tritium-transfer model results. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 178-179:212-231. [PMID: 28910625 DOI: 10.1016/j.jenvrad.2017.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/24/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Environmental transfer models assume that organically-bound tritium (OBT) is formed directly from tissue-free water tritium (TFWT) in environmental compartments. Nevertheless, studies in the literature have shown that measured OBT/HTO ratios in environmental samples are variable and generally higher than expected. The importance of soil-to-leaf HTO transfer pathway in controlling the leaf tritium dynamics is not well understood. A model inter-comparison of two tritium transfer models (CTEM-CLASS-TT and SOLVEG-II) was carried out with measured environmental samples from an experimental garden plot set up next to a tritium-processing facility. The garden plot received one of three different irrigation treatments - no external irrigation, irrigation with low tritium water and irrigation with high tritium water. The contrast between the results obtained with the different irrigation treatments provided insights into the impact of soil-to-leaf HTO transfer on the leaf tritium dynamics. Concentrations of TFWT and OBT in the garden plots that were not irrigated or irrigated with low tritium water were variable, responding to the arrival of the HTO-plume from the tritium-processing facility. In contrast, for the plants irrigated with high tritium water, the TFWT concentration remained elevated during the entire experimental period due to a continuous source of high HTO in the soil. Calculated concentrations of OBT in the leaves showed an initial increase followed by quasi-equilibration with the TFWT concentration. In this quasi-equilibrium state, concentrations of OBT remained elevated and unchanged despite the arrivals of the plume. These results from the model inter-comparison demonstrate that soil-to-leaf HTO transfer significantly affects tritium dynamics in leaves and thereby OBT/HTO ratio in the leaf regardless of the atmospheric HTO concentration, only if there is elevated HTO concentrations in the soil. The results of this work indicate that assessment models should be refined to consider the importance of soil-to-leaf HTO transfer to ensure that dose estimates are accurate and conservative.
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Affiliation(s)
- Masakazu Ota
- Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 Japan.
| | - Nana-Owusua A Kwamena
- Canadian Nuclear Safety Commission, 280 Slater Street, PO Box 1046, Station B, Ottawa, Ontario K1P5S9, Canada
| | - Steve Mihok
- Canadian Nuclear Safety Commission, 280 Slater Street, PO Box 1046, Station B, Ottawa, Ontario K1P5S9, Canada
| | - Volodymyr Korolevych
- Environmental, Radiological and Chemical Sciences Division, STN51A, Canadian Nuclear Laboratories, Chalk River, Ontario, Canada
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10
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Priest ND, Blimkie MSJ, Wyatt H, Bugden M, Bannister LA, Gueguen Y, Jourdain JR, Klokov D. Tritium ( 3 H) Retention In Mice: Administered As HTO, DTO or as 3 H-Labeled Amino-Acids. HEALTH PHYSICS 2017; 112:439-444. [PMID: 28350697 DOI: 10.1097/hp.0000000000000637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The objective of this study was to compare the biokinetics of injected H-labeled light (HTO) and heavy (DTO) water in CBA/CaJ mice and to compare the organ distribution and/or body content of H administered by chronic ingestion for 1 mo to C57Bl/6J mice, as either H-labeled water or H-labeled amino acids (glycine, alanine and proline). HTO and DTO were administered to CBA/CaJ mice by single intraperitoneal injection and body retention was determined for up to 384 h post-injection. Tritium-labeled water or H-labeled amino acids were given to C57Bl/6J mice ad libitum for 30 d in drinking water. Body content and organ distribution of H during the period of administration and subsequent to administration was determined by liquid scintillation counting. No differences were found between the biokinetics of HTO and DTO, indicating that data generated using HTO can be used to help assess the consequences of H releases from heavy water reactors. The results for H-water showed that the concentration of radionuclide in the mice reached a peak after about 10 d and dropped rapidly after the cessation of H administration. The maximum concentration reached was only 50% of that in the water consumed, indicating that mice receive a significant fraction of their water from respiration. Contrary to the findings of others, the pattern of H retention following the administration of a cocktail of the labeled amino acids was very little different from that found for the water. This is consistent with the suggestion that most of the ingested amino acids were rapidly metabolized, releasing water and carbon dioxide.
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Affiliation(s)
- Nicholas D Priest
- *Radiobiology and Health Branch, Canadian Nuclear Laboratories, Plant Road, Chalk River, Ontario, K0J 1J0, Canada; †Retired; ‡L'Insitute de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, Paris, France. §Tritium can be incorporated into a wide range of biological macromolecules and OBT represents a collective term for such tritium-containing macromolecules. Thus, various definitions of OBT exist. Within this study, term OBT refers to the three tritiated amino acids as described in Materials and Methods
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11
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Characteristics of the combustion water of organically bound tritium (OBT) measurements of fish samples. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5218-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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Kim SB, Farrow F, Bredlaw M, Stuart M. Changes in HTO and OBT activity concentrations in the Perch Lake aquatic ecosystem. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 165:280-285. [PMID: 27816047 DOI: 10.1016/j.jenvrad.2016.10.015] [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: 04/14/2016] [Revised: 10/21/2016] [Accepted: 10/26/2016] [Indexed: 06/06/2023]
Abstract
Perch Lake, a small shallow shield lake located on the Chalk River Laboratories (CRL) site, contains elevated levels of tritium due to inputs from a nearby nuclear waste management area. The releases have been going on for many years but tritium levels in Perch Lake have been gradually decreasing since about year 2000. Lake water, sediments, aquatic plants, clams and fish were collected during the summer and fall of 2003 and 2013 at three locations in the lake. HTO activity concentrations were measured in all samples and OBT activity concentrations were measured in sediments, plants, clams and fish. In 2003, 2013, HTO activity concentrations in lake water were roughly uniform in time and space, except close to the shoreline where concentrations were fluctuating according to stream water and groundwater tritium levels in streams entering the lake. HTO activity concentrations of biota were similar to concentrations in lake water at the site where they were collected. OBT activity concentrations in biota were not always correlating with the lake water HTO levels. OBT to HTO ratios were found to be less than 1 for aquatic plants, around 1 for clams and fish and above 1 for birds reared on the shore of the lake.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada.
| | - F Farrow
- Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
| | - M Bredlaw
- Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
| | - M Stuart
- Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada
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WITHDRAWN: Method development and validation of organically bound tritium analysis in environmental plant samples. FUSION ENGINEERING AND DESIGN 2016. [DOI: 10.1016/j.fusengdes.2016.06.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Kim SB, Olfert J, Baglan N, St-Amant N, Carter B, Clark I, Bucur C. Canadian inter-laboratory organically bound tritium (OBT) analysis exercise. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 150:236-241. [PMID: 26372740 DOI: 10.1016/j.jenvrad.2015.08.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/24/2015] [Accepted: 08/28/2015] [Indexed: 06/05/2023]
Abstract
Tritium emissions are one of the main concerns with regard to CANDU reactors and Canadian nuclear facilities. After the Fukushima accident, the Canadian Nuclear Regulatory Commission suggested that models used in risk assessment of Canadian nuclear facilities be firmly based on measured data. Procedures for measurement of tritium as HTO (tritiated water) are well established, but there are no standard methods and certified reference materials for measurement of organically bound tritium (OBT) in environmental samples. This paper describes and discusses an inter-laboratory comparison study in which OBT in three different dried environmental samples (fish, Swiss chard and potato) was measured to evaluate OBT analysis methods currently used by CANDU Owners Group (COG) members. The variations in the measured OBT activity concentrations between all laboratories were less than approximately 20%, with a total uncertainty between 11 and 17%. Based on the results using the dried samples, the current OBT analysis methods for combustion, distillation and counting are generally acceptable. However, a complete consensus OBT analysis methodology with respect to freeze-drying, rinsing, combustion, distillation and counting is required. Also, an exercise using low-level tritium samples (less than 100 Bq/L or 20 Bq/kg-fresh) would be useful in the near future to more fully evaluate the current OBT analysis methods.
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Affiliation(s)
- S B Kim
- CNL, Chalk River Laboratories, Chalk River, Canada.
| | - J Olfert
- CNL, Chalk River Laboratories, Chalk River, Canada
| | - N Baglan
- CEA/DAM/DIF- F91297 Arpajon, France
| | - N St-Amant
- Canadian Nuclear Safety Commission, Canada
| | - B Carter
- Ontario Power Generation, Canada
| | - I Clark
- University of Ottawa, Canada
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Kim SB, Stuart M. OBT analysis method using polyethylene beads for limited quantities of animal tissue. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 146:51-55. [PMID: 25913056 DOI: 10.1016/j.jenvrad.2015.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 03/31/2015] [Accepted: 04/03/2015] [Indexed: 06/04/2023]
Abstract
This study presents a polyethylene beads method for OBT determination in animal tissues and animal products for cases where the amount of water recovered by combustion is limited by sample size or quantity. In the method, the amount of water recovered after combustion is enhanced by adding tritium-free polyethylene beads to the sample prior to combustion in an oxygen bomb. The method reduces process time by allowing the combustion water to be easily collected with a pipette. Sufficient water recovery was achieved using the polyethylene beads method when 2 g of dry animal tissue or animal product were combusted with 2 g of polyethylene beads. Correction factors, which account for the dilution due to the combustion water of the beads, are provided for beef, chicken, pork, fish and clams, as well as egg, milk and cheese. The method was tested by comparing its OBT results with those of the conventional method using animal samples collected on the Chalk River Laboratories (CRL) site. The results determined that the polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Chalk River Laboratories, CNL, Chalk River, Ontario, K0J 1J0, Canada.
| | - M Stuart
- Environmental Technologies Branch, Chalk River Laboratories, CNL, Chalk River, Ontario, K0J 1J0, Canada
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Thompson PA, Kwamena NOA, Ilin M, Wilk M, Clark ID. Levels of tritium in soils and vegetation near Canadian nuclear facilities releasing tritium to the atmosphere: implications for environmental models. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 140:105-113. [PMID: 25461522 DOI: 10.1016/j.jenvrad.2014.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 11/06/2014] [Accepted: 11/07/2014] [Indexed: 06/04/2023]
Abstract
Concentrations of organically bound tritium (OBT) and tritiated water (HTO) were measured over two growing seasons in vegetation and soil samples obtained in the vicinity of four nuclear facilities and two background locations in Canada. At the background locations, with few exceptions, OBT concentrations were higher than HTO concentrations: OBT/HTO ratios in vegetation varied between 0.3 and 20 and values in soil varied between 2.7 and 15. In the vicinity of the four nuclear facilities OBT/HTO ratios in vegetation and soils deviated from the expected mean value of 0.7, which is used as a default value in environmental transfer models. Ratios of the OBT activity concentration in plants ([OBT]plant) to the OBT activity concentration in soils ([OBT]soil) appear to be a good indicator of the long-term behaviour of tritium in soil and vegetation. In general, OBT activity concentrations in soils were nearly equal to OBT activity concentrations in plants in the vicinity of the two nuclear power plants. [OBT]plant/[OBT]soil ratios considerably below unity observed at one nuclear processing facility represents historically higher levels of tritium in the environment. The results of our study reflect the dynamic nature of HTO retention and OBT formation in vegetation and soil during the growing season. Our data support the mounting evidence suggesting that some parameters used in environmental transfer models approved for regulatory assessments should be revisited to better account for the behavior of HTO and OBT in the environment and to ensure that modelled estimates (e.g., plant OBT) are appropriately conservative.
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Affiliation(s)
- P A Thompson
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario, K1P 5S9, Canada.
| | - N-O A Kwamena
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario, K1P 5S9, Canada
| | - M Ilin
- Canadian Nuclear Safety Commission, 280 Slater Street, P.O. Box 1046, Station B, Ottawa, Ontario, K1P 5S9, Canada
| | - M Wilk
- Department of Earth Science, 140 Louis-Pasteur, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada
| | - I D Clark
- Department of Earth Science, 140 Louis-Pasteur, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada
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Kim SB, Shultz C, Stuart M, Festarini A. Tritium uptake in rainbow trout (Oncorhynchus mykiss): HTO and OBT-spiked feed exposures simultaneously. Appl Radiat Isot 2015; 98:96-102. [PMID: 25656986 DOI: 10.1016/j.apradiso.2015.01.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/09/2014] [Accepted: 01/20/2015] [Indexed: 11/27/2022]
Abstract
There is currently considerable interest in organically bound tritium (OBT) formation in edible fish. The major questions revolve around whether or not tritium can accumulate in fish after being released into aquatic environments. Since OBT formation rates in large, edible fish are poorly understood, rainbow trout (Oncorhynchus mykiss) studies, where fish were simultaneously exposed to tritiated water (HTO) and OBT-spiked feed over 130 days, were conducted to evaluate tritium uptake. The measured HTO activity concentrations in fish tissue confirmed that HTO in fish tissue equilibrates quickly with HTO in tank water. The data obtained also confirmed that OBT uptake is faster when fish are ingesting OBT-spiked feed compared to when fish are living in tritiated water (and consuming non-OBT-spiked feed). The difference between the two exposure types is such that the groups exposed to tritiated water and OBT-spiked feed simultaneously were showing the same uptake rates as OBT-spiked feed only exposures. Contrary to what was expected, the rate of OBT uptake (from OBT-spiked feed) seemed to be higher in slow growing fish compared to fast growing fish. Another observation from these studies was that OBT activity concentrations in all organs (viscera) had a tendency to be higher than OBT activity concentrations measured in fish flesh.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - C Shultz
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - M Stuart
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - A Festarini
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
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18
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Huang YJ, Zeng F, Zhang B, Chen CF, Qin HJ, Wu LS, Guo GY, Yang LT, Shang-Guan ZH. Method validation and uncertainty evaluation of organically bound tritium analysis in environmental sample. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2014; 134:83-88. [PMID: 24695278 DOI: 10.1016/j.jenvrad.2014.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 03/01/2014] [Accepted: 03/13/2014] [Indexed: 06/03/2023]
Abstract
The analytical method for organically bound tritium (OBT) was developed in our laboratory. The optimized operating conditions and parameters were established for sample drying, special combustion, distillation, and measurement on a liquid scintillation spectrometer (LSC). Selected types of OBT samples such as rice, corn, rapeseed, fresh lettuce and pork were analyzed for method validation of recovery rate reproducibility, the minimum detection concentration, and the uncertainty for typical low level environmental sample was evaluated. The combustion water recovery rate of different dried environmental sample was kept at about 80%, the minimum detection concentration of OBT ranged from 0.61 to 0.89 Bq/kg (dry weight), depending on the hydrogen content. It showed that this method is suitable for OBT analysis of environmental sample with stable recovery rate, and the combustion water yield of a sample with weight about 40 g would provide sufficient quantity for measurement on LSC.
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Affiliation(s)
- Yan-Jun Huang
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Fan Zeng
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Bing Zhang
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Chao-Feng Chen
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Hong-Juan Qin
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Lian-Sheng Wu
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Gui-Yin Guo
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
| | - Li-Tao Yang
- Suzhou Nuclear Power Research Institute, CGNPG, 215004, PR China.
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19
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Kim SB, Baglan N, Davis PA. Current understanding of organically bound tritium (OBT) in the environment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2013; 126:83-91. [PMID: 23962797 DOI: 10.1016/j.jenvrad.2013.07.011] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 06/02/2023]
Abstract
It has become increasingly recognized that organically bound tritium (OBT) is the more significant tritium fraction with respect to understanding tritium behaviour in the environment. There are many different terms associated with OBT; such as total OBT, exchangeable OBT, non-exchangeable OBT, soluble OBT, insoluble OBT, tritiated organics, and buried tritium, etc. A simple classification is required to clarify understanding within the tritium research community. Unlike for tritiated water (HTO), the environmental quantification and behaviour of OBT are not well known. Tritiated water cannot bio-accumulate in the environment. However, it is not clear whether or not this is the case for OBT. Even though OBT can be detected in terrestrial biological materials, aquatic biological materials and soil samples, its behaviour is still in question. In order to evaluate the radiation dose from OBT accurately, further study will be required to understand OBT measurements and determine OBT fate in the environment. The relationship between OBT speciation and the OBT/HTO ratio in environmental samples will be useful in this regard, providing information on the previous tritium exposure conditions in the environment and the current tritium dynamics.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Nuclear Science Division, Chalk River Laboratories, AECL, Canada
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