1
|
Simon SL, Bouville A, Hoffman FO, Anspaugh LR. Why do we study science and collaborate? Thoughts on present-day cooperations with scientists of Russia. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2024; 44:034501. [PMID: 38958214 DOI: 10.1088/1361-6498/ad5b68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/25/2024] [Indexed: 07/04/2024]
Affiliation(s)
- Steven L Simon
- National Cancer Institute, Bethesda, MD, United States of America
| | - André Bouville
- National Cancer Institute, Bethesda, MD, United States of America
| | - F Owen Hoffman
- Oak Ridge Center for Risk Analysis, Oak Ridge, TN, United States of America
| | - Lynn R Anspaugh
- University of Utah, Salt Lake City, UT, United States of America
| |
Collapse
|
2
|
Mawassy Z, Henner P, Avellan A, Rose J. Comprehensive framework for overcoming scientific challenges related to assessing radioactive ultra-fine (nano/micro) particles transfer at the atmosphere-leaf interface. JOURNAL OF HAZARDOUS MATERIALS 2024; 467:133346. [PMID: 38320349 DOI: 10.1016/j.jhazmat.2023.133346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 12/07/2023] [Accepted: 12/20/2023] [Indexed: 02/08/2024]
Abstract
Food products are prone into contamination after a nuclear emission of radionuclides. While the mechanisms of emission and deposition of ultrafine radioactive particles are well documented, the transfer of these species from the atmosphere into plants is poorly assessed. This is evident in the lack of quantification of particles distributed within plants, especially regarding particles physical-chemical criteria to plant of different properties. Such knowledge gaps raise the concern about the representativeness of risk assessment tools designed for the transfer evaluation of ionic/soluble species to be qualified for simulating insoluble species exposure and proposes a possible underestimation. This highlights the possible need for special particle codes development to be implemented in models for future emissions. In addition, the later tools utilize transfer factors aggregating relevant sub-processes, suggesting another weak point in their overall reliability. As researchers specialized in the nuclear safety and protection, we intend in this perspective, to develop a compressive analysis of the interaction of ultrafine particles with plants of different specificities at different level processes starting from particles retention and gradual translocation to sink organs. This analysis is leveraged in providing insights for possible improvements in the current modeling tools for better real-life scenarios representation.
Collapse
Affiliation(s)
- Zeinab Mawassy
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SPDR/LT2S, F-13115 Saint-Paul-lez-Durance, France.
| | - Pascale Henner
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SPDR/LT2S, F-13115 Saint-Paul-lez-Durance, France.
| | - Astrid Avellan
- Géosciences Environnement Toulouse - CNRS-CNES-IRD-Université Toulouse III Observatoire Midi-Pyrénées, 14 av. Edouard Belin, 31400 Toulouse, France
| | - Jerome Rose
- CNRS, Aix-Marseille Université (AMU), iRD, INRAE, OSU Pytheas, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4, France
| |
Collapse
|
3
|
Kaminski MD, Daiyega N, Magnuson M. A Review of the Resuspension of Radioactively Contaminated Particles by Vehicle and Pedestrian Traffic-Current Theory, Practice, Gaps, and Needs. HEALTH PHYSICS 2024; 126:216-240. [PMID: 38381971 DOI: 10.1097/hp.0000000000001797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
ABSTRACT The resuspension of radioactively contaminated particles in a built environment, such as from urban surfaces like foliage, building exteriors, and roadways, is described empirically by current plume and dosimetry models used for hazard assessment and long-term risk purposes. When applying these models to radiological contamination emergencies affecting urban areas, the accuracy of the results for recent contamination deposition is impacted in two main ways. First, the data supporting the underlying resuspension equations was acquired for open, quiescent conditions with no vehicle traffic or human activities, so it is not necessarily representative of the urban environment. Second, mechanical disturbance by winds in urban canyons and during emergency operations caused by vehicle traffic and human activities are not directly considered by the equations. Accordingly, plume and dosimetry models allow the user to input certain compensating values, but the models do not necessarily supply users instructions on what values to use. This manuscript reviews the available literature to comprehensively and consistently pool data for resuspension due to mechanically induced resuspension applicable to urban contamination. Because there are few studies that directly measured radioactive resuspension due to vehicles and pedestrians, this review novelly draws on a range of other studies involving non-radioactive particles, ranging from outdoor air pollution emissions to indoor allergen transport. The results lead to tabulated, recommended values for specific conditions in the emergency phase to help users of plume and dosimetry models maintain the conservativeness needed to properly capture the potential radiation dose posed by mechanically induced resuspension. These values are of benefit to model users until better data are available. The results also suggest the types of data that may result in improved plume and dose modeling.
Collapse
Affiliation(s)
| | - Nico Daiyega
- Department of Physics, University of Illinois, Urbana-Champaign
| | - Matthew Magnuson
- US Environmental Protection Agency, Office of Research and Development/Center for Environmental Solutions and Emergency Response/Homeland Security and Materials Management Division
| |
Collapse
|
4
|
Anderson D, Kato H, Onda Y. Mode of Atmospheric Deposition in Forests Demonstrates Notable Differences in Initial Radiocesium Behavior. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15541-15551. [PMID: 36239269 DOI: 10.1021/acs.est.2c03451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The March 2011 Fukushima Dai-ichi Nuclear Power Plant accident in Japan released 520 PBq of radionuclides compared to a total release of 5300 PBq from the Chornobyl Nuclear Power Plant accident. Both nuclear accidents resulted in deposition of radiocesium throughout the northern hemisphere, and a plethora of studies have been performed regarding radiocesium (137Cs) behavior. However, few studies have assessed the impact of precipitation on 137Cs deposition in forests. Wide-scale environmental measurements from 2011 and 2016 were used to determine the differences in 137Cs deposition because of precipitation following the Fukushima accident. In areas where wet deposition processes were dominant, dense forests generally had lower ambient dose rates and levels of contamination on forest floors than other stands with fewer stems per hectare in 2011. Similar tendencies were not observed in areas that were primarily subject to dry deposition nor were any trends observed in 2016. 137Cs was retained in dense forest canopies for an extended period regardless of the deposition mode. Additionally, it was found that the initial retention of radionuclides by forest canopies is in general higher for areas with predominantly dry deposition. Incorporation of radiocesium into wood tissues was the same for both wet and dry deposition.
Collapse
Affiliation(s)
- Donovan Anderson
- Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki City 036-8564, Japan
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba City 305-8577, Japan
| | - Hiroaki Kato
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba City 305-8577, Japan
| | - Yuichi Onda
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba City 305-8577, Japan
| |
Collapse
|
5
|
Ulsh B. Response to Letters from Andrews and Tans, Edwards, and Musolino commenting on Skrable et al.-"World Atmospheric CO2, Its 14C Specific Activity, Non-fossil Component, Anthropogenic Fossil Component, and Emissions (1750-2018)". HEALTH PHYSICS 2022; 122:721-722. [PMID: 35486936 DOI: 10.1097/hp.0000000000001573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- Brant Ulsh
- Health Physics Editor-In-Chief (513) 805-3445
| |
Collapse
|
6
|
Anspaugh LR, Bouville A, Thiessen KM, Hoffman FO, Beck HL, Gordeev KI, Simon SL. A Methodology for Calculation of Internal Dose Following Exposure to Radioactive Fallout from the Detonation of a Nuclear Fission Device. HEALTH PHYSICS 2022; 122:84-124. [PMID: 34898517 PMCID: PMC8677618 DOI: 10.1097/hp.0000000000001503] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
ABSTRACT The purpose of this paper is to provide a methodology for the calculation of internal doses of radiation following exposure to radioactive fallout from the detonation of a nuclear fission device. Reliance is on methodology previously published in the open literature or in reports not readily available, though some new analysis is also included. Herein, we present two methodologic variations: one simpler to implement, the other more difficult but more flexible. The intention is to provide in one place a comprehensive methodology. Pathways considered are (1) the ingestion of vegetables and fruits contaminated by fallout directly, (2) the ingestion of vegetables and fruits contaminated by continuing deposition by rain- or irrigation-splash and resuspension, (3) the ingestion of vegetables and fruits contaminated by absorption of radionuclides by roots after tillage of soil, (4) the non-equilibrium transfer of short-lived radionuclides through the cow-milk and goat-milk food chains, (5) the equilibrium transfer of long lived radionuclides through milk and meat food chains, and (6) inhalation of descending fallout. Uncertainty in calculated results is considered. This is one of six companion papers that describe a comprehensive methodology for assessing both external and internal dose following exposures to fallout from a nuclear detonation. Input required to implement the dose-estimation model for any particular location consists of an estimate of the post-detonation external gamma-exposure rate and an estimate of the time of arrival of the fallout cloud. The additional data required to make such calculations are included in the six companion papers.
Collapse
Affiliation(s)
- Lynn R. Anspaugh
- Department of Radiology, University of Utah, Emeritus, Henderson, NV
| | | | | | | | | | | | | |
Collapse
|
7
|
Bouville A, Beck HL, Thiessen KM, Hoffman FO, Potischman N, Simon SL. The Methodology Used to Assess Doses from the First Nuclear Weapons Test (Trinity) to the Populations of New Mexico. HEALTH PHYSICS 2020; 119:400-427. [PMID: 32881739 PMCID: PMC7497484 DOI: 10.1097/hp.0000000000001331] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/17/2020] [Indexed: 05/21/2023]
Abstract
Trinity was the first test of a nuclear fission device. The test took place in south-central New Mexico at the Alamogordo Bombing and Gunnery Range at 05:29 AM on 16 July 1945. This article provides detailed information on the methods that were used in this work to estimate the radiation doses that were received by the population that resided in New Mexico in 1945. The 721 voting precincts of New Mexico were classified according to ecozone (plains, mountains, or mixture of plains and mountains), and size of resident population (urban or rural). Methods were developed to prepare estimates of absorbed doses from a range of 63 radionuclides to five organs or tissues (thyroid, active marrow, stomach, colon, and lung) for representative individuals of each voting precinct selected according to ethnicity (Hispanic, White, Native American, and African American) and age group in 1945 (in utero, newborn, 1-2 y, 3-7 y, 8-12 y, 13-17 y, and adult). Three pathways of human exposure were included: (1) external irradiation from the radionuclides deposited on the ground; (2) inhalation of radionuclide-contaminated air during the passage of the radioactive cloud and, thereafter, of radionuclides transferred (resuspended) from soil to air; and (3) ingestion of contaminated water and foodstuffs. Within the ingestion pathway, 13 types of foods and sources of water were considered. Well established models were used for estimation of doses resulting from the three pathways using parameter values developed from extensive literature review. Because previous experience and calculations have shown that the annual dose delivered during the year following a nuclear test is much greater than the doses received in the years after that first year, the time period that was considered is limited to the first year following the day of the test (16 July 1945). Numerical estimates of absorbed doses, based on the methods described in this article, are presented in a separate article in this issue.
Collapse
|
8
|
Cochran LD, Eckert AC, Hunt B, Kraus T. Uncertainty Analysis of Consequence Management Data Products. HEALTH PHYSICS 2020; 118:382-395. [PMID: 31985513 DOI: 10.1097/hp.0000000000001133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An interlaboratory effort has developed a probabilistic framework to characterize uncertainty in data products that are developed by the US Department of Energy Consequence Management Program in support of the Federal Radiological Monitoring and Assessment Center. The purpose of this paper is to provide an overview of the probability distributions of input variables and the statistical methods used to propagate and quantify the overall uncertainty of the derived response levels that are used as contours on data products due to the uncertainty in input parameters. Uncertainty analysis results are also presented for several study scenarios. This paper includes an example data product to illustrate the potential real-world implications of incorporating uncertainty analysis results into data products that inform protective action decisions. Data product contours that indicate areas where public protection actions may be warranted can be customized to an acceptable level of uncertainty. The investigators seek feedback from decision makers and the radiological emergency response community to determine how uncertainty information can be used to support the protective action decision-making process and how it can be presented on data products.
Collapse
|
9
|
Bouville A. Fallout from Nuclear Weapons Tests: Environmental, Health, Political, and Sociological Considerations. HEALTH PHYSICS 2020; 118:360-381. [PMID: 32118680 DOI: 10.1097/hp.0000000000001237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The process of nuclear fission, which was discovered in 1938, opened the door to the production of nuclear weapons, which were used in 1945 by the United States against Japan in World War II, and to the detonation of >500 nuclear weapons tests in the atmosphere by the United States, the former Soviet Union, the United Kingdom, China, and France from 1946-1980. Hundreds of radionuclides, most of them short-lived, were produced in the atmospheric tests. The radioactive clouds produced by the explosions were usually partitioned between the troposphere and the stratosphere: the activity that remained in the troposphere resulted in local and regional fallout, consisting mainly of short-lived radionuclides and in relatively high doses for the populations residing in the vicinity of the test site, whereas the activity that reached the stratosphere returned to the ground with a half-life of ~1 y and was composed of long-lived radionuclides that contaminated all uncovered materials on Earth to a small extent and led to low-level irradiation of the world population for decades or more. The health effects resulting from exposure to radioactive fallout constitute, in most cases, small excesses over baseline rates for thyroid cancer and leukemia. An extra 49,000 cases of thyroid cancer would be expected to occur among the US population from exposure to radioactive fallout from the atmospheric nuclear weapons tests that were conducted at the Nevada Test Site in the 1950s. In addition, there could be as many as 11,000 deaths from non-thyroid cancers related to fallout from all atmospheric tests that were conducted at all sites in the world, with leukemia making up 10% of the total. Public concern arose in part from the secrecy that surrounded the nuclear testing programs and, for a long time, the poor communication regarding the consequences of the tests, both in terms of radiation doses and of health effects. Sociological and political pressures contributed to the establishment of programs of compensation for radiation exposures and evidence of radiation-induced diseases in countries that incurred significant fallout from nuclear weapons testing.
Collapse
Affiliation(s)
- André Bouville
- National Cancer Institute, National Institutes of Health, Bethesda, MD (retired)
| |
Collapse
|
10
|
Kato H, Onda Y, Gao X, Sanada Y, Saito K. Reconstruction of a Fukushima accident-derived radiocesium fallout map for environmental transfer studies. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 210:105996. [PMID: 31262609 DOI: 10.1016/j.jenvrad.2019.105996] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/05/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
Ascertaining the initial amount of accidently released radiocesium is fundamental for determining the extent of radioactive contamination following nuclear accidents, and is of key importance to environmental transfer models. A series of the airborne monitoring surveys of radioactivity have conducted by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), and provide basic information on radioactive contamination following the accident. However, there are no clear guidelines regarding the selection of airborne monitoring survey results for estimating the initial fallout input in studies of the environmental transfer of radiocesium. This study reconstructed a fallout map of Fukushima accident-derived radiocesium based on a comparison of the radiocesium deposition densities (Dl) derived from the third and fifth airborne monitoring surveys. The Dl derived from the fifth airborne monitoring survey were adjusted for variation in the measured radioactivity associated with the influence of radioactive decay, natural weathering processes, variation in the calibration procedure, and other, undefined mechanisms. The calibrated deposition density of the fifth airborne monitoring survey for each land use type (A'5th*l) were used to establish the initial fallout map in the East Japan area. Furthermore, the airborne monitoring surveys which were independently conducted in each prefecture area were used to complement the lack of data in the South Kanto region and the mountainous area in the North Kanto region due to snow cover during the measurement period of the fifth airborne monitoring survey. The reconstructed initial fallout map of the Fukushima accident derived 137Cs was opened to the public via the database of the Center for Research in Isotopes of Environmental Dynamics, University of Tsukuba, Japan (www.ied.tsukuba.ac.jp/∼fukushimafallout/). Finally, the total atmospheric deposition of Fukushima Dai-ichi Nuclear Power Plant accident-derived radiocesium onto each prefecture and land uses was estimated based on the reconstructed map in this study.
Collapse
Affiliation(s)
- Hiroaki Kato
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki, 305-0006, Japan.
| | - Yuichi Onda
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki, 305-0006, Japan
| | - Xiang Gao
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki, 305-0006, Japan
| | - Yukihisa Sanada
- Fukushima Remote Monitoring Group, Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Minami-soma, Fukushima, 975-0036, Japan
| | - Kimiaki Saito
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Chiyoda-ku, Tokyo, 100-8577, Japan
| |
Collapse
|
11
|
Marshall S, Potter C, Medich D. Reassessment of Resuspension Factor Following Radionuclide Dispersal: Toward a General-purpose Rate Constant. HEALTH PHYSICS 2018; 114:500-506. [PMID: 29578898 DOI: 10.1097/hp.0000000000000802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A recent analysis of historical radionuclide resuspension datasets confirmed the general applicability of the Anspaugh and modified Anspaugh models of resuspension factors following both controlled and disastrous releases. While observations appear to have larger variance earlier in time, previous studies equally weighted the data for statistical fit calculations; this could induce a positive skewing of resuspension coefficients in the early time-period. A refitting is performed using a relative instrumental weighting of the observations. Measurements within a 3-d window are grouped into singular sample sets to construct standard deviations. The resulting best-fit equations produce tamer exponentials, which give decreased integrated resuspension factor values relative to those reported by Anspaugh. As expected, the fits attenuate greater error among the data at earlier time. The reevaluation provides a sharper contrast between the empirical models and reaffirms their deficiencies in the short-lived timeframe wherein the dynamics of particulate dispersion dominate the resuspension process.
Collapse
|
12
|
Gärdenäs AI, Berglund SL, Bengtsson SB, Rosén K. The grain storage of wet-deposited caesium and strontium by spring wheat - A modelling study based on a field experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 574:1313-1325. [PMID: 27639782 DOI: 10.1016/j.scitotenv.2016.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 06/06/2023]
Abstract
The aims of this study were to extend the Tracey model in order to quantify and to analyse spring wheat's grain storage dynamics of wet-deposited radionuclides. Tracey, a dynamic model of trace element cycling in terrestrial ecosystems, was extended with descriptions of wet-deposition, interception, foliar uptake and radioactive decay. Radionuclide fluxes were set proportional to corresponding water or carbon fluxes, simulated with CoupModel. The extended Tracey was calibrated against experimental data, where 134Cs and 85Sr were deposited on spring wheat at six growth stages in 2010 and 2011. Sensitivities of grain storage to wheat's and radionuclide properties were assessed, using the Eikos software, by 1000 Monte Carlo simulations for each of the 48 scenarios (combination of 2 radionuclides, 1 foliar uptake, 2 root uptake approaches, 6 deposition treatments and 2years). Simulations were accepted if simulated grain storage values were within 95% confidence intervals (CI) of measurements. We found that 15% of 134Cs and 85Sr simulations for 2011, and 6% of the 2010 simulations met the CI-criterion. Foliar uptake accounted for 99% and 90% of total plant uptake of 134Cs and 85Sr, respectively. Mean simulated grain storage at harvest increased with lateness of deposition, as the stored proportion of radionuclide deposited was 0.02% when deposition was before flowering, 2% between flowering and ripening, and 5% (2010) or 10% (2011, late harvest) after ripening, respectively. Similarly, the property that governed grain storage depended on the growth stage at time of deposition; stem and leaf fixation rates (deposition before flowering), grain fixation rates (between flowering and ripening) and grains' interception capacity (after ripening). We conclude that grains' interception capacities can be used to predict grain storage of radionuclides deposited in the riskiest period, i.e. close to harvest.
Collapse
Affiliation(s)
- Annemieke I Gärdenäs
- Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-75007 Uppsala, Sweden.
| | - S Linnea Berglund
- Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-75007 Uppsala, Sweden
| | - Stefan B Bengtsson
- Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-75007 Uppsala, Sweden
| | - Klas Rosén
- Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-75007 Uppsala, Sweden
| |
Collapse
|
13
|
Ota M, Nagai H, Koarashi J. Modeling dynamics of (137)Cs in forest surface environments: Application to a contaminated forest site near Fukushima and assessment of potential impacts of soil organic matter interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:590-604. [PMID: 26897402 DOI: 10.1016/j.scitotenv.2016.02.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/09/2016] [Accepted: 02/09/2016] [Indexed: 06/05/2023]
Abstract
A process-based model for (137)Cs transfer in forest surface environments was developed to assess the dynamic behavior of Fukushima-derived (137)Cs in a Japanese forest. The model simulation successfully reproduced the observed data from 3year migration of (137)Cs in the organic and mineral soil layers at a contaminated forest near Fukushima. The migration of (137)Cs from the organic layer to the mineral soil was explained by the direct deposition pattern on the forest floor and the turnover of litter materials in the organic layer under certain ecological conditions. Long-term predictions indicated that more than 90% of the deposited (137)Cs would remain within the top 5cm of the soil for up to 30years after the accident, suggesting that the forest acts as an effective long-term reservoir of (137)Cs with limited transfer via the groundwater pathway. The model was also used to explore the potential impacts of soil organic matter (SOM) interactions on the mobility and bioavailability of (137)Cs in the soil-plant system. The simulation results for hypothetical organic soils with modified parameters of (137)Cs turnover revealed that the SOM-induced reduction of (137)Cs adsorption elevates the fraction of dissolved (137)Cs in the soil solution, thereby increasing the soil-to-plant transfer of (137)Cs without substantially altering the fractional distribution of (137)Cs in the soil. Slower fixation of (137)Cs on the flayed edge site of clay minerals and enhanced mobilization of the clay-fixed (137)Cs in organic-rich soils also appeared to elevate the soil-to-plant transfer of (137)Cs by increasing the fraction of the soil-adsorbed (exchangeable) (137)Cs. A substantial proportion (approximate 30%-60%) of (137)Cs in these organic-rich soils was transferred to layers deeper than 5cm decades later. These results suggested that SOM influences the behavior of (137)Cs in forests over a prolonged period through alterations of adsorption and fixation in the soil.
Collapse
Affiliation(s)
- Masakazu Ota
- Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
| | - Haruyasu Nagai
- Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Jun Koarashi
- Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| |
Collapse
|
14
|
Rosén K, Vinichuk M. Interception and transfer of wet-deposited (134)Cs to potato foliage and tubers. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 151 Pt 1:224-232. [PMID: 26519923 DOI: 10.1016/j.jenvrad.2015.10.015] [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: 07/03/2015] [Revised: 10/09/2015] [Accepted: 10/16/2015] [Indexed: 06/05/2023]
Abstract
Contamination levels on potato foliage and tubers were investigated by repeated sampling after multiple foliar contaminations of wet-deposited (134)Cs at five different growth stages in a micro-plot field experiment in three successive years. Application of the radionuclide early in the growing season (deposition date 19-27 June, growth stage II = plant establishment) resulted in low (134)Cs activity concentration in potato tubers across sampling occasions (mean 60, 25 and 115 Bq kg(-1) dry weight (D.W.) for years 1, 2 and 3, respectively). Following radionuclide deposition in the middle of the growing season (15-24 July, growth stage III = tuber initiation), (134)Cs activity concentration in tubers across sampling occasions was found to be highest (mean 150, 850 and 660 Bq kg(-1) D.W. for years 1, 2 and 3, respectively). When the radionuclide was sprayed on at later stages (5-7 August, growth stage IV = tuber bulking), (134)Cs activity concentrations in tubers across sampling dates decreased (mean 75, 310 and 395 Bq kg(-1) D.W. for years 1, 2 and 3, respectively). Deposition in the second half of August (15-28 August, late growth stage IV and beginning of growth stage V = tuber maturation) resulted in yet lower (134)Cs activity concentration in tubers. Potato tubers may concentrate as much as up to 2 times more (134)Cs than foliage depending on deposition date of radionuclide.
Collapse
Affiliation(s)
- K Rosén
- Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, Box 7014, SE-75007, Uppsala, Sweden
| | - M Vinichuk
- Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Str., 10005, Zhytomyr, Ukraine.
| |
Collapse
|
15
|
Satoh D, Furuta T, Takahashi F, Endo A, Lee C, Bolch WE. Age-dependent dose conversion coefficients for external exposure to radioactive cesium in soil. J NUCL SCI TECHNOL 2015. [DOI: 10.1080/00223131.2015.1021286] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Iurian AR, Dercon G, Adu-Gyamfi J, Mabit L, Kis-Benedek G, Ceccatelli A, Tarjan S, Blake W. The interception and wash-off fraction of 7Be by bean plants in the context of its use as a soil radiotracer. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-3948-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
17
|
Perera S, Waller E, Akhtar A. Experimental Modeling of Wind-Driven Bin-by-Bin Resuspension Factors of Freshly Fallen Radionuclides After an Energetic Release From a Radiological Dispersal Device. JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2015. [DOI: 10.1115/1.4026390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Small-scale experiments were carried out to characterize the resuspension factor of radioactive lanthanum oxide powder in an environmentally controlled wind tunnel, with the majority using particle sizes less than 10 μm in order to assess the impact of wind resuspension stresses and surface roughness conditions on resuspension. Operational principles of the measuring devices used in the radionuclide resuspension experiments and corresponding uncertainties are discussed. The average bin-by-bin particle resuspension factors (ki) for particle sizes, in the range of 0.25–7.00 μm and 7.00–12.5 μm for downwind fallout locations, were calculated and are reported here as 1.14×10−3 1/m and 4.39×10−2 1/m, respectively.
Collapse
Affiliation(s)
- Sharman Perera
- University of Ontario Institute of Technology, ERC 4027, 2000 Simcoe St. N., L1H 7K4 Oshawa, ON, Canada e-mail:
| | - Edward Waller
- University of Ontario Institute of Technology, ERC 4063, 2000 Simcoe St. N., L1H 7K4 Oshawa, ON, Canada e-mail:
| | - Ali Akhtar
- University of Ontario Institute of Technology, FESNS, ERC 3092, 2000 Simcoe St. N., L1H 7K4 Oshawa, ON, Canada e-mail:
| |
Collapse
|
18
|
On peculiarities of vertical distribution of 239,240Pu, 238Pu and 137Cs activity concentrations and their ratios in lake sediments and soils. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3026-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
19
|
Stone MB, Stanford JB, Lyon JL, VanDerslice JA, Alder SC. Childhood thyroid radioiodine exposure and subsequent infertility in the intermountain fallout cohort. ENVIRONMENTAL HEALTH PERSPECTIVES 2013; 121:79-84. [PMID: 23099433 PMCID: PMC3553427 DOI: 10.1289/ehp.1104231] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/24/2012] [Indexed: 05/15/2023]
Abstract
BACKGROUND Above-ground and underground nuclear weapon detonation at the Nevada Test Site (1951-1992) has resulted in radioiodine exposure for nearby populations. Although the long-term effect of environmental radioiodine exposure on thyroid disease has been well studied, little is known regarding the effect of childhood radioiodine exposure on subsequent fertility. OBJECTIVES We investigated early childhood thyroid radiation exposure from nuclear testing fallout (supplied predominantly by radioactive isotopes of iodine) and self-reported lifetime incidence of male or female infertility or sterility. METHODS Participants were members of the 1965 Intermountain Fallout Cohort, schoolchildren at the time of exposure who were reexamined during two subsequent study phases to collect dietary and reproductive histories. Thyroid radiation exposure was calculated via an updated dosimetry model. We used multivariable logistic regression with robust sandwich estimators to estimate odds ratios for infertility, adjusted for potential confounders and (in separate models) for a medically confirmed history of thyroid disease. RESULTS Of 1,389 participants with dosimetry and known fertility history, 274 were classified as infertile, including 30 classified as sterile. Childhood thyroid radiation dose was possibly associated with infertility [adjusted odds ratio (AOR) = 1.17; 95% CI: 0.82, 1.67 and AOR = 1.35; 95% CI: 0.96, 1.90 for the middle and upper tertiles vs. the first tertile of exposure, respectively]. The odds ratios were attenuated (AOR = 1.08; 95% CI: 0.75, 1.55 and AOR = 1.29; 95% CI: 0.91, 1.83 for the middle and upper tertiles, respectively) after adjusting for thyroid disease. There was no association of childhood radiation dose and sterility. CONCLUSION Our findings suggest that childhood radioiodine exposure from nuclear testing may be related to subsequent adult infertility. Further research is required to confirm this.
Collapse
Affiliation(s)
- Mary Bishop Stone
- University of Utah Department of Family and Preventive Medicine, Salt Lake City, Utah 84108, USA
| | | | | | | | | |
Collapse
|
20
|
Siirila ER, Maxwell RM. A new perspective on human health risk assessment: development of a time dependent methodology and the effect of varying exposure durations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 431:221-232. [PMID: 22684123 DOI: 10.1016/j.scitotenv.2012.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/09/2012] [Accepted: 05/09/2012] [Indexed: 06/01/2023]
Abstract
We present a new Time Dependent Risk Assessment (TDRA) that stochastically considers how joint uncertainty and inter-individual variability (JUV) associated with human health risk change as a function of time. In contrast to traditional, time independent assessments of risk, this new formulation relays information on when the risk occurs, how long the duration of risk is, and how risk changes with time. Because the true exposure duration (ED) is often uncertain in a risk assessment, we also investigate how varying the magnitude of fixed size durations (ranging between 5 and 70 years) of this parameter affects the distribution of risk in both the time independent and dependent methodologies. To illustrate this new formulation and to investigate these mechanisms for sensitivity, an example of arsenic contaminated groundwater is used in conjunction with two scenarios of different environmental concentration signals resulting from rate dependencies in geochemical reactions. Cancer risk is computed and compared using environmental concentration ensembles modeled with sorption as 1) a linear equilibrium assumption (LEA) and 2) first order kinetics (Kin). Results show that the information attained in the new time dependent methodology reveals how the uncertainty in other time-dependent processes in the risk assessment may influence the uncertainty in risk. We also show that individual susceptibility also affects how risk changes in time, information that would otherwise be lost in the traditional, time independent methodology. These results are especially pertinent for forecasting risk in time, and for risk managers who are assessing the uncertainty of risk.
Collapse
Affiliation(s)
- Erica R Siirila
- Hydrologic Science and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401, USA.
| | | |
Collapse
|
21
|
Abstract
A complete, historical dataset is presented of radionuclide resuspension-factors. These data span six orders of magnitude in time (ranging from 0.1 to 73,000 d), encompass more than 300 individual values, and combine observations from events on three continents. These data were then used to derive improved, empirical models that can be used to predict resuspension of trace materials after their deposit on the ground. Data-fitting techniques were used to derive models of various types and an estimate of uncertainty in model prediction. Two models were found to be suitable: a power law and the modified Anspaugh et al. model, which is a double exponential. Though statistically the power-law model provides the best metrics of fit, the modified Anspaugh model is deemed the more appropriate due to its better fit to data at early times and its ease of implementation in terms of closed analytical integrals.
Collapse
Affiliation(s)
- Reed M Maxwell
- Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO 80401, USA.
| | | |
Collapse
|
22
|
Baldacci AE, Gattavecchia E, Kirchner G. Observations and modelling of thoron and its progeny in the soil-atmosphere-plant system. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2010; 101:992-1001. [PMID: 20727629 DOI: 10.1016/j.jenvrad.2010.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/29/2010] [Accepted: 07/29/2010] [Indexed: 05/29/2023]
Abstract
Samples of pasture vegetation, mainly Trifolium pratensis, were collected at the Botanic Garden of the University of Bologna during the period 1998-2000 and measured by gamma-spectrometry for determining thoron progeny. Concentrations of (212)Pb were between 1.5 and 20 Bq m(-2), with individual peaks up to 70 Bq m(-2). Soil samples were collected at the same location and physically characterised. Their chemical composition (particularly Th and U) was determined by X-ray fluorescence spectroscopy. Lead-212 on plants mainly originates from dry and wet deposition of this isotope generated in the lower atmosphere by the decay of its short-lived precursor (220)Rn, which is produced in the upper soil layers as a member of the natural thorium decay chain and exhales into the atmosphere. Concentrations of (220)Rn in the atmosphere depend on (1) the amount of Th present in soil, (2) the radon fraction which escapes from the soil minerals into the soil pore space, (3) its transport into the atmosphere, and (4) its redistribution within the atmosphere. The mobility of radon in soil pore space can vary by orders of magnitude depending on the soil water content, thus being the main factor for varying concentrations of (220)Rn and (212)Pb in the atmosphere. We present a simple model to predict concentrations of thoron in air and its progeny deposited from the atmosphere, which takes into account varying soil moisture contents calculated by the OPUS code. Results of this model show close agreement with our observations.
Collapse
Affiliation(s)
- A E Baldacci
- UCI-SCRM, University of Bologna, Via S. Donato 15, Bologna, Italy
| | | | | |
Collapse
|
23
|
Layton DW, Beamer PI. Migration of contaminated soil and airborne particulates to indoor dust. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:8199-205. [PMID: 19924944 PMCID: PMC2782798 DOI: 10.1021/es9003735] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, were used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase-out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust.
Collapse
Affiliation(s)
| | - Paloma I. Beamer
- CORRESPONDING AUTHOR FOOTNOTE: 1295 N. Martin Ave, PO Box 245210, Tucson, AZ 85724, TELEPHONE (520) 626-0006, FAX (520) 626-8009,
| |
Collapse
|
24
|
Pröhl G. Interception of dry and wet deposited radionuclides by vegetation. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2009; 100:675-682. [PMID: 19027204 DOI: 10.1016/j.jenvrad.2008.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 10/07/2008] [Accepted: 10/07/2008] [Indexed: 05/27/2023]
Abstract
Interception of dry and wet deposited radionuclides by vegetation is a key process in radioecological models that assess ingestion doses to the population following releases of radionuclides to the atmosphere. Radionuclides may be deposited during precipitation or as dry particles. Interception of wet deposited radionuclides is the result of a complex interaction of the vegetative development of the plant canopy, the amount of rainfall, and the chemical form of radionuclides. For the interception of dry deposits, particle size is a key parameter; interception is more effective for small particles and reactive gases. Due to the dependence on plant development, interception of both dry and wet deposits is subject to pronounced seasonality.
Collapse
Affiliation(s)
- Gerhard Pröhl
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Neuherberg, Germany.
| |
Collapse
|
25
|
Benke RR, Hooper DM, Durham JS, Bannon DR, Compton KL, Necsoiu M, McGinnis RN. Measurement of airborne particle concentrations near the Sunset Crater volcano, Arizona. HEALTH PHYSICS 2009; 96:97-117. [PMID: 19131732 DOI: 10.1097/01.hp.0000326447.78879.bf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Direct measurements of airborne particle mass concentrations or mass loads are often used to estimate health effects from the inhalation of resuspended contaminated soil. Airborne particle mass concentrations were measured using a personal sampler under a variety of surface-disturbing activities within different depositional environments at both volcanic and nonvolcanic sites near the Sunset Crater volcano in northern Arizona. Focused field investigations were performed at this analog site to improve the understanding of natural and human-induced processes at Yucca Mountain, Nevada. The level of surface-disturbing activity was found to be the most influential factor affecting the measured airborne particle concentrations, which increased over three orders of magnitude relative to ambient conditions. As the surface-disturbing activity level increased, the particle size distribution and the majority of airborne particle mass shifted from particles with aerodynamic diameters less than 10 mum (0.00039 in) to particles with aerodynamic diameters greater than 10 mum (0.00039 in). Under ambient conditions, above average wind speeds tended to increase airborne particle concentrations. In contrast, stronger winds tended to decrease airborne particle concentrations in the breathing zone during light and heavy surface-disturbing conditions. A slight increase in the average airborne particle concentration during ambient conditions was found above older nonvolcanic deposits, which tended to be finer grained than the Sunset Crater tephra deposits. An increased airborne particle concentration was realized when walking on an extremely fine-grained deposit, but the sensitivity of airborne particle concentrations to the resuspendible fraction of near-surface grain mass was not conclusive in the field setting when human activities disturbed the bulk of near-surface material. Although the limited sample size precluded detailed statistical analysis, the differences in airborne particle concentration over 900-y weathered volcanic and nonvolcanic deposits appeared to be potentially significant only under heavy surface disturbances.
Collapse
Affiliation(s)
- Roland R Benke
- Center for Nuclear Waste Regulatory Analyses, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166, USA.
| | | | | | | | | | | | | |
Collapse
|
26
|
Smith MA, Larsen IL, Fentiman AW. Fate of 60Co at a sludge land application site. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2008; 99:1611-1616. [PMID: 18649975 DOI: 10.1016/j.jenvrad.2008.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 06/04/2008] [Accepted: 06/09/2008] [Indexed: 05/26/2023]
Abstract
Vertical distributions of 60Co are determined in soil cores obtained from a 10-ha grassland, where anaerobically digested sludge was applied by surface spraying from 1986 to 1995 on the U.S. Department of Energy's Oak Ridge Reservation. These results, along with historical application records, are used to estimate vertical-migration rates and perform a mass balance. The presence of 60Co results solely from the sludge-application process. Soil, vegetation, and surface-water samples were collected. Eleven soil cores were sectioned into 3-cm increments and analyzed by gamma-ray spectrometry. No 60Co was detected in the vegetation or water samples. The downward migration rate of 60Co in the upper 15 cm of soil ranged from 0.50 to 0.73 cm/yr. About 98%, 0.020+/-0.011 Bq/cm2, of 60Co remained in the upper 15 cm of soil, which compared favorably with the expected 60Co activity based on historical records of 0.019+/-0.010 Bq/cm2.
Collapse
Affiliation(s)
- Michael A Smith
- Environmental Science Graduate Program, Ohio State University, Columbus, OH 43210, USA.
| | | | | |
Collapse
|
27
|
Weesner AP, Fairchild RW. Concentration of (137)Cs in soil across Nebraska. HEALTH PHYSICS 2008; 94:574-580. [PMID: 18469591 DOI: 10.1097/01.hp.0000308504.04309.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Atmospheric nuclear weapons testing from 1945 through 1980 produced radioactive fallout that was transported by stratospheric winds and deposited unevenly around the world. The accident at Chernobyl in 1986 also contributed to the fallout in some locations. The (137)Cs activity concentration from fallout has been measured as a function of depth in soil samples from five different locations across Nebraska. Soil samples 2-cm thick down to a depth of 30 cm were collected in Brown, Dawes, Lancaster, Red Willow, and Thurston Counties. Samples taken from each of the sites were dried, sieved, and counted using an HPGe gamma spectroscopy system to measure the activity concentration of (137)Cs at each depth in the soil. Activity concentrations as high as 216 Bq kg(-1) were measured in the samples. Dry soil bulk densities were calculated for each site based on soil type and used to calculate the area density of deposition. Area deposition densities up to 13,100 Bq m(-2) were measured, consistent with published estimates.
Collapse
|
28
|
Ramzaev V, Mishine A, Golikov V, Brown JE, Strand P. Surface ground contamination and soil vertical distribution of 137Cs around two underground nuclear explosion sites in the Asian Arctic, Russia. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2007; 92:123-43. [PMID: 17156902 DOI: 10.1016/j.jenvrad.2006.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 08/28/2006] [Accepted: 10/10/2006] [Indexed: 05/12/2023]
Abstract
Vertical distributions of 137Cs have been determined in vegetation-soil cores obtained from 30 different locations around two underground nuclear explosion sites--"Crystal" (event year - 1974) and "Kraton-3" (event year - 1978) in the Republic of Sakha (Yakutia), Russia. In 2001-2002, background levels of 137Cs surface contamination densities on control forest plots varied from 0.73 to 0.97 kBq m(-2) with an average of 0.84+/-0.10 kBq m(-2) and a median of 0.82 kBq m(-2). 137Cs ground contamination densities at the "Crystal" site ranged from 1.3 to 64 kBq m(-2); the activity gradually decreased with distance from the borehole. For "Kraton-3", residual surface contamination density of radiocaesium varied drastically from 1.7 to 6900 kBq m(-2); maximal 137Cs depositions were found at a "decontaminated" plot. At all forest plots, radiocaesium activity decreased throughout the whole vertical soil profile. Vertical distributions of 137Cs in soil for the majority of the plots sampled (n=18) can be described using a simple exponential function. Despite the fact that more than 20 years have passed since the main fallout events, more than 80% of the total deposited activity was found in the first 5 cm of the vegetation-soil cores from most of the forested landscapes. The low annual temperatures, clay-rich soil type with neutral pH, and presence of thick lichen-moss carpet are the factors which may hinder 137Cs transport down the soil profile.
Collapse
Affiliation(s)
- Valery Ramzaev
- St.-Petersburg Institute of Radiation Hygiene, Mira street 8, 197101, St.-Petersburg, Russia.
| | | | | | | | | |
Collapse
|
29
|
Schimmack W, Feria Márquez F. Migration of fallout radiocaesium in a grassland soil from 1986 to 2001. Part II: evaluation of the activity-depth profiles by transport models. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 368:863-74. [PMID: 16643986 DOI: 10.1016/j.scitotenv.2006.03.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 03/16/2006] [Accepted: 03/19/2006] [Indexed: 05/08/2023]
Abstract
The vertical migration of (134)Cs, deposited by the Chernobyl fallout (1986), and (137)Cs, deposited by the Chernobyl and the global fallout, in the soil of an undisturbed Bavarian grassland in Germany was investigated from 1986 to 2001. The activity-depth profiles of both isotopes at ten sampling dates were evaluated by the classical convection-dispersion equation and a random walk particle model. In both models, the apparent migration velocity v and the apparent dispersion coefficient D were assumed to be independent of time. However, optimized values of v and D were significantly different for the different locations sampled at different times. If nevertheless constant values of v and D were used, the simulated activity densities per soil layer were out of the range of the spatial variability of the observed activity densities determined in 2001. It is concluded that without further simultaneous investigations e.g. on bioturbation at the study site, migration parameters of radiocaesium determined by classical transport models based on convection and dispersion during the first years after the deposition of the activity cannot be used for predictive purposes.
Collapse
Affiliation(s)
- W Schimmack
- GSF-National Research Center for Environment and Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany
| | | |
Collapse
|
30
|
Schimmack W, Schultz W. Migration of fallout radiocaesium in a grassland soil from 1986 to 2001. Part I: activity-depth profiles of (134)Cs and (137)Cs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 368:853-62. [PMID: 16674997 DOI: 10.1016/j.scitotenv.2006.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 03/16/2006] [Accepted: 03/19/2006] [Indexed: 05/09/2023]
Abstract
The temporal changes of the vertical distribution of (134)Cs (deposited by the Chernobyl fallout in 1986) and (137)Cs (deposited by the Chernobyl and the global fallout) in the soil were investigated at an undisturbed Bavarian grassland site in Germany. At ten sampling dates between 1986 and 2001, the activity density of (134)Cs and (137)Cs was determined in various soil layers down to 80 cm depth. In 2001, the small-scale spatial variability of the radiocaesium activity was determined by sampling five plots within 10 m(2) (coefficient of variation about 20% for the upper soil layers). Between 1987 and 1990, substantial changes of the activity-depth profiles were observed. The percentage depth distributions of (134)Cs and (137)Cs were rather similar. The 50%-depth of the accumulated activity increased from 2.4 cm in 1988 to 5.3 cm in 2001 for (134)Cs and from 2.7 to 5.8 cm for (137)Cs. This indicates that at the study site the migration data of Chernobyl-derived (137)Cs can be estimated by those of total (137)Cs. In the second part of this study, the activity-depth profiles will be evaluated by the convection-dispersion model [Schimmack, W, Feria Márquez, F. Migration of fallout radiocaesium in a grassland soil from 1986 to 2001. Part II: Evaluation of the activity-depth profiles by transport models. Sci Total Environ 2006-this issue].
Collapse
Affiliation(s)
- W Schimmack
- GSF-National Research Center for Environment and Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
| | | |
Collapse
|
31
|
Simon SL, Kleinerman RA, Ron E, Bouville A. Uses of dosimetry in radiation epidemiology. Radiat Res 2006; 166:125-7. [PMID: 16808601 DOI: 10.1667/rr3385.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Steven L Simon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
| | | | | | | |
Collapse
|
32
|
Beck HL, Anspaugh LR, Bouville A, Simon SL. Review of Methods of Dose Estimation for Epidemiological Studies of the Radiological Impact of Nevada Test Site and Global Fallout. Radiat Res 2006; 166:209-18. [PMID: 16808609 DOI: 10.1667/rr3172.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Methods to assess radiation doses from nuclear weapons test fallout have been used to estimate doses to populations and individuals in a number of studies. However, only a few epidemiology studies have relied on fallout dose estimates. Though the methods for assessing doses from local and regional compared to global fallout are similar, there are significant differences in predicted doses and contributing radionuclides depending on the source of the fallout, e.g. whether the nuclear debris originated in Nevada at the U.S. nuclear test site or whether it originated at other locations worldwide. The sparse historical measurement data available are generally sufficient to estimate external exposure doses reasonably well. However, reconstruction of doses to body organs from ingestion and inhalation of radionuclides is significantly more complex and is almost always more uncertain than are external dose estimates. Internal dose estimates are generally based on estimates of the ground deposition per unit area of specific radionuclides and subsequent transport of radionuclides through the food chain. A number of technical challenges to correctly modeling deposition of fallout under wet and dry atmospheric conditions still remain, particularly at close-in locations where sizes of deposited particles vary significantly over modest changes in distance. This paper summarizes the various methods of dose estimation from weapons test fallout and the most important dose assessment and epidemiology studies that have relied on those methods.
Collapse
|
33
|
Henner P, Colle C, Morello M. Retention and translocation of foliar applied 239,240Pu and 241Am, as compared to 137Cs and 85Sr, into bean plants (Phaseolus vulgaris). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2005; 83:213-29. [PMID: 15936122 DOI: 10.1016/j.jenvrad.2005.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Revised: 04/05/2005] [Accepted: 04/14/2005] [Indexed: 05/02/2023]
Abstract
Foliar transfer of 241Am, 239,240Pu, 137Cs and 85Sr was evaluated after contamination of bean plants (Phaseolus vulgaris) at the flowering development stage, by soaking their first two trifoliate leaves into contaminated solutions. Initial retentions of 241Am (27%) and 239,240Pu (37%) were higher than those of 137Cs and 85Sr (10-15%). Mean fraction of retained activity redistributed among bean organs was higher for 137Cs (20.3%) than for 239,240Pu (2.2%), 241Am (1%) or 85Sr (0.1%). Mean leaf-to-pod translocation factors (Bq kg(-1) dry weight pod/Bq kg(-1) dry weight contaminated leaves) were 5.0 x 10(-4) for 241Am, 2.7 x 10(-6) for 239,240Pu, 5.4 x 10(-2) for 137Cs and 3.6 x 10(-4) for 85Sr. Caesium was mainly recovered in pods (12.8%). Americium and strontium were uniformly redistributed among leaves, stems and pods. Plutonium showed preferential redistribution in oldest bean organs, leaves and stems, and very little redistribution in forming pods. Results for americium and plutonium were compared to those of strontium and caesium to evaluate the consistency of the attribution of behaviour of strontium to transuranium elements towards foliar transfer, based on translocation factors, as stated in two radioecological models, ECOSYS-87 and ASTRAL.
Collapse
Affiliation(s)
- P Henner
- Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Saint-Paul-lez-Durance, France.
| | | | | |
Collapse
|
34
|
Madoz-Escande C, Garcia-Sanchez L, Bonhomme T, Morello M. Influence of rainfall characteristics on elimination of aerosols of cesium, strontium, barium and tellurium deposited on grassland. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2005; 84:1-20. [PMID: 15950331 DOI: 10.1016/j.jenvrad.2005.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 03/22/2005] [Accepted: 03/29/2005] [Indexed: 05/02/2023]
Abstract
This work is aimed at quantifying foliar transfer of cesium, strontium, barium and tellurium under the influence of rainfall characteristics (intensity, frequency and time elapsed between contamination and first rainfall). Grassland boxes were contaminated by dry deposition of multi-element aerosols of (137)Cs, (85)Sr, (133)Ba and (123m)Te. They were grown in a greenhouse under controlled conditions. The treatments consisted of mowing and applying rainfalls (8 and 30 mmh(-1)) at different times after the contamination. At a leaf area index of 5.9+/-1.9, interception of the aerosols was similar for the 4 radionuclides (83.8+/-5.9%). Dew produced significant radionuclide accumulation in the base of the vegetation and transfer to the soil. For moderate intensity, an early (2 days after contamination) first rainfall was as efficient, in terms of leaf wash-off, as a longer rainfall occurring later (6 days after contamination). For early rainfalls, eliminated activities were comparable because the influence of rain intensity was compensated by rain duration. However, for late rainfalls, wash-off efficiency increased with rainfall intensity. Total transfer factors (TTF) were determined on whole grass immediately after 4 rainfalls and at harvest. After 4 medium intensity rainfalls, rain frequency did not influence total transfer factors (TTF) of strontium, barium and tellurium (about 0.2, 0.3 and 0.35 Bq kg(fresh weight)(-1) by Bq m(-2), respectively). Cesium TTF value was lower in the case of a weekly rain (0.1 against 0.2 Bq kg(fresh weight)(-1) by Bqm(-2)). TTF values were similar for twice-a-week rainfalls, whatever their intensity. They were higher for weekly rains of high intensity (between 0.3 and 0.75 Bq kg(fresh weight)(-1) by Bqm(-2) against 0.1-0.35 Bq kg(fresh weight)(-1) by Bq m(-2), depending on the radionuclides). TTF values attested that wash-off was more efficient when rainfalls lasted longer. Field loss on the top of the leaves was well described by an offset exponential model. The half-lives varied with rainfall characteristics from 4 days for cesium, strontium and barium to 20 days for tellurium. The offset value varied between 0% for tellurium (high intensity rainfalls) and 14% for cesium (medium intensity rainfalls).
Collapse
Affiliation(s)
- C Madoz-Escande
- Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, DEI/SECRE/LRE, Cadarache, St-Paul-lez-Durance, France.
| | | | | | | |
Collapse
|
35
|
Madoz-Escande C, Santucci P. Weather-dependent change of cesium, strontium, barium and tellurium contamination deposited as aerosols on various cultures. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2005; 84:417-39. [PMID: 15979215 DOI: 10.1016/j.jenvrad.2005.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 04/10/2005] [Accepted: 04/14/2005] [Indexed: 05/03/2023]
Abstract
Various types of plants (wheat, bean, lettuce, radish and grass) were contaminated by dry deposition of radioactive aerosols ((137)Cs, (85)Sr, (133)Ba and (123 m)Te) in order to supplement the radio-ecological data necessary for operational post-accidental codes. A few days after deposition, rainfalls were applied to these cultures to evaluate the influence of some characteristics of the rain on the contamination of the culture over time. On the other hand, for wheat and bean, the influence of the humidity condition of the foliage at the contamination time was considered. For a given plant species at a given vegetative stage, the four radionuclides were intercepted in an identical way. The interception varied from 30% for bean (young sprout) to 80% for lettuce (near maturity). The global transfer factor values were dependent on both the radionuclides and the plant species; nevertheless, a higher value was obtained for cesium, regardless of the plant and the rainfall (from 0.006 m(2)kg(fresh)(-1) for wheat-grains - contaminated at the shooting stage - or for bean-pods - contaminated at the pre-flowering stage - to 0.1m(2)kg(fresh)(-1) for a whole lettuce). The analysis of the results allowed us on the one hand, to extract parameter values of the foliar transfer directly usable in operational codes, in particular those relating to barium and tellurium, unknown until then, and on the other hand, to lay the foundations of a future, more mechanistic model, taking into account the foliar processes in a finer way.
Collapse
Affiliation(s)
- C Madoz-Escande
- Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, DEI/SECRE/LRE, Cadarache, Bld 186, BP 3, 13115, St-Paul-lez-Durance Cedex, France.
| | | |
Collapse
|
36
|
Cazzola P, Cena A, Ghignone S, Abete MC, Andruetto S. Experimental system to displace radioisotopes from upper to deeper soil layers: chemical research. Environ Health 2004; 3:5. [PMID: 15132749 PMCID: PMC421741 DOI: 10.1186/1476-069x-3-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Accepted: 05/06/2004] [Indexed: 05/24/2023]
Abstract
BACKGROUND Radioisotopes are introduced into the environment following nuclear power plant accidents or nuclear weapons tests. The immobility of these radioactive elements in uppermost soil layers represents a problem for human health, since they can easily be incorporated in the food chain. Preventing their assimilation by plants may be a first step towards the total recovery of contaminated areas. METHODS The possibility of displacing radionuclides from the most superficial soil layers and their subsequent stabilisation at lower levels were investigated in laboratory trials. An experimental system reproducing the environmental conditions of contaminated areas was designed in plastic columns. A radiopolluted soil sample was treated with solutions containing ions normally used in fertilisation (NO3-, NH4+, PO4--- and K+). RESULTS Contaminated soils treated with an acid solution of ions NO3-, PO4--- and K+, undergo a reduction of radioactivity up to 35%, after a series of washes which simulate one year's rainfall. The capacity of the deepest soil layers to immobilize the radionuclides percolated from the superficial layers was also confirmed. CONCLUSION The migration of radionuclides towards deeper soil layers, following chemical treatments, and their subsequent stabilization reduces bioavailability in the uppermost soil horizon, preventing at the same time their transfer into the water-bearing stratum.
Collapse
Affiliation(s)
- Pietro Cazzola
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta and C.Re.A.A. – Via Bologna 148 I-10154 Torino, Italy
- Associazione Nazionale di Solidarietà "Smile – Un Sorriso per Chernobyl" – Via Trossi 9/c I- 13856 Vigliano Biellese (BI), Italy
| | - Agostino Cena
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta and C.Re.A.A. – Via Bologna 148 I-10154 Torino, Italy
- Associazione Nazionale di Solidarietà "Smile – Un Sorriso per Chernobyl" – Via Trossi 9/c I- 13856 Vigliano Biellese (BI), Italy
| | - Stefano Ghignone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta and C.Re.A.A. – Via Bologna 148 I-10154 Torino, Italy
| | - Maria C Abete
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta and C.Re.A.A. – Via Bologna 148 I-10154 Torino, Italy
| | - Sergio Andruetto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta and C.Re.A.A. – Via Bologna 148 I-10154 Torino, Italy
| |
Collapse
|
37
|
Madoz-Escande C, Henner P, Bonhomme T. Foliar contamination of Phaseolus vulgaris with aerosols of 137Cs, 85Sr, 133Ba and 123mTe: influence of plant development stage upon contamination and rain. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2004; 73:49-71. [PMID: 15001295 DOI: 10.1016/j.jenvrad.2003.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2003] [Revised: 08/01/2003] [Accepted: 08/06/2003] [Indexed: 05/24/2023]
Abstract
As part of a requirement to improve the assessment of the impact of radioactive fallout on consumed agricultural products, bean plants at four development stages (seedlings, preflowering, late flowering and mature plants) were contaminated by dry deposition of (137)Cs, (85)Sr, (133)Ba and (123m)Te aerosols. The influence of two rain scenarios and of the development stage upon contamination on interception, retention, and translocation to pods was studied. Interception of the four radionuclides was almost identical and varied from 30 to 60% with increasing development stage. The most important rain parameter was the time which elapsed between contamination and the first rain. Whatever the development stage, rain washed off more cesium from the leaves when it occurred 2 days after the deposit (37% at the seedling stage, for example) rather than later on (6 days, 27%), due to rapid migration of Cs in the plant. The first rain washed off nearly 40% of Ba whatever the scenario. For later stages, Sr and Ba were more washed off by heavy weekly rains than by weak twice-a-week rains, perhaps because of the Sr/Ba-contaminated material loss associated with wash off (desquamation of cuticles). Te showed little wash off (less than 5%). Wash off decreased with an older development stage for a weak rain intensity, due to the superimposition of leaves. Heavy rains removed this shelter effect. At harvest, rain effect was no longer detectable as foliar activity was similar for both rain scenarios. Translocation factors (TF) for strontium and barium increased from 6 x 10(-3) to 1 x 10(-1) with the plant development stage upon contamination, whereas those for cesium remained almost unchanged between 2 x 10(-1) and 4 x 10(-1). Flowering is the most critical stage towards residual contamination in pods at harvest, with the exception of direct deposit on pods at the mature stage (TF values are one order of magnitude higher). TF value for Te was 6.5 x 10(-2) and was due to direct deposit. Modelling reflected the trends, through the differential values of the wash off and absorption coefficients, of what was reported for experimental results.
Collapse
Affiliation(s)
- C Madoz-Escande
- Institute of Radioprotection and Nuclear Safety, Environmental Protection Department, Division for Laboratory Radioecological Studies and Research, Cadarache, Bât. 186, B.P. 3, 13115 St-Paul-Lez-Durance Cedex, France.
| | | | | |
Collapse
|