137Cs In Plants Research Articles

Effects of cattle manure compost application on crop growth and soil-to-crop transfer of cesium in a physically radionuclide-decontaminated field

Resuming crop production in physically decontaminated fields affected by radiocesium (134Cs and 137Cs) releases is crucial for restoring impacted areas. However, surface soil excavation to reduce radiocesium may lead to lower crop yield due to the loss of fertile topsoil. This study aimed to assess the effects of cattle manure compost (CMC) application on soil properties, crop growth, and 137Cs soil-to-crop transfer in a physically decontaminated field and pot experiment. Field trials were conducted during 2018–2022, with CMC (1 and 2 kg m−2 year−1) applied alongside conventional fertilization (CMC1 and CMC2 plots, respectively) in 2018–2019 and conventional fertilization alone in 2020–2022. Additionally, a pot experiment was used to evaluate the impact of CMC application in soil (1 kg m−2 year−1 for 5 years) on 137Cs transfer. In the field trial during 2018–2019, CMC1 and CMC2 plots exhibited higher soybean shoot dry weight (DW) compared with plots receiving conventional fertilization and additional K fertilizer (+K2O). CMC application also improved soil nutrient content. The transfer factor of 137Cs (TF-137Cs: plant 137Cs activity concentration/soil 137Cs activity concentration) followed the order CMC2 < CMC1 ≈ +K2O < conventional fertilization only (CF) and was negatively correlated with soil exchangeable K (Ex-K). During 2020–2022, when all plots received conventional fertilization alone, grain yields were higher in CMC1 and CMC2 plots than in the +K2O plot, with the lowest TF-137Cs in CMC2 plot followed by CMC1, +K2O, and CF plots. The pot experiment confirmed that CMC soil had a lower TF-137Cs and higher plant DW compared with CF soil with the same Ex-K level. Additionally, the soil exchangeable 137Cs (Ex-137Cs) level was significantly lower in CMC soil than CF soil. These findings demonstrate the potential of CMC application to improve crop growth and reduce 137Cs transfer in physically decontaminated fields.

Assessment of secondary radioactive contamination of a decontaminated land plot located on the territory of a recreation base in a wooded area

The article presents results of a long-term (1998–2021) radiological monitoring survey of a recreation base located in a wooded area in the zone of radioactive contamination after the accident at the Chernobyl nuclear power plant. Local mechanical decontamination of the soil had been made on the territory of the base in 1997. The evaluation of the secondary radioactive contamination of the decontaminated territory was performed by comparing dynamics of the radiological situation at the treated plot and the control, nondecontaminated, part of the base according to four main criteria: 1) dose rate of gamma radiation in the air from cesium radionuclides; 2) inventory of 137Cs in soil; 3) vertical distribution of 137Cs in soil; 4) activity concentration of 137Cs in plants and fungi. In 1998, the value of the 137Cs inventory in the upper 20 cm of soil in the control part of the territory of the base and in the decontaminated plot was 930 kBq/m2 and 143 kBq/ m2, respectively. By 2015, the value of the 137Cs inventory in the control area and the decontaminated plot had significantly decreased: by 35% and 36%, respectively. A decrease in the dose rate of gamma radiation in the air at the decontaminated plot and control area proceeded at the same rate, which is currently mainly determined by the decay of 137Cs. There was a gradual self-restoration of the forest ecosystem at the plot subjected to decontamination. Activity concentration of 137Cs in biota (pine, edible mushrooms) in the treated plot was many times lower than that in the control part of the recreation base. In general, there was no significant secondary radioactive contamination of the decontaminated plot in the 24 years after the intervention.

Soil fertilisation with 137Cs-contaminated and uncontaminated wood ash as a countermeasure to reduce 137Cs uptake by forest plants

The purpose of present study was to find out whether wood ash with a high pH value and neutralizing capacity reduces 137Cs uptake by forest plants many years after the radionuclide fallout. The effects of one-time point fertilisation with 137Cs-contaminated and uncontaminated wood ash alone or in combination with KCl on 137Cs transfer from soil to young leaves and green shoots of various dwarf shrubs and tree species were examined in a long-term fertilisation experiment (2012–2021) conducted in Bazar mixed forest, around 70 km from Chernobyl nuclear power plant. The results indicated minor effects of soil fertilisation, although there were differences between 137Cs uptake by species and years. Soil amendment with 137Cs-contaminated wood ash generally did not affect 137Cs uptake by young shoots and leaves of plants over the growing season in the first year and only slightly decreased Tag for 137Cs in the following years. The effect of a single application of 137Cs-uncontaminated wood ash on reducing 137Cs uptake by plants was generally negligible. Application of 137Cs-contaminated wood ash in combination with KCl reduced plant 137Cs uptake by about 45%, however, such reduction was only significant in some years for bilberry berries, young leaves and green shoots of lingonberry and alder buckthorn. Thus application of wood ash to 137Cs-contaminated forest soil many years after radionuclide fallout generally does not reduce 137Cs uptake by forest vegetation in a mixed forest ecosystem and this countermeasure should be applied with caution.

A Systematic Approach to the Development of a Methodology for Comparative Analysis of Scenarios for the Shelter Object Transformation into an Ecologically Safe System

A comprehensive assessment of the impact of wildfires in the Chornobyl Exclusion Zone on the adjacent territory within a radius of 100 km in the spring of 2020 and 2022 was carried out, considering the potential and realized radioecological criticality of the territory. The realized radioecological criticality was expressed in the estimated specific activity of 137Cs in plants, which was formed as a result of aerial and root pollution of agricultural vegetation in farm fields and gardens during the transfer and deposition of radionuclides during fires. The specific activity of 137Cs in plants was calculated based on the data on the integrated volumetric activity of 137Cs, obtained by the WRF-LEDI model of atmospheric transport, using the set of models “AeralPlant — SoilPlant” depending on the biological stage of plant development. According to the results of the calculations, thematic mapping was carried out with the selection of zones of maximum and minimum contamination of the territory, taking into account potential radioecological criticality. Regardless of the volume activity of 137Cs in the air and the direction of air transfer, the spatial nature of the distribution of the most critical areas is preserved. As a result, the most critical areas were identified, where dangerous levels of radiation exposure on the population are possible due to atmospheric transport of radionuclides caused by wildfires and extreme weather phenomena (dust storms) in the Chornobyl Exclusion Zone. Different scenarios of the regional land use structure were considered and thematic assessment maps were built, which are the basis of preventive planning of rehabilitation measures in case of critical situations in accordance with radiation safety norms.

The ratio of plant 137Cs to exchangeable 137Cs in soil is a crucial factor in explaining the variation in 137Cs transferability from soil to plant.

To mitigate radioactive cesium from soil to plant, increasing and maintaining the exchangeable potassium (ExK) level during growth is widely accepted after Tokyo Electric Company's Fukushima Dai-ichi Nuclear Plant accident in Japan. This is because the antagonistic relationship between soil solution K and 134Cs + 137Cs (RCs) concentrations changes the transfer factor (TF: designated as the ratio of radioactivity of plant organ to soil) of RCs. As the relationship between ExK and TF depends on the soil types, crop species, and other environmental factors, the required amount of ExK should be set to a safe side. Eleven years after the accident, as the activity of 134Cs was almost negligible, 137Cs became the main RCs in most of the agricultural fields in Fukushima Prefecture. We propose a new indicator, the concentration ratio of plant 137Cs to soil exchangeable 137Cs (Ex137Cs), instead of TF, which showed a better correlation with ExK even among soils with different properties (or mineralogy).

137Cs circulation in forest ecosystems on the territory of the Chornobyl exclusion zone (Plant)

Seasonal changes in the content of 137Cs in plants of the forest ecosystems on the territory of the Chornobyl exclusion zone have been studied. Samples were selected from 2013 till 2015 once per two weeks. The studied objects were one- and two-year-old needles and branches of the Scots pine (P. sylvestris). The 137Cs content was measured by the gamma spectrometry. In the needles and branches of P. sylvestris, the maximum values of 137Cs concentration are noted in the summer. The minimum values of 137Cs content in the studied organs of P. sylvestris are characteristic of the autumn-winter period. Probably, the annual fluctuations in the content of this radionuclide in various organs of the studied plants are a consequence of the existence of the constant circulation of 137Cs in the forest ecosystems, as a result of which this radionuclide not only gets from the soil into P. sylvestris, but is also excreted from its living tissues.

Накопичення 137Cs у суміші лучних трав на торфово-болотних ґрунтах зони Полісся у Рівненській області

The role and effectiveness of the combined action of various types of mineral fertilizers on the productivity of the agrocenosis and the accumulation of radionuclides by the phytomass of perennial grasses on peat-bog soil (Histic Gleysols) have been investigated. The research was carried out during 2011-2013. In a temporary field experiment with seeded perennial grasses (Dáctylis glomeráta, Bromopsis inermis, Phleum pratense) used for livestock feed. The aim of the research is to identify the features of the effect of radiological load on the quality of agricultural products in fertilized and non-fertilized areas by measuring the specific activity of radioactive 137Cs in the dry phytomass of collected herbs, the density of soil contamination and calculating the coefficients of the transfer of radionuclides from soil to pasture fodder. The activity of 137Cs in plants was determined by gamma spectrometer. The introduction of increased doses of potash (K120) and phosphorus fertilizers together with potash (P60 K120) was effective in reducing the activity of radiocaesium in the dry mass of feed. Over the three years of research on the variant with potash fertilizers, a decrease in 137Cs activity in the feed by an average of 2.9 times was recorded, and at the site of the combined application of potash and phosphate fertilizers – by 2.7 times compared with the control variant of the experiment (without fertilizers).

Transfer of 137Cs to Cereal Plants Due to Microorganisms Activity

Purpose. Evaluation of the role of individual strains of microorganisms in transfer of 137Cs in spring wheat and rapeseed plants. Methods. Fieldwork, laboratory experiments, inoculation, gamma spectrometry. Results. Soil microorganisms can both reduce and enhance the transition of 137Cs from soil to plants. Inoculating microorganisms, when used on nutrient poor soils, accelerate the growth of plants in length, which indicates an improvement in their growing conditions. Studies have shown that it does not depend on the localization of the microorganism on the root surface, because all analyzed bacteria belonged to the group colonizing the rhizosphere of the plant. In experiments with wheat, there was no significant reduction in 137Cs accumulation. The use of drug complexes based on the bacterial strains Agrobacterium radiobacter IMV B-7246 and A. chroococcum UKM B-6082 for inoculation of rapeseed and Azotobacter chroococcum UKM B-6003 can be considered as an additional radioprotective method of blocking the influx of 137Cs in these rural plants. Conclusions. Soil microorganisms can both reduce and increase the accumulation of 137Cs in plant biomass and this property does not depend on the localization of the microorganism on the root surface, because all analyzed bacteria belonged to the group colonizing the rhizosphere of the plant. The use of inoculation of seeds of agricultural plants with bacterial preparations under the conditions of cultivation on soil contaminated with radionuclides as an additional measure to reduce the accumulation of radionuclides in the green mass of plants is proposed.

Оценка радиационной обстановки в районе расположения судоремонтных предприятий, осуществляющих утилизацию судов с ядерной энергетической установкой

Purpose: To study radiation and health physics situation in the vicinity of the shipyards “The 10th Shipyard, a Holder of Order of the Red Banner of Labor” (JSC “10 SRZ”) and “The Nerpa Shipyard” – a branch of the JSC “The Shipyard Center “Zvezdochka” (SRZ “Nerpa”) after the completion of the main stage of nuclear submarine dismantling and to assess potential effect of on-going activities to the environment and population.&#x0D; Material and methods: The following methods were used in radiation survey: pedestrian gamma survey of the site using portable gamma spectrometry complexes, gamma spectrometry and radiochemistry methods to determine the activity of manmade radionuclides in samples of environmental media. &#x0D; Results: Radiation and health physics studies were carried out from 2013 till 2017. It was shown that gamma dose rate within the health protection zones and supervision areas (SA) of the shipyards including the territories of the nearest cities – Snezhnogorsk and Polyarnyi – was at the level of regional values and did not exceed 0.14 µSv/h. The activities of radionuclides in soil from the surveyed sites did not exceed 23 Bq/kg for 90Sr and 100 Bq/kg for 137Cs. Concentrations of 90Sr and 137Cs in plants (mosses) at the surveyed sites did not exceed 70 and 48 Bq/kg, respectively, this is a bit higher than the background levels of the reference village of Belokamenka (1 and 20 Bq/kg, respectively, for 90Sr and 137Cs). The activity of seawater (Barents Sea) in 2016–2018 reached 60 mBq/l for 90Sr and 4 mBq/l for 137Cs, at mean values from 2 to 4 mBq/l over the period between 1990 and 2000 for the studied radionuclides. Data for 137Cs and 90Sr measured in samples of local wild plants, in particular, mushrooms, did not exceed 100 Bq/kg, this is much lower than the established permissible specific activities.&#x0D; Conclusion: Considerable impact of the work on the dismantling of nuclear submarines, maintenance ships and ships with a nuclear energy installation on the radiation situation in the areas of shipyards and health effects in the population of Snezhnogorsk and Polyarnyi was not revealed. However, along the external border of the surveyed shipyards some local parts of the sites of 5500 m2 area were found, where the specific activities of 90Sr and 137Cs in soil exceeded background levels and bordered by the level of permissible specific activity for unlimited use of solid materials (137Cs – 100 Bq/kg).

Radioecological State of the Agrosphere in the 30-km Zone of the Siberian Chemical Combine During the Pre-Startup Period of a Prototype Power Complex

The results of radioecological monitoring of agricultural activities within the 30-km impact zone of the Siberian Chemical Combine are examined. The surface activity of 137Cs in soil and the specific activity of 137Cs in plants with similar indicators characteristic for NPP sites are analyzed and compared. The obtained data make it possible to evaluate the impact of a prototype electric power complex (PEPC) on the soil-and-vegetation cover and the products of agricultural activity, since the data make it possible to differentiate information on two basic parts – that associated with the activity of the Combine, on the one hand, and the other with the possible contribution of PEPC, on the other.

Changes of effective half-lives of 137Cs in three herbaceous plants and bioavailable 137Cs fraction in soil after the Fukushima nuclear accident

We measured cesium-137 concentrations from June 2011 to May 2016 in three wild edible herbaceous species, i.e. giant butterbur (Petasites japonicus), knotweed (Trifolium pratense), and mugwort (Artemisia indica var. maximowiczii), that were grown on the same sampling field in Chiba Prefecture, Japan. The pattern of plant 137Cs concentrations versus time could be described well with the two-component exponential decline (short-term and long-term components), and the half-lives of these three plant species were between 103 and 230 d for the short component and 970–3830 d for the long component. During April 2014 to May 2016, due to the slow decline in the 137Cs concentrations in these three plant species, we assumed that the bioavailable 137Cs fraction in the observation ground soil was almost the same in this period. Then, values of the aggregated transfer factor from soil to plant (Tag) were calculated for these plant species, and the values ranged from 5.3 × 10−5 to 1.6 × 10−4 m2 kg−1-fresh. We also calculated Tag values for wild edible herbaceous plants in Fukushima Prefecture using open data sources that were reported from January 2014 to June 2016. The five plant species included were giant butterbur (P. japonicus), western bracken fern (Pteridium aquilinum), Japanese royal fern (Osmunda japonica), ostrich fern (Matteuccia struthiopteris) and momijigasa (Parasenecio delphiniifolius). The Tag values ranged from 1.4 × 10−4 to 7.0 × 10−4 m2 kg−1-fresh and were similar to those measured in our Chiba field study.

BASIC EXPERIMENTS OF CS UPTAKE CAPABILITY FOR Eleocharis acicularis

&lt;p&gt;Soil in the Fukushima area has been polluted with the radioactive contaminants such as Cs by the accident of Fukushima Daiichi nuclear power plant in March 2011. Remediation of soil contaminated with radioactive Cs remains one of the most important problems. Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism to remove radioactive contaminants. Eleocharis acicularis is well known as heavy metal hyperaccumulator aquatic plant and expected as the strong candidate for application to Phytoremediation of polluted water and soil. In this study, a laboratory experiment was carried out to investigate the potential of E.acicularis for Phytoremediation of radioactive Cs contaminated site.The plants were grown hydroponically and placed in solutions containing Cs and K at different concentration (Cs concentration: 5 mg/L, K concentration: 0, 0.2, 2, 5, 50, 100 mg/L) in a period of 21days.In the experimental results, the highest concentration of Cs was 1560 mg/kg-DW in E. acicularis after 21 days. The concentration of Cs in plants decreased with the increasing initial concentration of K in the solution. This results indicate that E. acicularis has the ability to accumulate radioactive Cs from radioactive Cs contaminated soil and water, making it a good candidate species for radioactive Cs Phytoremediation.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt;Keywords&lt;/strong&gt; : Fukushima, Eleocharis acicularis, phytoremediation, Cs&lt;/p&gt;

Transfer of radiocesium to four cruciferous vegetables as influenced by organic amendment under different field conditions in Fukushima Prefecture

Soil-to-plant transfer of radiocesium (137Cs) in four cruciferous vegetables as influenced by cattle manure-based compost amendment was investigated. Komatsuna, mustard, radish and turnip were cultivated in three different 137Cs-contaminated fields at Nihonmatsu City in Fukushima Prefecture from June to August 2012. Results revealed that organic compost amendments stimulated plant biomass production and tended to induce higher 137Cs concentration in the cruciferous vegetables in most cases. Among the studied sites, Takanishi soil possessing low exchangeable potassium (0.10 cmolc kg−1) was associated with an increased concentration of 137Cs in plants. Radiocesium transfer factor (TF) values of the vegetables ranged from 0.025 to 0.119. The increase in 137Cs TFs was dependent on larger plant biomass production, high organic matter content, and high sand content in the studied soils. Average 137Cs TF values for all study sites and compost treatments were higher in Komatsuna (0.072) and radish (0.059), which exhibited a higher biomass production compared to mustard and turnip. The transferability of 137Cs to vegetables from soils was in the order Komatsuna > radish > mustard > turnip. The highest 137Cs TF value (0.071) of all vegetables was recorded for a field where the soil had high organic matter content and a high clay proportion of 470 g kg−1 consisting of Al-vermiculite clay mineral.

The role of dark septate endophytic fungal isolates in the accumulation of cesium by chinese cabbage and tomato plants under contaminated environments.

Following the 2011 Fukushima Daiichi Nuclear Power Plant accident, the preservation of the food chain from radionuclides contamination has become of crucial importance. The potential of Dark septate endophytic fungi in the management of Cs accumulation in plants under contaminated environments was investigated using Chinese cabbage and tomato plants. Four endophytic fungal isolates of different species, i.e. Pseudosigmoidea ibarakiensis I.4-2-1, Veronaeopsis simplex Y34, Helminthosporium velutinum 41-1, and as yet unidentified taxon 312-6 were tested In Vitro in two levels of Cs (5ppm and 10ppm). On the plant growth, the inoculation of the selected DSEs to both Chinese cabbage and tomato resulted in an increased biomass of up to 82% and 122%, respectively compared to control (non-inoculated) plants. With regards to the Cs accumulation, it varied with the host plant considered. In Chinese cabbage, DSEs inoculation caused higher Cs accumulation in above ground plant parts, whereas in tomato, Cs accumulation decreased significantly with three of the isolates tested, i.e., V. simplex Y34, P. ibarakiensis I.4-2-1, and the as yet unidentified taxon 312-6 suggesting low-risk transfer on the above ground plants parts as a result of high and negative plant reactions rather than high and positive reactions as it is the case with Chinese cabbage. These results suggested that DSEs can be recommended for use with Chinese cabbage to enhance phytoremediation of Cs in surrounding contaminated areas. With tomato, DSEs can be recommended for decreasing the accumulation of Cs in plants under contaminated environments.

Radiocesium accumulation in Egeria densa, a submerged plant – possible mechanism of cesium absorption

Radioactive cesium (Cs) was discharged into the environment in the northeast region of Japan after destruction of the nuclear power station in March 2011. In this work, we study the uptake and accumulation of Cs in a freshly submerged vascular plant, Egeria densa (Brazilian waterweed, Hydrocharitaceae), to investigate the behavior of Cs in the aquatic ecosystem and to predict the movement of the radionuclide to remove this Cs from the environment. We collected plants, waters, and sediments that had been contaminated by radioactive fallout in Fukushima Prefecture in September 2012. The activities of 134Cs, 137Cs, and 40K were measured using a germanium semiconductor detector. We found that the endogenous radioactive Cs concentrations in plants were correlated with those in the sediments. To discuss the uptake mechanism of Cs, stable 133Cs was applied separately to shoots and roots in a two-compartment bath. The results showed that the environmental Cs transferred to both shoot and root parts in plants. To analyze the detailed localization of Cs in plants, synchrotron radiation-based micro X-ray fluorescence (SR-μ-XRF) analysis was performed for the plants cultivated in a hydroponic medium containing 133Cs. The two-dimensional metal distribution of leaves was determined by μ-XRF with approximately 0.7 μm X-ray beams. The distribution showed the predominant localization of Cs, K as well as several divalent metals in the cell wall or apoplastic regions, suggesting the possible absorption mechanism of Cs in the plants. We concluded that E. densa plays an important role in the deposition of radioactive Cs in fresh water.

Measurement of distributions of cesium and rubidium in rice grains using micro-PIXE for detailed examinations of contaminated food

We used micro-PIXE to investigate the distribution of Cs and Rb in rice grains. We succeeded, for the first time, in measuring the elemental distributions in entire rice grains (with dimensions of 6.25 mm [Formula: see text] 6.25 mm) at micrometer spatial resolution. We found that Cs and Rb accumulated in the bran and germ of the rice. The distributions of P, K, Rb and Cs were similar within the rice grain. The concentrations of Cs and Rb in the rice were proportional to those in the soil, as well as to the exposure time. The uptake of Rb was significantly larger than that of Cs. Furthermore, the behavior of Rb was similar to that of Cs in the micrometer-scale regions in plants. It follows that the distribution of Rb can be used to investigate the behavior of radioactive Cs in plants.

Concentration of Cs in plants and water resulting from radioactive pollution

The consumption of plants cultivated in soils contaminated by radioactive cesium can lead to internal exposure and health problems in humans. It is therefore very important to clarify the uptake mechanism of radioactive cesium from contaminated soils. In this study, the variation of cesium concentrations in plants was examined using mediums that contained no potassium and different cesium concentrations of 50, 100, 250 and 500ppm. Raphanus sativus was selected as a typical edible vegetable and hydroponically cultivated. Cesium concentrations in leaves were analyzed with a submilli-PIXE camera. The concentration of cesium in plants was observed to increase as concentrations in the medium increased. As the concentration of cesium in the medium increased, the transfer coefficient decreased. However, there was little difference between the 250 and 500ppm treatments. In future work, PIXE analysis will be performed on different mediums and the relationship with other materials will be investigated.

Potential of monitoring nuclides with the epiphyte Tillandsia usneoides: Uptake and localization of 133Cs

Epiphytic Tillandsia plants are efficient air pollution biomonitors and traditionally used to monitor atmospheric heavy metal pollution, but rarely nuclides monitoring. Here we evaluated the potential of Tillandsia usneoides for monitoring 133Cs and investigated if Cs was trapped by the plant external surface structures. The results showed that T. usneoides was able to survive relatively high Cs stress. With the increase of Cs solution concentration, the total of Cs in plants increased significantly, which suggests that the plants could accumulate Cs quickly and effectively. Therefore, T. usneoides has considerable potential for monitoring Cs polluted environments. In addition, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis showed that Cs was detected in each type of cells in foliar trichomes, and the ratio of Cs in the internal disc cell was higher than that in ring cell and wing cell, which indicates that the mechanism of adsorption Cs in Tillandsia has an active component.

Model Validation of Radiocaesium Transfer from Soil to Leafy Vegetables

The accumulation of radionuclide in plant tissues can be estimated using a mathematical model, however the applicability of the model into field experiment still needs to be evaluated. A model validation has been conducted for radiocaesium transfer from soil to two leafy vegetables generally consumed by Indonesian people, i.e. spinach and morning glory in order to validate the transfer model toward field experimental data. The vegetable plants were grown on the soil contaminated with 134 CsNO 3 of 19 MBq for about 70 days. As the control, vegetables plant were also grown on soil without 134 CsNO 3 contamination. Every 5 days, both of contaminated and un contaminated plants were sampled for 3 persons respectively. The soil media was also tested. The samples were dried by infra red lamp and then the radioactivity was counted using gamma spectrometer. Data of 134 Cs radioactivity on soil and plants were substituted into mathematical equation to obtain the coeficient of transfer rate ( k 12 ). The values of k 12 were then used for calculating the 134 Cs radioactivity in the vegetable plants. The 134 Cs radioactivity in plants obtained from mathematical model analysis was compared with the radioactivity data obtained from the experiment. Correlation of 134 Cs radioactivity in vegetables plant obtained from the experiment with those obtained from model analysis was expressed as correlation coefficient, and it was obtained to be 0.90 and 0.71 for spinach and morning glory plants respectively. The values of 134 Cs in plants obtained from the model analysis can be corrected using standard deviation values, namely 48.65 and 20 for spinach at 0 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 &lt;t&lt;55 days and at 0&lt;t&lt;78 days, respectively. Whereas for morning glory the standard deviation value was 0.36. Although there are differences between 134 Cs radioactivity in vegetable plants obtained from model analysis and experiment data, the model of 134 Cs transfer from soil to plant can be used for analysing 134 Cs radioactivity on leafy vegetable plants grown on radiocesium contaminated soil. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Received: 31 March 2010 ; Revised: 23 April 2012 ; Accepted: 27 April 2012

Distribution of cesium-137 in tree crop products collected from residence islands impacted by the U.S. nuclear test program in the northern Marshall Islands

The Marshall Islands Program at the Lawrence Livermore National Laboratory has completed a series of radiological surveys at Bikini, Rongelap, Utrōk, and Enewetak Atolls in the Marshall Islands designed to take a representative sample of food supplies with emphasis on determining 137Cs activity concentrations in common food plants. Coconuts (Cocos nucifera L.) are the most common and abundant food plant, and provided a common sample type to characterize the level and variability of activity concentrations of 137Cs in plant foods collected from different islands and atolls. Other dominant food types included Pandanus (Pandanus spp.) and breadfruit (Actocarpus spp.). In general, the activity concentration of 137Cs in food plants was found to decrease significantly between the main residence islands on Bikini, Rongelap, Utrōk, and Enewetak Atolls. The mean activity concentration of 137Cs measured in drinking coconut meat and juice was 0.72 (95 % CI 0.68–0.77) and 0.34 (95 % CI 0.30–0.38) Bq g−1, respectively, on Bikini Island; 0.019 (95 % CI 0.017–0.021) and 0.027 (95 % CI 0.023–0.031) Bq g−1, respectively, on Rongelap Island; 0.010 (95 % CI 0.007–0.013) and 0.007 (95 % CI 0.004–0.009) Bq g−1, respectively, on Utrōk Island; and 0.002 (95 % CI 0.0013–0.0024) and 0.002 (95 % CI 0.001–0.0025) Bq g−1, respectively, on Enewetak Island. High levels of variability are reported across all islands. These results will be used to improve the accuracy and reliability of predictive dose assessments, help characterize levels of uncertainty and variability in activity concentrations of fallout radionuclides in plant foods, and allow atoll communities to make informed decisions about resettlement and possible options for cleanup and rehabilitation of islands and atolls.