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Abstract  

In order to understand the chemical form of soluble technetium in paddy soil and its availability to a rice plant, soil incubation and uptake experiments have been carried out using95mTc as a tracer. The chemical form of the soluble Tc was observed by gel chromatography and found not to be pertechnetate, but rather to be associated with soluble organic matter. An uptake experiment with rice seedlings using nutrient solution showed that this Tc-organic matter complex was less available than pertechnetate.

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Abstract  

In order to obtain information on the behavior of long-lived129I in the soil-plant-atmosphere system, two different experiments, transfer factors and volatilization of iodine, have been conducted by radiotracer techniques using125I. Soil-to-plant transfer factors varied very widely. Low values were found in tomato (0.0003) and rice (0.0019). The highest value for an edible part was seen in komatsuna,Brassica rapa L. (0.016), which is comparable to the IAEA recommended value of iodine for common crops (0.02). There was a tendency for older leaves to show higher concentrations than younger ones. The values for fruit, grain and beans were significantly lower than those for their leaves. Thus translocation of iodine with photosynthate from leaves into these plant organs was very small. Iodine in soil was found to be volatilized from the soil-rice plant system into the atmosphere as an organic iodine. Volatilization markedly decreased in the late cultivation period of rice plants.

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Abstract  

Transfer of radionuclides from soil to root vegetables (radish, carrot and turnip) has been studied by radiotracer experiments using Andosol, a typical soil type in Japan. The averages of the transfer factors of137Cs,85Sr,60Co,54Mn and65Zn for edible parts of the three vegetables were 0.02, 0.14, 0.004, 0.09 and 0.13, respectively. The transfer factor of141Ce for the edible part of carrot was 0.0002. The transfer factors obtained for the edible part of root vegetables were markedly lower than those for leaf vegetables.

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Abstract  

Dietary intakes of radiocesium and non-radioactive cesium in Japanese were estimated using a market basket study and found to be 61 mBq and 9.1 ng per person per day, respectively. Food categories having higher Cs contents (per g-fresh) were found to be as follows: mushrooms 35.9 ng; nuts and seeds 33.6 ng; meats 26.8 ng; fishes and shellfishes 21.6 ng; potatoes 19.2 ng; seaweeds 10.2 ng; and milk and milk products 7.19 ng. For137Cs, higher contents (per kg-fresh) were as follows: mushrooms 1.7 Bq; nuts and seeds 0.23 Bq; fishes and shellfishes 0.16 Bq; meats 0.13 Bq; potatoes 0.11 Bq; seaweeds 0.092 Bq; and milk and milk products 0.089 Bq. Distributions of stable cesium in the 18 food categories were similar to those of radiocesium.

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Abstract  

For three heavily exposed workers in the Tokai-mura criticality accident, the levels of 24Na, 42K and 82Br were measured in blood, urine, vomit and hair. 24Na showed the highest activity and was found to have a specific activity of 8.24·104, 4.34·104 and 1.23·104 Bq 24Na per g Na in blood of the three exposed workers. Based on these data the individual neutron fluences were calculated. Radionuclides were also measured in environmental samples from the JCO campus. The fission products 131I, 133I, 140Ba-140La and 137Cs were determined in plant samples and the activation products 59Fe, 46Sc, 60Co and 152Eu were identified in soil samples. 235U/238U ratios in soil and plant samples were measured by ICP-MS.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: K. Shiraishi, S. Ko, T. Ban-nai, H. Arae, K. Ayama, P. Zamostyan, N. Tsigankov, I. Los, and V. Korzun

Abstract  

Daily intakes of 134Cs and 137Cs in Ukrainians were estimated in relation to the health effects on habitants after the Chernobyl accident. Two hundred and sixty-eight diet samples were collected from 25 oblasts (regions) using a duplicate portion method. For Ukrainians, the range and median daily intakes of 137Cs were 0.53–571 and 8.8 Bq per person, respectively. Intakes of 134Cs were also detected in highly 137Cs contaminated areas. Daily intakes of 134Cs were in the range of not detected to 3.6 Bq per person. Using the highest radiocesium intakes, annual effective doses for 134Cs and 137Cs were estimated to be 2.5·10−2 and 2.7 mSv, respectively.

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