| 研究課題/領域番号 |
19J14291
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| 研究機関 | 弘前大学 |
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研究代表者 |
HU JUN 弘前大学, 保健学研究科, 特別研究員(DC2)
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| 研究期間 (年度) |
2019-04-25 – 2021-03-31
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| キーワード | radon / internal exposure |
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| 研究実績の概要 |
To test the mechanism of the radioactive microparticles intaking to the human body,a stable radioactive microparticles generation and exposure system are necessary, therefore a test experiment was carried out in Hirosaki University's radon and thoron exposure chambers. A novel direct 222Rn/220Rn progeny monitor was developed, which can measure the accumulative progeny concentration during the whole exposure period, and be used to estimate the activity concentration of the deposition progeny. The natural uranium rock and aerosol Generator were responsible to generate the aerosol particles and mixed with radon gas in the chamber to form the radioactive microparticles.A theoretical model of the direct progeny monitor was developed based on the experiment data.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The theoretical model of the mechanism of the direct progeny monitor was developed based on the experiment data. A parameter sensitivity analysis of the theoretical model of the direct progeny monitor was carried out to test its influential factors. The results show both the attachment process and the deposition process of 222Rn and 220Rn progeny are important to the performance of the progeny monitor. Moreover, dosimetry software package IMBA was applied to analyze the influential factors of inhalation dose, which can be competent to implement to evaluate the effective dose coefficient with the experimental data. These interim results are the basement to improve the method of internal exposure causing by the inhalation of radioactive microparticles.
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| 今後の研究の推進方策 |
The radon exposure experimental system will generate mixed aerosol and radon gas to form stable radioactive microparticles in the exposure chamber. The activity will be measured with the controlled aerosol size by progeny monitor. Then the influence of the mechanism of the coagulation, condensation and decay processes of the radioactive microparticles will be simulated by the theoretical model and validate with the experimental data. The validate theoretical model will be used to improve the input parameters of IMBA. The aerosol distribution, number of condensation nuclei and radon concentration will be measured in typical houses in Aomori, and China. And then, the risk assessment of the internal exposure in these areas will be evaluated by using the improved IMBA model.
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