| Project/Area Number |
18K10023
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 58020:Hygiene and public health-related: including laboratory approach
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| Research Institution | Hirosaki University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
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| Keywords | ラドン / トロン / 散逸率 / 測定器 / ZnS(Ag) / 光電子増倍管 / 性能評価 / 循環法 / 換算係数 / 捕集流量 / 差圧 / 較正場 / 吸い出し効果 / 沖縄県 / 放射線計測 / ZnS(Ag)シンチレータ / 温度補正係数 / 蓄積法 / 肺がん / 可搬型測定器 / 高自然放射線地域 |
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| Outline of Final Research Achievements |
Radon is normally generated by alpha-decay from radium in soil, rocks, building materials, and water. Radon inhalation is believed to increase the risk of lung cancer and is second only to tobacco smoking as a risk factor. In this study, a portable type radon and thoron exhalation monitor was developed to know the risk potential due to radon inhalation based on the accumulation method. The monitor developed in this study is equipped with an accumulation chamber of 4 L volume to accumulate radon and thoron gasses from the materials. Alpha-particles from radon, thoron and their decay products are detected by ZnS(Ag) scintillator which is connected to six photomultiplier tubes. In the field survey, we evaluated the conversion factor from counting rates obtained by the developed monitor to the radon and thoron exhalation rates by the comparative measurements with a circulation method which is composed an accumulation chamber and an electrostatic radon and thoron monitor.
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| Academic Significance and Societal Importance of the Research Achievements |
近年、国際放射線防護委員会はラドンの吸入被ばくによる線量評価に用いられる線量係数（放射能濃度から実効線量への換算係数）は従来の約2倍程度であることを報告したことから、国際的にラドンに対する健康影響関する議論が活発になっている。ラドンの発生源は土壌、建材、岩石、水などあらゆるものからである。したがって、その発生源情報（散逸率）を把握することは、ラドンの吸入被ばくによる潜在的リスクを推定するだけでなく、高い濃度レベルの家屋が発見された場合の低減策の検討にも役に立つ。開発した測定器は、取り扱いが簡単で可搬性に富むことから、ラドン・トロンの潜在的リスク評価の調査に応用することが可能である。
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