目的调查个旧地区居室内氡（^222Rn）、钍射气（^220Rn）及其子体水平，明确钍射气的剂量贡献。方法考虑住宅类型和地理分布因素，从个旧市郊某村选取建筑结构有代表性的50户住宅的主卧室，采用氡-钍射气鉴别探测器测量氡、钍射气浓度...目的调查个旧地区居室内氡（^222Rn）、钍射气（^220Rn）及其子体水平，明确钍射气的剂量贡献。方法考虑住宅类型和地理分布因素，从个旧市郊某村选取建筑结构有代表性的50户住宅的主卧室，采用氡-钍射气鉴别探测器测量氡、钍射气浓度，用沉积率装置测量钍射气子体浓度。其中14间居室采用连续性氡测量探测器和α谱氡、钍射气鉴别探测器测量氡、钍射气浓度，空气采样滤膜结合CR-39探测器测量钍射气衰变产物浓度，碘化钠闪烁计数器测量地表γ剂量率。结果50间居室的氡浓度为32～498Bq／m^3，平均136Bq／m^3；钍射气浓度为39～7908Bq／m^3，平均3297Bq／m^3；钍射气子体浓度为2．0～23．9Bq／m^3，平均10．2Bq／m^3。钍射气子体衰变产物致居民年平均有效剂量大于氡子体衰变产物的平均年有效剂量（2．9mSv vs 1．6mSv）。结论个旧市郊部分居室室内钍射气及其子体浓度高，钍射气子体的剂量贡献要高于氡子体的剂量贡献。在个旧开展氡致肺癌危险评价研究应当考虑钍射气子体的剂量贡献。展开更多
Objective:To develop a radon detectors calibration system at the Research Centre for Nuclear Science and Technology(CRSTN)of the Institute of Geological and Mining Research(IRGM)in Cameroon.Methods:A transparent box n...Objective:To develop a radon detectors calibration system at the Research Centre for Nuclear Science and Technology(CRSTN)of the Institute of Geological and Mining Research(IRGM)in Cameroon.Methods:A transparent box named radon chamber,a certified radon source,and a reference device have been provided to Cameroon by the International Atomic Energy Agency(IAEA)within the framework of a technical cooperation project.Depending on what radon levels are expected,two different configurations(Hookup Ⅰ and Hookup Ⅱ)of the system are adopted.Hookup Ⅰ is a closed loop,and Hookup Ⅱ is an open loop that samples fresh air.Results:The operation of the system generates a radon concentration of up to~30,000 Bq/m3 when applied the Hookup Ⅰ and of up to 1,000 Bq/m^(3) using the Hookup Ⅱ configuration.For the calibration of the detectors for environmental radon monitoring,a stabilized concentration of 1,000 Bq/m^(3) is enough.Furthermore,temperature,relative humidity,and pressure,in the reference instrument ranged from 23 to 40℃,32%-72%,and 929 to 936 mBar,respectively.Inside the radon chamber,temperature,relative humidity,and pressure are similar to the laboratory's condition.Conclusion:The present calibration system will be useful for the calibration of radon detectors.The system can also be used for various purposes such as research activities on radon,education on radon detection,radon measurement,radon mitigation,radon mapping,protection against radon,and research in the African region.展开更多
Objective:To develop a new system to accurately measure the radon exhalation from the latex pillows,and to estimate its potential exposure to users.Methods:The new system is composed of two loops,the first loop is des...Objective:To develop a new system to accurately measure the radon exhalation from the latex pillows,and to estimate its potential exposure to users.Methods:The new system is composed of two loops,the first loop is designed to trap background radon and thoron until their levels are nearly zero,and the second loop is the measurement loop to detect radon and thoron exhalation rates from the pillows.Results:The results showed that mass radon exhalation rated ranged from 0.18 Bq·kg^(-1)·h^(-1) to 0.78 Bq·kg^(-1)·h^(-1),with an average of(0.36±0.17)Bq·kg^(-1)·h^(-1) in the 9 samples.The average annual effective dose to users in a model room was estimated to be(15.51±12.69)μSv by assuming two pillows was used.Conclusion:These results demonstrate that the new system can effectively measure radon exhalation rates in latex pillows,and the potential exposure to radon exhalating from the pillows is very low.展开更多
文摘目的调查个旧地区居室内氡（^222Rn）、钍射气（^220Rn）及其子体水平，明确钍射气的剂量贡献。方法考虑住宅类型和地理分布因素，从个旧市郊某村选取建筑结构有代表性的50户住宅的主卧室，采用氡-钍射气鉴别探测器测量氡、钍射气浓度，用沉积率装置测量钍射气子体浓度。其中14间居室采用连续性氡测量探测器和α谱氡、钍射气鉴别探测器测量氡、钍射气浓度，空气采样滤膜结合CR-39探测器测量钍射气衰变产物浓度，碘化钠闪烁计数器测量地表γ剂量率。结果50间居室的氡浓度为32～498Bq／m^3，平均136Bq／m^3；钍射气浓度为39～7908Bq／m^3，平均3297Bq／m^3；钍射气子体浓度为2．0～23．9Bq／m^3，平均10．2Bq／m^3。钍射气子体衰变产物致居民年平均有效剂量大于氡子体衰变产物的平均年有效剂量（2．9mSv vs 1．6mSv）。结论个旧市郊部分居室室内钍射气及其子体浓度高，钍射气子体的剂量贡献要高于氡子体的剂量贡献。在个旧开展氡致肺癌危险评价研究应当考虑钍射气子体的剂量贡献。
基金partly funded by the investment budget of the Ministry of Scientific Research and Innovation,Cameroon(BIP 2020,2021)the Technical Cooperation Fund of the International Atomic Energy Agency(CMR9009).
文摘Objective:To develop a radon detectors calibration system at the Research Centre for Nuclear Science and Technology(CRSTN)of the Institute of Geological and Mining Research(IRGM)in Cameroon.Methods:A transparent box named radon chamber,a certified radon source,and a reference device have been provided to Cameroon by the International Atomic Energy Agency(IAEA)within the framework of a technical cooperation project.Depending on what radon levels are expected,two different configurations(Hookup Ⅰ and Hookup Ⅱ)of the system are adopted.Hookup Ⅰ is a closed loop,and Hookup Ⅱ is an open loop that samples fresh air.Results:The operation of the system generates a radon concentration of up to~30,000 Bq/m3 when applied the Hookup Ⅰ and of up to 1,000 Bq/m^(3) using the Hookup Ⅱ configuration.For the calibration of the detectors for environmental radon monitoring,a stabilized concentration of 1,000 Bq/m^(3) is enough.Furthermore,temperature,relative humidity,and pressure,in the reference instrument ranged from 23 to 40℃,32%-72%,and 929 to 936 mBar,respectively.Inside the radon chamber,temperature,relative humidity,and pressure are similar to the laboratory's condition.Conclusion:The present calibration system will be useful for the calibration of radon detectors.The system can also be used for various purposes such as research activities on radon,education on radon detection,radon measurement,radon mitigation,radon mapping,protection against radon,and research in the African region.
基金supported by the Thailand Institute of Nuclear Technology(TINT),Thailand.
文摘Objective:To develop a new system to accurately measure the radon exhalation from the latex pillows,and to estimate its potential exposure to users.Methods:The new system is composed of two loops,the first loop is designed to trap background radon and thoron until their levels are nearly zero,and the second loop is the measurement loop to detect radon and thoron exhalation rates from the pillows.Results:The results showed that mass radon exhalation rated ranged from 0.18 Bq·kg^(-1)·h^(-1) to 0.78 Bq·kg^(-1)·h^(-1),with an average of(0.36±0.17)Bq·kg^(-1)·h^(-1) in the 9 samples.The average annual effective dose to users in a model room was estimated to be(15.51±12.69)μSv by assuming two pillows was used.Conclusion:These results demonstrate that the new system can effectively measure radon exhalation rates in latex pillows,and the potential exposure to radon exhalating from the pillows is very low.
