Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations
Abstract
:1. Introduction
2. Materials and Methods
2.1. Ventilated-Type Accumulation Chamber System for Measuring Radon-Thoron Exhalation Rates from the Ground
2.2. Evaluation of Radon and Thoron Exhalation Rates Using the Ventilated Type Accumulation Chamber
2.3. Soil Parameters and Its Activity Concentrations of 226Ra and 228Ra
2.4. Comparison of the Exhalation Rates with the Other Methods
2.4.1. Accumulation Chamber with Scintillation Cell
2.4.2. In Situ Radon and Thoron Exhalation Rate Monitor
3. Results and Discussion
3.1. Physical Parameters of Soil and 226Ra and 228Ra Activity Concentrations at the Study Site
3.2. Radon and Thoron Concentration in the Ventilated-Type Accumulation Chamber
3.3. Comparison of Radon and Thoron Exhalation Rates Obtained by the Present System to Those Obtained by the Other Methods
3.4. Seasonal Variations of the Radon and Thoron Exhalation Rates
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Intercomparison | Methods | Radon Exhalation Rate (mBq m−2 s−1) | Thoron Exhalation Rate (mBq m−2 s−1) |
---|---|---|---|
1st measurement | Ventilated-type accumulation chamber | 3.6 ± 0.5 | 797 ± 336 |
Accumulation chamber with scintillation cell | 4.6 ± 2.9 | – | |
In situ monitor (MSZ) method | 1.1 ± 0.1 | 584 ± 103 | |
2nd measurement | Ventilated type accumulation chamber | 4.3 ± 0.5 | 1120 ± 321 |
Accumulation chamber with scintillation cell | 8.8 ± 5.3 | – | |
In situ monitor (MSZ) method | 5.1 ± 1.8 | 474 ± 177 |
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Modibo, O.B.; Tamakuma, Y.; Suzuki, T.; Yamada, R.; Zhuo, W.; Kranrod, C.; Iwaoka, K.; Akata, N.; Hosoda, M.; Tokonami, S. Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations. Int. J. Environ. Res. Public Health 2021, 18, 1489. https://doi.org/10.3390/ijerph18041489
Modibo OB, Tamakuma Y, Suzuki T, Yamada R, Zhuo W, Kranrod C, Iwaoka K, Akata N, Hosoda M, Tokonami S. Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations. International Journal of Environmental Research and Public Health. 2021; 18(4):1489. https://doi.org/10.3390/ijerph18041489
Chicago/Turabian StyleModibo, Oumar Bobbo, Yuki Tamakuma, Takahito Suzuki, Ryohei Yamada, Weihai Zhuo, Chutima Kranrod, Kazuki Iwaoka, Naofumi Akata, Masahiro Hosoda, and Shinji Tokonami. 2021. "Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations" International Journal of Environmental Research and Public Health 18, no. 4: 1489. https://doi.org/10.3390/ijerph18041489