Measurement of 222Rn and 220Rn exhalation rate from soil samples of Kumaun Hills, India
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The source terms, i.e., exhalation and emanation from soil and building materials are the primary contributors to the radon (222Rn)/thoron (220Rn) concentration levels in the dwellings, while the ecological constraints like ventilation rate, temperature, pressure, humidity, etc., are the influencing factors. The present study is focused on Almora District of Kumaun, located in Himalayan belt of Uttarakhand, India. For the measurement of 222Rn and 220Rn exhalation rates, 24 soil samples were collected from different locations. Gamma radiation level was measured at each of these locations. Chamber technique associated with Smart Rn Duo portable monitor was employed for the estimation of 222Rn and 220Rn exhalation rates. Radionuclides (226Ra, 232Th and 40K) concentrations were also measured in soil samples using NaI(Tl) scintillation based gamma ray spectrometry. The mass exhalation rate for 222Rn was varying between 16 and 54 mBq/kg/h, while the 220Rn surface exhalation rate was in the range of 0.65–6.43 Bq/m2/s. Measured gamma dose rate for the same region varied from 0.10 to 0.31 µSv/h. Inter-correlation of exhalation rates and intra-correlation with background gamma levels were studied.
KeywordsRadiation Exhalation rate Emanation rate Gamma dose rate
The investigators acknowledge the Board of Research in Nuclear Science (BRNS), Department of Atomic Energy (DAE), Mumbai, India, for extending their laboratory facilities for conducting the experimental work.
The present research was funded by Board of Research in Nuclear Science (BRNS), Department of Atomic Energy (DAE), Mumbai, India [Project no. 2013/36/61-BRNS/2470].
- Gaware JJ, Sahoo BK, Sapra BK, Mayya YS (2011) Development of online radon and thoron monitoring systems for occupational and general environments. BARC News Lett 318:45–51Google Scholar
- Kant K, SonkawadeRG Sharma GS, Chauhan RP (2009) Seasonal variation of radon, thoron and their progeny levels in dwellings of Haryana and Western Uttar Pradesh. Iran J Radiat Res 7:79–84Google Scholar
- Radiation U.N.S.C. on the E. of A, Radiation U.N.S.C. on the E. of A (2011) UNSCEAR 2010 Report to the General Assembly. Summary of low-dose radiation effects on health. New York: United NationsGoogle Scholar
- Ramola RC, Choubey VM, Prasad Y, Prasad G, Bartarya SK (2006) Variation in radon concentration and terrestrial gamma radiation dose rates in relation to the lithology in southern part of Kumaon Himalaya, India. Environ Earth Sci 41:714–720. https://doi.org/10.1016/j.radmeas.2006.03.009 Google Scholar
- UNSCEAR (2000) Sources and effects of ionizing radiation. United Nation Scientific Committee on the Effects of Atomic Radiation, New YorkGoogle Scholar
- Valdiya KS (1980) Geology of kumaun lesser Himalaya. Wadia Institute of Himalayan Geology, DehradunGoogle Scholar