Estimation of radon in groundwater and analysis of radon and thoron exhalation rates of the soil in Mokokchung district, Nagaland, India

The present study of the analysis of radon in groundwater and its exhalation rates in soil was carried out in 19 selected locations in Mokokchung district, Nagaland, India. The survey was carried out by employing a portable scintillation-based smart RnDuo monitor. The radon (222Rn) mass exhalation rates of the soil were found to vary from 27 mBqKg- 1h- 1 to 40 mBqKg-1h-1 with an average of 31 +/- 0.8 mBqKg- 1h- 1. While the thoron (220Rn) surface exhalation rate of the soil was found to vary from 714.6 Bqm- 2h-1 to 2166.6 Bqm- 2h-1 with an average of 1009.9 +/- 77.1 Bqm- 2h-1. The radon (222Rn) in drinking water was found to vary from 1.48 BqL-1 to 2.22 BqL-1 with an average of 1.82 +/- 0.04 BqL-1 and is below the world average values as set by USEPA (1991), WHO (2004) and UNSCEAR (2008). Furthermore, the total effective dose range is below the WHO (2003) recommendation.