Assessment of Thoron exhalation from the soil samples of tectonically active Ghuttu Window region: Radiation health hazard perspective

Thoron, an isotope of radon, emits highly energetic alpha particles, and the high-level exposure of its daughter products is responsible for lung cancer. The study focuses on Thoron transportation via its emanation and exhalation process. It is useful to analyze the emanation and exhalation rates of the soil for the specific characteristic of radon isotopes and their health hazard. Our analysis is based on soil samples collected from different locations of the Ghuttu Window and its vicinity from Tehri Garhwal, Uttarakhand, India. Measurements are performed in active mode using the Smart Rn-Duo instrument. The results clearly show that Thoron surface exhalation rate varies from 1040.4 +/- 112 to 4077.2 +/- 222 mBq/m(2)/s with an average of 2701.53 +/- 862.15 mBq/m /s. The Thoron emanation rate ranges from 90.05 to 476.93 mBq/kg/s with an average value of 277.21 mBq/kg/s. A strong positive correlation between emanation and exhalation rate of Thoron exists. However, some values are quite high in the active tectonic zones, but dose exposure due to Thoron is found below health risk.