Seasonal variability of 222 Rn and 220 Rn equilibrium factors in indoor environment of Kumaun Himalaya, India

In present study, 222 Rn, 220 Rn and progeny concentrations have been estimated by using passive techniques for radiological protection purpose. The average equilibrium factor for 222 Rn has been found to be 0.43, 0.29 and 0.30 for rainy, winter and summer seasons, respectively and 0.06, 0.05 and 0.05 for rainy, winter and summer seasons for 220 Rn. The annual equilibrium factor for 222 Rn was found quite close to the globally accepted value of 0.40 while for 220 Rn it was higher than the globally accepted 0.02. A statistically significant difference was obtained between inhalation dose estimated using global assumed equilibrium factors and calculated equilibrium factors.