Indoor 222Rn and 220Rn variations: Evidence for Boyle’s law

Background: Radon and its daughter product are a major source of natural radiation exposure, the measurement of radon concentration in dwellings is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contributes significantly to total inhalation dose and is well established that radon when inhaled in large quantity causes lung disorder. In view of this the authors have measured 222Rn and 220Rn levels in dwellings of different volumes at Bangalore Metropolitan, India. Materials and Methods: Integrated and long duration measurements of radon were carried out using twin cup dosimeters with Solid State Nuclear Track Detector technique. Results: Results showed that concentrations of 222Rn, 220Rn, their progenies and dose rates in dwellings decreased with increase in room volume. Conclusions: The annual effective inhalation dose due to 222Rn, 220Rn and their progenies from the study ranged between 0.2–4.4 with an arithmetic mean of 1.7 ± 1.1 mSv y-1. The dwellers of lower volumes are posed to high dose rates.