Measurement of indoor 222 Rn, 220 Rn and decay products along with naturally occurring radionuclides in some monuments and museums of Punjab, India

Radon ( 222 Rn) and Thoron ( 220 Rn) are radioactive noble gases which are produced in the decay chain of primordial radionuclides 238 U and 232 Th. These gases have been established as an important source of inhalation radiation dose to human which increases risk of lung cancer. Similarly the terrestrial 226 Ra, 232 Th, 40 K are known to contribute to cumulative external background exposure to humans. In the present study, these radionuclides of concern were measured in the environment of monuments and museums in the state of Punjab and the resultant dose was calculated for the occupants. The calculated Annual Inhalation Dose level varied from 1.5 to 4.0 mSv with mean of 3.0 ± 0.8 mSv. The cumulative dose from all radionuclides 226 Ra, 232 Th and 40 K is 47.0 ± 11.56 nGyh −1 , found well within the safe limits of 86 nGyh −1 .