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Radon (222Rn) and Thoron (220Rn) are radioactive noble gases which are produced in the decay chain of primordial radionuclides 238U and 232Th. These gases have been established as an important source of inhalation radiation dose to human which increases risk of lung cancer. Similarly the terrestrial 226Ra, 232Th, 40K 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 226Ra, 232Th and 40K is 47.0 ± 11.56 nGyh−1, found well within the safe limits of 86 nGyh−1. [ABSTRACT FROM AUTHOR]