A comparative study of natural 40K content estimated through whole body counting and dietary intake around Narora Atomic Power Station

773 radiation workers at NAPS, aged 20 to 59 years, were monitored using Shadow Shield Whole Body Counting System having NaI (Tl) crystal coupled with NETS-3 1 K Multi Channel Analyser (MCA) to determine the 40K activity in the body and assess internal dose due to naturally occurring 40K. The data have been segregated to make analyses for vegetarian and non-vegetarian. The average annual dose from 40K for the subjects is evaluated as 156.4 ± 36.1 mSv. Natural 40K content in 463 environmental samples collected from Narora environ estimated using NaI(Tl) well type detector coupled with 1 K NETS-3 Multichannel analyser (MCA). Assessment of daily intake of natural 40K has been estimated from average daily intake of dietary items and the associated 40K activity. It works out to be 67.17 ± 16.28 Bq/d and that obtained through analysis of complete meal samples was 73.22 ± 9.78 Bq/ d. The average annual dose to a member of public of this region due to natural 40K through ingestion route works out to be 152.12 ± 36.83 mSv/year. (author)