Gamma Dose Rate and Annual Effective Dose Equivalent in Uttara Kannada District, Karnataka, India.

This study reports the gamma absorbed dose rate (GADR) in 88 locations within five different geological regions of Uttara Kannada district. The measurements were made using a UR-705 environmental radiation dosimeter. The outdoor gamma absorbed dose rate varies from 44.5 to 220.0 nGy h^–1 with the mean value of 78.0 nGy h^–1, which is 1.3 times higher than the international average value of 59 nGy h^–1. The indoor gamma absorbed dose rate varies from 57.3 to 242.5 nGy h^–1 with an average of 90.0 nGy h^–1, which is slightly higher than the world average of 84 nGy h^–1 as suggested by UNSCEAR-2000. The estimated dose rate varies with the geological background and soil type. The total AEDE ranges from 0.3 to 1.38 mSv year^–1 with an average of 0.53 mSv year^–1. The average total AEDE is lower than the dose limit of 1 mSv year^–1 for public, suggested by ICRP-1991. [ABSTRACT FROM AUTHOR]