Gamma radiation dose rate in indoor, outdoor and underground atmosphere around Tehri dam project, Uttarakhand, India.

The natural pollution level due to gamma radiation was measured in about 22 residential houses around the Tehri Dam Project in Uttarakhand state by using Environmental Radiation Dosimeter. Both urban and rural houses were selected for the measurements. The recorded gamma dose rate in indoor atmosphere was found to vary from 25.1 μR/h to 67 μR/h with a mean value 38.6 μR/h whereas in traditional rural houses the obtained values varied from 42.6 μR/h to 83.5 μR/h with mean value 60.3 μR/h. In outdoor atmosphere, it was found to vary from 25.1 μR/h to 60 μR/h with an average value 35.8 μR/h. It is observed that the dose rates are higher in rural houses than that in modern houses. Efforts have also been made to observe deviation of dose rate in the underground (Power House) atmosphere of Tehri Dam Project in vertical and horizontal mode. It was observed that dose rate remain almost same in horizontal mode, but a significant variation has been found in the vertical mode. In addition, the variation of dose rate with type of building material, trend and mode of construction of houses and the age of houses are also discussed in detail. [ABSTRACT FROM AUTHOR]