Natural radionuclide distribution in soils of Gudalore, India

The concentration of primordial radionuclides in soil samples of Gudalore T aluk in the Udagamandalam district has been measured from the gamma ray spe ctrum of the soil. The mean activities of Th-232, U-238 and K-40 are 75.3 /- 44.1, 37.7 +/- 10.1 and 195.2 +/- 85.1 Bq kg(-1) dry weight, respectivel y. The average outdoor absorbed dose rate in air at a height of 1 m above g round is 74.3 +/- 27.8 nGy h(-1), corresponding to an annual effective dose equivalent of 455.6 mu Sv, The dose equivalent ranges from 168.3 to 1250.5 mu Sv. The results have been compared with other global radioactivity meas urements and evaluations. (C) 2000 Elsevier Science Ltd. All rights reserve d.