Study of environmental radon exhalation, radium and effective dose in Dilli-Jeypore coalfield, India using LR-115 (II) nuclear track detectors

The radium contents, radon exhalation rates and corresponding annual effective doses due to inhalation of radon from coal and soil of Dilli-Jeypore coalfield of Assam, India have been measured using LR-115 (II) nuclear track detectors in the context of health risks. In the present paper, the results of the study with their corresponding geometric means (GM), geometric standard deviations (GSD) and error estimates for both coal and soil samples are presented. The estimated values for coal samples are in the range 1274.2-1658.8 Bq/m(3), 16.0-20.8 mBq/kg/h, 532.5-693.2 mBq/m(2)/h, 16.4-21.4 Bq/kg and 38.7-50.3 mu Sv/y for radon activity, mass exhalation rate, surface exhalation rate, radium content and annual effective dose, respectively. In the case of soil, the values for radon activity, mass exhalation rate, surface exhalation rate, radium content and annual effective dose were estimated to be in the range 1308.8-2105.6 Bq/m(3), 16.4-26.4 mBq/kg/h, 547.0-880.0 mBq/m(2)/h, 16.9-27.1 Bq/kg and 39.7-63.9 mu Sv/y, respectively. The lifetime fatality risk estimates have also been assessed.