Radon concentrations in coal mines of Baluchistan, Pakistan

Prolonged exposure to radon, the largest source (69%) of natural radioactiv ity, may cause lung cancer and bronchial tissue damage. So monitoring of ra don at places of high radioactivity and in underground mines is important t o assess the radiological hazards to occupational workers. For these reason s radon measurements were carried out in some coal mines of Baluchistan, Pa kistan. The measurements were based upon passive detection of radon using C N-85 track detectors in Box Type Dosimeters. The radon concentration varied from 121 to 408 Bq m(-3) in the mines under study. The computed radon dose varied from 1.38 to 4.67 mSv yr(-1) with an average of 2.19 +/- 0.5 mSv yr (-1). These coal mines have been found to be safe from radon-related health hazards. (C) 2000 Elsevier Science Ltd. All rights reserved.