Risk assessment of radon in soil collected from chromite mines of Khanozai and Muslim Bagh, Balochistan, Pakistan

Abstract Radon is an inert gas that can transfer from rock, soil and accumulate in enclosed areas such as dwellings and mines. It is reported that exposure of miners to radon gas and its progenies can cause lung cancer. Therefore, monitoring of radon in underground mines is important to assess the health hazards to the miners. Keeping in view these facts measurement of radon in soil collected from chromite mines of Khanozai and Muslim Bagh, Balochistan was carried out using CR-39 track detector. The concentration of radon in soil collected from chromite mines of Khanozai was ranged 0.67 ± 0.06 to 1.94 ± 0.10 kBq/m3 with an average of 1.23 ± 0.69 kBq/m3 while in case of Muslim Bagh its values ranged from 0.49 ± 0.071 to 2.12 ± 0.11 kBq/m3 with an average of 1.26  ± 0.08 kBq/m3. The average values of radon exhalation rate were 9.95 ± 0.6 and 10.20 ± 0.68 Bq/m2 h from soil collected from chromite mines of Khanozai and Muslim Bagh, respectively. In addition to radon concentration and exhalation rate, radium activity (226Ra) were also calculated. Average values of radium activity for Khanozai and Muslim Bagh chromite mines were found 3.02 and 3.09 Bq/kg, respectively. The values obtained for radon exhalation rate were found below the average value of 57.60 Bq/m2 h recommended by UNSCEAR. Therefore, it is concluded that the mines understudy are safe from health hazards related to radon gas.