Comprehensive assessment of radiological hazards in chromite mines at Khanozai and Muslim Bagh, Balochistan, Pakistan

The concentrations of natural radioactivity in soil samples collected from chromite mines of two different towns, Khanozai and Muslim Bagh, districts of Pishin and Killa Saifullah, respectively, were measured using a high purity germanium (HPGe) detector. The average values of ²²⁶Ra, ²³²Th and ⁴⁰K in soil of Khanozai chromite mines were found to be 26.414, 37.321 and 404.561 Bq kg^-1, respectively. In Muslim Bagh chromite mines, these values were found to be 17.59, 29.677 and 380.475 Bq kg^-1, respectively. The maximum average values of radium equivalent (Ra_eq), external hazard index (H_ex) and internal hazard index (H_in) were found to be 110.851, 0.299 and 0.356 Bq kg^-1, respectively, in chromite mines of Khanozai, while the minimum average values were found to be 89.253, 0.276 and 0.275 Bq kg^-1, respectively, in Muslim Bagh chromite mines. Similarly, maximum average values of absorbed dose rate (D_R), external absorbed dose rate (D_out) and internal absorbed dose rate (D_in) were found to be 50.742, 54.651 and 77.058 nGy h^-1, respectively, in soil of Khanozai chromite mines while the minimum average values were found to be 41.311, 44.385 and 62.583 nGy h^-1, respectively, in Muslim Bagh chromite mines. Also, the maximum average values of annual effective dose risk (AEDR), gamma activity index (I_γ) and alpha activity index (I_α) were found to be 2.30 × 10^-1 mSv y^-1, 0.409 and 0.132, respectively, in soil of Khanozai chromite mines while the minimum average values were found to be 2.02 × 10^-1 mSv y^-1, 0.333 and 0.087, respectively, in Muslim Bagh chromite mines. The values were found to be below the world permissible range. Therefore, it is concluded that the chromite mines under the study have no health hazards.