Natural Radioactivity and External Dose Rates in Tailing Samples from Rosterman Gold Mine, Kakamega County, Kenya

Abstract

In this article, documented results of natural radionuclide concentrations in tailings at Rosterman gold mine, Kakamega county, Kenya were evaluated. Thirty tailing samples from Rosterman gold mine were collected as per standard sampling procedures and were analyzed for 238U, 232Th and 40K by NaI (TI) gamma-ray spectroscopy. The activities of 238U, 232Th and 40K was found to vary from 39 ± 1.63 Bq/Kg to 118 ± 4.43 Bq/Kg, 72 ± 2.24 Bq/Kg to 223 ± 8.36 Bq/Kg and 85 ± 3.6 Bq/Kg to 362 ± 10.65 Bq/Kg respectively. Radium equivalent activities were found below 370 Bq/Kg in all the collected samples. External gamma dose rates estimated from the levels of radionuclides in tailings had a range of 32 ±3.4 nGy/h to 68 ± 5.83 nGy/h. Hence, mining of gold at Rosterman has minimal significant health implications to the general population and the miners.