Environmental radioactivity measurement in soils of an abandoned potash deposit at Holle, Republic of Congo

Abstract

The main objective of the present study was to assess natural radioactivity level from soils of an abandoned potash mine and its surroundings at Holle locality in Hinda district, the Republic of Congo. Samples were analyzed using an HPGe gamma spectrometer. Activity concentration values obtained varied from 21.01 ± 6.47 to 117.3 ± 2.69 Bq/kg with a mean value of 46.15 ± 4.69 Bq/kg of 40K; that of 238U varied from 17.36 ± 10.74 to 40.04 ± 8.58 Bq/kg with a mean value of 25.14 ± 10.06 Bq/k, while that of 232Th varied from 8.68 ± 3.7 to 27.33 ± 2.69 Bq/kg with a mean value of 18.16 ± 2.94 Bq/kg. Mean activity concentration values obtained for 238U, 232Th and 40K were relatively low compared to the world average values. Radiological hazard indices associated were also calculated and found to be under recommended limits. Results pointed out that radioactivity level in the region was relatively low. Consequently, soils of the surrounding abandoned potash mine can be used for buildings construction.