Terrestrial gamma dose rates and physical-chemical properties of farm soils from ex- tin mining locations in Jos-Plateau, Nigeria

The result of the decades of commercial tin mining activities left a legacy derelict landscapes and impoverished agricultural farm lands in the Jos, Plateau Nigeria. This situation is largely seen to impede environmental, agricultural sustainability and development in the area. It is the purpose of this study to provide a better perspective on the high radioactivity area in Jos Plateau and its implication on farm soil and would seek for any correlation between natural radioactivity and soil physical-chemical properties following the decades of mining activities in the area. To achieve this, soil samples were collected from different cultivated farmlands in three prominent ex-mining areas; Bitsichi, Bukuru and Ropp. The soil samples were analyzed for radioactivity levels due to 226Ra, 232Th and 40K using gamma-ray spectroscopy while physical-chemical parameters were determined using standard methods. Most of the physical and chemical properties of farm soils indicated low values in heavy mined area (Bitsichi) and relatively high values in low mined areas (Bukuru and Ropp). The farm soils across the locations were essentially acidic. Results also showed no obvious correlation between physical-chemical properties and the radionuclide concentration of 226Ra, 232Th and 40K in the farm soils. The outdoor radiation exposure to a farmer during farming operations in these mining areas and the likely associated radiological health risks were considered low and almost insignificant.Keywords: Farm soil, tin mining, terrestrial gamma effective dose rate, soil physical-chemical properties, natural radionuclide concentration, Jos-Plateau, Nigeria