This study evaluated terrestrial gamma radiation, radiological hazard indices and heavy metal contamination in soils from the Shakwatu artisanal gold mining area, Nigeria. In-situ background dose rates were measured across the mining field, while soil, tailings and mineral samples were analysed for activity concentrations of 238U, 232Th and 40K using gamma spectrometry. Heavy metal concentrations were also determined to assess pollution and ecological risks. The measured background dose rates exceeded recommended safety limits, indicating enhanced radiation associated with exposed mineralized zones and mine tailings. However, the mean activity concentrations of 238U, 232Th and 40K were 3.94, 6.60 and 139.90 Bq/kg, respectively, which are below the global averages reported by the United Nations Scientific Committee on the Effects of Atomic Radiation. The calculated radiological hazard indices were within permissible limits, suggesting low radiological risk and suitability of the soils as building materials. Heavy metal analysis showed elevated concentrations of lead, arsenic, chromium, copper and zinc, while cobalt, cadmium and nickel were below detection limits. Pollution and ecological risk indices indicated moderate contamination. These findings highlight the need for continuous environmental monitoring, proper tailings management and radiation protection measures in artisanal mining areas.
Magaji et al. (Thu,) studied this question.