Assessment of the radiological health hazards around mine sites in Jos Area, Nigeria
摘要
Mining activities contribute to the accumulation of radionuclides, necessitating an assessment of the level of radioactivity around mine sites and the potential radiological hazards they pose to human health and the environment. This study assesses the radiological impacts of mining activities on the residents of selected mining areas at Rayfield, Gero, Sabongida Kanar, Kuru Jantar, Bisichi and Barkin Ladi in Jos Area, Nigeria. The activity concentration of 40K, 226Ra and 232Th in 24 mine wastes and 36 soil samples collected from farmlands adjoining the selected mine sites were determined by using a gamma–ray spectrometer fully equipped with an MPC 2000 radiation counter. This was done in accordance with the provisions of International Atomic Energy Agency (IAEA). Subsequently, the radiological hazard indices due to the radionuclides were evaluated following standard procedures. The mean activity concentrations of 40K, 226Ra and 232Th in both the mine waste and soil samples of the study area were found to exceed the global average terrestrial concentrations of 400, 35 and 40Bq/kg for 40K, 226Ra and 232Threspectively. The mean outdoor annual effective dose (OAED) for mine waste (7.6 ± 0.2 mS/yr) and soil samples (1.9 ± 0.04 mS/yr) was higher than the mean value of the control (1.46 ± 0.37) as well as the acceptable limits of 1 mS/yr for non-radiation workers, the world and Nigerian averages. Excess lifetime cancer risk (ELCR) values significantly exceed the global average of 0.52 × 10–3. The values of the hazard parameters like the radium equivalent activity (Raeq), OAED as well the ELCR were significantly higher than the recommended values and therefore pose considerable radiological hazard either on direct contact or being used as construction materials. The different hazard indices show a potential source of high radiological exposure. The findings indicate serious radiological health and environmental risks, requiring strict policy interventions, safer mining practices, remediation plans, and restrictions on the utilization of these mine wastes in construction and farming.