Level and Potential Radon (222Rn) Radiation Risk in Groundwater Samples at Jimba-Oja, Northcentral Nigeria

Abstract: Radon (222Rn) concentration in groundwater was investigated using the Rad7 detector. This investigation was necessary due to the impact of a new mining company in Jimba-Oja, which may affect the surface water supply, potentially percolating into subsurface water sources. Nine (9) samples were collected from hand-pump wells and analyzed in the laboratory. The estimated radon concentration ranged from 3.08 Bq. L-1 to 9.18 Bq. L-1 with an average value of 5.00 BqL-1. The average AED for groundwater ingestion by adults, children, and infants was calculated at 36.50, 54.75, and 63.88 μSv.y^(-1), respectively. The average AEDtotal values were 162.50 μSv.y^(-1) for adults, 180.75 μSv.y^(-1) for children, and 189.88 μSv.y^(-1) for infants. The results indicate that the AED for infants exceeds the permissible limit of 100 μSv.y^(-1), while the values for children and adults remain within the recommended limit of 200 μSv.y^(-1). Thus, the health risk from radiological exposure is within allowable limits for children and adults but poses a potential risk for infants. Although 222Rn concentrations in groundwater samples are low, are currently low, there may still be probabilistic effects on local inhabitants over time. To monitor 222Rn levels, we recommend repeating these measurements in the same wells and season within the next two years to ensure consistency and detect any changes in radon levels. Keywords: Radon (222Rn) concentration, Groundwater, Jimba-Oja, Dose rate.