Title: Radiological Assessment of Natural Radionuclides in Irrigation Farm Soils of Igabi Local Government Area, Kaduna State, Nigeria Using X-Ray Fluorescence (XRF)
Authors: Shehu Balarabe
Shafiu Mannir Kangiwa
Modu Mustapha Gambo
Volume: 10
Issue: 2
Pages: 323-328
Publication Date: 2026/02/28
Abstract:
The presence of naturally occurring radioactive materials (NORMs) in agricultural soils poses potential radiological risks through food-chain transfer and prolonged environmental exposure. This study assessed the activity concentrations and associated radiological hazards of 238U, 232Th, and 40K in irrigated farm soils within Igabi Local Government Area, Kaduna State, Nigeria, using Energy Dispersive X-ray Fluorescence (XRF) analysis. A total of nine composite soil samples were collected from three locations (Danmani, Rigasa, and Airport areas), prepared under controlled laboratory conditions, and analyzed for elemental concentrations, which were subsequently converted to activity concentrations (Bq/kg). The mean activity concentrations ranged from 8.86-19.48 Bq/kg for 238U, 4.95-5.97 Bq/kg for 232Th, and 541.81-935.72 Bq/kg for 40K. While 238U and 232Th values were below the global averages recommended by UNSCEAR (50 Bq/kg and 40 Bq/kg, respectively), 40K exceeded the world average of 500 Bq/kg across the study sites, likely due to geological formations, fertilizer application, and sediment deposition. The absorbed dose rates (29.67-51.27 nGyh?¹), annual effective dose (0.18-0.32 mSv/y), and hazard indices (Hex: 0.18-0.35; Hin: 0.16-0.27) were all below internationally permissible limits, indicating low radiological risk to farmers and residents. The findings confirm that the soils are radiologically safe for agricultural use and habitation. However, because XRF provides indirect activity estimation, confirmatory measurements using gamma spectrometry are recommended. Regular environmental monitoring and controlled fertilizer management are also advised to prevent long-term radionuclide accumulation and ensure sustainable agricultural safety.