Determination of Gross Alpha and Beta Radioactivity in Selected Water Samples from Kware LGA, Sokoto State, Nigeria

Abstract

The mobilization of naturally occurring radioactive materials (NORMs) into water resources constitutes a critical public health imperative in mining-impacted regions, yet systematic radiological surveillance remains critically deficient across Nigeria's northwestern sedimentary basins. This study presents the first determination of gross alpha and gross beta activity concentrations in water samples from selected mining localities in Kware Local Government Area (LGA), Sokoto State, Nigeria. Six representative samples (KWASOK1–KWASOK6) were collected via stratified random sampling with proportional allocation, preserved through UV-assisted organic matter deactivation and acidified filtration, and analyzed using a Hidex 300SL liquid scintillation counter with triple-to-double coincidence ratio (TDCR) counting and pulse shape discrimination. Gross alpha activity ranged from 0.027 ± 0.11 to 1.078 ± 0.01 Bq/L (mean: 0.392 ± 0.214 Bq/L), while gross beta activity ranged from 3.121 ± 0.02 to 11.186 ± 0.19 Bq/L (mean: 6.982 ± 1.227 Bq/L). One-sample t-tests confirmed statistically significant exceedance of the WHO gross beta guideline (1.0 Bq/L; t = 4.877, p = 0.005, Cohen's d = 1.991), with 100% of samples surpassing permissible thresholds and 33% exceeding the gross alpha limit (0.1 Bq/L). The absence of alpha-beta correlation (r = − 0.062, p = 0.907) indicates decoupled contamination pathways alpha-emitters localize to discrete ore contacts while beta-emitters distribute basin-wide through phosphate weathering. Estimated lifetime cancer risks (3.25 × 10⁻³ to 6.50 × 10⁻³) exceed global background thresholds, demanding immediate regulatory classification of Kware LGA as a radiological priority zone with mandatory remediation and health screening.