Radionuclide Contamination in Water Sources in Kaabong District, Uganda

Abstract This study assessed the activity concentrations of 226 Ra, 232 Th, and 40 K in water samples from selected boreholes in the Kaabong District. The study sampled boreholes from the sub-counties of Loyoro, Sidok, Kaabong Central, Kaabong East, and Kasile. The radioactivity concentration of the radionuclides was determined using gamma-ray spectrometry. We assessed radiological health risks by calculating the annual effective dose (AED) for infants, children, and adults, and the excess lifetime cancer risk (ELCR). The AED and ELCR were compared with the World Health Organization (WHO) safety limits. Results indicated the presence of gamma radiation from 226 Ra, 232 Th, and 40 K in the water samples. The overall average activity concentration in the sub-counties for the radiation was: 1.19 Bq/L for 226 Ra, 2.10 Bq/L for 232 Th, and 0.62Bq/L for 40 K. These levels of activity concentration are above the safety limits of 1.0 Bq/L for 226 Ra and 232 Th. The activity concentration for 40 K, was below the WHO recommended limit of 10.0 Bq/L. The AED averages were above the safety limits of 100 \(\:\mu\:\)Sv/y for adults. For children, the communities in Loyoro, Sidok, and Kaabong East ingested more than 100 \(\:\mu\:\)Sv/y of gamma radiation associated with 226 Ra. For Kaabong Central and Kasile, the ingestion rate is below the 100 \(\:\mu\:\)Sv/y safety limit. Overall, the results indicated radiological risks associated with the sampled borehole water.