Radiological Impact Assessment of Radon Levels in Drinking Water and its Associated Health Risks in Aniocha North, Delta State, Nigeria

Groundwater is a major source of natural water for domestic, industrial and agricultural use; however, its contamination by 222Rn has become a major source of human health concern globally. To assess the associated health risks of radon exposure to various age groups within Aniocha North Local Government Area (LGA) of Delta State, Nigeria, twenty water samples from 12 surface reservoirs and eight boreholes were collected from five communities within the local government and analyzed using RAD7. The measured concentrations of 222Rn in the sampled water, ranges from 0.278 in OBIOR 5 to 9.281 in ISSELE-AZAGBA 3 with mean concentration of 3.808 , found to be lower than the recommended threshold by the United States Environmental Protection Agency. The estimated radiological indices revealed that the average annual effective doses due to ingestion of radon are 8.82714×10-6, 3.9998×10-6, and 2.79296×10-6 for adults, children and infants respectively. Inhalation dose ranged from 0.0004158 to 0.02338812 with a mean of 0.008689212 all of which are below 0.1 , radiogenic cancer risk (RCR) are 0.001937832, 0.000875817, 0.000610314, for adults, children and infants while for excess lifetime cancer risk (ELCR) are 3.39845×10-5, 1.53992×10-5, 1.07529×10-5 for adults, children and infants. Results reveal that there is no significant public health risk from 222Rn ingested and inhaled from sampled water within study area.