Annual Effective Dose Estimation from Radon Concentration in Commonly Consumed Bottled Water in Northcentral Nigeria

Radon (222Rn), the heaviest among the noble gas in the periodic table of element, is radioactive nuclide that is naturally available in rocks, soil and water. In this study, a total of ten (10) brands of commonly consumed commercial bottled water in northcentral Nigeria were collected and assigned for their radon concentration using liquid scintillation counter (LSC). The highest radon (222Rn) concentration of 0.073 Bq/l was recorded in C Way bottled water while Mr. V bottled water recorded the lowest 222Rn concentration value of 0.016 Bq/l. These values were below the parametric reference level of 11.1 Bq/l set by United State of America Environmental Protection Agency and lower than the permissible limit of 100 Bq/l by World Health Organization (WHO) and European Union. Computed total annual effective dose due to ingestion and inhalation of waterborne radon recorded the highest mean value of 0.187 μSv/y in C Way Bottled water and lowest value of 0.041 μSv/y in Mr. V bottled water. Mean total annual effective dose recorded for all the bottled water samples were found to be significantly lower than the safety limit of 0.1 mSv/y recommended by WHO. The likelihood of any radiation incidence among the public due to consumption of commercial bottled water is therefore negligible.