Assessment of Radon-222 in Selected Water Sources in Gwagwalada, Gwagwalada Area Council, FCT, Abuja, Nigeria

The exposure of a population to high concentration of Radon-222 for a long period has significant health effects ranging from respiratory functional changes to cancer of the lungs. Also, a very high level of Radon-222 in drinking water can lead to stomach and gastrointestinal tract cancer. In this work, the activity concentrations of Radon-222 (222 Rn) were investigated from thirty (30) water samples which includes twenty (20) borehole water samples and ten (10) well water samples from Gwagwalada town using liquid scintillation counter at the Centre for Energy Research and Training (CERT) Ahmadu Bello University Zaria, Nigeria. Radon-222 concentrations obtained from this analysis ranged within (7.72 to 172.30) Bq/L. The highest and the lowest Radon-222 activity concentration were recorded from borehole and well water samples at Abattoir and kasuwan Derey respectively. Borehole water samples recorded the highest mean radon concentration of 45.11Bq/L while well water samples recorded the lowest mean Radon-222 concentrations of 27.60Bq/L. From computed results, it was observed that 88.89% of the recorded values were found to be above the world average Maximum Contamination Level (MCL) of 10Bq/L set by the World Health Organization and the MCL of 11.1Bq/L set by the United States Environmental Protection Agency (USEPA, 1991). Similarly, 15% of the recorded values were above the recommended action level of 100Bq/L set by the World Health Organization (WHO, 2008). Also, the corresponding Mean Annual Effective Doses estimated for the three (3) categories of people from the two (2) water types were found to be (0.331, 0.662 and 2.318) mSv/y in borehole water for adults, children and infant respectively. While due ingestion of Radon-222 in well water samples were found to be (0.201, 0.403 and I.417) mSv/y for adults, children and infants respectively. All the Mean Annual Effective Doses were found to be above World Health Organization's...