RADIOLOGICAL RISKS OF RADIUM-226 ON GROUNDWATER BASED-DRINKING IN KUBWA AND GOSA AREA OF ABUJA , NORTH CENTRAL NIGERIA

摘要

The radiological risks associated with radium-226 in groundwater samples were analyzed using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The mean annual effective dose from the natural radionuclide of radium-226 (226R) was estimated to be 2.2 x 10‒5 mSv. In the groundwater samples, Lifetime average daily dose (LADD) ranged from 1 x 10‒3 to 2 x 10‒3 μg kg‒1 day‒1. The LADDs and the highest cancer mortality risk was found at Kubwa borehole with a value of 3.1 × 10‒8 and lower value reported at Gosa borehole with a value of 1.8 x 10‒8 . The highest cancer morbidity of 9.7 x 10‒9 was noted at Kubwa whereas lower value of 5.2 x 10‒9 reported at Gosa borehole. The radiological risks of 226Ra in the water samples were found to be low, typically in magnitude of 10−7. With this low level of radiological implications, it may be the chemical toxicity associated with 226Ra as a heavy metal. The values obtained in the study area may not pose radiological hazards to the residents that rely on groundwater. At the same time, measures of groundwater quality protection and monitoring should be enhanced and new supply source which has lower risk must found.