Asssesment of Natural Radionuclides and Associated Radiation Hazards in Water Sources of Islamabad, Pakistan

This paper reports concentrations of Ra-226, Th-232 and K-40 in drinking waters in Pakistan. The aim is to estimate the radiological hazard and assess the safety of drinking water. Radiation hazard indices, and Excess Lifetime Cancer Risks are reported from all measurements. Different water samples have been collected from Islamabad (33o 38'N, 73o 09’E) and analysed using a High Purity Germanium Detector (HPGe). The average concentration values of Ra-226, Th-232 and K-40 were 6+/-0.6 Bq/L, 32+/-1 Bq/L and 74+/-2 Bq/L respectively. The radium equivalent activity was 58 Bq/L, the outdoor external dose was 0.2 nGy/h, the indoor external dose was 46 nGy/h and total average annual dose was 0.2 nGy/h. The excess lifetime cancer risk found equal to 0.8×10^-3. All reported values are lower than the globally calculated values and within recommended limits.