MEASUREMENT OF NATURAL RADIOACTIVITY IN TAP WATER SAMPLES FOR SELECTED REGIONS IN ADEN GOVERNORATE, YEMEN

Abstract

In the present work, we have measured specific activity concentrations of in eleven tap water samples for selected regions in Aden governorate by using high purity germanium detector (HPGe). The (HPGe) detector (CANBERA-model 7229N, USA) with an efficiency of 35% and energy resolution (2.6keV) at energy (1332.6keV) for ⁶⁰Co, the high purity N-type semiconductor detector with physical characteristics of (geometry closed-end coaxial, (3×3 inch). The results have shown that, The highest value of specific activity concentration of ²²⁶Ra was found in in T7 Daar-Saad region which was equal to (0.525±0.29)Bq/L, while the lowest value of specific activity concentration of ²²⁶Ra was found in T11 Aden Assughra region which was equal to (0.017±0.006)Bq/L with an average value of (0.228±0.13)Bq/L. The highest value of specific activity concentration of ²³²Th was found in in T5 Khor-makser region which was equal to (0.319±0.18)Bq/L,  while the lowest value of specific activity concentration of ²³²Th was found in T11 Aden Assughra region which was equal to (0.009±0.001)Bq/L with an average values of (0.129±0.089)Bq/L. The highest value of specific activity concentration of (⁴⁰K) was found in in T2 (Al-Ma^,allah) region which was equal to (0.4±0.26)Bq/L, while the lowest value of specific activity concentration of (⁴⁰K) was found in T11 Aden Assughra region which was equal to (0.027±0.004)Bq/L with an average values of  (0.141±0.021)Bq/L respectively. The annual ingestion effective dose (AED) ranged from (3.05 to 98.77μSv/y), (5.67 to 178.16μSv/y), and (3.41 to 119.08μSv/y), with average values of 42.65μSv/y, 78.62μSv/y and 48.62μSv/y, for infants, children and adults respectively. The excess lifetime cancer risk (ELCR) have been calculated, its values were lower than the world’s average value of (0.29×10⁻³) as reported by EPA. The overall annual effective dose and cancer risks corresponding to radionuclide intake in tap water were below the recommended maximum values. It was inferred from the findings of this study that the water used as the sample does not have any significant radiological impacts to human body and is safe to be used as drinking water.