Radiological Health Risk Due To Gamma Dose Rates Around Okposi Okwu and Uburu Salt Lakes, Ebonyi State (Published)
Human beings are always exposed to varying doses of terrestrial ionizing radiation which may pose immediate or long – term health risk at radiation doses higher than the suggested safe limit by radiation protection and measurement agencies. Therefore, it is important to quantitatively measure and evaluate the radiological health risk due to gamma dose rates around salt lake environments. In situ measurement of gamma dose level around Okposi Okwu and Uburu salt lakes in Ohaozara Local Government Area of Ebonyi State had been conducted using two well calibrated nuclear radiation metres (Radalert – 100 and Digilert – 50) and geographical position system (GPS). Readings were taking randomly in thirty one sampling geographical locations each around the salt lakes at the gonad level of about one metre above the ground to determine the absorbed dose rate (D) nGyh-1, annual effective dose equivalent (AEDE) mSvy-1 and the excess lifetime cancer risk (ELCR). Comparatively, the D, AEDE and ELCR values obtained for Uburu salt lake were higher than Okposi Okwu salt lake. The D and ELCR values recorded for the two salt lakes exceeded the suggested safe limit 84 nGyh-1and for general public respectively, while the AEDE for the two lakes were found to be in good agreement with the 0.48 mSv prescribed standard safe limit for the general public. In general, the results showed that terrestrial background ionizing radiation due to radionuclides in soil within the salt lakes is high and chances of developing cancer by immediate populace over a long term exposure is very significant. Measurements have been taken as representing the baseline values for terrestrial outdoor gamma dose rate around the salt lakes. Length of time spent within the salt lakes and farming around the lakes should be minimized. There is also need to investigate the radionuclide content of food crop cultivated near the salt lakes.
Keywords: Dose Rate, Excess Lifetime Cancer Risk, Okposi Okwu., Radiation, Salt Lake, Uburu