Assessment of Excess Life Time Cancer Risk from Gamma Radiation Exposure Rate in Two Tertiary Institutions in Bayelsa State, Nigeria (Published)
The present study assessed the excess lifetime cancer risk associated with gamma radiation exposure rate in two tertiary institutions in Bayelsa State, Nigeria using Radalert 100xTM, nuclear radiation monitor which uses a Geiger Mueller tube to detect radiation emissions. The studied campuses of Niger Delta University (NDU) and Federal University of Otuoke (FUO) were delineated into eleven (11) and Ten (10) sections respectively. Results of the measurements showed that the highest exposure rate of 0.05mR/h (2.66msvy-1) was recorded at NDUIP against 0.04mR/h (2.128msvy–1) of FUOHL. Excess lifetime cancer risk analysis showed that at NDUIP, it was 1.866 x 10-3 and 1.500 x 10-3 at FUOHL. In calculated mean values for exposure rate (ER), Absorbed Dose Rate (ADR), Annual Effective Dose Equivalent (AEDE) and excess lifetime cancer rate (ELCR) it was; 0.030mR/h (1.596mSvy-1), 238.06nGy/h, 0.290mSvly and 1.020 x 10-3 respectively for NDU and 0.02mR/h (1.064mSvy-1), 204.45 nGy/h, 0.250mSvy-1 and 0.880 x 10-3 respectively in FUO. Compared with world average value (WAV) of 0.013mRlh (0.6916msvy-1) for ER, 59.00nGy/h for ADR, 0.070mSvy-1 for AEDE and 0.290 x 10-3 for ELCR respectively. The calculated dose to organ showed that the testes have the highest organ dose of 0.087mSvy-1 in NDU and 0.070mSvy-1 in FUO respectively. The obtained mean values in both campuses exceed the WAV. However, the obtained results do not impose alarming danger, but effort should be made for control measures in compliance with ALARA Principle.
Keywords: Radiation, Risk Assessment, exposure, lifetime
Measurement and Analyses of indoor radon level at a University in South-Eastern Nigeria (Published)
Lung cancer has been linked to exposure to the naturally occurring ionizing radiation, radon gas (22Rn). Radon is ubiquitous in our environment. However, the level of concentration of this gas is influenced by the geological, geographical, meteorological conditions of a particular environment. The indoor radon concentration is also influenced by factors such as air-conditioning system, ventilation, age of building etc. In this study, the level of indoor radon was measured in 55 offices located within Abia State University, Uturu in South Eastern Nigeria using a Corentium digital radon detector. Uturu is well known for vegetation with high granitic and sedimentary rocks. Offices were chosen to vary between those that are furnished with air conditioning systems and those that are without such facility. Measurements were taken between December 2017 to June 2018. The result of the measurements showed that the indoor radon concentration for all the offices varied between. This value is lower than the intervention level of recommended by International Commission on Radiological Protection (ICRP). The annual effective dose for the offices ranged from which is below the recommended ICRP intervention level of. Hence, there is low risk of adverse health effect and lung cancer induction to the staff of Abia State University.
Keywords: Effective dose, Nigeria, exposure, indoor radon, lung cancer