Assessment of Background Ionizing Radiation of Engineering Laboratories in Federal Polytechnic Nekede Owerri, Imo State, Nigeria

Abstract

In-situ measurement of background ionizing radiation level of the Faculty of Engineering Technology (FET) in Federal Polytechnic Nekede, Owerri, Imo State has been carried out, with the use Radiation meters (Digilert-200). The Global Positioning System (Garmin 765) was utilized in measuring the coordinates of the sampling points. The aim of the study is to assess the rate of radiation exposure to students and staff during practical work in the Laboratories. Four (4) engineering laboratories within the faculty were randomly selected. The outdoor exposure dose rate varies from 0.006 - 0.017 mR/hr, 0.006 - 0.015 mR/hr, 0.008 -0.015 mR/hr, 0.009-0.014 mR/hr with mean value of 0.011 mR/hr ,0.009 mR/hr,0.014 mR/hr, 0.012 mR/hr for Computer Engineering Laboratory, Mechatronics Laboratory, Mechanical Engineering Laboratory and Automatic Laboratory respectively. The indoor exposure dose rate varies 0.009 - 0.013 mR/hr, 0.009 – 0.019 mR/hr, 0.006 -0.015 mR/hr, with mean of 0.013 mR/hr,0.012 mR/hr and 0.012 mR/hr for Air Conditioning Laboratory, Mechanical Engineering Laboratory and Automatic Laboratory respectively.  The outdoor absorbed dose rate varies from 52.2 -147.9 nGy/hr, 52.2-130.5 nGy/hr, 69.6 -147.9 nGy/hr,78.3 -121.8 nGy/hr, with mean value of 96.76 nGy/hr, 79.75 nGy/hr,111.86 nGy/hr and 100.69 nGy/hr and the indoor absorbed dose rate varies from 78.3-130.5, 78.3- 169.7, 52.2-130.5 (nGy/hr) with mean 111.7 nGy/hr, 109.7 nGy/hr, 101.8 nGy/hr respectively. The outdoor excess life cancer risk (ELCR) varies from 0.22x10-3 - 0.56 x10-3,0.22x10-3- 0.56x10-3,0.299x10-3-0.56x10-3 and 0.34x10-3-0.52x10-3 with mean of 0.44x10-3,0.34x10-3,0.54x10-3 and 0.45x10-3 for Computer Engineering Laboratory, Mechatronics Laboratory, Mechanical Engineering Laboratory and Automatic Laboratory respectively, while the indoor excess life cancer risk (ELCR) varies from 0.36-0.56x10-3,0.34x10-3-0.85x10-3 and 0.22x10-3-0.56x10-3 with mean 0.48x10-3,0.48x10-3 and 0.44x10-3.The results show that the estimated radiological parameters from the radiation exposure dose rate are all higher than their world standard values, except the annual effective doses and the outdoor and indoor exposure dose rate which are within their respective stipulated standard. This high value of Absorbed dose and excess life cancer risk may not constitute any immediate health effects on students and staff but there is a potential health effects for a long term in the future for an individual who may spent he/her life time within the immediate environment such as development of cancer due to the accumulation of high doses.