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.
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.
Evaluation of the Knowledge and Awareness of Non-Ionizing Radiation among Final Year Students of College of Medical Science University of Maiduguri. (Published)
This study was aimed at evaluating the level of knowledge, types, and Potential hazards of non-ionizing radiation among final year students of college of medical science, University of Maiduguri. A prospective cross sectional survey study was conducted among final year students of college of medical sciences, for 6 months periods, March to August, 2014. A total of 335 structured 12 items self-completion questionnaires were randomly distributed to participants and 312 were filled out and returned, with a response rate of 93.1%. Data was analyzed using descriptive statistics, where mean, percentages and frequencies where computed There were about 184, (59%) male participants and 128, (41%) female participants in the study with age ranged from 21 to 45 years with mean age of 28years. Majority of the respondents were within the age group of 21-26 years with 171, (54.8%). The department of MBBS/BDS had 122 (39.1%), BMLS had 61 (19.6%), Radiography had 52 (6.7%), Nursing Science had 38 (12.2%), physiotherapy had 20 (6.4%) and Anatomy had 19 (6.1%) number of participants. Majority of respondent, 162 (51.9%) wrongly thought ultraviolet ray, microwaves, radio waves and Extremely Low Frequency radiation are types of ionizing radiation. While 108 (34.6%) knew they are types of non-ionizing radiation. About 153 (49%) wrongly believed that ultrasonography (USS) and Magnetic Resonance Imaging (MRI) uses ionizing radiation for diagnosis, while 139, (44.6%) knew they do not use ionizing radiation, and 20 (6.4%) did not know. Majority of the respondents 247 (79.2%), knew that excessive exposure to non-ionizing radiation could be hazardous. This study found insufficient knowledge on non-ionizing radiation and their types among final year students of college of medical science, however, participants were seen to have appreciable knowledge on potential hazards of non-ionizing radiation.
Gamma Dose Rate, Annual Effective Dose and Collective Effective Dose of Food Crop Producing Region of Ondo State, Nigeria (Published)
The activity concentrations of natural gamma-emitting radionuclides 238U, 232Th and 40K in soils from 7 sampling sites in Ondo State, southwestern Nigeria have been measured by using a well calibrated high resolution gamma ray spectrometer. The mean activity concentration values of 39.24±1.12, 52.86±1.40 and 445.02±12.24 Bq kg-1 for 238U, 232Th and 40K respectively were obtained for the State. Absorbed dose rates in outdoor air were calculated to be in the range of 12.35±0.65 and 179.59±4.1 nGy h-1 with an overall mean value of 67.50±1.86 nGy h-1. The corresponding outdoor annual effective dose rates were estimated to be between 22.7 and 330.6 μSv y-1 for the area assuming 30% occupancy factors. The average outdoor annual effective dose rate for most of the towns is 64882.95 μSv y-1 representing 92.65% of the world average value (70000 μSv y-1) given by UNSCEAR. The value of the collective effective dose as calculated from the outdoor annual effective dose rates was found to be 540858 person-Sv