Ezekiel O. Agbalagba

Bio: Ezekiel O. Agbalagba is an academic researcher from Federal University of Petroleum Resource Effurun. The author has contributed to research in topics: Wafer & Cadmium zinc telluride. The author has an hindex of 5, co-authored 24 publications receiving 111 citations. Previous affiliations of Ezekiel O. Agbalagba include Texas A&M University.

Gross &#945 and &#946 Activity Concentration and Estimation of Adults and Infants Dose intake in Surface and Ground Water of Ten Oil Fields Environment in Western Niger Delta of Nigeria

Abstract: The oil and gas rich Niger Delta region of Nigeria is characterized by environmental degradation leading to environmental pollution from oil and gas activities. This study examined the gross α and β activity in thirty (river/stream, well and tap) water samples collected from ten oil fields in the Western Niger Delta region of Nigeria. The counting system employed in this analysis is the Gas-flow proportional counter {Eurisys Measure IN20 low- background multiple (eight) channel counter}. Gross alpha activity concentration range from 0.01±0.002 to 0.7±0.01 (0.15±0.003) Bql -1 , 0.01±0.003 to 0.5±0.01 (0.1±0.003)Bql -1 and 0.02±0.001 to 35.1±1.1 (4.1±0.1) Bql -1 while beta activity concentration ranged from 1.1±0.04 to 13.2±0.1 (6.0±0.1) Bql -1 , 0.7±0.1 to 54.7±1.3 (8.9±0.2)Bql -1 and 0.7±0.03 to 151.2±1.8 (40.1±0.9)Bql -1 for well, tap and river waters respectively. Correlation value between α and β activities in well, tap and river water is 0.025, 0.047 and 0.512 respectively. The results show that except for the alpha activity in the tap water samples, the average natural activity concentrations of α- and β-emitting radionuclides in the samples are slightly above the WHO recommended limit. For all samples the gross β activities are higher than the corresponding gross α activities. The mean effective equivalent dose intake per year due to alpha activity in the water samples for adults and infants are: 76.4±1.8 and 20.9±55μSvy -1 , 54.6±1.3 and 14.9±0.4 μSvy -1 , and 2118±70 and 584±19.2μSvy -1 in well, tap, and river water samples respectively. The results obtained for dose intake are below the WHO recommended reference level of 0.1mSvy-1, except for the water sample from Uzere river. This study indicates that the water sources evaluated, especially the rivers, are contaminated radiologically. @JASEM

Studies on the Radiological Impact of Oil and Gas Activities in Oil Mineral Lease 30 (Oml30) Oil Fields in Delta State, Nigeria

Abstract: A preliminary studies on the radiological impact of oil and gas exploration activities in the oil and gas production land area of Delta State has been carried out insitu, using two radiation meters (Digilert 50 and 100) synchronized and calibrated and a geographical positioning system (GPS). Readings were taken in nine different facilities in each of the oil and gas fields and one sample each in their host communities. Measured radiation values in the oil field facilities ranged from 0.011 ± 0.003 mRh-1 in Evwreni campsite to 0.031 ± 0.01 mRh-1 at the Otorogu gas plant. Mean field exposure rates/equivalent dose rates in the oil fields ranged from 0.016 ± 0.006 mRh-1 (1.4 ± 0.5 mSvy-1) to 0.0213 ± 0.008 mRh-1 (1.8 ± 0.7 mSvy-1). While in the host communities values ranged from 0.011 ± 0.003 mRh-1 (0.9 ± 0.3 mSvy-1) in Evwreni community to 0.021 ± 0.007 mRh-1 (1.8 ± 0.7 mSvy-1) in Otujeremi town and the control study area value been 0.009 ± 0.002 mRh-1 (0.8 ± 0.06 mSvy-1). The results show that all the oil and gas fields and host communities except Evwreni community yearly radiation dose rate exceeded the 1mSvy-1 maximum permissible limit recommend for the public and non-nuclear industrial environment by International Council on Radiological Protection [1]. All the oil fields and host community except Ughelli East and Evwreni community radiation levels exceeded the normal world average BIR level of 0.013 mRh-1 and other reported values in similar environment. This shows that the oil fields environment and the host communities have been impacted radiologically. However, these results obtained may not have immediate health hazard, but will pose some long-term health side effects on the staff working in the facilities and residents of the host communities. Interim proactive measures are recommended while further and a detail study is ongoing.

Optimizing CdZnTeSe Frisch-Grid Nuclear Detector for Gamma-Ray Spectroscopy

Abstract: Wide bandgap semiconductor materials capable of detecting X-rays and gamma-rays at room temperature without cryogenic cooling have great advantages that include portability and wide-area deployment in nuclear and radiological threat defense. Additional major applications include medical imaging, spectroscopy, and astrophysics. Most current room-temperature ionizing radiation detector devices are fabricated from cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe). Cadmium zinc telluride selenide (CdZnTeSe or CZTS) can be grown with high crystal yield compared to CdTe and CdZnTe. Thus, CZTS has the advantage of lowering the cost of room-temperature nuclear detectors. Thick CdTe-based detectors are prone to the trapping of charge carriers, thus limiting energy resolution and efficiency. A Frisch-Grid configuration helps to solve this problem. This research is focused on optimizing the Frisch-grid configuration for a CZTS detector. The CZTS was grown by traveling heater method. Infrared images of the CZTS matrix largely showed the absence of tellurium inclusions. The resistivity of the CZTS obtained from a current-voltage plot is of the order of $10^{10}~\Omega $ .cm. The charge-transport characterized by measuring the electron mobility-lifetime product is $4.7 \times 10^{-3}$ cm2/V. Detector resolution was measured for various Frisch-ring widths. For a $4.8 \times 4.9 \times 9.7$ mm3 detector, the best Frisch-ring widths were found to be 3–4 mm. A detector resolution of 1.35% full-width-at-half-maximum was obtained for the 3-mm width at −2300 V bias voltage for the 662-keV gamma peak of 137Cs. A resolution of 1.36% was obtained for the 4-mm width at −1800 V applied bias.

Radiometric and Radiogenic Heat Evaluation of Natural Radioactivity in Soil Around Solid Minerals Mining Environment in South-Eastern Nigeria

Abstract: Radionuclides activity concentrations in soil around ten solid mineral mining sites have been investigated using sodium iodide [Na(TI)] gamma spectroscopy. Four soil samples and a control sample were collected from each of the selected sites for analyses. The obtained results showed mean concentration values of 33.2 Bq kg−1 for 226Ra, 100.7 Bq kg−1 for 40K and 77.7 Bq kg−1 for 232Th. The estimated radiological risk parameter results have shown average values of 67.5 ηGy h−1 for the Absorbed Dose Rate (DR), 82.8 μSv y−1 for the Annual Effective Dose Equivalent (AEDE), 151.4 Bq kg−1 for the Radium Equivalent (Raeq) and 457.1 mSv y−1 for the Annual Gonadal Equivalent Dose (AGED) which is highly comparable to the allowable WHO value of 300 mSv y−1 and the control value of 177.7 mSv y−1. The average Excess Life Cancer Risk (ELCR) value obtained was 289.6 × 10−6 and the control value 112.9 × 10−6. The average External Hazard Index (Hex), Internal Hazard Index (Hin), Representative Gamma index ( Iγ), and Activity Utilization Index (AUI) obtained were 0.4, 0.5, 1.1 and 1.3, respectively. The Radiogenic Heat produced Q ranged from 248.4 pW kg−1 in Awkuke (ironstone mine) to 608.5 pW kg−1 in Ama-Echi (Silica mine) with an average heat value of 415.8 pW kg−1. The obtained result for lithology [clay] identification showed a mixed clay lithology type. The overall results were found to be higher when compared to previously reported values from similar mineral mining areas, which indicates radiological contamination.

Concentrations of TENORMs in the petroleum industry and their environmental and health effects

Abstract: Crude oil and its products and wastes are among the significant sources of naturally occurring radioactive materials (NORMs). These materials may be enhanced to high levels due to technological and human activities, which are called technologically enhanced naturally occurring radioactive materials (TENORMs). Thus, the average radioactivity of these radionuclides sometimes exceeds the exemption level of 10 000 Bq kg−1, which is recommended by the IAEA's safety standards. TENORMs in the oil and gas industry may generate greater radioactivity levels, which eventually represents potential environmental and health risks. This will require continuous attention by monitoring and surveillance during routine processes in the petroleum industry. In this paper, a comprehensive review of the published literature is conducted to evaluate the TENORM concentrations in the oil and gas industry. Moreover, their environmental and health hazards in different regions of the world are discussed.