Umar Ibrahim

Bio: Umar Ibrahim is an academic researcher from Nasarawa State University. The author has contributed to research in topics: Oryza sativa & Tailings. The author has an hindex of 1, co-authored 4 publications receiving 22 citations.

Health and ecological hazards due to natural radioactivity in soil from mining areas of Nasarawa State, Nigeria

Abstract: Nasarawa State is located in north central Nigeria and it is known as Nigeria's home of solid minerals. It is endowed with barite, copper, zinc, tantalite and granite. Continuous releases of mining waste and tailings into the biosphere may result in a build-up of radionuclides in air, water and soil. This work therefore aims to measure the activity concentration levels of primordial radionuclides in the soil/sediment samples collected from selected mines of the mining areas of Nasarawa State. The paper also assesses the radiological and radio ecological impacts of mining activities on the residents of mining areas and their environment. The activity concentrations of primordial radionuclides ((226)Ra, (232)Th and (40)K) in the surface soils/sediment samples were determined using sodium iodide-thallium gamma spectroscopy. Seven major mines were considered with 21 samples taken from each of the mines for radiochemistry analysis. The human health hazard assessment was conducted using regulatory methodologies set by the United Nations Scientific Committee on the Effects of Atomic Radiation, while the radio ecological impact assessment was conducted using the ERICA tool v. 1.2. The result shows that the activity concentrations of (40)K in the water ways of the Akiri copper and the Azara barite mines are 60 and 67% higher than the world average value for (40)K, respectively. In all mines, the annual effective dose rates (mSv y(-1)) were less than unity, and a maximum annual gonadal dose of 0.58 mSv y(-1) is received at the Akiri copper mine, which is almost twice the world average value for gonadal dose. The external hazard indices for all the mines were less than unity. Our results also show that mollusc-gastropod, insect larvae, mollusc-bivalve and zooplankton are the freshwater biotas with the highest dose rates ranging from 5 to 7 µGy h(-1). These higher dose rates could be associated with zinc and copper mining at Abuni and Akiri, respectively. The most exposed terrestrial reference organisms are lichen and bryophytes. In all cases, the radio ecological risks are not likely to be discernible. This paper presents a pioneer data for ecological risk from ionizing contaminants due to mining activity in Nasarawa State, Nigeria. Its methodology could be adopted for future work on radioecology of mining.

Comparative performance assessment of the most commonly used personnel radiation dosimeters in Nigeria

Abstract: Radiation dosimeters exhibit several performance properties characterized by their precision and accuracy, linearity, dose and energy dependence, stability and spatial resolution. However, these characteristics may not be satisfied by all dosimeters. The dosimetric performances of Instadose and Thermolumniscence dosimeters (TLDs) which are the two most commonly used personal dosimeters in health care institutions were comparatively assessed under clinical settings in which a GE haulum XR 6000 X-ray machine with a frequency of 50/60 Hz was used to serially irradiate Mironinstadose and TLD 100H badges to a controlled exposure factors and readings of absorbed doses for instadose were obtained from a portable computer with internet access, while that of TLDs was obtained through heating using Harshaw 4500 automatic TLD reader at Center for Energy Research and Training (CERT), Zaria. The dose equivalent quantities measured were; Hp (10), Hp (3) and Hp(0.07) all in mSv, representing deep, eye lens and shallow doses respectively. Results of measured doses ranged between 0.74 mSv to 22.96 mSv for instadose and 0.71 mSv to 35.42 mSv for TLD badges in all performance tests conducted. Homogeneity results were 9% and 12%, reproducibility was 7.2% and 3.9% while percentage deviation for linearity test was below 10% for both instadose and TL dosimeters. The performance tests results of instadose and TL dosimeters were assessed based on the criteria of the International Electrotechnical Commission (IEC) 1066 standard. The assessment revealed good performance indices within the requirement of the IEC standard. However, TL dosimeters demonstrate high sensitivity in the self-irradiation test exceeding the standard mSv values.

Contamination and Pollution Risk Assessment of Heavy Metals in Rice Samples (Oryza sativa) from Nasarawa West, Nigeria

Abstract: Aim: This study was undertaken to assess the heavy metals contamination level in rice grains (Oryza sativa) from Nasarawa West, Nigeria. Study Design: To estimate the contamination factor, degree of Contamination and Pollution load index of rice samples from Nasarawa west using the world health organization/food and agricultural organization acceptable limits of some toxic Heavy Metals in Food as reference heavy metals concentration. Place and Duration of Study: The research was carried out in the Department of physics, Nasarawa State University, Keffi, from September 2017 to April 2018. Methodology: Fifteen (15) samples each were taken from various locations from the rice fields in Keffi, Kokona, Karu, Nasarawa, and Toto respectively. Rice grain samples were dried in an open air at an ambient temperature to constant weight. Husks were removed. Then, the grain rice samples were pulverized and were passed through a 2.00 mm sieve and stored in closed polyethylene bags for irradiation using ECLIPSE Ш Energy Dispersive X – Ray Fluorescence (EDXRF) XR–100 CR spectrometer supplied by AMTEK INC. MA; USA. Results: The values of contamination factor of rice samples from the study area were in the order of Zn < Cu < Ni < Cr < Pb and are all less than 1, indicating a ‘low risk’ of contamination with the value of Cd >> 6 presenting a very high contamination risk of Cadmium. The Pollution Load Index value observed in Nasarawa West were in the order of Nasarawa (0.0683) < Keffi (0.0773) < Toto (0.0972) < Kokona (0.0988) < Karu (0.1389) and are all less than unity (1), indicating that the rice samples were not polluted by Cd, Cu, Cr, Ni, Pb and Zn. Conclusion: Findings from this study will help in making policies and preferring solution to public health related issues and further studies may be important.

Assessment of Heavy Metals Concentration in Swampy Agricultural Soil of Nasarawa West, Nigeria

Abstract: Aim: This research was carried out to investigate the concentration of heavy metals in swampy agricultural soil of Nasarawa west, Nigeria. Study Design: To compare the swampy soil heavy metal concentrations with regulatory standard or allowable values by the World Health Organization (WHO) and other National and International standards. Place and Duration of Study: Department of Physics, Nasarawa State University Keffi between January, 2018 and October, 2018. Methodology: Ten soil samples from each of thefive sampling locations (Karu, Keffi, Kokona, Nasarawa, and Toto) were randomly collected. A total of fifty (50) soil sampleswere collected within the period of one week. The collected samples were stored in polyethylene bag and labeled properly and taken to the Center for Energy Research and Development (CERD) at Obafemi Awolowo University Ile- ife Osun State, Nigeria. At CERD, elemental analysis was carried out for the fifty sample using X- ray fluorescent spectrometry analyzer. Results: The range of mean concentration of Zn, As, Cd, Pb, Fe, Ni, and Cu (in KR, KF, KK, NS, and TT locations) are 243.60- 502.80 mg/kg, 7.40- 37.00mg/kg, 260.90- 524.50 mg/kg, 167.80- 336.60 mg/kg, 20222.90- 58170.50 mg/kg, 342.20- 555.10 mg/kg, and 266.60- 515.90 mg/kg respectively. The average mean of all the sample locations are found to be higher than the WHO allowable concentration limits of As (20 mg/kg), Pb (100 mg/kg), Cd (3 mg/kg), Zn (300 mg/kg), Fe (n.a), Ni (50 mg/kg), and Cu (100 mg/kg)respectively. There is high concentration Zn, As, Cd, Pb, Fe, Ni, and Cu in the swampy soil. Conclusion: The results indicates that the swampy agricultural soils of Nasarawa west (Karu, Keffi, Kokona, Nasarawa, and Toto) are contaminated with toxic metals (Zn, As, Cd, Pb, Fe, Ni, and Cu).

Activity concentrations of 226Ra, 228Ra, 222Rn and their health impact in the groundwater of Jordan

Abstract: The activity concentrations of 226Ra, 228Ra and 222Rn were measured in 87 groundwater samples to estimate the activity concentrations of these radionuclides and health impact due to intake of these radionuclides in groundwater of Jordan. The mean activity concentrations of 226Ra, 228Ra and 222Rn in groundwater were found to be 0.293 ± 0.005 Bq L−1, 0.508 ± 0.009 Bq L−1 and 58.829 ± 8.824 Bq L−1, respectively. They give a mean annual effective dose of 0.481 mSv with mean lifetime risk of 24.599 × 10−4, exceeding the admissible limit of 10−4. Most of the received annual effective dose (59.15% of the total) is attributed to 228Ra.

Radionuclide concentrations and excess lifetime cancer risk due to gamma radioactivity in tailing enriched soil around Maiganga coal mine, Northeast Nigeria

Abstract: Background: Human ac vi es such as mining enhance the radioac vity levels above normal background which can lead to an incremental increase in the radia on risk to the popula on. Materials and Methods: 20 tailing enriched soil samples collected around Maiganga coal mine, Gombe, Northeast Nigeria were assessed for their Ra, Th and K contents using HPGe gamma-ray detector. Results: The mean ac vity values of 11.90±3.0, 17.72±3.6 and 70.44±20.4 Bq kg were obtained for Ra, Th and K respec vely. These values were below the world average values documented by UNSCEAR. The ra o of Th:Ra obtained was 1.5, which showed that Th ac vity was higher than the ac vity of Ra while K recorded the highest ac vity concentra on in the studied samples. Sta s cal analysis iden fied strong posi ve rela onships among all radiological parameters and confirmed that Ra, Th and K were the major contributors to radia on dose. Radium equivalent ac vity (Raeq), absorbed gamma dose rate (DR), annual effec ve dose (AEDE), ac vity u liza on index (AUI), external and internal hazard indices (Hex and Hin), gamma representa ve index (Iγr), annual gonadal dose (AGDE) and excess life me cancer risk (ELCR) were calculated to quan fy the radia on risk to the public from exposure to Ra, Th and K in the studied samples. The mean values of these hazard parameters were within the acceptable limits provided for human safety and environmental protec on. Conclusion: The use of the tailing enriched soil samples of Maiganga coal mine for any purpose whatsoever does not therefore pose any immediate radiological risk to the coal workers or the general public.