Mapping of Terrestrial Radioactivity Levels in Surface Soil. A Case Study of Damaturu L.G.A, Yobe State, Nigeria.

Communication in Physical Sciences 2019, 4(2): 95-102 Authors: Habu Tela Abba, Miftahu Gambo Idris and Jibrin Suleiman Yaro  Received 15 November 2019/Accepted 14 December 2019 Preliminary measurement of the natural radioactivity levels due to terrestrial radionuclides in surface soil samples withinDamaturu L.G.A in Yobe state was carried out. To estimate the radioactivity levels of unsampled locations, geostatistical analysis, using IDW interpolation method was used to plot maps for the spatial distribution of the radionuclides for the entire study area using ArcGIS software. Activity concentration of 226Ra, 232Th and 40K were determined in 55 soil samples by gamma spectroscopy. The activity concentrations were calculated to range from 7 to 227 Bq kg−1 for 226Ra, 21 to 463 Bq kg−1 for 232Th and 20 to 1035 Bq kg−1 for 40K. The mean values of 226Ra, 232Th, and 40K were found to be 37.2, 45.3, and 185 Bq kg−1, respectively. The results obtained are slightly higher than the worldwide average values (except for 40K) recommended by UNSCEAR (2000). The result could be useful in evaluating gamma radiation exposure to the general public living in the area

Geological influence on the terrestrial gamma radiation dose rate in Jos Plateau, Nigeria

Natural environmental terrestrial gamma radiation dose (TGRD) rate measurements have been carried out across the geological formations of Jos Plateau, Nigeria. External gamma radiation dose rates ranged between 11 and 714 nGy h-1 with a mean value of 204 nGy h-1. Relationship between TGRD levels and geological type was determined. Statistical comparative method one way analysis of variance (ANOVA) was used to compare the TGRD means for the various types. The statistical results revealed in some instances, significant differences among the mean values of TGRD rates for the different underlying geological structures. Annual effective dose and collective effective dose for the general public due to exposure to terrestrial gamma radiation were estimated at 0.25 mSv y-1 and 1.20x102 mSv y-1, respectively. Isodose map for exposure rate due to TGRD wasplotted using ArcGIS software. The results will serve as database for natural background radiation for the country.Keywords: Natural radiation; Terrestrial gamma radiation dose (TGRD); geological type; Analysis of variance (ANOVA

Natural radiation and radioactivity in soil and groundwater of Jos Plateau, Nigeria

This study aimed to establish baseline data on the natural environmental gamma radiation and radioactivity levels as well as to evaluate the corresponding radiological health impacts for Jos plateau, Nigeria. It employed the use of portable NaI(Tl) survey meter and hyper pure germanium spectrometer to measure external gamma dose rate and to determine the specific activity concentration of terrestrial radionuclides, 226Ra, 232Th and 40K in soil samples, respectively. External gamma dose rates were measured at 811 locations while activity concentration were determined for 102 soil samples. The mean value for the measured gamma dose rate was found to be approximately four times the world average value while the mean values for the activity concentration of 226Ra, 232Th and 40K were found to distinctly exceed their corresponding world reference values for continental soil. Gamma dose rate and activity concentration of the terrestrial radionuclides for each geological formation and soil type of the area are presented. Statistical relationships between gamma dose rate with the different geological formations and soil types of the area are established. Younger granites geological formation and Haplic acrisols soil type were found to contribute the highest to the natural background radioactivity and 232Th was found to be the highest contributor to the terrestrial gamma dose rate for the study area. Various groundwater samples were also measured for concentration of U and Th using inductive coupled plasma mass spectroscopy and the concentrations of U ranged from 1.4 to 35 ??g L-1 with a mean value of 13.15 ??g L-1 while for Th ranged from 0.10 to 11.1 ??g L-1 with a mean value of 1.85 ??g L-1. Few groundwater samples were found to have values exceeding the recommended limit of U provided by WHO and USEPA for drinking water. Radiological health impact parameters namely radium equivalent, external hazard index, annual effective dose, collective dose and excess lifetime cancer risk due to soil radioactivity and annual ingestion dose as well as radiotoxicity risks due to ingestion of groundwater were also evaluated. It is found that, an individual leaving in this area is most likely to incur a radiological health related risks due to natural radiation. Isodose maps for gamma rates and the spatial distribution pattern of activity concentration of 226Ra, 232Th and 40K for the study area were produced using ArcGIS mapping software. The results revealed that Jos Plateau has above normal levels of natural background radiation. The data here presented will be useful for radio–geochemical investigation and as a reference data to asses possible changes in the environmental background radiation levels due to local and transnational releases of radioactive materials from artificial sources and also useful for preparing radiological map for Nigeria

Population Doses from Gamma Radiation Exposure around Damaturu Metropolis, Yobe State, Nigeria

Communication in Physical Sciences 5(2): 205-209 Authors: Habu Tela Abba and Agada Livinus Emeka Received 2 May 2020/Accepted 25 May 2020 Humans are exposed to radiation in their environment with or without their consent; and the exposure to natural background radiation is an unpreventable event on  earth. Exposure to terrestrial   background   gamma   radiation in Damaturu   metropolis   was   measured   in   65  locations  using  a  hand  held  radiation  survey  meter (RDS-31). The gamma absorbed dose rate in air 1 m above ground surface ranged from 5 to 165 nGy h−1 with a mean value of 56±5 nGy h−1.The study results revealed that, higher dose ratesare located around the main roads within the city. The mean value was found to be within the set limit   by   UNSCEAR   for   normal  background radiation. Thus, the dose  rates are classified  as  low radiation level  and  are  below the  level  to  cause acute health effects in humans. The results obtained would serve as baseline data for further studies on background radiation in the study area

The Effect of Temperature and Active layer thickness on the Performance of CH3NH3PbI3 Perovskite Solar Cell: A Numerical Simulation Approach.

In this work, General-purpose Photovoltaic Device Model (GPVDM) software was used to investigate the performance of a perovskite solar cell with CH3NH3PbI3 as its active layer. GPVDM is a free general-purpose tool for simulation of light harvesting devices. The model solves both electrons and holes drift-diffusion, and carrier continuity equations in position space to describe the movement of charge within the device. The model also solves Poisson's equation to calculate the internal electrostatic potential. Recombination and carrier trapping are described within the model using a Shockley-Read-Hall (SRH) formalism, the distribution of trap states can be arbitrarily defined. The software gives an output that contains the Current-Voltage (I-V) characteristic curves. A study into the effect of active layer thickness and temperature on the performance of the solar cell device was carried out. The optimal active layer thickness was found to be 3 x 10-7m. When the thickness exceeds 3 x 10-7 m, then the efficiency drops. At the optimal thickness of 3 x 10-7m, the devices were found to have power conversion efficiency up to 14.7%. On other hand the fill factor (FF) decreases as the thickness increases. The FF is highest at active layer thickness of 1 x 10-7m. The effect of device temperature also studied and the optimal working temperature was found to be 300 K, where power conversion efficiency and FF are 15.4 % and 0.76 respectively

NORMs distribution in coastal soils and sediments of River Yobe, north-eastern Nigeria: an evaluation of the potential radiological hazards

A preliminary study which aimed to establish a reference data on naturally occurring radioactive materials (NORMs) for River Yobe has been conducted. Soil and sediment samples were collected along the coastal areas of the river and analyzed to determine the specific activities of NORMs such as 238U, 232Th and 40K. Gamma spectrometry technique using NaI (Tl) detector was employed to determine the specific activities f the natural radionuclides. The mean activity concentration in the soil samples for 238U, 232Th and 40K were found to be 23±1.5, 36±2.5 and 395±9.1Bq kg−1 and for the sediment samples are 60±2.6, 45±3.6 and 324±6.8Bq kg−1 respectively. These values, in some cases exceed the world reference values of 30, 35 and 400 Bq kg−1 for 238U, 232Th and 40K respectively. Parameters of radiological hazard, were also estimated based on specific activity of the radionuclides to assess the radiological impacts due to exposure on the users of the river. The results were found to be within the worldwide recommended safety limits.Keywords: Annual effective dose, NORMs,238U.232Th.40K. River Yob

Spatial Distribution of Naturally Occurring Radioactive Materials in Soil and the Consequent Population Effective Dose

Communication in Physical Sciences 4(2):133-140 Authors: Habu Tela Abba and Muhammad Sani Isa Received 20 September2019/Accepted 29 November 2019 Protection and assessment of any radiation pollution resulting from the use and disposal of radioactive materials to the large extent is based on the knowledge of natural radioactivity levels of an environment. Therefore, this work was designed to determine the distribution of naturally occurring radionuclides materials (NORMs) (in some residential areas within plateau state). Concentrations of 226Ra, 232Th and 40K in soil across the eight geological formations of Jos Plateau were measured using high resolution HPGe detector. The activity of 226Ra varied between 34 1 and 1006  Bq kg-1, 67 2 and 1695 37 for 232Th and between 67 4 and 2465 45 Bq kg-1for 40K.The mean concentration exceeded their corresponding global average values. Annual effective dose due to gamma radiation for general public were within the permissible limit of 1 mSv. The radiometric data obtained from the study could be useful for geochemical exploration in the study area

Determination of the Gross Alpha and Beta Activity Concentration in Groundwater from Damaturu

Communication in Physical Sciences, 2022, 8(2): 179-186 The major source of potable water in Damaturu is underground water especially boreholes and artesian wells which may contain radioactive substances. The presence of radioactivity in water may pose severe health risk to consumers. In light of this, the gross alpha and beta activity concentration of 15 borehole water samples from Damaturu were analysed using the gasless channel MPC 2000B-DP proportional counter. The highest concentration of alpha activity was recorded for samples from Gwange with 50.26 2.78mBq L. This was also found to have the highest activity concentration 79.87 5.26 mBq Lfor beta activity. The lowest alpha activity concentration was obtained in New Abbari with 0.79 1.19 mBq L and the lowest beta activity concentration was obtained in Waziri Ibrahim 10.24 3.05 mBq L . The mean alpha and beta activity concentrations in the study area ar15.76 1.74 mBq L and 35.11 4.09 mBq L, respectively. All the samples analysed are below the 0.5 Bq L and 1.0 Bq L screening level set by the WHO (2011) for alpha and beta activity concentration, respectively. The annual gonadal equivalent dose (AGED) and committed effective dose (CED) were calculated for the samples and it was found that all the samples were within the 1mSv yr limit set by the ICRP for members of the public. Therefore, the level of radioactivity in the water samples may not pose a significant health risk. It is recommended that this study be expanded to analyse all potable water sources in the study area using an improved method of analysis

Annual Effective Dose Due to Background Gamma Radiation in Buni Gari, Yobe State

Communication in Physical Sciences, 2023, 10(1): 67-72 Authors: Habu Tela Abba*, Jasini Waida, Busari Kahinde Abdulsemiu Received: 07 May 2023/Accepted 27 September 2023 In this study, we aimed to assess the levels of gamma radiation both outdoors and indoors in Buni Gari, Yobe State. Our goal was to determine the annual effective dose associated with gamma radiation and to investigate whether the presence of active quarrying companies around the town has had any notable impact on the background radiation levels. Geiger Muller (G. M) detector known as X5C plus, was used to carry out the measurement. To ensure the accuracy of our readings, the G.M detector was positioned one meter above ground level to minimize ground-related effects. During outdoor measurements, we maintained a distance of at least six meters from nearby building walls to avoid any interference from the building materials. Our findings indicated that the average gamma dose rates for outdoor and indoor measurements were 55.8 ± 8.2 nSv/h and 62 ± 6.4 nSv/h, respectively. We calculated the average annual effective dose resulting from background gamma radiation to be 0.372 mSv, which was found to be lower than the global average value of 0.48 mSv. In conclusion, the average annual effective dose from background gamma radiation in Buni Gari was below the global average. When we compared our results with a previous study conducted in 2019 to determine the effective dose of environmental gamma radiation in the same town, we found that the presence of quarrying activities around the town over four years did not significantly change the annual effective dose of Buni Gar