scholarly journals Radiometric Survey of Granitic Quarry Site of Ebony State, Nigeria

2019 ◽  
pp. 1-9
Author(s):  
M. Onwuka ◽  
C. P. Ononugbo

Radiometric survey of the granitic quarry site at Ishiagu and its environment was done using two radiation monitors and geographical positioning system (GPS) for GIS mapping. In-situ measurement of exposure rate was carried out following the international standard organizational standard between May 2018 and June 2019. The measured average exposure rates ranged from 0.010± 0.002 to 0.038 ± 0.003 mRh-1 with mean value of 0.026 ±0.005 mRh-1. The estimated outdoor absorbed dose rate ranged from 87.0 to 330.6 nGyh-1 with mean value of 228.38 nGyh-1. The equivalent dose rate ranges from 0.84 to 3.20 mSvy-1 with mean value of 2.21 mSvy-1. The mean annual effective dose equivalent (AEDE) calculated was 0.28 mSvy-1 while the mean excess lifetime cancer risk (ELCR) was 0.98 x 10-3. The estimated annual effective dose to different organs showed that the testes have the highest annual effective  dose of 0.191 mSvy-1 followed by ovaries and kidney of 0.135 and 0.139 mSvy-1 respectively while the liver has the lowest annual effective  dose of 0.103 mSvy-1. The radiation contour map of the area showed the distribution of radiation of high and low areas. The result showed that the radiation exposure rate and its associated radiological risk parameters exceeded the safe limits prescribed by ICRP and also the values reported in literatures. However, these values may not constitute acute health risk but long term exposure of residents and workers may be detrimental to their health. Therefore adequate monitoring of this quarry site is necessary to checkmate the exposure rate and provide some protective measures for quarry workers.

2020 ◽  
Vol 35 (2) ◽  
pp. 154-164
Author(s):  
Sreten Ilic ◽  
Tatjana Golubovic ◽  
Natasa Pajic ◽  
Mirjana Djurasevic ◽  
Aleksandar Kandic

This paper presents the results of analyses of radionuclide content in the samples of the surrounding soil and clayey material of ?Zbegovi? open-pit mine in Donje Crniljevo, Serbia. Samples from 78 sites were collected and prepared. The activity concentrations were determined for radionuclides: 238U, 232Th, 40K, 226Ra, and 137Cs. The mean values obtained are as follows: 23 Bqkg?1, 89 Bqkg?1, 372 Bqkg?1, 56 Bqkg?1, and 11 Bqkg?1, respectively. Concentrations of 238U, 40K, and 226Ra in the studied area do not deviate from the values obtained for the soil in Serbia. The concentration of 232Th in the studied area is slightly higher relative to average values for soil, and slightly lower compared to similar deposits of clayey material in the world. Measurements performed showed that the open-pit mine of clayey material is completely uncontaminated surface as far as 137Cs is concerned, while there are sites where measured 137Cs concentrations are significantly higher, which is due to topographic differences and inhomogeneous surface contamination of land after the Chernobyl accident. To assess the radiological risks in the observed area, the following indices were determined: absorbed dose rate, annual outdoor effective dose, absorbed dose for biota, excess lifetime cancer risk outdoors as well as external radiation hazard index. The mean value of the estimated absorbed dose rate in the given area amounts to 80.1 nGyh?1, and the annual outdoor effective dose ranges from 46.9 to 134 Sv. Absorbed dose rate for biota in the studied area is 1.31 10?4 Gyd?1. The mean excess lifetime cancer risk outdoors for the population is 3.8 10?4, and t he mean value of the external radiation hazard index obtained in this study is 0.48, which is consistent with the world average. A low dose of radiation will not pose a risk to the population and biota in the studied area.


2012 ◽  
Vol 27 (4) ◽  
pp. 392-398 ◽  
Author(s):  
Saeed Rahman ◽  
Muhammad Rafique

Radioactivity levels in building materials, collected from the Islamabad capital territory have been determined by using a gamma spectrometric technique. Measured specific activities of 226Ra, 232Th, and 40K in material samples ranged from 8 ? 1 to 116 ? 6 Bq/kg, 9 ? 1 to 152 ? ? 5 Bq/kg, and 29 ? 6 to 974 ? 23 Bq/kg, respectively. The radium equivalent activity, absorbed dose rate, annual effective dose, and gamma index were evaluated from the measured amounts of radioactivity to assess the radiation hazard associated with the studied building materials. The mean radium equivalent activity, the absorbed dose rate and annual effective dose estimated ranged from 81 ? 6 to 221 ? 11 Bq/kg, 38 ? 3 to 104 ? 5 nGy/h, and 0.23 ? 0.02 to 0.64 ? 0.03 mSv, respectively. The ranges of the calculated Raeq were found to be lower than the values recommended for construction materials (370 Bq/kg). The mean values of the internal and external hazard indices were found in the range of 0.30 ? 0.02 to 0.78 ? 0.05 and 0.22 ? 0.02 to 0.60 ? 0.03, respectively. The results of the materials examined indicate no significant radiological hazards arise from using such material in building construction.


Author(s):  
C. P. Ononugbo ◽  
O. Azikiwe ◽  
G. O. Avwiri

Radioactivity distribution and transfer factor (TF) in plants are crucial parameters used to assess radioactive contamination in the environment, impact of soil radioactivity on agricultural crops and its risks to humans.  The root crop cassava (Manihot esculenta) provides about 50 percent of the calories consumed in Nigeria. Gamma - ray spectroscopy was used to measure activity concentrations of 226Ra, 232Th and 40K in cassava root and soil. The average activity concentration of 40K, 226Ra and 232Th in cassava was 565.31± 13.17, 21.89±5.94 and 817.28±2.52 Bqkg-1 respectively. The mean activity concentration   40K, 226Ra and 232Th in soil range from 92.07±35.08 to 689.28±14.35 Bqkg-1with a mean value of 413.64±21.22 Bqkg-1, 5.37 ± 8.90 to 64.93 ± 7.23 Bqkg-1 with a mean value of 54.43 ± 3.22 and BDL to 928.15 ± 2.36 Bqkg-1 with a mean value of 561.67 ± 2.21 Bqkg-1. The transfer values for 226Ra, 232Th and 40K were in the range of 0 to 1.81, 0 to 3.41 and 0.68 to 4.5 respectively. The high value of transfer factor for 40k may be due to its importance in plant growth, fertilization and adaptability of plant to environmental pressures. It may have also been enhanced by the application of NPK fertilizers in those farms. Thorium showed the highest mean transfer factor which may be due to its higher accumulation in soil and higher uptake by plants (Figure 3). The average transfer factors of 226Ra (0.99) < 40K (1.55) < 232Th (1.66) show that although activity concentration of the natural radioisotopes in the area under study are high, the rate at which they are transferred to cassava are still moderate.  The average values of radium equivalent activity (Raeq), absorbed dose rate (D), annual effective dose rate (AEDE), internal hazard index and excess life cancer risk (ELCR) are 1009.27 Bqk-1, 346.50 nGyh-1, 1.51 mSvy-1, 2.78 and 3.92 x 10-3 for respectively. These values were higher than their corresponding permissible values of 370Bqk-1, 55nGyh-1, 1.0 mSvy-1, 1.0 and 0.29 x 10-3 respectively. The mean values of Hex and Hin are greater than unity and may, therefore, constitute a significant radiological health risk. The mean annual gonad dose estimated value of 2943.90 mSvy-1  was above the world acceptable value of 300 mSvy-1 and the annual effective dose in all the samples except in few locations as shown in Figure 2, exceeded the safe value of 1.0 mSvy-1. The use of soil from these farms and the crops may constitute a threat to the bone marrow and general health conditions of the inhabitants.


Author(s):  
A. Ibitola, Gilbert ◽  
Ajanaku Olanrewaju ◽  
Ilori, Abiola Olawale ◽  
R. O. Aremu ◽  
I. A. A. Omosebi

The aim of this present study is to collect soil samples and some commonly consumed food materials in Ondo State, Nigeria such as tubers (cassava, Manihot esculent and yam, Dioscorea alata) samples and vegetables (waterleaf, Talinium triangulare and bitter leaf, Vernonia amygdalina) samples at some selected locations in Okitipupa, Ondo state, Southwestern, Nigeria in order to determine the following natural radionuclides (40K, 238U and 232Th) levels using a well calibrated NaI(TI) which is well shielded with a detector coupled to a computer resident quantum MCA2100R Multichannel. The transfer factors, annual absorbed dose rate and the annual effective dose in the samples collected were estimated. The results showed that the measured natural radionuclides were present in the mean concentrations of 323.79 ± 12.45 Bqkg-1, 81.87 ± 45.30 Bqkg-1 and 57.62 ± 18.04 Bqkg-1 for 40K; 11.76 ± 36.03 Bqkg-1, 4.67 ± 10.12 Bqkg-1 and 3.45 ± 2.10 Bqkg-1 for 238U and 9.66 ± 0.89 Bqkg-1, 3.07 ± 2.45 Bqkg-1  and 2.45 ± 0.92 Bqkg-1  for 232Th for soil, yam and cassava samples respectively. The results also showed that the radionuclides were present in the concentrations of 11.76 ± 36.03 Bqkg-1 and 9.66 ± 0.89 Bqkg-1 for 40K; 9.67 ± 8.53 Bqkg-1 and 7.87 ± 1.89 Bqkg-1 for 238U and 8.63 ± 6.08 Bqkg-1 and 6.58 ± 0.76 Bqkg-1 for 232Th for waterleaf and bitter leaf samples respectively. The soil-to-yam transfer factors were found to be 0.26, 0.40 and 0.32 for 40K, 238U and 232Th and soil-to-cassava yam transfer factors were found to be 0.18, 0.29 and 0.25 for 40K, 238U and 232Th respectively. The soil-to-waterleaf transfer factors were found to be 0.37, 0.82 and 0.82 for 40K, 238U and 232Th while the soil-to-bitter leaf transfer factors were found to be 0.32, 0.74 and 0.68 for 40K, 238U and 232Th respectively. The mean absorbed dose rate was 25.08 ± 0.57  and the mean annual outdoor effective dose was 46.17 . The annual effective dose reported for this present study area represents 65.95% of the world average value of 70.00 and 47.11% of Nigeria value of 98.00 mSvy-1  


2021 ◽  
Vol 5 (1) ◽  
pp. 34-51
Author(s):  
E C D K Addison ◽  
R A Opoku ◽  
C E B N Addison ◽  
W I Aniagyei

Purpose: A study was conducted to estimate the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR) caused by the presence of an artificial cobalt-60 radioactive source producing ionizing radiation levels within the radiotherapy facility at Komfo Anokye Teaching Hospital (KATH) in Ghana. This study validated the safety of cobalt-60 radioactive sources, as well as the notion of calculating the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR), which contributed to reducing occupational and public exposures inside the facility. Methodology: The investigation was carried out with the use of a portable OD-01 Ionization Chamber Survey Meter. The absorbed dose rate (ADR) in air was changed between 5 m and 40 m, with measurements taken inside and around the cobalt 60 bunker, as well as at sixteen other sites within the radiation facility. Findings: From 5 m to 40 m surrounding the Cobalt-60 source, the estimated Absorbed Dose Rate in air inside the cobalt-60 bunker ranged from 0.299 0.001 to 0.977 0.005 Sv/h, with an average of 0.498 0.005 Sv/h. The estimated Annual effective dose equivalent varied from 1.100 mSv/yr to 3.595 mSv/yr around the cobalt-60 source inside the Co-60 bunker. Radiation exposure levels ranged from 0.268 0.008 Sv/h to 0.678 0.005 Sv/h, with an average of 0.440 0.004 Sv/h observed around the fifteen sites chosen. Excess Lifetime Cancer has values ranging from 3.85 10-3 to 12.58 10-3 and 3.45 10-3 to 8.73 10-3. Risks were evaluated for the cobalt and the sixteen places inside the plant. The absorbed dose values at 5 m, 10 m, and 15 m inside the Co-60 bunker and the location Co-60 bunker as part of the facility exceeded the ICRP-recommended limit of 0.57. The AEDE and ELCR levels were within the ICRP's acceptable limits. The AEDE and ELCR statistics acquired indicate that the Cobalt-60 unit and its surroundings are radiation safe, although the likelihood of employees contracting cancer from the absorbed dose and background ionizing radiation is significant over a lifetime. Recommendation: However, it is recommended that absorbed dose level monitoring and evaluation of the Radiation Therapy Technologist (RTT) and other workers surrounding the unit be monitored on a regular basis. It is also recommended that Occupational Staff, such as RTTs, spend as little time as possible in the bunker  


Author(s):  
G. O. Avwiri ◽  
J. Ekpo ◽  
Y. E. Chad-Umoren

The aim of this study is to determine the occupational hazards due to exposure to gamma radiations from oil and gas facilities. In-situ measurement of radiation exposure rate of some Oil Field Facilities in Rivers State, Nigeria  carried out using Digilert 200 and Radalert 100 nuclear radiation monitor and a geographical positioning system (Garmin GPSMAP 76S). The average exposure rates of the facilities range from 0.010±0.002 to 0.015±0.001, for indoor and 0.014±0.003 to 0.027±0.003  for outdoor. The mean absorbed dose rates for indoor varied from 92.1 to 121.1 nGyh-1 while the mean outdoor absorbed dose varied from 120.4 to 234.2 nGyh-1. The estimated indoor annual effective dose varied from 0.14 to 0.19 mSvy-1 while the outdoor annual effective dose varied from 0.23 to 0.36 m Svy-1.The estimated indoor excess lifetime cancer risk (ELCR) range from 0.56× to 0.65x10-3 and outdoor ranged from 0.65×5 to 1.26×. The respective mean values of absorbed dose, AEDE and ELCR for indoor and outdoor measurements at the different locations exceeded the world permissible values of 60, 70 and 0.29× respectively. The result of this work indicated that used oilfield pipe market recorded the highest exposure rate. This could be due to radiations from scales on the pipes and may pose health challenged for long term exposure.


2020 ◽  
Vol 24 (3) ◽  
pp. 435-442 ◽  
Author(s):  
M. Atipo ◽  
O. Olarinoye ◽  
B. Awojoyogbe ◽  
M. Kolo

Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibratedhand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 μSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.  Keywords: Gamma-radiation; mine; absorbed dose rate; radiation exposure.


2017 ◽  
Vol 14 (3) ◽  
pp. 619-624
Author(s):  
Baghdad Science Journal

In this research the specific activity of natural radionuclides 226Ra, 232Th and 40K were determined by sodium iodide enhanced by thallium NaI(TI) detector and assessed the annual effective dose in Dielac 1 and 2 and Nactalia 1 and 2 for children of less than 1 year which are available in Baghdad markets. The specific activity of 40K has the greater value in all the types which is in the range of allowed levels globally that suggested by UNSCEAR. The mean value of annual effective doses were 2.92, 4.005 and 1.6325 mSv/y for 226Ra, 232Th and 40K respectively.


2021 ◽  
Vol 8 (S1-Feb) ◽  
pp. 97-103
Author(s):  
Niranjan R S ◽  
Ningappa C ◽  
Nandakumar V ◽  
Harshavardhana C N

All individual living beings on the earth are exposed continuously to the radiations coming from terrestrial and extraterrestrial sources and also from their own bodies. The indoor and outdoor ambient gamma radiations are measured in and around Nuggihalli- Holenarasipura schist belts of Hassan district in Karnataka state. The measurements are carried out using the environment radiation dosimeter UR 705 which is a portable detector. Absorbed dose rate and annual effective dose rate are estimated by measuring the exposure rate. The total annual effective dose calculated from both indoor and outdoor varies from 0.68 to1.62 mSv.y-1 with an average value of 1.16 mSv.y-1. The calculated indoor and outdoor annual effective doses are found to be higher than the world average.


Sign in / Sign up

Export Citation Format

Share Document