Journal Article•
Effective dose from natural background radiation in Keffi and Akwanga towns, central Nigeria
15 Jan 2014-Iranian Journal of Radiation Research (International Journal of Radiation Research)-Vol. 12, Iss: 1, pp 47-52
TL;DR: In this article, an in situ assessment of the indoor and outdoor background radiaƟ on in Akwanga and Keffi towns of Nasarawa state Nigeria was carried out using a halogen-quenched Geiger Muller (GM) detector.
Abstract: Background: Human is exposed to radiaƟ on in their environment with or without their consent; and the exposure to natural background radiaƟ on is an unpreventable event on earth. Materials and Methods: An in situ assessment of the indoor and outdoor background radiaƟ on in Akwanga and Keffi towns of Nasarawa state Nigeria was carried out using a halogen-quenched Geiger Muller (GM) detector (Inspector alert Nuclear radiaƟ on monitor SN: 3544). Each of these towns was divided into at least 20 sampling areas where at least ten readings were taken in order to have a reliable data. Results: The mean indoor and outdoor annual effecƟ ve dose of Akwanga were 1.29± 0.13mSv/yr and 0.31±0.04 mSv/yr respecƟ vely; and that of Keffi were 1.08± 0.15mSv/yr and 0.25±0.04 mSv/yr respecƟ vely. The radiaƟ on levels in both highly populated towns were found to be within the safe limit for areas of normal background set by UNSCEAR (2.4 mSv/yr). Conclusion: These results would serve as a baseline upon which other exposures would be assessed and in the future, serve as reference for dosimetry and decontaminaƟ on in situaƟ ons of radiaƟ on poisoning of these towns.
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TL;DR: In this article, the authors presented a radiometric survey of background ionizing radiation (BIR) dose levels in ten quarry sites located in Ebonyi State, Nigeria and obtained results indicated dose rates ranging from from 0.14 to 0.18 μSv/h with mean of 0.15±0.01 μSV/h at the excavation section (ES) and quarrying section (QS) of the investigated quarry sites.
Abstract: The study presents a radiometric survey of Background Ionizing Radiation (BIR) dose levels in ten quarry sites located in Ebonyi State, Nigeria. In-situ BIR dose rate measurements, by means of nuclear radiation survey meter, at 1 m above ground level were carried out at the excavation section (ES) and quarrying section (QS) of the investigated quarry sites. The obtained results indicated dose rates ranging from from 0.14 to 0.18 μSv/h with mean of 0.15±0.01 μSv/h at the ES and 0.16 to 0.19 μSv/h with mean value of 0.18±0.01 μSv/h at the QS. While the values obtained at the QS are respectively higher than those measured at the ES, they are all higher than the worldwide average value of 84 nSv/h signifying BIR elevated environments. The estimated mean annual effective dose (AED) and excess lifetime cancer risk (ELCR) are 0.27±0.03 mSv/y and 0.94×10–3 respectively at the ES and 0.31±0.02 mSv/y and 1.07×10–3 at the QS. The obtained AED values for all the sites are well above the outdoor worldwide average value of 0.07 mSv/y but lower than the International Commission on Radiological Protection recommended permissible limits of 1.0 mSv/y for the general public. Generally, the BIR levels of the quarry sites are within acceptable limits and no immediate radiological health threat may be derived from the current levels. However, long-term health effects due to continuous exposure to low-level radiation doses may manifested in future over a lifetime exposure of 70 years as indicated by the ELCR values.
Keywords: Background ionizing radiation, Dose rate, Annual effective dose, Quarry site, Ebonyi State
6 citations
Cites background from "Effective dose from natural backgro..."
...While the current values are higher than those measured in some building types in Ondo State, Nigeria (Oladele et al., 2018), along river Alaknanda and Ganges, India (Sharma et al., 2014) and in Guilan Province, Iran (Basirjafari et al., 2014), they are however within worldwide range of 20 – 200 nSv/h from different countries (UNSCEAR, 2000)....
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...…values are higher than those measured in some building types in Ondo State, Nigeria (Oladele et al., 2018), along river Alaknanda and Ganges, India (Sharma et al., 2014) and in Guilan Province, Iran (Basirjafari et al., 2014), they are however within worldwide range of 20 – 200 nSv/h from…...
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...Though the present dose rates in the quarry sites are elevated, they are still below the levels that can initiate immediate health effects to the workers (Sharma et al., 2014)....
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TL;DR: In this paper, Gamma spectrometer using HPGe detector was used to measure the radioacvity and assess the radiological hazards and annual effec ve dose of gamma radia on.
Abstract: Background: Natural radionuclides in rock samples, primarily 238 U (uranium), 232 Th (thorium) and 40 K (potassium), are the main source of radia on exposure to workers and general public and their measurement is of paramount importance from radia on protec on point of view. Materials and Methods: Gamma spectrometry using HPGe detector was used to measure the radioac vity and assess the radiological hazards and annual effec ve dose. The data is sta s cally significant. Results: In the studied rock samples, the mean ac vity of 238 U, 232 Th, 40 K is 12.15 ± 1.68 Bq/kg, 45.17 ± 6.92 Bq/kg and 639.24 ± 115.86 Bq/kg, respec vely. The mean values of radium equivalent ac vity, radiological hazards external hazard index (Hex), Internal hazard index (Hin), Gamma index (Iγ) and Alpha index (Iα) are 125.96 ± 14.94 Bq/kg, 0.34 ± 0.04, 0.37 ± 0.04, 0.48 ± 0.06 and 0.06 ± 0.00 respec vely. The mean values of absorbed dose rate, indoor and outdoor annual effec ve dose of gamma radia on are 59.55 ± 7.16 nGy/h, 0.29 ± 0.04 mSv and 0.07 ± 0.00 respec vely. A strong posi ve correla on was observed between the radium equivalent ac vity and the absorbed dose (correla on coefficient R2 = 0.99). Conclusion: The present inves ga ons showed that the inborn radioac vity is within the world and Indian average value. And the findings indicate that the studied samples do not pose any significant radia on hazard to the public in large and the workers in par cular and when used as construc on material also.
6 citations
Cites background from "Effective dose from natural backgro..."
...Hex = ARa / 370 + ATh / 259 + AK / 4810 (3) Hin = ARa / 185 + ATh / 259 + AK / 4810 (4) Iγ = ARa / 300 + ATh / 200 + AK / 3000 (5) Iα = ARa / 300 (6)...
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...It is also found in phosphate rocks, lignite and monazite sands, whereas 40K is present in mineral waters and brines, and in various minerals such as carnallite, feldspar, saltpeter, greens and sylvite (5-7)....
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TL;DR: A study of the terrestrial background ionizing radiation (BIRIR) levels of Bunker and Okpara mining site environment in Enugu state has been carried out to estimate the excess lifetime cancer risk as mentioned in this paper.
Abstract: A study of the terrestrial Background Ionizing Radiation (BIR) levels of Bunker and Okpara mining site environment in Enugu state has been carried out to estimate the excess lifetime cancer risk. A radiation monitoring meter (digilert 100) and a geographical positioning system (GPS) for GIS mapping were used. The monitoring of the BIR levels was carried out in one calendar year after delineating the environment of the two mining sites into four monitoring locations each. Average BIR levels measured ranged from 0.009 mRh−1 (0.76 mSvy−1) in Enugu new market (Bunker) mine site to 0.039 mRh−1 (2.52 mSvy−1) in Okpara mine site with overall mean value of 0.017 ± 0.007 mRh−1 (1.39 ± 0.60 mSvy−1). The computed average outdoor absorbed dose rate for the study area ranged from 113.10 ± 34.80 ηGyh−1 in Bunker mining area to 217.50 ± 78.30 ηGyh−1 in Okpara mining area, with a mean value of 143.55 ± 52.20 ηGyh−1. The mean annual effective dose equivalent (AEDE) calculated for the study coal mining sites was 0.18 ± 0.07 mSvy−1, while the mean excess lifetime cancer risk (ELCR) was (0.61 ± 0.14) ×10−3 mSvy−1. The dose received by organs was highest in the testes (0.12 mSvy−1), while the liver had the lowest dose values of 0.06 mSvy−1. The study revealed that of the 8 sampling locations and 3840 exposure measurements made, 74.1 % exceeded the world ambient standard levels of 0.013 mRh−1 (1.0 mSvy−1) recommended by UNSCEAR, and the recorded values were higher compared to values reviewed in literature. But the reported results may not constitute any immediate health risk to the residents and coal miners in the study area. The calculated Excess Lifetime Cancer Risk values indicates that the chance of developing cancer by residents and workers in the mine sites of the study area is low and the effective dose for adult organs investigated is insignificant to cause any health related sicknesses or damage to the investigated organs from the present exposure rate.
6 citations
Cites methods from "Effective dose from natural backgro..."
...The practices of radiation protection have been developed to ensure that human exposure to radiation is guided by the principle of ALARA (As Low As Reasonably Achievable) (Ramli et al. 2014)....
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TL;DR: In this article, in-situ measurements of absorbed dose rates of background gamma radiation in 146 outdoor locations within Enugu urban areas were carried out by means of a hand held radiation survey.
5 citations
10 Apr 2020
TL;DR: The obtained estimated excess lifetime cancer risk indicates low chances of contracting cancer and the radiation doses to the adult organs investigated is insignificant and the environment radiologically impaired.
Abstract: The assessment of terrestrial background ionizing radiation levels within fossil fuel and gas dispensing environments to evaluate the radiological risk around Warri metropolis has been conducted using a digilert 200 Nuclear Radiation monitor meter and a GPS. The GIS monitoring of the BIR levels was carried out between September and December 2018 by delineating the city into eight zones using GIS mapping. The measured average exposure rates ranged from 0.006mRh-1(0.50 𝑚𝑆𝑣𝑦-1) to 0.026mRh-1(2.19𝑚𝑆𝑣𝑦-1) with an overall mean value of 0.015±0.004mRh-1 (1.26±0.32 𝑚𝑆𝑣𝑦-1). The estimated mean outdoor absorbed dose rate for the regions ranged from 116.60±40.38nGyh-1 in Jeddo region to 148.9±49.63nGyh-1 in PTI region and a mean of 129.82±32.98𝜂Gyh-1.The AEDE evaluated is 0.16±0.04 𝑚𝑆𝑣𝑦-1 while the ELCR value is 0.56±0.014µ𝑆𝑣𝑦-1. The estimated dose to organs testes receiving the highest organ dose of 0.10 𝑚𝑆𝑣𝑦-1 while the liver receives the lowest dose to organ of 0.06 𝑚𝑆𝑣𝑦-1. The GIS mapping of the examined facilities revealed that radiation levels in 38 of the 61 sampling locations (62.3%) exceeded the global ambient permissible level of 13.0 𝜇Rh-1 (1.0 𝑚𝑆𝑣𝑦-1) reported by UNSCEAR, therefore the measured values are adjudged high and the environment radiologically impaired. But, these may not cause any short- team health risk to the fuel/gas attendants and attendees in these stations. The obtained estimated excess lifetime cancer risk indicates low chances of contracting cancer and the radiation doses to the adult organs investigated is insignificant.
4 citations
References
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Book•
18 Jun 2009
TL;DR: The Bornu Basin (Nigerian Sector of the Chad Basin).- Sokoto Basin and the Mid-Niger (Bida) Basin this paper, and the Dahomey Basin.
Abstract: GEOLOGY - IGNEOUS AND METAMORPHIC ROCKS.- The Basement Complex.- The Younger Granites.- GEOLOGY - SEDIMENTARY BASINS.- Cretaceous - Cenozoic Magmatism and Volcanism.- The Benue Trough.- The Bornu Basin (Nigerian Sector of the Chad Basin).- The Sokoto Basin (Nigerian Sector of the Iullemmeden Basin).- The Mid-Niger (Bida) Basin.- The Dahomey Basin.- MINERAL RESOURCES.- The Niger Delta Basin.- Solid Mineral Resources.- Petroleum Resources.- Policy Issues and Development Options.
580 citations
TL;DR: Inhabitants of high background radiation areas had about 56% the average number of induced chromosomal abnormalities of normal background radiation area inhabitants following this exposure, which suggests that adaptive response might be induced by chronic exposure to natural background radiation as opposed to acute exposure to higher levels of radiation in the laboratory.
Abstract: People in some areas of Ramsar, a city in northern Iran, receive an annual radiation absorbed dose from background radiation that is up to 260 mSv y−1, substantially higher than the 20 mSv y−1 that is permitted for radiation workers. Inhabitants of Ramsar have lived for many generations in these hig
396 citations
"Effective dose from natural backgro..." refers background in this paper
...Previous studies have shown that areas with high background radiation are found in Yangjiang, China; Kerele, India; and Ramsar, Iran (7); and in Asia, maximum outdoor measurement was recorded in Malaysia and the maximum indoor measurement was recorded in Hong A....
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...Previous studies have shown that areas with high background radiation are found in Yangjiang, China; Kerele, India; and Ramsar, Iran (7); and in Asia, maximum outdoor measurement was recorded in Malaysia and the maximum indoor measurement was recorded in Hong Background: Human is exposed to radia on in their environment with or without their consent; and the exposure to natural background radia on is an unpreventable event on earth....
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TL;DR: The average annual outdoor radiation exposure dose rate due to the radioactivity concentration of 40 K, 238 U and 232 Th in the soil across different environments in Nigeria have been carried out using the low-cost method of in situ γ ray spectrometry as discussed by the authors.
Abstract: The outdoor radiation exposure dose rates due to the radioactivity concentration of 40 K, 238 U and 232 Th in the soil across different environments in Nigeria have been carried out using the low-cost method of in situ γ ray spectrometry. Measurements were made in 18 cities, spread across the three major zones of the country. The radioactivity concentrations of these radionuclides in the soil were used to determine their radiation absorbed dose rates in the air. The range of average total dose rate due to the three radionuclides in the Eastern zone is between 0.025 and 0.081 μGy.h -1 with an average of 0.040 ± 0.006 μGy.h -1 , 0.041 and 0.214 μGy.h -1 with a mean of 0.089 ± 0.014 μGy.h -1 for the Western zone and between 0.066 and 0.222 μGy.h -1 with a mean of 0.102 ± 0.032 μGy.h -1 for the Northern zone. The average annual outdoor effective dose equivalents of 51 ± 8 μSv.y -1 114 ± 18 μSv.y -1 and 130 ± 41 μSv.y -1 have been estimated for the Eastern, Western and Northern zones, respectively. The average annual effective dose equivalent for the country has been estimated to be 98 ± 15 μSv.y -1 and the collective effective dose equivalent as 9.7 X 10 3 man.Sv.y -1 . Measurements have been taken as representing the baseline values of natural radioactivity as no artificial radionuclide was detected at any of the sites surveyed.
75 citations
Journal Article•
TL;DR: The average annual effective dose for gamma background radiation in Lorestan province has been 0.72 mSv, which was more than the global value (0.48 mSV) and a poor correlation coefficient between was observed altitude and absorbed dose rates.
Abstract: Background: The exposure of human being to ionize radiation from natural sources is a continuing, inescapable feature of life on earth. Direct measurement of absorbed dose rates in air has been carried out in many countries of the world during the last few decades. Such investigations can be useful for assessment of public dose rates, the performance of epidemiological studies, and keeping reference-data records to ascertain possible changes in the environmental radioactivity duo to nuclear, industrial, and other human activities. Materials and Methods: The measurements of the outdoor and indoor- environmental exposures including cosmic and terrestrial components were accomplished by a portable Geiger Muller detector (RDS -110). The measurements were made during daylight from September to October 2009, in five areas within nine big cities of Lorestan province. In each area, one building was randomly selected for indoor and outdoor measurements. Measurements were made for each region and an average value was used to calculate the exposure rate from gamma background radiation. Results: The results showed the Maximum and minimum outdoor dose rates as 166±44 and 65±8 nSvh-1 in Borujerd and Pol-e- dokhtar, respectively. The average of outdoor dose rates was determined 113±26 nSvh-1. Also the maximum and minimum values of indoor dose were 157±52 and 74±14 nSvh-1 in Borujerd and Pol-e-dokhtar, respectively. The average indoor dose rates were determined as 119±27 nSvh-1. Conclusion: The average annual effective dose for gamma background radiation in Lorestan province has been 0.72 mSv, with the range of 0.3– 0.6 mSv which was more than the global value (0.48 mSv). A poor correlation coefficient between was observed altitude and absorbed dose rates. Iran. J. Radiat. Res., 2011; 9(2): 8993
31 citations
TL;DR: Results indicate that the indoor background gamma radiation is comparable for both mining environments, and the outdoor gamma dose rates appear to be generally lower at the Okaba open cast mine than at Okpara.
Abstract: Measurements of the background terrestrial gamma radiation dose rates at different indoor and outdoor locations on the surfaces of Okpara underground and Okaba open cast mines in Nigeria were made. Two duly calibrated low-level gamma survey metres were held 1 m above the ground surface for these measurements. Measurements were also made at various locations inside the mine tunnel at the Okpara mine. Results indicate that the indoor background gamma radiation is comparable for both mining environments. The mean outdoor gamma dose rate determined for the Okaba mining environment is 10.4 nGy h - 1 as against 11.7 nGy h - 1 for Okpara. The ranges are 8.5-16.5 nGy h - 1 for the Okpara measurements and 7.5-14.0 nGy h - 1 for Okaba. Thus, the outdoor gamma dose rates appear to be generally lower at the Okaba open cast mine than at Okpara. The indoor dose rate values range from 11.0 to 17.0 nGy h - 1 in both environments. These indoor measurements have nearly the same mean values 14.4 and 14.5 nGy h - 1 for Okpara and Okaba environments, respectively. The indoor to outdoor dose rate ratio is 1.2 for Okpara and 1.4 for Okaba. These values are in consonance with the corresponding ratio given in literature. Dose rate measurements inside the mine tunnel at the Okpara mine are higher than the surface indoor measurements ranging from 13.5 to 20.5 nGy h - 1 with a mean of 16.5 nGy h - 1 . The higher dose rate values measured in the mine tunnel are attributable to the concentration of radon in the 'closed' environment of the mine tunnel.
16 citations