Levels Of Natural Background Radiation Research Articles

Environmental Radiological Impact and Risk Assessment of Natural Radioactivity at the Heap Leach Facility of Tarkwa Goldmine, Ghana: Radiotoxicity and Public Exposure

In this study, a comprehensive investigation was conducted to determine the radioactivity levels of naturally occurring radioactive materials (NORMs) in heap pads/soil and water samples within and around the operational area of Tarkwa Gold Mine in Ghana. Gamma-ray spectrometry was used to determine the activity concentrations of 238U, 232Th, and 40K in heap pads/soil, and 226Ra, 228Th, and 40K in water samples. The average activity concentrations of 226Ra and 228Th in all water samples were below the World Health Organisation (WHO) recommended guidelines for drinking water. Similarly, the average activity concentrations of measured radionuclides in heap pads/soil samples taken from depths of 0–20 cm and 20–50 cm were found to be below the worldwide average reported values. The annual effective dose to the public was estimated to be around 0.16 mSv, which is below the recommended limit. The values of the hazard indices are also below the recommended limits, implying that if heap pads/soils are used for building purposes and construction, they will not pose any significant radiation hazard. The results of this study indicate that radiation levels are within the natural background radiation levels reported in the literature and are consistent with findings from similar studies conducted in Ghana.

Assessment of NORMs (238U, 232Th, 40K) and radiation hazard indices in Beldih apatite mine region of Purulia district, West Bengal, India.

The radiation arising from naturally occurring radioactive materials (NORMs) is the foremost contributor to the collective dose received by the global population. The present study aims to measure the natural background radiation level and the associated gamma radiation dose in air in the Beldih apatite mine region of Purulia district, India. This study is primarily focused on the determination of 238U, 232Th and 40K activities in the sub-surface soil of the study area. The measurements were carried out using a High Purity Germanium (HPGe) detector-based gamma-ray spectrometer with a relative efficiency of 80%. To achieve uniformity in exposure estimations, radium equivalent activity has been calculated. Additionally, the internal hazard index, external hazard index, radioactivity level index and gamma dose rates have been evaluated to estimate the radiation hazard levels in the study area. The comparison of obtained concentrations and hazard indices with global data (UNSCEAR. (2008). Sources, effects and risks of ionizing radiation. United nations scientific committee on the effects of atomic radiation (report to the general assembly, with Annexes).) suggests that this region lies in a relatively high background radiation zone.

Monitoring of outdoor natural gamma absorbed dose rate in air in Hyderabad, Telangana, India.

The Indian Environmental Radiation Monitoring Network continuously monitors the outdoor natural gamma absorbed dose rate in air at different locations throughout India by employing Geiger-Mueller (GM) detector-based field-installed environmental radiation monitors (ERMs). Hyderabad, Telangana, India is known to have high natural background radiation levels due to the presence of high concentrations of primordial radionuclides in its granitic rocks. There are a total of 59 ERMs installed at various locations across Hyderabad. Long-term monitoring data of these locations are presented in this paper. The mean values of outdoor natural gamma absorbed dose rate in air at the monitoring locations were found to vary in the range of 104-258 nGy.h-1 with a mean of 193±40 nGy.h-1. The mean annual effective dose due to outdoor natural gamma radiation was estimated to be 0.24±0.05mSv.y-1. Analysis of the long-term seasonal variation of outdoor natural gamma absorbed dose rate in air showed that the same was lowest during monsoons.

Natural background outdoor gamma radiation levels and mapping of associated risk in Siddipet district of Telanagana State, India

Studies on natural background outdoor environmental radioactivity levels were conducted in Siddipet district of Telangana state, India. The investigation was carried out in the major villages/mandal head quarters of the district using scintillation detector (NaI(Tl)) based μR- survey meter. The exposure rates measured on ground level and at 1 m height from ground (in μR.h−1) were converted into absorbed dose rates (in nGy.h−1) and annual effect doses (mSv) using appropriate conversion factors. The natural background radiation levels at 1 m height were found to vary from 139 nGy h−1 to 435 nGy h−1 with an average of 235±47 nGy h−1. The background radiation levels were observed to follow the normal distribution with a little deviation at the outliers. The excess lifetime cancer risk (ELCR) was also estimated.

Baseline assessment of naturally occurring radionuclides in borehole water of Asikam-gold mining community in Ghana

The main source of drinking water and domestic usage for the population of Asikam in the Fanteakwa South Municipality is from hand-dug wells and mechanized boreholes. This study assessed naturally occurring radionuclides Radium-226(Ra-226), Thorium-232(Th-232) and Patassium-40(K-40) in the water from these sources. A random sample of 20 sampling points made up of 7 manually dug wells and 13 mechanically drilled boreholes were taken from Asikam Communities. The radioactive contents of the selected water sources were characterized and analysed using gamma spectrometry system with High Pure Germanium Detector. This assessment was carried out to determine the level of natural radioactivity that the processing of gold ore at the Asikam illegal mining site in Ghana exposes the public to. The mean activity concentrations of Ra-226, Th-232, and K-40 were obtained as 0.30 Bq/L, 0.49 Bq/L, and 2.44 Bq/L in the water samples respectively. The results from this study were found to be lower than the Guidance levels recommended by the World Health Organization (WHO, 2011; IAEA,2014) of 1 Bq/l for Ra-226 and Th-232. The estimated average committed annual effective dose for water samples was 0.17 mSv/yr which is lower than the 1 mSv/yr recommended limits for public exposure by the WHO. The cancer fatality risk and hereditary consequences from exposure to naturally occurring radionuclides which may result from the Asikam community's mining and mineral processing operations were evaluated and found to be insignificant. The findings of this study demonstrate radioactivity levels are within the range of natural background radiation levels as reported in the literature, and they compare favorably with findings from comparable studies conducted nationally and internationally. This study provides important baseline information for future research in the study area.

Recent review of natural and artificial background radiation dosimetry studies in Saudi Arabia.

This paper includes a review of the natural background radiation of the Kingdom of Saudi Arabia. The review deals with natural radioactivity measurements conducted in the past few decades in the Kingdom. The numerous research works reviewed refer to different materials soils processed building material, terrestrial (dwellings) and mining sites. For the measurements, different experimental techniques were adopted. The highest mean specific activity of 238U, 232Th and 40K in soil samples was found to be 39.0, 25.6, and 343.0Bq/kg, respectively. While the world average values are 33, 45 and 420Bq/kg, respectively. For building materials, the highest mean values for 226Ra, 232Th and 40K were 89, 106 and 773Bq/kg, respectively. The mean indoor and outdoor dose rates were 455µGy/y (Riyadh City) and 883µGy/y (Al-Khamis City), respectively. For the mining sites the mean values for 238U, 226Ra, 228Ra, gross α and gross β, were 0.12, 0.33, 21, 0.78 and 2.44Bq/kg, respectively. Based on the available data it is concluded that most of the natural background radiation levels in the measured locations were within acceptable limits, while a few isolated locations showed elevated dose rates. This review suggests that new improved radiological survey methods be employed to cover the entire country, and that areas identified with comparably high dose rates be re-assessed, especially, in dwellings and mining sites.

Exposure of health professionals in the emergency department from portable radiography machines: a prospective cohort study

Background: Portable radiography machines are excellent diagnostic tools, but prolonged exposure to X-rays can damage tissue. The most severe concerns include increased cancer risk, cataract development, and fetal harm in pregnant workers. This study investigates whether healthcare personnel in the emergency department (ED) are exposed to X-ray ionizing radiation in excess of the National council on radiation protection and measurements limit. Methods: A 5-month prospective cohort study was conducted. The sample population included healthcare professionals in the ED at King Abdulaziz Medical City, Saudi Arabia. All physicians and nurses were requested to wear thermoluminescent dosimeter (TLD) monitors while working in the ED. TLD monitors worn by consultants, residents, and nurses were assessed at the end of the study. Results: Sixty-one participants met the inclusion criteria, and two TLDs served as controls to quantify natural background radiation levels. One of the 61 participants measured 0.1 mSv, and the rest measured lower, indicating that the average radiation dose to health professionals in the ED, such as consultants, residents, and charge nurses, is below 0.1 mSv. A total of 9,327 X-ray examinations were conducted by the participants, most commonly of the chest, followed by the pelvis. Conclusion: Radiation exposure is not a major occupational concern, even during peak ED hours. The degree of radiation exposure measured in this study was far below the minimum permissible exposure level for ED staff. Therefore, additional protective equipment or individual surveillance with dosimeters appears unnecessary.

Environmental and Hygiene Requirements for Ensuring Radiation Safety During the Construction and Reconstruction of Buildings in The Russian Federation

The levels of natural background radiation in certain territories of the Russian Federation differ significantly from each other and can vary widely. Most of the population receives radiation doses from natural sources of ionizing radiation from 2 to 4 mSv/year, but in some areas their radiation levels exceed 10 mSv/year. The population of the Russian Federation receives the main collective dose of radiation from natural radiation while living and working in enclosed residential, public and industrial buildings. In them, the levels of ionizing radiation in buildings, as a rule, depend on the level of the radiation background of the territory, which is determined by the geological, geochemical features of the area and its terrain, as well as on the type of building, radioactivity of the building materials used, emanation and exhalation of radon and daughter products of its decay into rooms from the ground and building materials used. The average annual individual doses of ionizing radiation in buildings, with the exception of certain territories, are small, but they can in isolated cases cause somatic and genetic effects in humans. To reduce the likelihood of such consequences in the Russian Federation, a system of legal and organizational provision of radiation safety of the population during the construction and reconstruction of buildings was developed, environmental and hygienic requirements for it were determined.

Measurement of natural background radiation level in Darchula district, Nepal

Natural background radiation level within Darchula district of Nepal was measured using a simple portable Geiger-Müller counter. Data were collected along six different directions at different places (three-five places) of the sample sites of the district and was averaged. The average data value with their standard deviation was used for analysis. In this study, the maximum radiation counts of 51.16 2.30 CPM were reported at Satan and the minimum counts of 25.96 2.30 CPM at Gokuleshwar. The observed radiation level of the Darchula district shows that the district is below the radiation risk level (nearly 100 CPM).

Long-term investigation of environmental radioactivity levels and public health around the Qinshan Nuclear Power Plant, China

To evaluate the impact of the Qinshan Nuclear Power Plant (Qinshan NPP) in normal operation on the surrounding environment and population, the radioactivity levels of drinking water and the ambient environment, as well as the residents’ cancer incidence, were continuously monitored for a period of 9 years (2012–2020). All of the gross α and β radioactivity concentrations in drinking water were less than the WHO recommended values (0.5 Bq/L for gross α and 1 Bq/L for gross β). The results of ambient environment accumulated dose monitored by thermoluminescent dosimeters (TLDs) indicated that the ambient environment radioactive level around the Qinshan NPP is consistently at natural background radiation levels. The age-dependent annual effective doses due to the ingestion of tap water or exposure to the outdoor ambient environment are lower than the reference dose of 0.1 mSv/year. The corresponding excess risks are at relatively low levels. Thus, the consumption of drinking water and outdoor activities are not expected to give rise to any detectable adverse effects on the health of the public around the Qinshan NPP. For all cancers combined, the age-standardized incidence rate by the Chinese 2000 standard population of the inhabitants living around Qinshan NPP is consistent with that of Zhejiang Province as a whole. Based on current radiation risk estimates, radiation exposure is not a plausible explanation for any excess cancers observed in the vicinity of the Qinshan NPP.

Modelling of indoor external and internal exposure due to different building materials containing NORMs in the vicinity of a HNBRA in Mahallat, Iran

In this study, by considering the Naturally Occurring Radioactive Materials (NORMs) contained in the building materials used in Mahallat, Iran - an area exposed to a high level of natural background radiation - residential scenarios were simulated by applying the computer code RESRAD-BUILD to estimate the long-term Effective Dose rate of three different cases of basic building materials utilized in walls, floors and ceilings. Maximum effective dose rates of between 504 and 1433 μSv yr−1 were calculated in the second case study, tiled cement floor. The highest external and radon doses were also calculated to be 369 and 1064 μSv, respectively. The simulation results revealed that 232Th and 40K contribute the most and least to the indoor dose, respectively. As a result of a sensitivity analysis, it was found that the air exchange rate is a key variable to easily reduce the radiological impacts of building materials. It was also shown that due to the presence of 226Ra, the sensitivity of effective dose to changes in wall thickness was higher than other radionuclides found in the building materials.

Chronic Background Radiation Correlates With Sperm Swimming Endurance in Bank Voles From Chernobyl

Sperm quantity and quality are key features explaining intra- and interspecific variation in male reproductive success. Spermatogenesis is sensitive to ionizing radiation and laboratory studies investigating acute effects of ionizing radiation have indeed found negative effects of radiation on sperm quantity and quality. In nature, levels of natural background radiation vary dramatically, and chronic effects of low-level background radiation exposure on spermatogenesis are poorly understood. The Chernobyl region offers a unique research opportunity for investigating effects of chronic low-level ionizing radiation on reproductive properties of wild organisms. We captured male bank voles (Myodes glareolus) from 24 locations in the Chernobyl exclusion zone in 2011 and 2015 and collected information on sperm morphology and kinetics. The dataset is limited in size and there overall was a relatively weak correlation between background radiation and sperm quality. Still, some correlations are worth discussing. First, mid-piece segments of spermatozoa tended to be smaller in bank vole males from areas with elevated background radiation levels. Second, we demonstrated a significant positive relationship between background radiation dose rates and the proportion of static spermatozoa among males within and among study locations after 10 as well as 60 min of incubation. Our results provide novel evidence of damaging effects of low dose ionizing radiation on sperm performance in wild rodent populations, and highlight that this topic requires further study across the natural gradients of background radiation that exist in nature.

Radiation safety of food raw materials and food products

Intensive use of radioactive isotopes in industry, abnormal emissions of nuclear fission products into the environment gradually increase the level of natural background radiation. As a result, there is a problem of farming, the main producer of food for the population, raw materials for industry, associated with the control of the level of contamination of soil, water, and livestock products. It is necessary to constantly monitor the radiation situation, namely the content of cesium-137 in soil, water, as well as in animal products both in the North-Western region and in other subjects of the Russian Federation. Due care must be taken when organizing the feeding of productive animals (dairy cows, beef cattle in the final fattening period), whose products, without an additional processing stage, can be directed to consumption by the population.

ASSESSMENT OF RADIATION DOSE LEVEL AT KABBA COLLEGE OF AGRICULTURE, DIVISION OF AGRICULTURAL COLLEGES, AHMADU BELLO UNIVERSITY, ZARIA

Background radiation involves the measure of the level of ionizing radiation present in the environment at a particular location. This research seek to generate data of the natural background radiation level of some selected Sections at Kabba College of Agriculture, using RadEye G20 survey meter. A total of 15 sections of the College were randomly selected and the background radiation dose rate of the sections were measured. The indoor dose rate ranged from (0.09 – 0.13) 𝜇Sv/yr, while the outdoor dose rate ranged from (0.07 - 0.10) 𝜇Sv/yr. The indoor annual effective dose were observed to be greater than the outdoor annual effective dose in all the College Sections measured. The lowest total annual effective dose 0.75 𝑚𝑆𝑣/𝑦𝑟 was found at the Academic staff block. The highest total annual effective dose of 1.09 𝑚𝑆𝑣/𝑦𝑟 was found at the livestock building, this might be due to the high-altitude nature of the area and the rocky materials used in the construction of the building. The highest total annual effective dose of the study area was slightly above the recommended limit of 1.0 𝑚𝑆𝑣/𝑦𝑟. The result obtained from this research may not constitute immediate health risk to the staff and student of the college

Residential exposure to natural background radiation at birth and risk of childhood acute leukemia in France, 1990–2009

BackgroundThe role of natural background radiation (NBR) in childhood acute leukemia (AL) remains unclear. Several large record based studies have recently reported heterogeneous results. Differences in exposure assessment timing may explain this heterogeneity. ObjectivesIn a previous ecological study we did not observe any association between childhood AL incidence in France and NBR exposure at the time of diagnosis. With the same methodology, the present study focused on NBR exposure at the time of birth. Based on data from the French national registry of childhood cancer, we analyzed all AL together, and lymphoblastic and myeloid AL, separately. MethodsWe included 6,059 childhood AL cases born and diagnosed in mainland France between 1990 and 2009. NBR levels in municipalities of residence at birth were estimated by cokriging models, using NBR measurements and precise geological data. The incidence rate ratio (IRR) per unit variation of exposure was estimated with Poisson regression models, with adjustment for socio-demographic indicators and ultraviolet radiation levels. NBR exposures were considered at the time of birth, and cumulatively from birth to diagnosis. We also estimated a total NBR dose to red-bone marrow (RBM). ResultsThere was no evidence for an association between NBR exposure at birth and childhood AL incidence, neither overall (gamma radiation: IRR = 0.99 (0.94,1.05) per 50 nSv/h; radon: IRR = 0.97 (0.91,1.03) per 100 Bq/m3) nor for the main AL types. The conclusions were similar with the cumulative exposures, and the total RBM dose. ConclusionsThe study was based on high quality incidence data, large numbers of AL cases, and validated models of NBR exposure assessment. In all, the results further support the hypothesis that NBR are not associated to childhood AL in France.

Radioactivity of building materials in Mahallat, Iran – an area exposed to a high level of natural background radiation – attenuation of external radiation doses

In this study, mass activity of naturally occurring radioactive materials were measured in twenty-three building material samples, use extensively in the area exposed to a high level of natural background radiation (Mahallat, Iran), to determine the radioactivity index and changes to the level of indoor gamma radiation. The mass activity of 232Th, 226Ra and 40K were within the ranges from 18 ± 3 to 44 ± 10 Bq/kg (average of 27 ± 6 Bq/kg), 22 ± 5 to 53 ± 14 Bq/kg (average of 34 ± 6 Bq/kg) and 82 ± 18 to 428 ± 79 Bq/kg (average of 276 ± 58 Bq/kg), respectively. The gamma dose rates for population were estimated between 48 ± 9 and 111 ± 26 nGy/h with exception of radon exhalation from building materials. Since the air kerma rate in the town varies from 0.8 to 4 μGy/h, the attenuation coefficient was calculated for buildings made of the aforementioned materials. Additionally, the annual gamma radiation doses for inhabitants were calculated based on time spent outdoors and indoors.

SiPM-Based Detector for High-Resolution Measurements in Pulsed Radiation Fields

Modern ionizing radiation generators used for medical imaging and radiotherapy operate in the pulsed regime or have short exposure times. This classifies them as pulsed sources. Electronic dosimeters that measure dosimetric quantities, the ambient dose equivalent [ $H^\ast $ (10)], and the personal dose equivalent [ $H_{\mathrm {p}}$ (10)] that show satisfactory performance in pulsed fields are emerging, but the accuracy of $H^\ast $ (10) rate (d $H^\ast $ (10)/ $\text{d}t$ ) measurements of short pulses is lagging behind. With the goal of solving this problem, we developed a novel system for measurements of $H^\ast $ (10) and $H^\ast $ (10) rate in pulsed fields. The measurement chain is composed of a thallium-doped sodium iodide scintillation crystal optically coupled to a silicon photomultiplier, an amplifier, and a high memory depth digital storage oscilloscope. To investigate the detector performance, a series of measurements in a pulsed radiation field was made for in-beam and scattered radiation. Both the $H^\ast $ (10) and $H^\ast $ (10) rates were successfully measured with 1-ms time resolution, while the best-achieved resolution was 1 and 10 nSv/h, respectively. The analysis of the $H^\ast $ (10) rate response showed that the detector measurement range is from natural background radiation levels (~100 nSv/h) up to 250 mSv/h.

Radiation safety and environmental impact assessment of sludge TENORM waste produced from petroleum industry in Egypt

The characterization and radiological study of sludge technically enhanced naturally occurring radioactive materials (TENORM) waste samples collected from the production of oil and gas at Gabal EL Zeit eastern desert in Egypt were carried out using different analytical and radiological spectrometry. The sludge TENORM waste sample was fractionated to 3 different particle sizes (< 1mm, < 1.6mm, < 2mm) as well as bulk sample. Sludge TENORM waste (bulk and different sizes) samples were characterized by Fourier transform infrared (FTIR), energy dispersive x-ray, (EDX) and x-ray diffraction (XRD). The mean activities of bulk and different sizes for U-238, Ra-226, Pb-210, Ra-224, K-40 and U-235 were high levels of natural background radiation. Radiation hazard indices were calculated to assess the risk of these samples on workers and the environment. Some of the representative radiation indices such as radium equilibrium Raeq, absorbed dose rate Dabs, annual effective dose rate Dann, external and internal hazard index Hex, Hin, annual gonadal dose equivalent AGDE, activity utilization index AUI, excess lifetime cancer risk factor ELCR, representative gamma index Iᵧr, and alpha index Iα were derived and compared with the world average values. The results demonstrated that there is a harmful radiation effect posed to the public or factory workers.

A Radon Background-subtraction Algorithm for Electronic Personal Dosimeters.

Many first responders are outfitted with electronic personal dosimeters to recognize and be alerted to radiological hazards during their response operations. These dosimeters provide invaluable measurement data for force protection, allowing the first responder to assess a response situation and take protective measures for themselves and other individuals involved based on instrument readings of dose rate or cumulative dose. However, capabilities of common electronic personal dosimeters to identify and distinguish various contributions to the instrument reading, in particular from natural radiological sources, are rather limited. An algorithm has been developed for two-channel electronic personal dosimeters that quantifies the signal contribution from radon progeny and allows for background subtraction from radon and radon progeny in the instrument reading. This algorithm will be particularly useful in operational scenarios where first responders may be subject to rapidly changing levels of natural background radiation, which could mimic the presence of anthropogenic sources of ionizing radiation.

Efficacy of mathematical models in predicting the concentration of indoor radon in areas with high levels of natural background radiation

Efficacy of mathematical models in predicting the concentration of indoor radon in areas with high levels of natural background radiation