Background Radiation Levels Research Articles

The Enhancement of Background Radiation as A Result of Using Natural Building Materials

People living and working in buildings constructed from natural materials such as sandstone, concrete, calcite, gypsum, marble and granite are exposed to a surplus of background radiation from naturally occurring radioactive materials. The above materials contain naturally occurring radioactive elements such as potassium, radium, uranium, thorium and their progeny, which enhance the contribution to the ambient background radiation levels, consequently increasing the health risk. The unstable and hazardous radionuclides contribute remarkably to the level of background radiation in houses, schools and many other national institute buildings. Radiation levels at various locations were measured on the main campus of the German Jordanian University (GJU), in the area of Mushaqar, South Amman, Jordan. Thermal Lithium Dosimeters (TLD) were placed in 22 offices in different buildings. Subsequently, the radiation doses from the TLDs were estimated, then, the weekly averages and annual doses were calculated. The results indicated that the total background radiation levels ranged between 2 mSv/year to 10.58 mSv/year with an average of 4.62 mSv/year. This average is higher than the background radiation averages for the city of Amman, the Royal Scientific Society (RSS) buildings and the worldwide average dose of 2.4 mSv/year for a human being (ICRP 1990). Furthermore, radiation levels at GJU were higher in the ground floor offices, which is consistent with natural background radiation behaviour in a multi-storey building.

Impact assessment of naturally occurring radioactive materials on the public from gold mining and processing at Newmont Golden Ridge Limited, Akyem, Eastern Region of Ghana

Baseline radioactivity levels of naturally occurring radioactive materials within the operational area and surrounding communities of Akyem Gold Mine of Newmont Golden Ridge Limited of Ghana were determined based on direct gamma-ray spectrometry to quantify the radionuclides of interest, namely,238 U,232 Th, and 40 K in soil samples. The average activity concentrations of 238 U,232 Th, and 40 K in the soil samples were 11.90, 11.39, and 139.71 Bq/kg, respectively. For the water samples, the concentration values of gross-alpha and gross-beta for all the water samples were below the Ghana Standards Board (now Ghana Standards Authority) and World Health Organization recommended guideline values for drinking water quality. The annual average effective dose to the public due to gamma ray exposures from the soil samples was estimated to be 0.03 mSv which is below the UNSCEAR 2000 average reference level of 0.07 mSv for public exposure control. The results obtained in this study also show that radiation levels are within the natural background radiation levels found in literature and compare well with the results of similar studies in Ghana.

Investigation of Background Radiation Level Within X-ray Machine Environment

In this study, a Geiger Muller ionization counter has been used to investigate the variation of background radiation dose level with time in a typical x-ray machine room and its environment. This is to monitor the effect of x-ray exposure on the background ionizing radiation level. The results showed that within a period of 3 hours, the cumulative background radiation dose in the x-ray room grew from s s Gy to around 84 . 90 ́ 10 - 10 - an initial level of 38 . 78 ́ Gy compared with nearby rooms where the s cumulative radiation grew from almost zero to a maximum value of about 46 . 9 ́ Gy within the 10 - same period. It was observed that after a radiation exposure from the machine, the background s radiation dose rate took about 25 minutes to decay from a maximum level of around 45 ́ Gy/hr to 10 - - s 17 . 47 ́ 10 the background level about Gy/hr which was found to be higher than the background dose rates in other nearby locations. While the dose rate in the x-ray machine room was higher than the s 10 - maximum dose limit of 12 ́ Gy/hr recommended for members of the public by the International Committee for Radiation Protection (ICRP), the dose rates in the other locations studied in the neighbourhood of the x-ray machine were within the limit.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus—the ‘D-shuttle’ project—

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter ‘D-shuttle’ for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

A faster sample preparation method for determination of polonium-210 in fish

In order to facilitate Health Canada’s study on background radiation levels in country foods, an in-house radio-analytical method has been developed for determination of polonium-210 (210Po) in fish samples. The method was validated by measurement of 210Po in a certified reference material. It was also evaluated by comparing 210Po concentrations in a number of fish samples by another method. The in-house method offers faster sample dissolution using an automated digestion system compared to currently used wet-ashing on a hot plate. It also utilizes pre-packed Sr-resin® cartridges for rapid and reproducible separation of 210Po versus time-consuming manually packed Sr-resin® columns.

Sex ratio at birth: scenario from normal- and high-level natural radiation areas of Kerala coast in south-west India.

Newborns were monitored for congenital malformations in four government hospitals located in high-level (ambient dose >1.5 mGy/year) and normal-level (≤ 1.5 mGy/year) natural radiation areas of Kerala, India, from August 1995 to December 2012. Sex ratio at birth (SRB) among live singleton newborns and among previous children, if any, of their mothers without history of any abortion, stillbirth or twins is reported here. In the absence of environmental stress or selective abortion of females, global average of SRB is about 1050 males to 1000 females. A total of 151,478 singleton, 1031 twins, 12 triplets and 1 quadruplet deliveries were monitored during the study period. Sex ratio among live singleton newborns was 1046 males (95 % CI 1036-1057) for 1000 females (77,153 males:73,730 females) and was comparable to the global average. It was similar in high-level and normal-level radiation areas of Kerala with SRB of 1050 and 1041, respectively. It was consistently more than 1000 and had no association with background radiation levels, maternal and paternal age at birth, parental age difference, gravida status, ethnicity, consanguinity or year of birth. Analysis of SRB of the children of 139,556 women whose reproductive histories were available suggested that couples having male child were likely to opt for more children and this, together with enhanced rate of males at all birth order, was skewing the overall SRB in favour of male children. Though preference for male child was apparent, extreme steps of sex-selective abortion or infanticide were not prevalent.

Scattered radiation doses absorbed by technicians at different distances from X-ray exposure: Experiments on prosthesis.

This work aimed to investigate the spatial distribution of scattered radiation doses induced by exposure to the portable X-ray, the C-arm machine, and to simulate the radiologist without a shield of lead clothing, radiation doses absorbed by medical staff at 2 m from the central exposure point. With the adoption of the Rando Phantom, several frequently X-rayed body parts were exposed to X-ray radiation, and the scattered radiation doses were measured by ionization chamber dosimeters at various angles from the patient. Assuming that the central point of the X-ray was located at the belly button, five detection points were distributed in the operation room at 1 m above the ground and 1-2 m from the central point horizontally. The radiation dose measured at point B was the lowest, and the scattered radiation dose absorbed by the prosthesis from the X-ray's vertical projection was 0.07 ±0.03 μGy, which was less than the background radiation levels. The Fluke biomedical model 660-5DE (400 cc) and 660-3DE (4 cc) ion chambers were used to detect air dose at a distance of approximately two meters from the central point. The AP projection radiation doses at point B was the lowest (0.07±0.03 μGy) and the radiation doses at point D was the highest (0.26±0.08 μGy) .Only taking the vertical projection into account, the radiation doses at point B was the lowest (0.52 μGy), and the radiation doses at point E was the highest (4 μGy).The PA projection radiation at point B was the lowest (0.36 μGy) and the radiation doses at point E was the highest(2.77 μGy), occupying 10-32% of the maximum doses. The maximum dose in five directions was nine times to the minimum dose. When the PX and the C-arm machine were used, the radiation doses at a distance of 2 m were attenuated to the background radiation level. The radiologist without a lead shield should stand at point B of patient's feet. Accordingly, teaching materials on radiation safety for radiological interns and clinical technicians were formulated.

Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation

Purpose: The ‘Linear no-threshold’ (LNT) model predicts that any amount of radiation increases the risk of organisms to accumulate negative effects. Several studies at below background radiation levels (4.5–11.4 nGy h−1) show decreased growth rates and an increased susceptibility to oxidative stress. The purpose of our study is to obtain molecular evidence of a stress response in Shewanella oneidensis and Deinococcus radiodurans grown at a gamma dose rate of 0.16 nGy h−1, about 400 times less than normal background radiation.Materials and methods: Bacteria cultures were grown at a dose rate of 0.16 or 71.3 nGy h−1 gamma irradiation. Total RNA was extracted from samples at early-exponential and stationary phases for the rt-PCR relative quantification (radiation-deprived treatment/background radiation control) of the stress-related genes katB (catalase), recA (recombinase), oxyR (oxidative stress transcriptional regulator), lexA (SOS regulon transcriptional repressor), dnaK (heat shock protein 70) and SOA0154 (putative heavy metal efflux pump).Results: Deprivation of normal levels of radiation caused a reduction in growth of both bacterial species, accompanied by the upregulation of katB, recA, SOA0154 genes in S. oneidensis and the upregulation of dnaK in D. radiodurans. When cells were returned to background radiation levels, growth rates recovered and the stress response dissipated.Conclusions: Our results indicate that below-background levels of radiation inhibited growth and elicited a stress response in two species of bacteria, contrary to the LNT model prediction.

Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation.

There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation.

Investigation of Building Materials and the Street’s Surface Radioactive Emission

Protection of the environment is becoming more important role as pollution and magnetic loads from electronic devices are growing as never before. The radioactive background radiation does not explore explicit increase nevertheless more and more attention is paid to this. An increasing number of countries are paying more attention to measurements of the levels of background radiation from various radioactive sources and to the values of their exposure limits. It is known that the vast majority of background radiation in the enviroment comes from radioactive construction (buildings, roads, etc.) built by humans. It is important to understand its sources, evolution, determining parameters, etc. Radioactivity of the human-built environment is assessed on the basis of building materials, construction techniques, and dose-loading related to building technologies. The Department of General and Environmental Physics in the Juhasz Gyula Teacher Training College at the University of Szeged (Hungary) out radioactive measurements related to background radiation, especially the absorbed dose load from full gamma radiation. Among a wide range of measurements, the most important are: The power of radiation from walls and other parts of buildings. The field, such as radioactivity mapping of the environment. Using maps, we not only have actual data for the radioactivity, but we can follow the impact of the human-built environment (buildings, streets, etc.) on whole background radiation (Koteles, 1994).

Natural radioactivity and radon exhalation rates in man-made tiles used as building materials in Japan.

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon ((222)Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of (226)Ra, (228)Ra and (40)K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg(-1), respectively. The (222)Rn exhalation rates in the tiles were 8.8-21 μBq m(-2) s(-1). The ranges of experimental activity concentrations and (222)Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y(-1), which is lower than the reference level range (1-20 mSv y(-1)) for abnormally high levels of natural background radiation published in the ICRP Publication 103.

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia.

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively.

Cumulative effects of radioactivity from Fukushima on the abundance and biodiversity of birds

Species differ in their susceptibility to radiation because of differences in their ability to sustain toxic and genetic effects caused by radiation. We censused breeding birds in Fukushima Prefecture, Japan, during 2011-2014 to test whether the abundance and diversity of birds became increasingly negatively affected by radiation over time. The abundance of birds decreased with increasing levels of background radiation, with significant interspecific variation. Even though levels of background radiation decreased over time, the relationship between abundance and radiation became more negative over time. The relationship between abundance and radiation became less negative with increasing trophic levels. These findings are consistent with the hypothesis that the negative effects of radiation on abundance and species richness accumulate over time.

Assessment of Effective Dose Equivalent from Internal Exposure to 222Rn in Ramsar City

Introduction In this study, effective dose equivalent for the public due to internal exposure to 222radon (222Rn) was evaluated in three regions of Ramsar, a northern coastal city in Iran. Materials and Methods Measurements were carried out using a radon monitoring device. Outdoor and indoor radon concentrations were measured within 24 hours with an integration interval of 3 hours. Regions were selected with respect to our previous study on areas of Ramsar with high levels of environmental background radiation. Results This study showed that indoor 222Rn concentration reached to 465 Bq/m3 in one of the selected regions (Talesh Mahalleh) in early morning (5-8 a.m.). Our study also showed that the average effective dose equivalents (due to both indoor and outdoor exposures) in the selected regions (Talesh Mahalleh, Sadat Mahalleh, and Chaparsar) were 9.5±2.8, 5.1±2.1, and 3.2±1.2 mSv/y, respectively. Conclusion It is clear that the annual effective dose from internal exposure to 222Rn in areas of Ramsar with high levels of natural radiation was significantly higher than the maximum annual effective dose permissible for public.

The human cancer in high natural background radiation areas

The studies of health effects in human populations living in places with high levels of natural background radiation are of crucial importance for understanding the impact of low doses of ionising radiation. The paper reviews some exemplary literature that addresses the likelihood of the radiation-induced cancer in aforementioned regions. It is shown that using Bayesian analysis one can arrive at an essentially different conclusion concerning dose-effect dependence from the one which could be guessed from first glance. The general conclusion is that cancers do not correlate with elevated radiation in regions with high natural background radiation.

Effect of high background natural radioactivity on human mitochondrial DNA in Ramsar, the north of Iran

Radioactivity is known to induce tumours, chromosome lesions, and mini-satellite length mutations, but also effects on the DNA sequence. Ramsar region, in the north of Iran with the highest background of natural radiation (226Ra) in the world, with a densely populated area, offers an opportunity to characterise radiation-associated DNA mutations. We sampled 30 individuals from this area and 15 cases from Tehran as controls. We sequenced their mtDNA and found multiple variations in multiple nucleotide positions in Ramsar inhabitants. 16519 and T > C were the most frequent NPS and variables in our study. In this preliminary investigation, we conclude that an elevated level of natural background radiation in Ramsar region had a significant effect on the control region of mtDNA. We think this is the first report from Ramsar in this field. Moreover, using molecular and biological pathways and study of gene expression to understand the cellular and molecular response of human mtDNA to low-dose radiation exposure is recommended.

Atomic bomb testing and its effects on global male to female ratios at birth.

Fallout from atomic bomb testing may travel great distances before precipitating. Males are born in excess of females in a ratio that approximates 0.515 (M/T: male live births divided by total live births. Radiation increases M/T by causing lethal malformations that affect female more than male foetuses, decreasing total births. This study was carried out in order to ascertain whether the effects of increased background radiation levels from atomic weapon testing had any widespread effects on M/T and births in the Americas, Europe, Asia and Australasia in relation to the Partial Test Ban Treaty of 1963. Annual live births by gender were obtained from a World Health Organization dataset and annual number of atomic bomb tests were also obtained (historical data). Overall, 94.5% of births studied showed a uniform reduction in M/T between the early 1950s to the late 1960s, followed by an increase to the mid-1970s, with a subsequent decline. A negative correlation of M/T with total births was found in 66% of births studied, and these were the regions which exhibited the rising M/T pattern in the 1970s. The birth deficit for countries with significant correlations of total births with M/T (North America, Europe and Asia) was estimated at 10090701. A rising M/T was found in most regions in temporal association with atomic weapon testing. Most of these regions also had an associated decline in total births. Elevated levels of man-made ambient radiation may have reduced total births, affecting pregnancies carrying female pregnancies more than those carrying male pregnancies, thereby skewing M/T toward a higher male proportion.

Heterogeneous relationships between abundance of soil surface invertebrates and radiation from Chernobyl

Although pollution due to nuclear accidents constitutes some of the largest environmental disasters, there is surprisingly little information available on the relationship between abundance of animals and background radiation. We sampled invertebrates with pit-fall traps at Chernobyl in areas differing in background radiation level by more than four orders of magnitude. We obtained samples from 58 traps for 19 taxa of which five showed positive associations (Acari, Araneae, Formica sp., Homoptera), while four showed negative associations (Coleoptera, Collembola, Vespa, Insecta). These relationships were independent of other environmental factors such as habitat, humidity and ecotype. Estimates of the relationship between abundance and background radiation from the pitfall trap study were similar to those from an independent study based on invertebrates found under slices of wood placed on the ground. The differences in relationship between abundance and radiation among taxa may arise from direct effects of radiation. The findings reported here have implications for choice of animal taxa for efficient monitoring of the biological impact of radiation on animals.

Investigation of background radiation level in Krusadai Island Mangrove, Gulf of Mannar, India

Natural radioactive concentration analysis was carried out in the sand sediments that were collected from the shallow inner shelf region of an ecologically sensitive mangrove forest area at Krusadai Island in Gulf of Mannar near Rameswaram, Tamil Nadu, India. A NaI (Tl) detector based gamma ray spectrometer was used for analysing the samples. The Activity concentration of the primordial radionuclide 238U was below detectable limit (BDL) for all the locations, 232Th had the range between BDL to 27.81 ± 8.9 Bq/kg while 40K had the range from BDL to 413.13 ± 49.6 Bq/kg. The other radiological parameters were calculated and all are found to be well below the prescribed limit. The study concludes that the Krusadai island mangrove forest region as a radiologically safer region for the endemic biota.

CMS RPC muon detector performance with 2010-2012 LHC data

The muon spectrometer of the CMS (Compact Muon Solenoid) experiment at the Large Hadron Collider (LHC) is equipped with a redundant system made of Resistive Plate Chambers (RPCs) and Drift Tube (DT) chambers in the barrel, RPC and Cathode Strip Chambers (CSCs) in the endcap region. In this paper, the operations and the performance of the RPC system during the first three years of LHC activity are presented. The stability of the RPC performance, in terms of efficiency, cluster size and noise, is also reported. Finally, the radiation background levels on the RPC system have been measured as a function of the LHC luminosity. Extrapolations to the High Luminosity LHC conditions are also discussed.