Radon Detectors Research Articles

Determination of indoor radon gas levels in some buildings constructed with Ahlat stone in Ahlat/Bitlis

Ahlat stone that is commonly used country wide specially Bitlis and neighbour cities is a volcanic stone (andesitic tuff) with a porous structure. Radon gas levels were determined in buildings constructed with Ahlat stone and concrete by using CR-39 passive detectors. Additionally, radon gas levels in tap waters of the some buildings were also detected by using active radon detection system. The radon gas level results were compared with smoking habit of household, ventilation periods and reasons of death if there are.

THE CD/DVD METHOD AS A TOOL FOR THE HEALTH PHYSICS SERVICE AND VENTILATION DIAGNOSTICS IN UNDERGROUND MINES.

The CD/DVDs used as radon (222Rn) and thoron (220Rn) detectors can provide a sufficiently sensitive and cost-efficient option for passive radiation monitoring in underground mines. This note presents results of measurements made under real environmental conditions by CD/DVDs. Comparison with conventional diffusion chambers was made and good correspondence was observed. Correlation between 222Rn and 220Rn was studied by CD/DVDs and no signs for any correlation were observed. Dedicated study in a mine gallery showed that CD/DVDs can be successfully used for the purposes of ventilation diagnostics by identifying sources of air contaminated with radon.

Measurement of Radon Concentration in Drinking Water in Bhiwani District of Haryana

ABSTRACT This investigation aims to evaluate the concentration of dissolved radon in drinking water and to assess the associated radiation doses for infants, children and adults in Bhiwani district of Haryana The radon concentrations were measured in 82 drinking water samples collected from 32 villages/towns in the Bhiwani district. The measurements were performed by RAD7, an electronic radon detector manufactured by Durridge Company Inc. The mean radon concentration ranged between 1.3 ± 0.4 and 13.4 ± 2.2 Bq l−1. The mean radon concentrations from two locations exceeded the maximum contamination level (MCL) of 11 Bq l−1 recommended by United States Environmental Protection Agency. The total annual effective doses due to ingestion and inhalation of radon in drinking water varied from 10.1 to 104.4 µSv y−1 for infants, 5.8 to 59.6 µSv y−1 for children and 6.6 to 67.7 µSv y−1 for adults and the average values were found to be 46.3, 26.5 and 30.1 µSv y−1, respectively.

Thoron exhalation rate in stony materials: A simplified approach

A significant percentage of the thoron present in indoor environments is often attributable to building materials. It is therefore interesting to estimate the thoron exhalation rate from these materials. However, the detection of thoron is not a simple task: the very short half life of thoron and the lack of strong gamma emissions, prevents the use of the simplest and powerful radiometric techniques normally utilized in radon detection. Specific instruments have thus been developed in order to measure this radionuclide: alpha delayed coincidence counters (measuring the alphas emitted in a short sequence by 220Rn and 216Po) and alpha spectrometry are the most widely used instruments. However, a more simple approach, allowing the evaluation of the thoron (220Rn) exhalation rate by measuring only the radon one (222Rn), would be very welcomed. This goal can be achieved taking into account that a mathematical relationship between the thoron and radon exhalation rates JTh and JRn (Bq/(m2·s)) can be theoretically established. The thoron exhalation rate of any building material can thus be calculated by measuring only the corresponding radon exhalation rate, provided that the activity concentrations of the parents radionuclides (224Ra and 226Ra) are known. Operating in this way, it would be possible to obtain the thoron exhalation rates for the large majority of the building materials normally employed: in fact, the activity concentration data of many building materials are, in general, easily available. Following this approach a formula is proposed as a screening tools for stony materials.

Novel and label-free colorimetric detection of radon using AuNPs and lead(II)-induced GR5 DNAzyme-based amplification strategy.

Radioactive radon decays into a stable daughter product, 210Pb, which was used as the detection target to determine the radon radiation dose in a new technique. Pb2+ triggers DNAzyme to cleave a molecular beacon (MB), resulting in the stem-loop structure opening and forming two single DNA strands (ssDNA). The ssDNA binds to unmodified gold nanoparticles and effectively prevents their aggregation in a salt solution. The detached enzyme strands continue to complement the remaining MB to amplify the response signal. The method proposed in this study exhibited a good linear relationship for Pb2+ and radon concentrations in the range of 6.22 × 102-1.02 × 105Bqh/m3 with a detection limit of 186.48Bqh/m3 using an ultraviolet-visible spectrometer. In practical applications, this sensitive method can avoid radioactive damage in field testing, and the detection limit meets the national standard in China. Importantly, this simple, highly sensitive strategy uses simple equipment and has a strong anti-interference ability. Graphical abstract.

Geo-spatial analysis of radon in spring and well water using kriging interpolation method

Abstract Radon activity concentration was measured in 101 springs and well water samples collected from Muzaffarabad city and its outskirts. Sixty springs and 41 well water samples were analyzed, using RAD7, an electronic radon detector manufactured by Durridge Company Inc., for the estimation of radon borne activities and their relevant effects. Results obtained show that for spring water, the water borne radon activity varied from 0.246 ± 0.348 to 34.36 ± 5.54 Bq L−1 with an average value of 10.16 ± 2.42 Bq L−1. For well water, the water borne radon activity varied from 0.86 ± 0.10 to 16.12 ± 0.22 Bq L−1 with an average value of 4.21 ± 0.13 Bq L−1. Concentration of radon borne activities were subsequently used for determination of inhalation and ingestion doses. The inhalation and ingestion doses for spring water samples varied from 0.0062 ± 0.0087 to 0.865 ± 0.14 mSv y−1 and 0.052± 0.073 to 7.22 ± 1.16 mSv y−1, respectively. The inhalation and ingestion doses for well water varied from 0.022 ± 0.0025 to 0.41 ± 0.0054 mSv y−1 and 0.18± 0.021 to 3.38 ± 0.045 mSv y−1, respectively. 33.33% of spring and 7.32% of well water samples were found with values above the recommendation levels of the United States Environmental Protection Agency (∼11.1 Bq L−1). As a single measurement cannot serve as a best estimate of the unsampled areas in the region, Kriging interpolation method, a geo-statistical method, was used to get an estimate of spatial distribution of water borne radon in the area of study. Kriging mapping shows that higher radon concentrations are found in areas with lithology consisting of sandstones, siltstones, shales and claystones.

Relationship between Grain Size Distribution and Radon Content in Surficial Sediments of Wadi Arar, Saudi Arabia

Surficial sediments with low radon content are desirable materials in construction applications. In this study, the relationship between grain size and radon content was investigated in sediments collected from seven sites in Wadi Arar, Saudi Arabia, with the intent of determining whether grain size analysis could be used for rapidly assessing the suitability of potential construction materials. Thirty-five samples were collected (five per site) and the grain size distribution was determined using sieves. Radon contents were measured on composite samples with a RAD7 radon detector. Among the sediment types (gravel, coarse sand, medium sand, fine sand, and silt and clay), the best linear correlations between grain size and radon contents were found for the coarse sand (negative slope, r=0.82) and fine sand (positive slope, r=0.78). Polynomial relationships were also tested. A fourth-degree polynomial equation effectively described the correlation between grain size and radon content (R2 = 0.933). As shown by this model, the highest correlations with radon contents were detected at grain sizes smaller than 2.0 mm. Thus, grain size may be useful for preliminary site assessment work.

Potential factors that impact the radon level and the prediction of ambient dose equivalent rates of indoor microenvironments

This study aimed to measure the equilibrium equivalent radon (EECRn) concentration in an old building (Building-1) and a new building (Building-2) with mechanical ventilation and a natural ventilation system, respectively. Both buildings were located at the campus of University Kebangsaan Malaysia. The concentration of indoor radon was measured at 25 sampling stations using a radon detector model DOSEman PRO. The sampling was conducted for 8 h to represent daily working hours. A correlation of the radon concentration was made with the annual inhalation dose of the occupants at the indoor stations. The equilibrium factor and the annual effective dose on the lung cancer risks of each occupant were calculated at each sampling station. The average equilibrium equivalent radon measured in Building-1 and Building-2 was 2.33 ± 0.99 and 3.17 ± 1.74 Bqm−3, respectively. The equilibrium factor for Building 1 ranged from 0.1053 to 0.2273, and it ranged from 0.1031 to 0.16 for Building 2. The average annual inhalation doses recorded at Building-1 and Building-2 were 0.014 ± 0.005 mSv y−1 and 0.020 ± 0.013 mSv y−1, respectively. The annual effective dose for Building-1 was 0.034 ± 0.012 mSv y−1, and it was 0.048 ± 0.031 mSv y−1 for Building-2. The values of equilibrium equivalent radon concentration for both buildings were below the standard recommended by the International Commission on Radiological Protection (ICRP). However, people may have different radon tolerance levels. Therefore, the inhalation of the radon concentration can pose a deleterious health effect for people in an indoor environment.

The development of $$^{222}\hbox {Rn}$$222Rn detectors for JUNO prototype

The radioactive noble gas $^{222}$Rn, which can be dissolved in water, is an important background source for JUNO. In this paper, based on the water system of JUNO prototype, two kinds of high sensitivity radon detectors have been proposed and developed. The sensitivity of Si-PIN Rn detector, which uses a Si-PIN photodiode to detect the $\alpha$ from $^{214}$Po decay, is $\sim$9.0~mBq/m$^3$. The sensitivity of LS Rn detector, which uses liquid scintillator to detect the coincident signals of $\beta$ from $^{214}$Bi decay and $\alpha$ from $^{214}$Po decay, is $\sim$64.0~mBq/m$^3$. Both of the two kinds of Rn detector have the potential to be developed as an online Rn concentration monitoring equipment for JUNO veto detector.

Estimated radon concentration in drinking water samples for different regions of Hilla City, Iraq

In this study, the concentration of radon in water has been measured for 17 samples from different regions of Al-Kifl in the province of Babylon, Iraq. This study was performed using the electronic radon detector RADH2O, where the highest value was 0.199 Bq.L−1 and the lowest value was 0.0 Bq.L−1 and the effective dose for human exposure to radon average is 5.09*10−7 Sv.y−1. The results of radon concentrations and annual effective dose in all samples show no significant radiological risk for the inhabitants in the region of study. We have chosen this subject for the current study because of the importance of water in human life and living, and the lack of previous studies in this study area.

Estimated radon concentration in drinking water samples for different regions of Hilla City, Iraq

In this study, the concentration of radon in water has been measured for 17 samples from different regions of Al-Kifl in the province of Babylon, Iraq. This study was performed using the electronic radon detector RADH2O, where the highest value was 0.199 Bq.L−1 and the lowest value was 0.0 Bq.L−1 and the effective dose for human exposure to radon average is 5.09*10−7 Sv.y−1. The results of radon concentrations and annual effective dose in all samples show no significant radiological risk for the inhabitants in the region of study. We have chosen this subject for the current study because of the importance of water in human life and living, and the lack of previous studies in this study area.

Investigation of the activity of Rn-222 along a small stream in the Representative Basin of Juatuba - MG

ABSTRACT For thousands of years, water has been the focus of experimentation toward solving the challenges associated with human water supply, navigation, irrigation, and sanitation. The use of tracers to study water resources is an efficient approach that can facilitate the modeling of many hydrological scenarios. The goal of this paper is to show results of research that tracked the presence of Rn-222, a natural tracer, in the surface waters of a small watercourse in southeastern part of Brazil. RAD 7, which is an electronic and portable radon detector, was the main instrument used in this survey. We analyzed 117 water samples and converted the radon activity results to effective radiation doses with respect to the hypothetical human consumption of these waters. We also analyzed the sediments of the watercourse. The obtained data showed that the radon activity in the studied waters varies between 0.52-76.96 Bq/m3. We determined the effective dose of all samples to be less than 1 mSv y−1, and its consumption to present no risk to human health. The existence of connections between surface and subsurface waters in the stream is possible, and radon peaks may indicate the existence of discharge zones into the surface water body.

Determination of Radon Gas Activity Levels in Drinking Water in Ahlat/Bitlis

Radon gas ( 222 Rn) that is a radioactive noble gas is second important reason of lung cancer. The penetration of the radon gas into the houses mostly takes place through the cracks in the building and tap water. Because of these reasons, radon gas detection in water is important for human health. In this study radon gas activity levels have been determined in a total of 14 tap water and spring water samples taken from different parts of Ahlat/Bitlis by AlphaGuard active radon detection system. Radon gas activities ranged from 3.16 Bql -1 to 15.68 Bql -1 and mean value is 10.11 Bql -1 .

Review of high-sensitivity Radon studies

A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.

INTRODUCTION AND TESTING OF A SIMPLIFIED METHOD FOR THE EVALUATION OF THE RADON EMANATION.

The radioactive noble gas radon is identified as the highest risk factor for lung cancer after smoking. The exhalation of radon from building materials can contribute to the radon indoor activity concentration. Therefore, the emanation of radon might be a crucial factor. It is defined as the release of radon from the solid soil matter into the pore space of the material. This article describes a new on-site measurement method for the emanation of radon from building materials at industrial sites. Therefore, a closed vessel with sample material and a passive radon detector inside is used to measure the integrated build-up-curve of the activity concentration. Additionally, a brief overview on existing radon emanation measurement methods is given.

RADON IN SPRING WATER IN THE REGION OF SEYDİŞEHİR OF KONYA PROVINCE, TURKEY.

Water samples for radon-gas analyses were collected from springs in and around the town of Seydişehir. Radon concentration in the spring water has been measured using the AlphaGUARD PQ 2000PRO radon detector. Radon activity results varied from 1.85 to 99.27 Bq l-1. The radon level at the measurement points could have been controlled by local geological conditions (i.e. faults) and human activities. We also calculated annual effective doses resulting from the consumption of these water samples.

Demonstration of radon removal from SF6 using molecular sieves

The gas SF6 has become of interest as a negative ion drift gas for use in directional dark matter searches. However, as for other targets in such searches, it is important that radon contamination can be removed as this provides a source of unwanted background events. In this work we demonstrate for the first time filtration of radon from SF6 gas by using a molecular sieve. Four types of sieves from Sigma-Aldrich were investigated, namely 3Å, 4Å, 5Å and 13X. A manufactured radon source was used for the tests. This was attached to a closed loop system in which gas was flowed through the filters and a specially adapted Durridge RAD7 radon detector. In these measurements, it was found that only the 5Å type was able to significantly reduce the radon concentration without absorbing the SF6 gas. The sieve was able to reduce the initial radon concentration of 3875 ± 13 Bqm−3 in SF6 gas by 87% when cooled with dry ice. The ability of the cooled 5Å molecular sieve filter to significantly reduce radon concentration from SF6 provides a promising foundation for the construction of a radon filtration setup for future ultra-sensitive SF6 gas rare-event physics experiments.

Radiochemical evaluation of groundwater around Mika uranium mineralization and environs

Naturally occurring radon gas (222Rn) exists in groundwater and previous study of the problem of natural radioactivity in drinking water from wells drilled in rock types rich in uranium has shown tendency to have high radon concentration. It has been widely reported that radon is contributing the largest component of human exposures to natural radiation and it is considered as the second major cause of lung cancer, after cigarrete smoking. Seventeen (17) groundwater samples around Mika Uranium mineralization were collected and 222Rn concentrations were measured using the DURRIDGE RAD7 electronic radon detector. Radon (222Rn) concentrations in the groundwater ranged from 2350 to 46,200 Bq/m3 with an average of 29,400 Bq/m3. The results show that 76.5% of the groundwater samples collected have 222Rn concentrations far above the US.E.P.A maximum contaminant level (MCL) of 11.1 Bq/l (for states without radon monitoring policy and enhanced indoor air programs), while 23.5% has values lower. Meanwhile, all 222Rn values were below the MCL of 100 Bq/l recommended by European Union (EU) for measurements that warrant consideration of possible remedial actions. Borehole samples show relatively higher 222Rn concentrations than samples collected from open-wells. The annual effective dose due to ingestion (Hing) of 222Rn in the groundwater ranged from 0.05 to 0.92 mSv, with an average of 0.59 mSv. These values are within the ICRP recommended reference level of 1 mSv/yr for the intake of radionuclide in water by the general public for a prolonged exposure.

Assessment of annual effective dose due to radon concentrations in deep and shallow wells within Ekiti State, Nigeria

Drinking water samples obtained from different groundwater sources in Ekiti State, Nigeria were assayed for radon concentration with the aid of a Durridge RAD7 electronic radon detector. In the three types of well considered, higher radon contents were found in hand-dug wells with manual pumps while hand-dug wells with removable covers presented the least radon content. The total annual effective dose incurred through the consumption of groundwater in the study area is found to be within the guideline value of 0.1 mSv recommended by European Union and WHO.

Measurement of radon concentration in super-Kamiokande’s buffer gas

To precisely measure radon concentrations in purified air supplied to the Super-Kamiokande detector as a buffer gas, we have developed a highly sensitive radon detector with an intrinsic background as low as 0.33±0.07mBq∕m3. In this article, we discuss the construction and calibration of this detector as well as results of its application to the measurement and monitoring of the buffer gas layer above Super-Kamiokande. In March 2013, the chilled activated charcoal system used to remove radon in the input buffer gas was upgraded. After this improvement, a dramatic reduction in the radon concentration of the supply gas down to 0.08±0.07mBq∕m3. Additionally, the Rn concentration of the in-situ buffer gas has been measured 28.8±1.7mBq∕m3 using the new radon detector. Based on these measurements we have determined that the dominant source of Rn in the buffer gas arises from contamination from the Super-Kamiokande tank itself.