Radon Concentration Measurements Research Articles

Electromagnetic and Radon Earthquake Precursors

Earthquake forecasting is arguably one of the most challenging tasks in Earth sciences owing to the high complexity of the earthquake process. Over the past 40 years, there has been a plethora of work on finding credible, consistent and accurate earthquake precursors. This paper is a cumulative survey on earthquake precursor research, arranged into two broad categories: electromagnetic precursors and radon precursors. In the first category, methods related to measuring electromagnetic radiation in a wide frequency range, i.e., from a few Hz to several MHz, are presented. Precursors based on optical and radar imaging acquired by spaceborne sensors are also considered, in the broad sense, as electromagnetic. In the second category, concentration measurements of radon gas found in soil and air, or even in ground water after being dissolved, form the basis of radon activity precursors. Well-established mathematical techniques for analysing data derived from electromagnetic radiation and radon concentration measurements are also described with an emphasis on fractal methods. Finally, physical models of earthquake generation and propagation aiming at interpreting the foundation of the aforementioned seismic precursors, are investigated.

Assessment of the activity concentration of radon and its health hazard in surface water around the Rooppur Nuclear Power Plant (RNPP) site, Bangladesh

ABSTRACT Radon is a colourless, unscented, radioactive inert gas. As a gaseous element, Rn-222 can be effectively breathed in, leading to a health hazard. The main objective of this study is to measure the amount of Rn-222 concentration in surface water and its associated health hazards around the Rooppur Nuclear Power Plant (RNPP) construction site area in Bangladesh. Twenty water samples were collected each year (2022 and 2023) from different specific locations of the Padma River and investigated for radon concentration through a Durridge RAD7 detector with RAD H2O accessories. The range of radon activity in surface water measured from 0.070 ± 0.035 to 0.385 ± 0.211 BqL−1 with a mean activity of 0.194 ± 0.114 BqL−1 in the year 2022 and in the year 2023, the range of radon activity in surface water measured from 0.035 ± 0.070 to 0.455 ± 0.239 BqL−1 with an average activity of 0.228 ± 0.140 BqL−1. All the radon concentration results were below the recommended limits of WHO (100 BqL−1) and USEPA (11.1 BqL−1). The ranges of annual effective dose (AED) were from 0.1911 to 1.051 µSvy−1 and from 0.095 to 1.242 µSvy−1 in the years 2022 and 2023, respectively, which were lower than the AED recommended by WHO (0.1 mSvy−1). The mean values of excess lifetime cancer risk are 0.0021 × 10−3 and 0.0025 × 10−3 in the years 2022 and 2023, respectively, which were lower than the average standard value recommended by UNSCEAR (0.29 × 10−3). The result of this investigation can be applied as baseline data for radon concentration measurement in the under-construction nuclear power plant site area vicinity of Bangladesh.

A review of approaches to assessment of potential radon hazard of land plots

According to Rosstat statistics, in recent years there has been a tendency in the Russian Federation to increase the intensity of construction, while both the number of buildings put into operation and their total area are increasing. The assessment of the potential radon hazard of land plots for construction provides the possibility of timely inclusion of the necessary protective (preventive) measures against radon in the design of buildings. This is a legal requirement in cases where the density of radon flux from the ground surface within the building area exceeds the established hygienic standards (action levels). The paper presents a review of Russian and foreign approaches to assessing the potential radon hazard of land plots conducted within the framework of engineering and environmental surveys. The current regulatory requirements to radiation safety indicators of land plots for construction of residential, public and industrial buildings and facilities in the Russian Federation are analyzed. The main drawbacks of the algorithm for determining the potential radon hazard of land plots, used in the current guidelines MU 2.6.1.2398-08 approved at the federal level more than 15 years ago, are described. Critical remarks (the unsuitability of the value of density of radon flux from the ground surface for designing radon protective and mitigation (remedial) measures, lack of consideration of seasonal variations of radon flux density, etc.) accumulated over the years as a result of practical application of these guidelines are presented. Benefits and drawbacks of foreign approaches to assessing the potential radon hazard of the territory based on the results of measurements of radon concentration in soil gas, as well as the very possibility of a transition in Russian regulations from the density of radon flux from the ground surface to the radon concentration in soil gas, are analyzed. Some rational proposals of various Russian research teams on improving the algorithm for determining the potential radon hazard of land plots are considered.

Detector upgrade for 222Rn concentration in high purity nitrogen measurement

To ensure the low background of the Jiangmen Underground Neutrino Observatory (JUNO) detector, high purity nitrogen (HPN) is used as a cover gas in direct contact with the liquid scintillator, which serves as the target material for neutrinos. The radon concentration in this nitrogen should be less than 10 μBq/m3. Given the background of the old detector, which is 2.20 ± 0.64 mBq/m3, combined with its enrichment efficiency of 51.0 % at a flow rate of 25 standard liters per minute (SLM), the effective measurement of radon concentrations below 10 μBq/m3 in HPN is a major challenge. A highly sensitive radon detector was upgraded to measure the radon concentration in HPN. A low background radon detection chamber was constructed based on the method of electrostatic collection and electrolytic polishing of low background steel with an internal surface roughness of ≤ 0.2 μm. The background of the radon detection chamber was reduced to 1.47 ± 0.19 mBq/m3. An automatic enrichment system based on 472 g low background activated carbon was developed. The introduction of a large amount of activated carbon has led to a significant increase in the enrichment flow rate to 200 SLM. In addition, the enrichment efficiency of the system simultaneously improved to 71 %. The relationship between the collection efficiency of the detection chamber and the applied voltage was calibrated. The result measured with this detector, shows that the radon concentration in HPN is 2.38 ± 0.30 μBq/m3.

Radiological monitoring and assessment of the radiation situation in the Kungur Ice Cave

This article presents the results of comprehensive radiological studies conducted in 2021 in order to assess the radiation situation in the Kungur Ice Cave (hereinafter referred to as the KIC). Since the cave is a fairly popular sightseeing object, therefore, the safety of both tourists and workers is a key task for scientific study. The radiation safety assessment was carried out taking into account the parameters of the radiation (gamma) background, measurements of radon and thoron concentrations, microclimatic indicators (air temperature, humidity), airflow rate, illumination and calculation of the indicator of a special assessment of working conditions (SAWC). Such comprehensive and detailed studies were conducted in the KIC for the first time, allowing some patterns to be identified and confirmed. For the indicators of gamma-activity and radon concentration, there is a clear dependence on the season of the year, which is directly related to microclimatic indicators, as well as to compliance with the ventilation regulations that have been established in the cave. The applied ventilation modes provide safe values of the radiation background and toron. In the summer months, the average radon content in the cave exceeds the maximum permissible concentrations by a factor of 7, which required calculation of the time of work in the cave. For the first time, special assessment of working conditions has been calculated for Kungur Ice Cave, but only for the winter period. The SAWC is defined for a working group consisting of engineers, workers and guides, taking into account such parameters as temperature, illumination, humidity, severity and intensity of labor and ionizing radiation (radiation background). According to preliminary data, the overall assessment of labor based on all parameters falls under the “harmful” class of conditions.

A humidity resistant radon source developed by ion exchange of radium in a membrane

ObjectiveTo develop a humidity resistant radon source on a membrane based on the ion exchange technique. Methods226Ra in its standard solution was adsorbed in the HP membrane through cation exchange. The radioactivity of 226Ra in the membrane was determined through the measurements of 226Ra activities in the solution before and after the adsorption using a HPGe γ spectrometer. The emanation coefficients of radon from the membrane in different humidity conditions were quantified through the measurements of radon concentrations in a close loop mode using the AlphaGUARD DF2000 radon monitor. Long-term measurements of radon concentrations in the close loop and a standard chamber using the membrane as radon source were performed to verify the stability of radon emanation from the source. ResultsA piece (70 ​mm ​× ​20 ​mm) of the HP membrane could adsorb 51.2 kBq of 226Ra in about 30 ​min. The emanation coefficient of radon from the membrane could reach as high as 0.997, and it was hardly changed in a humidity range from 7.5% RH to 94.5 ​% RH. The variation of the radon production rate from the source was only ±1.2 ​% in two weeks at a general laboratory condition, and its emanation stability was also confirmed in a standard radon chamber by using the membrane source for one month. ConclusionThe radon membrane source developed in this study has a stable emanation coefficient regardless the environmental humidity. It can be used as a flow-through radon source in a standard radon chamber.

Estimation of radon concentration in groundwater in the mining zone of Haryana, India, for lungs and stomach annual effective dose.

The groundwater is being used for drinking and irrigation purposes in vast swathes of the Aravalli Mountain range. Since the radioisotope presence in groundwater is affected by the local mining processes, the radiation monitoring in groundwater of mining regions is of paramount importance. In the present work, we have estimated the 222Rn presence in the mining region of Aravalli in the southern part of Haryana. We measured the Radon concentration in 51 water samples from the intended area using the RAD7 alpha detector. The measured radon concentration in some of the water samples collected from the vicinity of the mining zone is higher than that of the United Nations Scientific Committee on the Effects of Atomic Radiation recommended value. Furthermore, we have estimated the annual effective doses for the lungs and stomach contributed by ingestion and inhalation. Though the calculated dose values in collected samples are not in the critical range, further monitoring of background radiation in the Aravalli region is required.

Assessment of indoor radon concentration in the dwellings of the industrial areas of Kannur District, Kerala.

All organisms on the earth-crest are exposed to natural background radiation since the evolution of the earth, as many environmental matrices such as soil, air, water bodies, vegetation, etc., act as the sources of natural radioactivity. The present study deals with the evaluation of indoor concentration of 222Rn (radon) in different dwellings with various construction materials used for the roof and floor in the industrial sites of Kannur district, Kerala. A pinhole-based dosemeter coupled with LR-115 Solid State Nuclear Track Detector and Direct Radon Progeny Sensor (DRPS) were respectively used for the measurement of indoor radon concentration and equilibrium equivalent concentration of radon. The indoor radon concentrations were found to vary from 102.30 Bqm-3 to 184.75 Bqm-3 and the values were within the recommended limits provided by International Commission on Radiological Protection (ICRP). The annual effective doses and excess lifetime cancer risks were observed in the range of 2.58-4.66 mSvy-1 and 7.68×10-3-15.60×10-3, respectively, and both exceed the world average values recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000. The study shows that, the houses with marble floors and concrete roofs have comparatively higher values of radon concentration, which indicates the significant contribution of construction materials to the enhanced radiation levels inside the dwellings.

Calculation the Excess Lifetime Lung Cancer Risk and Human Health Risk Assessment by Inhalation of Radon Gas in the Health Centers of Al–Hay City in Wasit, Iraq Using LR-115 Detector

In this paper, the technology used to measure radon concentrations in 8 health centers of Al- Hay city in Wasit, Iraq (December 2019) is one of the types of solid state nuclear track detectors, LR-115. After that, the annual effective dose rate and the excess lifetime cancer risk were calculated for the selected positions in the study area. The detectors were exposed to radon for 45 days, the etched detectors, using an optical microscope, to calculate the track densities, essentially depend on the alpha ray emitted from radon which later on easy converted to radon concentration values. Radon concentration ranges are from (183.47±22.93 to 17.15±2.14) Bq/m3 with a mean of (100.483Bq/m3), which lower than the appropriate radon levels recommended by ICRP "International Commission on Radiological Protection". The readings of "Excess Lifetime Cancer Risk" (ELCR), which ranges from 3.9 ×10-3 to 8.05 ×10-3 with an average value of 0.53% showing that human health is not under risk even it does not develop any lung cancer while human inhale the radon.

Measurement of indoor radon concentrations and doses assessment in the area of Tuzla Canton, Bosnia and Herzegovina

Measurement of indoor radon concentrations and doses assessment in the area of Tuzla Canton, Bosnia and Herzegovina

Radon concentration measurement with a high-sensitivity radon detector at the Yemilab

The radiation emitted from radon is a critical background in rare event search experiments conducted at the Yemi Underground Laboratory (Yemilab) in Jeongseon, Korea. A Radon Reduction System (RRS) has been developed and installed in Yemilab to reduce radon concentration in the air. The RRS primarily provides a purified air of 50 m3/h to the cleanroom used to assemble crystal detectors in the AMoRE, a neutrinoless double beta decay search experiment. RRS can reduce the radon level by a factor of 300, so a high-sensitivity radon detector was required. A highly sensitive radon detector was constructed using a 70 L chamber with a large PIN photodiode to measure radon concentration in the purified air. The radon detector shows an excellent resolution of 72 keV (FWHM) for 6.003 MeV alphas from 218Po decay and a sensitivity down to 23.8 ± 2.1 mBq/m3 with a boil-off N2 gas sample. The radon concentration level from the RRS measured by the radon detector was below 0.29 Bq/m3 with a reduction factor of about 300.

Enhancing radon detection accuracy with charcoal canister: A simple method for measuring radon

Charcoal canisters are widely used devices for measuring radon concentration in the atmosphere, but they are sensitive to humidity. A newly designed super absorbent polymer (SAP) filter was applied to charcoal canisters to enhance their resistance to ambient humidity, thereby improving the accuracy of radon concentration measurements. The charcoal canister with the SAP filter had an error of approximately 1.3–2.6% compared to the reference value (measured by RAD7), whereas the charcoal canister without the SAP filter exhibited an error of 12–18% compared to the reference value. Additionally, the charcoal canister with the SAP filter demonstrated over 90% of response value even under very high relative humidity conditions of 90%, indicating strong resistance to ambient humidity.

Radon Concentration Level in Selected offices at Bells University of Technology, Ota, Ogun State

Radon, a radioactive gas that emanates naturally from the earth crust is accountable for about 50% of the effective dose of ionizing radiation received by humans. Most radon susceptiveness occurs in homes and work places, it comes from the natural disintegration of uranium in soil, rock and water and escalate to the air that we breath, hence it is important to monitor the actual level of exposure in most buildings. This work analysed the indoor radon concentration in air at twenty different offices of different building at Bells University of Technology using Rad7 detector. The mean measured radon concentration ranges from 0-56.7 Bq/m3 for all the study locations. The mean absorbed dose, equivalent dose and effective dose were calculated with the radon concentration which are 0.152 mGy/y, 3.045 mSv/y and 0.365 mSv/y respectively. The results obtained are below the world set limit as recommended by International Commission on radiological protection, except for office 7 which slightly exceed the recommended limit. Thus, the study concluded that good ventilation is very important in the reduction of radon concentration level in our work places.

Risk assessment of radon exposure inside residential dwellings in Safi city, Morocco

ABSTRACT A radon study was conducted in 50 residences in Safi city, Morocco, using LR-115 detectors. The annual effective dose and Excess Lifetime Cancer Risk were also estimated. The measured radon concentrations ranged between the Lower Limit of Detection (LLD) and 132 Bq.m−3 with an arithmetic mean of 53 Bq.m−3 and a geometric mean of 41 Bq.m−3 (2.32). The results indicated that 58% of the obtained values exceeded the worldwide average value (39 Bq.m−3). In addition, the results revealed significant impacts of floor level and region on indoor radon levels. Inhabitants of the surveyed houses were found to receive a mean annual effective dose of 1.5 ± 0.1 mSv.y−1, corresponding to an Excess Lifetime Cancer Risk of 0.6%. Importantly, all annual effective dose values were below the recommended action level by the ICRP (3–10 mSv.y−1). Using the Ordinary Kriging method implemented in the QGIS software, an indoor radon map was created based on the collected data. The findings in this study serve as baseline values for future studies concerning radon concentrations and their fluctuations.

Counting alpha particles produced by radon daughters using commercial off-the-shelf complementary metal oxide semiconductor (COTS CMOS) image sensors

Radon (Rn-222) is the main source of radiation exposure to human beings from natural radiation; it is of great significance to study the measuring methods and measuring instruments of radon for natural radiation protection. In recent years, the application of pixel detectors in radiation detection has attracted attention. In this paper, a Commercial Off-the-Shelf Complementary Metal Oxide Semiconductor (COTS CMOS) image sensor which replaces the glass for protection covering in front of the sensors was used to perform a series of measurements to identify alpha particles. During the experiment, the CMOS image sensor was used to record a video during the sampling period, and then use the FFmpeg software to take screenshots of the video by frame. MATLAB was used to count bright spots from the image frames. A measurement chamber was designed to measure radon concentrations, and when the relative humidity was constant, the count of alpha particles by the CMOS image sensor increased along with the increase of the concentration. The experiments verified the feasibility of the low-cost COTS CMOS image sensors to monitor radon.

Development of low-radon ultra-pure water for the Jiangmen Underground Neutrino Observatory

The Jiangmen Underground Neutrino Observatory (JUNO) is a state-of-the-art liquid scintillator-based neutrino physics experiment under construction in South China. To reduce the background from external radioactivities, a water Cherenkov detector composed of 35 kton ultra-pure water and 2,400 20-inch photomultiplier tubes is developed. Even after specialized treatment, ultra-pure water still contains trace levels of radioactive elements that can contribute to the detector background. Among which 222Rn is particularly significant. To address this, an online radon removal system based on the JUNO prototype has been developed. By integrating micro-bubble generators to enhance degasser’s radon removal efficiency, the radon concentration in water can be reduced to 1 mBq/m3 level, meeting the stringent requirements of JUNO. Additionally, a highly sensitive online radon concentration measurement system capable of detecting concentrations ∼1 mBq/m3 has been developed to monitor the radon concentration in water. In this paper, the details regarding both systems will be presented.

Environmental radon, fracking wells, and lymphoma in dogs.

Multicentric lymphoma (ML) in dogs resembles non-Hodgkin lymphoma (NHL) in humans. Human NHL is associated with multiple environmental exposures, including to radon and volatile organic compounds (VOCs). The objective of this study was to determine whether ML in dogs was associated with environmental radon or proximity to horizontal oil and drilling (fracking), a source of VOC pollution. We identified dogs from the Golden Retriever Lifetime Study that developed ML (n = 52) along with matched controls (n = 104). Dog home addresses were categorized by Environmental Protection Agency radon zone and average residential radon by county, as well as by distance from fracking and associated wastewater wells. We found no significant differences in county level radon measurements. Individual household radon measurements were not available. There was no difference in residential proximity to active fracking wells between dogs with ML and unaffected dogs. While dogs with ML lived closer to wastewater wells (123 vs 206 km; P = .01), there was no difference in the percentage of cases vs controls that lived in close proximity (20 km) to a fracking well (11.5% for cases, 6.7% for controls; OR 1.81, 95% CI 0.55 to 5.22; P = .36), or a wastewater well (6.7% for cases, 4.4% for controls; P > .99). These data suggest that more proximate sources of chemical exposures need to be assessed in dogs with ML, including measurements of individual household radon and household VOC concentrations.

Radon Levels and Risk Assessment due to its Ingestion and Inhalation from Groundwater of Lapai, North-Central Nigeria

Radon exposure through ingestion or inhalation from groundwater can be a significant public health concern due to its carcinogenic effects. This study assessed the health risks of radon exposure from groundwater in Lapai, Nigeria, using a Rad7 detector to measure radon concentration levels. The measured concentrations ranged from 5.36 ± 0.22 BqL-1 to 0.52 ± 0.06 BqL-1 with an average value of 2.82 ± 0.14 BqL-1. The annual effect dose due to ingestion of Radon obtained varies in the range of 2.76 to 28.34 μSva-1, 1.02 to 10.43 μSva-1, and 1.33 to 13.69 μSva-1 for infants, children, and adults, respectively. While the effective dose per year from inhalation of Radon released from water by adults has values in the range of 1.31 to 13.50 μSva-1. Radon levels were within permissible limits of UNSCEAR and USEPA, and the annual effective doses from inhalation and ingestion were within WHO's safe range. Nonetheless, monitoring is advised, especially during the rainy season when contamination levels may increase.

Automatic tracking of the energy spectrum areas of Po-218 and Po-214 at various temperatures

Radon and its decay products emit internal radiation in the respiratory system upon inhalation, which is a significant contributor to the development of lung cancer in humans. Accurate measurement of radon concentration is undoubtedly very important. Among the commonly used radon measurement methods, the electrostatic collection method stands out. This method involves counting the energy spectrum peaks of alpha particles, generated by the decay of radon daughters Po-218 and Po-214, which are collected on the surface of a semiconductor detector to determine radon concentration. According to experimental findings, measurements at different ambient temperatures cause Po-218 and Po-214 to peak drift. This drift adversely affects the accuracy of radon measurement using traditional methods. This study focuses on the characteristics of α-energy spectra from Po-218 and Po-214. It calculates the peak heights for all α-energy spectra and identifies the two peaks with the highest heights. Subsequently, an algorithm is developed to automatically track the peak positions of Po-218 and Po-214, accurately locating their counting intervals. The results demonstrate that the algorithm successfully achieves the desired outcomes through experiments conducted at different temperatures and measurement durations, thus validating its effectiveness. This method holds significant practical value in ensuring the accuracy of radon measurement.

An Evaluation of Radon Concentrations in Arin Lake, Bitlis

Arin Lake, situated in the Bitlis province, is a soda lake that holds significant ecological importance as a habitat for migratory bird species such as flamingos and white-headed ducks. In order to investigate the potential radiation exposure to the environment and living organisms in the area, radon concentration levels and dose calculations were determined for water samples collected from 27 different points in Arin Lake. The radon levels were determined using the AlphaGUARD PQ2000 PRO radon monitoring system, which has the range of 2–2.106 Bqm−3. The results of the radon concentration measurements are between 0.06 and 0.39 Bq/L, with a mean of value of 0.17 Bq/L. The annual effective doses for ingestion (Deff-ing) and inhalation (Deff-inh) were calculated at values ranging from 0.14 to 0.99 µSv/year. The radon levels were found to be lower than international standard values. Furthermore, the outcomes of this research were subjected to comparison with other studies in the literature.