Radon Activity Research Articles

Cancer Risk estimation in the samples of Iraqi manufactured Medicinal Plants

In this study, measurement of alpha emitters such as radon-222, radium-226, and uranium-238 levels in Iraqi of medical plants samples using CR-39 detector. As well as, annual average internal dose (AAIED) and risk of an excess cancer fatality per million persons (RECFPMP) due to ingestion of radon, radium, and uranium from samples in the present study were calculated. The average values with stander error of radon-222, radium-226, and uranium-238 activity in unit Bq/kg were 5.22 ±0.94, 0.3409 ±0.061, and 5.20 ±0.942, respectively. While, the average values of AAIED and RECFPMP due to alpha emitters in all samples of medical plants were 0.348±0.063 μSv/y and 1.21±0.221, respectively. Analysis of samples has been studied and therefore compared with the internationally published and permissible range that has been recommended by the international scientific committees. Accordingly, it was found that radiation levels in medicinal herbs available in local markets were fallen within natural and allowed limits and therefore don't impose any danger out of the radioactive aspect in terms of human consumption and use of medical treatment.

Дозы облучения населения Лунинца и Микашевичей за счет радона в воздухе жилых помещений

This article contains information about the levels of radon in the air of residential premises in the settlements of Luninets and Mikashevichi and their environs (Brest region, Republic of Belarus), as well as doses to the population of these territories, formed by the inhalation intake of this radioactive noble gas. The study of the integral weighted average value of the volumetric activity of radon in the air of residential premises was carried out by the track method using integrated radon track radiometers based on an accredited laboratory. Based on data on the content of radon in the air of residential premises, doses were calculated for the population of Luninets and Mikashevichi, and an analysis was made of factors that could affect the magnitude of this dose (features of building materials of residential premises, household communications, location of the house). Exposure doses to the population due to radon in the air of residential premises fell in the range from 0.9 to 7.7 mSv/year with a non-normal distribution. In the course of the study, it was found that the type of dwelling has the most significant effect on the level of radon in the air of residential premises: doses for the population living in private residential buildings with brick walls are significantly higher compared to similar doses for the population living on the first floors apartment buildings. A comparison was made of the levels of radon in the air of residential premises and doses for the population of Luninets and Mikashevichi. The levels of radon in the air of residential premises of Luninets are significantly higher than those in Mikashevichi, which refutes the impact of granite mining on the level of radon in the air of residential premises of this settlement. The calculation of lifelong oncological risks for the population of Luninets and Mikashevichi was made. When calculating 0.6*10-5 for each Bq/m3, the soncological risks fell within the range from 0.00009 to 0.00074. Based on the measurement results, maps were created that clearly demonstrate the distribution of radon levels in the air of residential premises of the studied settlements and their environs.

Estimation of radon-gas, uranium-238 concentrations in the surface soil samples and alpha risk index at many Northern Iraqi Refineries

Radon gas concentrations and uranium-238 concentration in soil samples at the surface (depth = 15 cm) were determined for fifteen samples in three refineries (Al-Kasak, Al-Qayarah, Baiji) using “sealed can technique”. CR-39 solid-state nuclear pathway detectors. The concentration of radon in surface samples at the Al-kasak refinery ranged from (1509 to 8323.2 Bq/m3) with an average of (4916.1 Bq/m3), and the surface exhalation rate in surface soil samples ranged from (1110.3 to 612.7 Bq/m3) with an average (861.5 Bq/m3). The effective activity of radon (ARn222) are (15.82 to 8.84 Bq/kg) with an average (12.33 Bq/kg).In a Al-Qayara refinery, the radon concentration in surface samples ranged from (11709.6 to 10281 Bq/m3) with an average of (10995.3 Bq/m3), and the surface exhalation rate in surface soil samples ranged from (861.5 to 756.3 Bq/m3) with an average of (808.9 Bq/m3), the effective activity of radon gas (ARn222) are (12.28 to 10.756 Bq/kg) averaged (11.518 Bq/kg).In the Baiji refinery, the radon concentration in surface samples ranged from (13501 to 5062 Bq/m3) with an average of (9281.5 Bq/m3), and the surface exhalation rate in the surface soil samples ranged from (992 to 372 Bq/m3) with an average of (682 Bq/m3),...

Measurement of Indoor Seasonal and Regional Radon (222Rn) Gas Activity in Çanakkale (Turkey)

Radon gas, which undergoes radioactive decay, can cause damage to the lung tissue and lung cancer over time in indoor environments where it is inhaled. Radon gas radioactivity concentrations were measured using CR-39 passive solid state nuclear track detectors (SSNTD) in the basement and ground floor simultaneously in summer and winter periods in 17 dwellings in Çanakkale (Turkey). Accordingly, an average of 163.67 Bq.m-3 in basements in summer, 63.26 Bq.m-3 in ground floors in summer, 148.73 Bq.m-3 in basements in winter, and 77.57 Bq.m-3 in ground floors in winter. In addition, annual effective dose (AEDE) values and lifetime cancer risk (ECLR) parameters were calculated using radon activity concentrations. Accordingly, the basement and mean AEDE values in the summer period were found to be 4.52 mSv.y-1 and 1.59 mSv.y-1, respectively. In winter, it was found as 3.75 mSv.y-1 and 1.95 mSv.y-1.

Radon Exhalation Rate and Annual Effective Dose for Different Rock Types and Excess Lifetime Cancer Risk from Radon Exposure

Purpose: Radon (222Rn) and its decay products clinging to airborne particles settle in the lungs when inhaled and can lead to lung cancer. The main source of 222Rn is rocks and soil in the Earth's crust and causes indoor radon exposure when local geological material is used as a building material. Accordingly, the primary objective of the study is to determine the radon activity concentrations (CRn) and exhalation rates (EA and EM) from different rock types taken from the Aliağa-İzmir region. The study also estimates the annual effective dose (AED) and the excess lifetime cancer risk (ELCR).
 
 Material and Methods: For the measurement of the CRn, EA, and EM in different rock types, the can technique with LR-115 detector was utilized. The AED and the ELCR were estimated using the CRn in the samples.
 
 Results: It was found that the CRn, EA, EM, AED, and ELCR values for the examined rock samples were ranged between 66±4 and 1711±13 Bq m−3, 51±3 and 1309±10 mBq m-2 h-1, 2.68±0.18 and 64.02±0.47 mBq kg-1 h-1, 1.67 and 43.16 mSv y−1, and 0.006 and 0.151, respectively.
 
 Conclusion: The higher radiological risks in terms of radon exposure were related to the rocks of volcanic origin.

Radon Progeny Adsorption on Facial Masks.

The radioactive noble gas radon and its short-living progeny are inhaled during respiration, depositing their decay energies in the lungs. These progeny are considered responsible for more than 95% of the total effective dose and are, together with radon, classified as carcinogenic for lung cancer. Consequently, filtration of the progeny could reduce the dose to the lungs. In our study, we investigated the filtration properties of FFP2 versus surgical masks (II R) for radon and its decay products. The masks were attached to a measurement device, which enabled determination of the size distribution of radon progeny, ranging from unattached to clustered progeny. In parallel, it measured the radon activity concentration during experiments. By comparing background measurements without mask and experiments with masks, the percentage of retained unattached radon progeny was determined for FFP2 (98.8 ± 0.6%) and II R masks (98.4 ± 0.7%). For clustered progeny, the retained fraction was 85.2 ± 18.1% for FFP2 and 79.5 ± 22.1% for II R masks while radon was not filtered. We can show that masks are effective in filtering radon progeny and thus are capable of reducing the total effective dose to the lungs.

Detailed geophysical studies of the Ilych-Chikshinskaya fault system (Izyma-Pechora Monocline)

Research subject. The Ilych-Chikshinskaya fault system involved in the structure of the Izhma-Pechora monocline. The Ilych-Chikshinskii deep fault is the southern branch of the Pripechorskaya fault system, which separates the Timansky and Pechoromorsko-Bolshezemelsky geoblocks. Materials and methods. The data obtained during profile detailed magneto-metric and radon surveys, the materials of fund seismic surveys, and the maps of gravitational and magnetic fields of various scales were used. Measurements of the volume radon activity were carried out using portable radiometers РРА-01М-01 and Alfarad plus. Magnetometric observations were carried out with a MINIMAG magnetometer. Results. Radon surveys on two profiles were conducted in different years. According to the obtained results, the faults of the Ilych-Chikshin skaya system have no obvious manifestation in the radon field. The volume radon activity in different periods varied across a wide range from 50–200 to 200–600 Bq/m3, which indicates the absence of a constant deep source of radon. According to the data of detailed magnetometric surveys, the Ilych-Chikshinskii fault, against the background of a calm negative field, corresponds to a gradient zone of 4 km wide. Conclusion. The presence of low-intensity discontinuous radon anomalies along the line of profiles is associated with increased concentrations of parent uranium radionuclides in the soil and near-surface rocks. Since the rocks of the basement and sedimentary cover are nonmagnetic, the local magnetic anomaly indicates the presence of mafic and ultramafic intrusions in the zone of the Ilych-Chikshinskii fault.

Method for calculating radon activity and radon rejection using a beta-gamma detector

Radon interferes with concentration measurements used by atmospheric radioxenon systems. We demonstrate a method to quantify the amount of radon that is present in the detectors, the impact of radon activity on the minimum-detectable-concentrations, and how to determine the needed radon rejection levels. An example calculation shows a radon rejection level of 105 is sufficient to limit impact on the detector sensitivity. We anticipate this method will give analysist a better understanding of radon present in their measurements and allow system designers to tailor their systems’ radon rejection better for its location.

RADON MONITORING IN SELECTED KINDERGARTENS IN SLOVAKIA.

In 17 kindergartens in Slovakia indoor radon survey was performed over a period of 1y. In selected kindergartens also continuous monitoring of indoor radon activity concentration was conducted for ~2 weeks, as well as soil radon measurements. Annual average of indoor radon concentration, measured using track detectors, ranged between 75 and 1810Bqm-3. Soil radon concentration ranged from 13 to 320kBqm-3. The relationship between activity concentrations measured in soil air and indoors has a linear character.

MONTE CARLO SIMULATION OF POLONIUM ION COLLECTION IN ELECTROSTATIC FIELD FOR THE PURPOSE OF RADON DETECTOR DEVELOPMENT.

Radon detectors based on an electrostatic collection of polonium and detection of its alpha decay are a popular choice for the measurement of radon activity. Due to the nature of $^{222}$Rn decays, 88% of radon progeny have a positive charge, thus enabling their collection on an electrode. A simulation software focused on the drift and diffusion of ions in an electric field has been developed, providing a tool to study and characterise such detectors. It has been found that one such device achieves only 44% collection efficiency, caused by the loss of a large fraction of the ions before reaching the collection diode. An improvement of the design is therefore proposed, changing the placement of the sensor resulted in an simulated increase of the collection efficiency up to 93%. Preliminary measurements performed using prototypes of these detectors confirm the results of the simulations.

Thermal infrared remote sensing and soil gas radon for detecting blind geothermal area

Geothermal resources in the Wugongshan area are abundant and most closely associated with faults. Due to the dense vegetation covering the research area, locating the geothermal resources using conventional ground technologies is costly and challenging. This paper proposes and implements a novel method in the area under examination. More specifically, remote sensing information (Landsat 8) and known geological information are used to delineate the geothermal target area. On January 19, 2021, the land surface temperature in the study area ranged between 7.7 and 21.2 °C. Combining the geothermal geological features of the regional area, two areas, namely Tangjiashan and Sanjiang, are delineated as geothermal target areas. The probable location of faults is determined by measuring the soil gas radon concentration. The relative coefficient KQ of radon activity attained in profiles varies between 1.7 and 13.2. The average values of KQ between different areas are ranked as Wenjia > Tangjiashan > Hongjiang > Sanjiang. Generally, areas with higher KQ of radon activity have higher land surface temperature (LST). Thus, the KQ and LST can be used to evaluate the shallow geothermal potential. Finally, by integrating the interpretation of remote sensing and soil radon measurements, the fault location is identified, and the result is successfully used to guide the drilling of geothermal wells in the Tangjiashan area.

Factors influencing radon transport in the soils of Moscow.

This article delves into the factors that may influence radon flux, such as soil properties and weather conditions, on the example of two experimental locations with different soil compositions, composed primarily of clay and sand, respectively. The experimental location with sandy soil was previously observed to have anomalously high radon flux levels. Radon monitoring was performed routinely, approximately at the same time of day and in parallel on both of these locations to exclude the influence of diurnal variations. The results show that radon transport in these locations differs in mechanism: Location with clay soil has diffusive radon transport, with an average radon flux density of 37.4 ± 24.9mBqm-2s-1 and a range of 0.3-167.8mBqm-2s-1, while the location with sandy soil has convective radon transport with an average radon flux density of 93.6 ± 51.2mBqm-2s-1 and a range of 9.8-302.2mBqm-2s-1. This corresponds to about 8.3% of RFD measurements on site with clay soils exceeding the national reference level of 80mBqm-2s-1 and 45.6% exceeding them on the site with sandy soils. Average radon flux density values were then compared to meteorological variables using Pearson correlation analysis with Student's t-test. It was observed that radon flux density correlates the most with ambient air temperature both for diffusive and convective radon transport mechanisms, while a weaker inverse correlation is observed with atmospheric precipitation and wind speed for the diffusive mode of radon transport, but not for the convective. Radon activity concentration in soil air correlates with the radon flux density and air temperature in the case of convective radon transport, but does not correlate in the case of diffusive transport.

Origin and transport of radon in a dry and in a wet mofette of COVASNA, Romania

The appearances of significant efflux of carbon dioxide through soil surfaces is a frequent natural phenomena in the wider vicinity of relatively young volcanic fields. These mofettes are often utilised as dry carbon dioxide spas to treat patients suffering from cardiovascular diseases. The carbon dioxide always carries some naturally occurring radioactive radon gas with it. On the one hand this radon gas might pose some radiation risk for the patients and staff of such carbon dioxide spas, on the other hand it may be used as a natural tracer for the study of transport of its carrier gas in the subsurface and in the pools. In this work we have measured the spatial variation of radon activity concentration in the gas phase of the carbon dioxide gas pool of the Cardiology Hospital and in the gas and water phases of the Hell-Mud, which is a wet open pit mofette in the city of Covasna. We have developed a hydro- and gas-geological conceptual and mathematical model with which we were able to describe the measured spatial and temporal behaviour of radon gas concentration. We have found that the relatively low radon concentrations at the bottom of these pools can be explained by removing the radon content of water by intense bubbling degassing of the oversaturated carbonated waters.

Radiological safety assessment of drinking water in Darjeeling hill and foothill areas: An experimental finding

Abstract This study intends to shed light on the radiological quality of potable water in one of the most important hill stations, Darjeeling, and its surrounding foothill areas of West Bengal, India, which has not yet been explored. A radon concentration measuring study has been carried out in 62 water samples collected from both natural springs (SW) and tube wells (TW) in the above mentioned area using an AlphaGUARD radon monitor. The measured maximum and minimum radon levels of drinking water samples collected from natural springs are 13.04 Bq/l and 0.43 Bq/l respectively while those for tube wells are 71.02 Bq/l and 1.02 Bq/l respectively. The average radon activities in the two water sources separately and together are 2.88 ± 0.41 and 25.67 ± 3.89 and 10.96 ± 1.97 Bq/l respectively. This study reveals that the average radon concentrations of water samples from both sources in this area are much below the reference level of 100 Bq/l as prescribed by the WHO and EU Commission. The evaluated radon activities are used to determine inhalation, ingestion and then total annual effective dose (AED). The average total AEDs for the two types of water sources separately and together (SW + TW) are 7.86 ± 1.11, 70.07 ± 10.64 and 29.93 ± 5.37 μSv/y respectively. The evaluated average total AEDs for the two types of drinking water sources separately and together are also much below the reference limit of 100 μSv/y prescribed by the above mentioned two agencies. It suggests that the drinking water of this region is radiologically safe so far as water-borne radon hazards are concerned.

Low-cost radon monitoring with validation by a reference instrument

This article reports radon tracing using a low-cost, locally manufactured smart electronic device with comparison to a reference device. Developed for radiation protection and nuclear security, the proposed device consists of a ZP 1200 Geiger-Müller (GM) tube detector with low-cost components including an Arduino microcontroller board, a DHT11 temperature (T) and relative humidity (RH) sensor, and XBee-based Internet of Things (IoT) wireless transmission modules. The reference device measures radon concentration, temperature, and relative humidity in indoor spaces. Typically, the developed device provides data of atmospheric parameters (T, RH) and the ambient dose equivalent rate H*(10). From the ambient dose equivalent rate in µSv/h, the radon activity concentration (in Bq/m3) is determined using standard and recognized conversion coefficients. The coefficients vary according to the ambient radiation strength and range from 5500 to 8900 (Bq/m3)/(µSv/h). The developed device and the reference instrument were used for one month in several dwellings in the city of Yaoundé-Cameroon. Periodic average values of 27.5 ± 2.0 °C (developed device) and 26.2 ± 2.0 °C (reference) for temperature, 74.1 ± 6.4% (developed device) and 73 ± 6% (reference) for relative humidity, and 1500 ± 163 Bq/m3 (developed device) and 1465 ± 164 Bq/m3 (reference) of cumulated radon activity concentrations were obtained for a 24-hour period. Statistical analyzes carried out on the results of the devices provide a linear regression coefficient of R2 = 0.9978, demonstrating good agreement between the instruments.

Specific regional features of radon activity in environmental objects and indoor spaces in the Volgograd region

The protection and preservation of human health under present-day conditions of high urbanization rate is one of the priority tasks of contemporary construction. And here, the environmental safety of the residential buildings to be constructed is one of the most important factors. It is significantly affected by ionizing radiation for which radioactive radon gas is one of the sources. The level of public exposure depends on the concentration of radon in the aerial environment of outdoor territories and indoor spaces. The article considers the radon-related characteristics of the territories and indoor spaces in the Volgograd region and, based on the obtained results, provides calculations of the average annual effective equivalent doses of public exposure caused by radon and its daughter decay products in the region.

A Preliminary Study of the Characteristics of Radon Data from Indoor Environments and Building Materials in the Campania Region Using PCA and K-Means Statistical Analyses

For a healthy indoor environment, it is important to understand which materials and factors favor the generation of high levels of indoor radon. A preliminary multivariate statistical analysis was carried out on two datasets concerning indoor radon and building materials in the Campania Region using Principal Component Analysis (PCA) and the k-means partitional analysis technique. A total of 13 parameters related to building materials were used. The results show the greater contribution of building materials of volcanic origin to the concentration of indoor radon and thoron activity and the different influence of the parameters of the 31 materials analyzed. The same analyses applied to the indoor radon values of 694 rooms in the Campania Region were equally effective in assessing the structural characteristics of indoor environments that most influence indoor radon levels. The study provided an effective assessment of the influence on radon activity of several environmental parameters, which are often not adequately considered.

Radon in dead-end caves in Europe

We report the results of 3-years of Radon-222 monitoring in six show caves across Europe, selected with the feature of having only one, or no natural entrance, defined as dead-end caves. The caves are located in Spain, Slovakia, Slovenia, and Czechia. The consecutive monitoring was performed between January 2017 and January 2020. Continuous measurements of the radon activity concentration using spectrometry detection and analysis of the α-particles of 222Rn progeny were performed. Meteorological parameters influencing gas flow were recorded inside and outside of the caves. Although the radon activity concentrations differed from one cave to another, all six of the studied caves revealed very similar trends, showing evident seasonal variability with higher values in summer and lower values in winter. The measured values of radon activity concentrations ranged between 633 and 26,785 Bq/m3. The temperature differences between the inside and outside of the caves is the main radon movements driving force. The results of this study have significant practical implications, making it possible to provide cave administrators with recommendations regarding employee or visitor time-limited access to the investigated caves. Ours is the first comparative study encompassing the most interesting dead-end caves in Europe.

Radon Solubility and Diffusion in the Skin Surface Layer.

In specific situations such as bathing in a radon spa, where the radon activity concentration in thermal water is far higher than that in air, it has been revealed that radon uptake via skin can occur and should be considered for more precise dose evaluation. The primary aim of the present study was to numerically demonstrate the distribution as well as the degree of diffusion of radon in the skin, with a focus on its surface layer (i.e., stratum corneum). We developed a biokinetic model that included diffusion theory at the stratum corneum, and measured radon solubility in that tissue layer as a crucial parameter. The implementation of the model suggested that the diffusion coefficient in the stratum corneum was as low as general radon-proof sheets. After a 20-min immersion in water, the simulated depth profile of radon in the skin showed that the radon activity concentration at the top surface skin layer was approximately 103 times higher than that at the viable skin layer. The information on the position of radon as a radiation source would contribute to special dose evaluation where specific target cell layers are assumed for the skin.

Health Effects of Natural Environmental Radiation during Burning Season in Chiang Mai, Thailand.

This paper presents the first measurement of the investigation of the health impacts of indoor radon exposure and external dose from terrestrial radiation in Chiang Mai province during the dry season burning between 2018 and 2020. Indoor radon activity concentrations were carried out using a total of 220 RADUET detectors in 45 dwellings of Chiang Mai (7 districts) during burning and non-burning seasons. Results show that indoor radon activity concentration during the burning season (63 ± 33 Bq/m3) was significantly higher (p < 0.001) compared to the non-burning season (46 ± 19 Bq/m3), with an average annual value of 55 ± 28 Bq/m3. All values of indoor radon activity concentration were greater than the national (16 Bq/m3) and worldwide (39 Bq/m3) average values. In addition, the external dose from terrestrial radiation was measured using a car-borne survey during the burning season in 2018. The average absorbed rate in the air was 66 nGy/h, which is higher than the worldwide average value of 59 nGy/h. This might be due to the high activity concentrations of 238U and 323Th in the study area. With regards to the health risk assessment, the effective dose due to indoor radon exposure, external (outdoor) effective dose, and total annual effective dose were 1.6, 0.08, and 1.68 mSv/y, respectively. The total annual effective dose is higher than the worldwide average of 1.15 mSv/y. The excess lifetime cancer risk and radon-induced lung cancer risk during the burning season were 0.67% and 28.44 per million persons per year, respectively. Our results substantiate that indoor radon and natural radioactive elements in the air during the burning season are important contributors to the development of lung cancer.