Radon Volume Activity Research Articles

Parameter Variations in the Subsoil Radon Field at the Paratunka Station of the Petropavlovsk-Kamchatsky Geodynamic Test Site in 2011–2016

A network of stations for subsoil radon monitoring is in operation at the Petropavlovsk-Kamchatsky geodynamic testing area and is aimed at detection of strong earthquake precursors. At all stations, measurements are carried out using gas-discharge counters located at different depths within aeration zones of soft sediments. The volume activity of radon (VA Rn) is monitored at the most equipped station Paratunka (PRT) at three measurement sites located across the regional fault. The radon flux density (RFD) is measured from the surface. The article reviews responses in the dynamics of VA Rn and RFD from the surface at the PRT station prior to the Kamchatka earthquakes with magnitudes М W > 5 that occurred over the period of 2011–2016. The revealed RFD seasonal cycle is likely related to the seasonal variations in air temperature. The postseismic effect caused by the strongest deep Okhotsk earthquake (May 24, 2013, М W = 8.3) is detected in the RFD data. The behavior of VA Rn dynamics during time periods of the strong earthquakes is different. The results confirm the existing opinion on the formation of narrowly localized zones of Rn runoff to the atmosphere owing to both vertical and horizontal irregularities in the top layer of soil, which can react differently to changes in the geoenvironment stress–strain. On the basis of the real-time radon monitoring data, the authors have issued partially successful short-term prediction for several earthquakes. The results of this work confirm the opinion of many researchers that radon monitoring can be used in the short-term prediction of strong earthquakes.

Effect of Radon on oncological morbidity of the population: comparative analysis of some regions of Ukraine and France

<p><span lang="EN-US">Radon contributes about 50% to the total annual effective dose of human radioactive irradiation. This gas is the main radiological pollutant of ecosystems. The question of studying the effect of radon on increasing the risk of the incidence of lung cancer is relevant in the context of European sanitary and hygienic research. We give in this article a comparative description of the results of experimental studies of volumetric activity of radon inside the air of the first floors of residential premises in Corsica island (France) and town of Rivne (Ukraine). «Kodak-alpha» integrated solid-state track detectors were used in France for three measurement campaigns between 1990 and 1999 (152 measurements in residential buildings and 638 in the schools of the island). In Ukraine, we did research using the “Alfarad Plus” Express Radon meter from 2013 to 2017 (200 measurements in the apartments of the first floors of buildings). The regions studied are similar in several parameters, which affect the increase in the percentage of cancer diseases: geology of underlying soils, the structure of housing and building material, the number of people and incidence of lung cancer, smoking factor, etc. We found that the volume activity (VA) of radon in indoor air in-house compared regions have close in value. The main reason is the similarity of the underlying granites in terms of radon emanation power. The average geometric value of radon VA in living quarters for various measurement campaigns in Corsica is in the range from 81 to 152 Bq/m<sup>3</sup> (the average of them is 134 Bq/m<sup>3</sup>). This value for Rivne is 127 Bq/m<sup>3</sup>. VA of radon in residential areas of Rivne have a lognormal distribution. Building norms for equivalent equilibrium volumetric activity (EEVA) of radon in the premises of Rivne are exceeded in 6.6% of buildings, Corsica - from 6 to 10% (this depends on the measurement campaign). Here, the average concentration of radon in housing is over 400 Bq/m<sup>3</sup>. We calculated the relative risk of lung cancer incidence due to radon for the population of the studied regions. The Jacobi and BEIR-VI models were used for Rivne for 70 years of exposure, and the BEIR-VI model was taken for Corsica for 110 years of exposure. The proportion of deaths from lung cancer is in Corsica from 30 to 48%, while for Rivne - about 50%. Consequently, the percentages of deaths from lung cancer caused by radon with an average value of VA in housing 134 Bq/m<sup>3</sup>, for men and women Corsica are 21.3% and 22.6% respectively (21.5% for the entire population) of the total number of deaths from this disease. In the quantitative form it is 33 people (men - 28, women - 5) out of 155 people died for a year from lung cancer. For residents of Rivne, the percentage of deaths from lung cancer is 25.1%, average value of VA in housing is 127 Bq/m<sup>3</sup>. 53 people die on average for a year from lung cancer caused by radon (men - 47, women - 6) of 214 deaths per year lung cancer lot. A preliminary assessment of the synergistic interaction between smoking and radon showed that there could be a 50% increase in morbidity due to radon for smokers, compared to non-smokers. However, these data are not sufficiently representative and therefore further research is needed.</span><span lang="EN-US">Rivne; Corsica; living rooms; volumetric activity of radon; lung cancer</span></p>

RESULTS OF SAMPLING ANALYSIS OF RADON CONTENT IN PRESCHOOL AND SCHOOL ORGANIZATIONS IN THE LENINGRAD REGION

The results of the radon screening in the premises of the preschool and school institutions in the Leningrad region are analized. The data were obtained from measurements of radon volume activity by the integral method. As objects of control were selected the old buildings built before 2000 and relatively new buildings. It is shown that the territory of the Leningrad region is highly heterogeneous by the potential radon hazardous. The highest levels of radon were identified in the surveyed buildings in Boksitogorsk, Volosovo, Vyborg and Slantsy.

ROLE OF THE STRUCTURAL FACTOR IN THE DISTRIBUTION OF HIGH-RADON GROUNDWATER IN THE SOUTHWESTERN FLANK OF THE SOUTH BAIKAL RIFT BASIN

This article discusses the distribution patterns of high-radon groundwater at the southwestern shore of LakeBaikal. This region is a flank of the South Baikalrift basin, characterized by high geodynamic activity and complex fault patterns, without any special geochemical conditions with regard to the content of uranium in the rocks. Based on our observations and measurements, we consolidated the first massive database on radon volume activity (Q) in a variety of local water sources. In the Kultuk–Vydrino area, the Q values vary from zero to 81.1 Bq/l, according to the analysis of the water samples from 93 springs, lakes, small streams, wells, and drilled holes. The highest concentrations of radon are discovered in the groundwater samples. Such values are unevenly scattered across the study area. The chain of the maximum Q values trends northwestwards along the LakeBaikalshore. This distribution pattern of radon, as well as the locations of individual water sources with Q>15 Bq/l are predetermined by the structural factor. The paragenetic analysis of faults and joints in the Kultuk–Vydrino area shows that this factor includes both the structure and stages in the development of the regional largest Main Sayan fault zone (the southwestern flank of the South Baikalbasin is a segment of this zone). The water sources with increased concentrations of radon are located in zones with a high density of the 2 nd order faults, especially on sites wherein the NW-striking faults cross the transverse faults that have experienced repeated activation. Temperature T is an additional factor influencing the degree of radioactivity in water. A relationship between T and Q is reverse. Water sources with Q>15 Bq/l associated with the 2 nd order fault zones may occur also due to a locally lower temperature of groundwater. Our study gives evidence that the southwestern coast ofLake Baikal is promising for finding high-radon water sources. Using such water in balneo­logy can become a valuable contribution to the tourism and recreational potential of the region. This prospect is especially important for the town ofBaikalsk that is now developing without its township-forming enterprise: the notorious pulp-and-paper mill has been completely shut down.

Картирование территории Гомельской, Могилёвской и Витебской областей по комплексному радоновому показателю и объёмной активности радона в жилых зданиях

Картирование территории Гомельской, Могилёвской и Витебской областей по комплексному радоновому показателю и объёмной активности радона в жилых зданиях

MEASUREMENT AND ANALYSIS OF VALUES USED IN ASSESSMENT OF RADON HAZARD AREAS IN THE RUSSIAN FEDERATION AND THE CZECH REPUBLIC

The results of measurement and the comparative analysis of the density of radon flux (RF), the volume activity of radon in soil pore space and permeability of soils (the Czech Republic) are shown in this article. It is shown that the measured values are highly volatile, which means that the used methods for estimating radon require further development.

THE REPUBLIC OF BELARUS RADON DANGER MAP

Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment. The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas. Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package. Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions. Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents.

Radiation Situation at Construction Sector Objects in Caucasus Mineral Waters Region and Prospects of its Decrease

The paper considers the topical issues of radiation situation at the objects of the construction sector and the municipal economy in the resort Caucasus Mineral Waters region. The radiation characteristics such as gamma-radiation dose rate of territories and rooms, the indoor radon volume activity, the content of naturally occurring radionuclides in construction materials were studied. It was determined that for all the characteristics examined in various territories and buildings the exceedance of the allowable norms is registered. The guests of the resort cities do not get an elevated level of exposure to radiation during the short time period. In order to avoid the dangerous level of exposure to radiation caused by the objects of construction sector and municipal economy to the local residents, it is required to exclude the erection of buildings and constructions without the radiation control as well as to examine the radiation characteristics of the operated building stock of the resort region. A software program has been suggested, the application of which allows forming a radiation characteristics database as well as developing electronic maps of the radiation situation in the cities of the Caucasus Mineral Waters region.

ОСНОВА ДЛЯ СОСТАВЛЕНИЯ ТЕМАТИЧЕСКИХ КАРТ РАДОНОВОГО ПОТЕНЦИАЛА НА ТЕРРИТОРИИ ГОМЕЛЬСКОЙ И МОГИЛЁВСКОЙ ОБЛАСТЕЙ

Objective: to determine correlative relations between the indoor volume activity of radon and the parameter defining the content and nature of radon in rocks. Material and methods. The results of indoor volume activity in rural settlements of Gomel and Mogilev regions measured by specialists of Scientific and Research Institute of Industrial and Marine Medicine (Saint Petersburg) in 1992, the exposure doze power maps before the Chernobyl Disaster made by specialists of the Republican Unitary Enterprise «Belgeology» over 1969-1985, and the geologist rocks maps with various uranium content were used as the basis for radon risk mapping. Results and conclusion. We have proposed the complex radon factor that may be calculated as the relative content of uranium in rocks multiplied by the relative value of rock penetration. The regression dependence of volume activity on the complex radon value taken on average in Gomel and Mogilev regions has essentially high correlative coefficient - 0.76. Such correlation is enough to use this parameter based on the measurements of rock radon characteristics in Gomel and Mogilev regions for radon risk mapping.

Origin of anomalies of radon volume activity during failure of rocks

Experimental and theoretical research into the processes of radon emanation during failure of rocks has been carried out. We propose a physical model for the mechanisms of origin of anomalies of radon volume activity. Based on the obtained experimental data, relative changes in the open porosity and specific inner surface of rock during its failure have been studied.

Определение среднегодовой объемной активности радона на рабочих местах

Radiation safety under the influence of radiation’s natural sources, in particular radon, is provided by control related to a value
 of average annual equivalent equilibrium volume activity of radon and thoron affiliated products in facilities’ air. Definition of
 radon’s average annual equivalent equilibrium volume activity according to single measurements of radon’s volume activity may
 lead to essential mistakes in assessment related to radiation situation on workplaces. Radiation control techniques carrying out on
 compliance to hygienic requirements on indicators of facilities’ radiation safety are analyzed in this paper. Results of experimental
 studies related to radon’s volume activity in rooms with permanent human presence are considered. Recommendations on
 determination of actual values of radon’s average annual volume activity and of radon’s volume activity measurements frequency
 carrying out are given.

Estimation of radondanger of the prydniprovska part of Pechersk district of Kyiv

Background and anomalous levels of volume activity of radioactive gases in soil air were defined from the data of radioecological researches conducted by means of emanation survey on the territory of Kyiv. It was found that the higher and anomalous levels of volume activity of these gases are formed by fracture zones within the limits of which dangerous conditions may be formed for the inhabitants of the houses constructed above the zones. The area of the Prydniprovska part of Pechersk district of Kyiv has been researched in detail. Based on the levels of volume activity of radon and thoron this area is divided into two parts: the eastern part is radon-thoronsafe while the central and western ones, on the contrary, are dangerous. We think that it is connected with the submeridional radon-thoronbearing zone which exists due to presence of the fracture zone of the similar direction in the bowels. 

Development of an ultra-sensitive radon detector for the SuperNEMO experiment

The SuperNEMO experiment is devoted to neutrinoless double beta decay detection and main R&D of the detector design is already finished. The crucial role in such low background experiments plays the suppression of background. One of the most important sources of radioactivity is the radon gas and its daughter products. The radon activity in the volume of the detector will be reduced significantly using the antiradon facility already installed in the Modane underground laboratory which provides air with a radon volume activity at the order of ∼ mBq/m3. To be able to measure low radon activities at the output of this antiradon facility in reasonable time of measurement the develoment of new ultra-sensitive radon detector is currently carried out. The detection is based on electrostatic collection of radon progenies (214Po, 218Po) on a Si PIN diode. Our idea is to increase the volume of the detector up to 1 m3 divided into smaller subdetectors (50–100 l) to improve the detection effectiveness and consequently the sensitivity. Two prototypes of sensitive radon detectors were constructed (50 l and 300 l). Preliminary results of the detection efficiency and the background measurement for the first prototype are also presented.

Radon dose calculation methodology for underground workers in the Czech Republic

The project focused on classifying the level of irradiation from natural ionising radiation sources for workers in publicly accessible caves and in caves used for speleotherapy, with applicability to other underground workplace. A correct and accurate procedure (and calculation) is defined for determining the effective dose that workers are exposed to in caves, based on the results of integral measurements of radon volume activity and on the length of time spent by workers in the caves. A review was made of various approaches for evaluating lung irradiation found in the literature. Experimental measurements of cave atmosphere characteristics (continuous measurement of radon volume activity, continuous and integral measurements of radon decay products, interior climatic parameters and aerosol spectra) were the main sources for the methodology.

Measurement of the volume activity of radon in uranium waste zones

The accumulation and behavior of radon in the home, school, preschool and other buildings during the summer and winter are investigated and an assessment is made of the dose load on the residents of the settlements located next to the uranium wastes. Methods of active and passive measurement of the volume activity of radon were used to accomplish this. The results of measurements of the radon activity in rooms are presented, the radon dose loads on the population are evaluated, and the radon-dangerous sections are indicated.

Radon as a “Deterministic” indicator of natural and industrial geodynamic processes

Radon has been regarded as an actual precursor to such geodynamic phenomena as rockfalls in deep mines and tectonic earthquakes. Nevertheless, a physical relationship between radon volume activity (RVA) and stress pattern in the rock mass, until recently, has remained obscure. Radon monitoring carried out in deep mining excavations has revealed that the RVA clearly locates the position of extension and compression zones within the rock mass. Furthermore, a monitoring of soil radon in an active seismic region elucidated the RVA behavior reflecting compressional and extensional stress during rock mass surface bending in connection with geodynamic processes. Based on the experiments, a new model is proposed here for the precursors to geodynamic events and their connection with radon exhalation.

Radon-in-water standard

The radon-in-water standard installed at the Czech Metrology Institute in 1994 is based on a generator producing radium-free radon solution and on a measurement system for generator calibration and stability checking. The generator consists of about 6 L cylindrical vessel with a solid phase 222Rn source with 99.9% air emanation power and an external circuit for solution homogenisation. Standard solutions are prepared by charging water in the vessel with radon for an appropriate period; radon volume activity of the solution may vary from 300 to 2000 Bq/L; its uncertainty is less than 2.5%.

Effective dose assessment for workers in caves in the Czech Republic: experiments with passive radon detectors

The new RAMARN system for radon volume activity measurement was developed in 2003 and has been in use since then. RAMARN system consists of a plastic chamber that is conically cylindrical in shape and about 0.5 l in volume; a bare Kodak LR 115 is located on the bottom of this diffusion chamber. The size was chosen to avoid the influence of deposited decay products of radon. Kodak has a spectrometric character--the tracks are visualized only for alphas with energies between 1 and 3 MeV that touch the foil; thus the effective volume has a lens shape. The response therefore corresponds to diffused radon and half of (218)Po born by radon gas decay. The experiments described below were conducted as one part of a routine methodology control, focused on classifying worker irradiation from natural ionizing radiation sources in show caves and in caves used for speleotherapy.

Radon and air ion balance

In connection with the study of equilibrium among radon and its conversion products attention has been paid to air ionisation or, more precisely, to light atmospheric ions. Air ionisation variability and relationship between positive and negative ions concentration in the presence of ionizing radiation, local and microclimatic conditions have been observed. A very good correlation between light atmospheric ions concentration and radon volume activity or equilibrium equivalent of radon decay products has been found. Concrete measurements were conducted in karst caves and mine galleries without any meteorological influences. It was discovered that in most cases negative ions concentration predominated over positive ions concentration. This non-equilibrium was caused by a number of factors. In this work we have concentrated our attention to microclimatic and regime conditions of the individual locations.

A new technique for measuring radon exposure at working places

A new technique has been developed based on passive diffusion sampling and alpha track detection for monitoring radon exposure at working places. It is based on a device to be turned on and off at monitoring sites to permit accurate measurements of timed exposures. This technique is useful for radioprotection applications on personal and area monitoring of radon volume activity: timed measurement intervals and addition of sequential exposures. Additionally, the device allows accurate calibration with the application of radon reference atmospheres. Calibration facilities have been realized which allow starting detector exposure only at stationary conditions to avoid effects of varying radon concentration during exposure of passive integrating detectors. The contribution of the initial transient to the overall exposure ranged from about 3% to 10% according to calibration protocol. Experimental data evidence better performances of this new technique with respect to other measuring devices for integrating measurements based on radon diffusion samplers and polymeric nuclear track detectors (CR-39, LR-115 and polycarbonate). A better accuracy of calibration factor is obtained. The technical apparatus is presented and preliminary results described.