Measurements Of Radon Activity Concentration Research Articles

Radon Equilibrium Factor and the Assessment of the Annual Effective Dose at Underground Workplaces

The equilibrium factor F is one of the parameters that should be considered when assessing the effective dose based on radon activity concentration. Since the equilibrium factor in various environments ranges theoretically from a value close to 0 to 1, it is expected that dose assessment based on one recommended coefficient value may lead to an underestimation or overestimation of the dose. That is why it is essential to measure this quantity if the basis for dose assessment is the radon concentration and not the concentration of radon decay products. The equilibrium factors were determined based on measurements of radon activity concentration and potential alpha energy concentration and varied from 0.15 to 0.94, with an arithmetic mean of 0.55. The average effective dose calculated for the employee taking into account these values was 31 mSv, assuming an annual working time of 1800 h. In turn, the average effective dose calculated for the equilibrium factor of 0.2 as recommended by the International Commission on Radiological Protection (ICRP) was equal to 13 mSv.

Assessment of Indoor and Water Radon Concentrations in Esenyurt and Beylikdüzü Districts of Istanbul, Marmara Region, Turkey

The radon activity concentration measurements for indoor and tap water were studied in Esenyurt and Beylikdüzü districts of Istanbul Province, Turkey. The mean radon concentration value received from thirty-six passive radon detectors was obtained as 63.56 Bq/m3. The mean annual effective dose for indoor radon measurements is 1.60 mSv/y in this measurement period. The radon activity results of calculated tap water samples were under 0.8 Bq/L. The annual effective doses resulting from ingestion and inhalation were calculated to evaluate the health risk across various age groups. All radon measurement results, and the associated calculated data for ingestion and inhalation remained below the threshold values established by international organizations

Experience from radon in soil gas comparison measurements held in Czech Republic and in other countries, 1992–2022

Radon 222Rn, an inert natural radioactive gas, a daughter product in the 238U natural decay series, a source of alpha radiation, together with its short-lived decay products is a dominant source of absorbed radiation doses in the population. Rocks and building materials are fundamental sources of radon in dwellings. Elevated indoor radon activity concentration in houses and workplaces, surpassing recommended reference levels, is not desirable. Since radon penetrates into the houses from the geological basement, various technical aids for protection of houses have been developed. Their individual application derives from the radon potential of a building site. Radon risk mapping of building sites became a standard procedure for gauging the local radon potential. Various instruments and techniques of measurements of radon activity concentration in soil gas (Bq/m3) at building sites are available. Since radon in soil gas and radon measurement techniques are affected by several natural and technical conditions, resultant values of radon risk mapping by individual organizations vary, sometimes fundamentally. Radon comparison measurements at selected reference sites are an important tool for single organizations to verify their radon measuring procedures and reliability of their reported results. Based on legislative regulations, comparison measurements at established radon reference sites are a part of the obligatory activities for radon risk mapping at building sites in the Czech Republic. Experience and analyses of 30-year radon in soil gas comparison measurements in the Czech Republic show the dispersion of values reported by participating organizations and indicate that more than 10% of participants do not fulfill the established local criteria. This paper introduces requirements for the establishment of radon reference sites, documents their natural variability, recommends the procedure of radon comparison measurement, and analyses its results. A long-term experience was gained by testing organizations from the Czech Republic (1992–2022) as well as from the international comparison measurements organized in the Czech Republic and in several other countries (2010–2021).

Radon Activity Concentration Measurements in the Water Collected from the Lower Zab River in the Kurdistan Region of Iraq

This study aims to assess radon levels in the water of the Lower Zab River. Knowing the radon concentrations is crucial for understanding the potential risks to human health and implementing protective measures. ARAD7-H2O detector has been used to measure the radon concentration in 28 water samples from the Lower Zab River in the Kurdistan Region of Iraq. Results show that the radon activity concentrations ranged from 0.5 to 4 Bq.L−1, with an average of 0.61 Bq.L−1, and the resulting annual effective dose (AED) varied from 0.137 to 60.06 Sv.y−1, with an average of 12.08 Sv.y−1. The average radon concentration and AED in the measured samples are below the reference levels recommended by the ICRP and the World Health Organization. Consequently, the LZR water is suitable for human consumption and use and does not present any health hazards related to radon exposure.

Mapping in a radon-prone area in Adamawa region, Cameroon, by measurement of radon activity concentration in soil.

The radon-prone area of the Adamawa region in Cameroon is characterized by high natural radiation background resulting from the high concentrations of radium-226, thorium-232, and indoor radon. To produce a radon-risk map, radon measurements in soil were carried out in the city of Ngaoundere. The radon activity concentration in soil gas ranged from 256 to 166kBqm-3 with a mean of 80kBqm-3 and a standard deviation of 38kBqm-3. The area is mostly classified as high risk (80%) according to the Swedish classification, and 20% as medium risk. A low-risk area was not observed. Granite-like geology sites were characterized by higher radon concentration. A ratio of about 295:1 was obtained for soil radon gas to indoor radon concentrations, with a positive correlation (R = 0.40), and a transfer factor of 3 per mil. These results demonstrate that in situ measurements of radon concentration in soil can provide accurate information on the level of indoor radon concentrations. Geostatistical and deterministic interpolation techniques have been used to obtain a radon map by comparing the suitability of ordinary kriging and inverse-distance-weighted (IDW) interpolation methods. It turned out that there is not much difference in the prediction errors of the two techniques (Root Mean Square Error = 34.4 for ordinary kriging and 34.3 for IDW). It is concluded that both methods give acceptable results. In situ measurements and geostatistical analysis allow assessment of expected indoor radon exposure in a given area at reduced costs and time required. However, for the investigated area, more research is needed to produce reliable radon-risk maps.

Experiences with accreditation for radon measurement laboratories.

The adoption of the Council Directive 2013/59/EURATOM into Austrian national law generated new challenges for businesses, authorities and measurement services. The law defines radon priority regions in which all employers are obliged to hire an authorised radon-monitoring service to determine radon activity concentration at workplaces in basements and on ground floors. In this paper, an overview of our experiences with the process of becoming an accredited and authorised radon-monitoring body using integrating and time-resolved radon measurement equipment is given. The main challenges to overcome, such as determination of measurement uncertainty, conducting metrologically traceable calibration of the track-etch detector system, information not covered by ISO 11665-1, ISO 11665-4 and ISO 11665-5, availability of proficiency tests, etc., are described. This paper aims to be a guideline for laboratories seeking accreditation in the field of radon activity concentration measurements.

222Rn Activity Concentration Measurement and its Radiological Risks in the Environment of Barserin Village, Erbil-Iraq

222Rn Activity Concentration Measurement and its Radiological Risks in the Environment of Barserin Village, Erbil-Iraq

Recent Progress in Radon Metrology at IFIN-HH, Romania

The practical implementation of the European Council Directive no. 2013/59/EURATOM in Romania requires reliable indoor measurements of the radon (222Rn) activity concentration in air. In Romania, several Testing Laboratories were designated for radon activity and/or radon activity concentration in air measurements by the Romanian National Commission for Nuclear Activities Control (CNCAN). The calibration of the instruments used for indoor radon activity concentration measurements is very important. IFIN-HH, through its Ionizing Radiation Metrology Laboratory (LMRI), performed advanced research in the field of radon metrology, using radon standard sources prepared by LMRI, its radon chamber facility and a new reference radon monitor. The most recent results are described in this article. The radon chamber facility from IFIN-HH was technically improved, and new equipment and methods were set up and tested in order to provide new calibration services for customers. Additionally, calibration of the radon monitors was performed, as well as of the systems with solid-state nuclear track detectors, used for radon in air activity concentration measurements. IFIN-HH/LMRI obtained the CNCAN designation as Calibration Laboratory for installations measuring the radon activity concentration in air.

Assessment of the public effective dose due to the 222Rn radioactivity in drinking water: results from the Calabria region, southern Italy

In this article authors report experimental results obtained for radon activity concentration measurements in drinking waters, coming from the Calabria region, southern Italy. The 222Rn specific activity in the investigated samples, measured with the Durridge RAD7 + RAD H2O setup, was compared with that one derived from international guidelines (the European Directive 2013/51/Euratom) and Italian regulations (the Italian Legislative Decree 28/2016) and it was used, with the dose conversion factor for 222Rn, to estimate the annual effective dose, for the public of the investigated region, due to the ingestion of radon dissolved in water. Obtained results represent a main reference for the investigated area, and they are useful to determine the associated radiological health risks for the population.

New S-chamber Mid-Term electrets: Experimental characterization and uncertainty evaluation

Electret ion chambers are widely used passive detectors, employed for measurements of radon activity concentration in air. These devices are made of a Teflon electret coupled to an interchangeable ion chamber. A new type of electret produced by Rad Elec Inc., named Mid-Term, is used together with the S-type (200cm3) chamber. It is designed to be operated in an intermediate range with respect to the standard Short-Term and Long-Term electrets. This work describes the complete characterization of such device, performed according to the ISO guidelines. The characterization was carried out in the secondary standard calibration laboratory of Politecnico di Milano Italy, and with a traceable radon chamber. The coefficients and equations presented can be used by operators to assess both the radon activity concentration and the related uncertainty, with the only requirement of the knowledge of the background gamma air kerma rate of the specific measurement site and its related uncertainty.

Soil types and their relations with radon concentration levels in Middle Governorate of Gaza Strip, Palestine

<p>Determination of natural radioactivity has been carried out in surface and core agricultural soil samples collected from various sites in the Middle Governorate – Gaza Strip, Palestine. Mechanical and chemical analysis has been done to determine soil characteristics. Radon activity concentration measurements were carried out using solid state nuclear tracks detectors, Cr-39. The mechanical analysis results show that they belong to two classes, sandy loam and loamy sand. The sandy loam soil was observed in the eastern side of the study area, whereas the loamy sand was observed in western and middle parts. The radon concentration levels were higher in core samples and were proportionate to the soil depth. Also they were higher in sandy loam than loamy sand soil samples. The radon concentration levels had a positive correlation with fine grains (clay- to silt-size) of soil sample which translocated from upper to lower horizons of soil during its development. Additionally, there was a positive correlation with pH and water content, whereas a negative correlation was observed with organic matter and potassium contents. The positive correlation referred to a large specific surface of fine grains which were located in lower horizons of soil and were able to adsorb more water and consequently led to high radon concentration levels.</p>

Radon activity concentration measurements in water sources from Perak state Malaysia

Radon activity concentration in water samples from Perak state Malaysia and their possible health risk was assessed. The Samples were from lakes, hot springs, and rivers. The RAD7 Detector was used for in-situ measurement of radon concentration. The radon activity concentration ranged from 0.04 ± 0.08 — 3.98 ± 0.39 Bq l – 1, with mean of 0.69 Bq l – 1 and standard deviation of 0.92 Bq l – 1. The activity concentration ranged from 0.08 ± 0.12 — 0.45 ± 0.27, 0.04 ± 0.08 — 0.62 ± 0.32, 0.33 ± 0.23 — 3.98 ± 0.39 Bq l – 1, with a mean of 0.24 ± 0.19, 0.30 ± 0.21, 1.26 ± 0.34 Bq l – 1 for lakes, hot springs, and rivers respectively. The result was below the UNSCEAR, USEPA and WHO action levels of 11.1 Bq l– 1and100 Bq l – 1respectively. The 222Rn contribution from water to indoor air was found to be below the recommended action level . The annual effective dose for inhalation and ingestion ranged from 0.000102 — 0.009954 mSv y – 1 and 0.000102 — 0.010112 mSv y – 1, with mean annual effective dose of 0.001733 and 0.001759 mSv y – 1 respectively. The effective doses for both inhalation and ingestion were below the world average of 0.002 mSv y – 1. The 222Rn activity concentration in the study could be termed normal and without threat to human health.

ANALYSIS OF RADON TIME SERIES RECORDED IN SLOVAK AND CZECH CAVES FOR THE DETECTION OF ANOMALIES DUE TO SEISMIC PHENOMENA.

Anomalies in the radon (222Rn) releases in underground environments are one of the phenomena that can be observed before earthquake occurrence. Continuous measurements of radon activity concentration, and of meteorological parameters that influence the gas emission, were performed in three Slovak and Czech caves during 1-y period (1 July 2016-30 June 2017). The radon activity concentration in caves shows seasonal variations, with maxima reached during summer months. The anomalies in the radon time series are identified using a combination of three mathematical methods: multiple linear regression, empirical mode decomposition and support vector regression. The radon anomaly periods were compared with earthquake occurrences in Europe. Coincidences between both phenomena were found, since all monitored caves reflect contemporaneous local tectonic changes. The results indicate that radon continuous monitoring could assist a better understanding of radon emissions, along active tectonic structures, during seismic events.

RADON ACTIVITY CONCENTRATION IN WATERS OF SPRINGS IN SELECTED AREAS OF WESTERN SLOVAKIA.

This paper presents the results of measurements of radon activity concentration (RAC) in spring waters and natural wells in three mountains of Slovakia (Strážov Mountains, Považský Inovec and Little Carpathians). These mountains provide drinking water for inhabitants of surrounding towns and villages. Little Carpathians is the most seismically active area in Slovakia. Považský Inovec, where 2 out of 11 uranium deposits of Slovakia are located, is interesting due to increased uranium mineralization. We have collected samples from more than 170 natural water sources, many of which exceed the guide value of 100Bql-1, with a maximum value of 274Bql-1. The median of these data (15Bql-1) is also higher than the national median in groundwater (11.6Bql-1). From the obtained data, we have created maps representing RAC of groundwaters for the whole territory. These maps were also compared with the geological maps.

Радиационная обстановка на рабочих местах персонала наземных объектов Приаргунского производственного горно-химического объединения

Purpose: To obtain data of radiation survey in workplaces of the personnel of the Priargun Production Mountain Chemical Association (OJSC PPMCA), who work at the premises of the ground facilities. 
 Material and methods: In the course of the radiation survey. Integral track methods were used to measure radon activity concentration by REI-1 track cameras of the TRACK-REI-1M kit. 
 To assess the activity balance factor between radon and its radionuclide progenies, short term measurements of radon activity concentration (AC) and effective equilibrium concentration (EEC) of radon by handle radiometers of radon and its progenies. Gamma dose rate was measured by handle dosimeters.
 Results: Annual AC, EEC and effective dose due to radon and external gamma exposures in workplaces at the ground facilities of OJSC PPMCA have been obtained. Total number of the inspected workshops is 138, including 121 workshops occupied by the A group personnel, and 17 – by the B group personnel. 
 Conclusions: It was shown that annual doses 20 mSv could be exceeded for the A group personnel who work at three workshops shaft 8K of the mine-2, one workshop of building 630A of the Hydro-metallurgical Plant and one workshop of shaft 5 B of G mine.
 In the workshops of the B group personnel, 5 mSv annual effective doses can be exceeded 2 and more times at the premises of canteen number 18 and administrative domestic building of mine-2.

Air radon equilibrium factor measurement in a Waste Water Pre-Treatment Plant

We analyze in this paper a Waste Water Pre-Treatment Plant (WWTP) located at the Mediterranean coast with air radon concentration above Spanish action level (600Bq per cubic meter).This paper presents a method for radon equilibrium determination by gamma spectrometry measuring of the radon progeny concentrations in the air, in order to estimate WWTP workers effective dose more exactly.The method is based on simultaneous sampling of air through a filter paper and alpha spectrometry measurement of radon activity concentration in the air.According to the measured radon activity concentration in the air of 368±45Bq/m3 the equilibrium factor between radon and progenies is estimated to be F=0.27, which is in good agreement with expected values.

Measurements of radon activity concentration in mouse tissues and organs.

The purpose of this study is to investigate the biokinetics of inhaled radon, radon activity concentrations in mouse tissues and organs were determined after mice had been exposed to about 1MBq/m3 of radon in air. Radon activity concentrations in mouse blood and in other tissues and organs were measured with a liquid scintillation counter and with a well-type HP Ge detector, respectively. Radon activity concentration in mouse blood was 0.410 ± 0.016Bq/g when saturated with 1MBq/m3 of radon activity concentration in air. In addition, average partition coefficients obtained were 0.74 ± 0.19 for liver, 0.46 ± 0.13 for muscle, 9.09 ± 0.49 for adipose tissue, and 0.22 ± 0.04 for other organs. With these results, a value of 0.414 for the blood-to-air partition coefficient was calculated by means of our physiologically based pharmacokinetic model. The time variation of radon activity concentration in mouse blood during exposure to radon was also calculated. All results are compared in detail with those found in the literature.

First radon measurements and occupational exposure assessments in underground geodynamic laboratory the Polish Academy of Sciences Space Research Centre in Książ Castle (SW Poland)

The article presents the results of the first radon activity concentration measurements conducted continuously between 17th May 2014 and 16th May 2015 in the underground geodynamic laboratory of the Polish Academy of Sciences Space Research Centre in Książ. The data were registered with the use of three Polish semiconductor SRDN–3 detectors located the closest (SRDN–3 No. 6) to and the furthest (SRDN–3 No. 3) from the facility entrance, and in the fault zone (SRDN–3 No. 4).The study was conducted to characterize the radon behaviour and check it possibility to use with reference to long– and short–term variations of radon activity concentration observed in sedimentary rocks strongly fractured and intersected by systems of multiple faults, for integrated comparative assessments of changes in local orogen kinetics.The values of radon activity concentration in the underground geodynamic laboratory of the Polish Academy of Sciences (PAN) Space Research Centre in Książ undergo changes of a distinctly seasonal character. The highest values of radon activity concentration are recorded from late spring (May/June) to early autumn (October), and the lowest – from November to April. Radon activity concentrations varied depending on the location of measurement points. Between late spring and autumn they ranged from 800 Bq·m−3 to 1200 Bq·m−3, and even 3200 Bq·m−3 in the fault zone. Between November and April, values of radon activity concentration are lower, ranging from 500 Bq·m−3 to 1000 Bq·m−3 and 2700 Bq·m−3 in the fault zone. The values of radon activity concentration recorded in the studied facility did not undergo short–term changes in either the whole annual measuring cycle or any of its months.Effective doses received by people staying in the underground laboratory range from 0.001 mSv/h to 0.012 mSv/h. The mean annual effective dose, depending on the measurement site, equals 1 or is slightly higher than 10 mSv/year, while the maximum dose exceeds 20 mSv/year. The estimated annual effective doses are comparable to the standard value of 20 mSv/year defined by Polish law for people employed in the conditions of radiation exposure. They are also in the range of annual effective dose value (8 mSv/year) recommended in workplaces by International Commission on Radiation Protection.

Method to Measure Indoor Radon Concentration in an Open Volume with Geiger-Mueller Counters: Analysis from First Principles

A simple method employing a pair of pancake-style Geiger-Mueller (GM) counters for quantitative measurement of radon activity concentration (activity per unit volume) is described and demonstrated. The use of two GM counters, together with the basic theory derived in this paper, permit the detection of alpha particles from decay of and progeny ( 218Po, 214Po) and the conversion of the alpha count rate into a radon concentration. A unique feature of this method, in comparison with standard methodologies to measure radon concentration, is the absence of a fixed control volume. Advantages afforded by the reported GM method include: 1) it provides a direct in-situ value of radon level, thereby eliminating the need to send samples to an external testing laboratory; 2) it can be applied to monitoring radon levels exhibiting wide short-term variability; 3) it can yield short-term measurements of comparable accuracy and equivalent or higher precision than a commercial radon monitor sampling by passive diffusion; 4) it yields long-term measurements statistically equivalent to commercial radon monitors; 5) it uses the most commonly employed, overall least expensive, and most easily operated type of nuclear instrumentation. As such, the method is par-ticularly suitable for use by researchers, public health personnel, and home dwellers who prefer to monitor indoor radon levels themselves. The results of a consecutive 30-day sequence of 24 hour mean radon measurements by the proposed GM method and a commercial state-of-the-art radon monitor certified for radon testing are compared.

Prototype of a primary calibration system for measurement of radon activity concentration

To calibrate measurement devices for monitoring the activity concentration of 222Rn in air, a prototype of a calibration facility is tested using a solid 226Ra source and a high-purity germanium (HPGe) detector. An emanation box was mounted on the detector for online gamma measurements. Inside this box, a 32.8kBq ±3% 226Ra standard source was placed. An AlphaGUARD control radon monitor was connected to the emanation box with a pumping air system in an open flow mode as a reference monitor. The emanation coefficient of the source was controlled online by comparing the gamma activity of 214Bi (Eγ=609.3keV), progeny of 226Ra, to that of the calibration source. A standard 137Cs source, installed within the emanation box, was used as a reference for gamma spectroscopy using the HPGe detector, with a total systematic error of 4% and a random error less than 2%. The ratio between gamma measurements and AlphaGUARD was 0.94±0.4; which is within the 9% uncertainties of AlphaGUARD calibration.