Search

The natural radioactive decay of uranium in rocks and soils gives rise to the presence of radon in groundwater. The existence of radon in groundwater at activity levels way higher than the reference limits set by US-EPA and WHO was widely covered in literature. The exposure to elevated levels of radon in ground and drinking water have been reported in literature to cause adverse health impacts. The aim of the present paper is to give an overview of radon gas in groundwater followed by the safe limits suggested by international organizations and agencies such as US-EPA and WHO. The paper also discusses the health effects associated with the exposure to radon levels and the estimation of the annual effective dose through ingestion and inhalation. This is followed by the radon levels around the world as well as the corresponding annual effective doses reported in literature. The determination techniques of radon levels in water covered in literature such as liquid scintillation counting, gamma-ray spectrometry and emanometry were also discussed and reviewed in the present work. Next, the paper sheds light on the most frequently used treatment techniques such as aeration, adsorption, filtration as well as biological techniques and evaluates their efficiency in mitigating radon levels in water. The paper also highlights the main precautions and future mitigation plans for radon in groundwater as well as delved onto future research perspectives of radon. It was found out that the type of rock played a key role in determining the radon levels. For instance, granitic rock types were reported to contribute to the elevation in the groundwater radon levels due to their characteristic permeability as a result of the formed fractures as well as their natural incorporation of high levels of uranium. Some of the reported radon levels in groundwater in literature were way higher than the guidelines set by the World Health Organization (WHO) for drinking water and US-EPA alternative higher maximum contaminant level. This review paper could be of importance to researchers working on the evaluation as well as the treatment of radon gas in water as it will provide a critical and state of the art review on radon gas in groundwater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The epidemiological approach to converting radon exposure to effective dose is examined. Based on the definition of the effective dose, the dose conversion is obtained from the equivalence of lung-specific detriment associated with low-LET radiation and with radon exposure. This approach most reliably estimates effective dose per radon exposure on the basis of epidemiological data and implicitly includes the radiation weighting factor required to calculate the effective dose from radon exposure using the dosimetric approach, applying biokinetic and dosimetric models. Consistency between the results of the epidemiological and dosimetric approaches is achieved by using a radiation weighting factor of about 10 for alpha particles instead of the current ICRP value of 20. In contrast, the epidemiological approach implemented in ICRP 65, and referred to as dose conversion convention, was based on direct comparison of total radiation detriment with lung detriment from radon exposure. With the revision of radiation detriments in ICRP 103, this approach can be judged to overestimate the effective dose per radon exposure by about a factor of two because the tissue weighting factor for lung differs from the value of relative detriment to which it relates., (© 2024. The Author(s).)

In Harghita and Covasna County (Romania) are many mofettes. The mofette is mainly CO 2 composed low temperature volcanic gas emanation. The mofettes can contain important quantities of radon. In these regions of Romania, the mofettes have long been used on curative purposes. We proposed monitoring the seasonal variation of radon activity concentration (RAC) in 10 frequented mofettes. Measurements in mofettes have shown radon concentrations ranging from a few hundred to several thousand becquerels per cubic meter (Bq/m³). The same trend can be observed for most mofettes. In the spring and summer months, the radon activity concentration values are higher than in the autumn and winter period. We found that a moderate negative relationship can be observed between the RAC and atmospheric pressure variations. From the average RAC values measured above the gas level in the indoor air of the mofettes, the annual effective dose received by the patients during a treatment session and by the mofette workers (if any) was calculated. The annual effective dose of inhaled radon received by patients during a treatment session does not exceed the annual dose limit for the population (1 mSv), but in mofettes with staff, the effective dose they receive can be significant, which already requires attention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Radon is known as the main source of radiation for the general public. Results of extensive measurements of radon in water samples collected from private wells, natural springs and public water supply in Croatia are presented and annual effective doses are estimated. Measurements were performed by two different methods: the emanometry method (by using the AlphaGUARD instrument with additional AquaKIT module) and/or the liquid scintillation method (by using LSC TriCarb 2900). Water samples were collected in public water supplies in urban areas as well as private wells and springs in rural areas. The obtained average radon activity concentration based on the extensive measurement of almost 1000 water samples is 4.1 ± 1.9 Bq/l, with a minimum value of 0.2 and maximum value of 36 Bq/l respectively. The wide range of measured values is a consequence of the source of the water sample (ground/natural water versus treated water) as well as the geological structures around the water source. All estimated ingestion doses due to radon assuming consumption of 2 l of water per day from the observed source were within the interval 6.3-36.8 μSv (with calculated average and standard deviation 19.3 ± 10.3 μSv) for the water consumption from private wells and natural springs and 2.4-40.0 μSv (with calculated average and standard deviation 13.0 ± 10.5 μSv) for the water consumption from the public water supplies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Naturally occurring radioactive gases which tend to build up (radon and thoron) in indoor environs can cause deleterious health effects including the development of lung cancer. The present study aims to measure 222 Rn and 220 Rn levels in dwellings in different seasons in the environs of Dakshina Kannada region of India. The 222 Rn and 220 Rn concentrations were measured in the monsoon, autumn, winter, and summer seasons using Solid State Nuclear Track Detector (SSNTD, LR-115 type II) films fixed in single-entry pinhole cylindrical twin-cup dosimeters. The higher 222 Rn levels in indoors were observed during winter with an average concentration of 38.8 Bq m -3 and lower during summer with an average of 14.1 Bq m -3 . The average indoor thoron concentration was also highest in winter with an average value of 25.5 Bq m -3 and lowest in summer with 8.8 Bq m -3 . The annual inhalation dose ranged from 0.44 to 1.06 mSv year -1 with a mean value of 0.66 mSv year -1 . The annual effective dose varied from 1.03 to 2.57 mSv year -1 with an average value of 1.59 mSv year -1 . The assessed values have been contrasted with the limit suggested by the UNSCEAR and the ICRP and were found to be within the permissible level. The normality of frequency distribution curves of 222 Rn and 220 Rn concentrations was assessed by the Kolmogorov-Smirnov test., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Elevated radon concentrations in drinking water pose an increased risk of cancer among nonsmokers. A Monte-Carlo Simulation was employed to assess the effective dose and cancer risk associated with radon exposure in humans, utilizing a systematic review and meta-analysis of related studies. These studies were sourced from databases including PubMed, Web of Science, Scopus, Science Direct, and Google Scholar, focusing on drinking water from Nigeria's six geopolitical zones. The random effects models revealed a 222 Rn concentration in drinking water of Nigeria at 25.01, with 95% confidence intervals (CI) of 7.62 and 82.09, indicating significant heterogeneity of (I 2 = 100%; p  < 0.001). The probabilistic risk of effective dose revealed a best-scenario (P 5%) at Kundiga and Magiro that exceeded the World Health Organization's (WHO) recommended effective dose limit of 200 µSv/y. Conversely, the worst-case scenario (P 95%) indicated concentrations surpassing the recommended limit at Kundiga, Edbe, Magiro, Ekiti, and Abeokuta. Excess Life Cancer Risk for infants, children, and adults attributed to the ingestion and inhalation of radon from various drinking water sources exceeded the recommended values of 0.2 x 10 -3 established by the International Commission on Radiological Protection (ICRP) and the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). It underscores the necessity for treating radon-polluted water, employing methos such as aeration and granular activated carbon (GAC) processes.

The present study aimed to determine the concentration of radon ( 222 Rn) levels of indoor air of spas and of spring water sites in the Turkish cities of Nigde and Aksaray, both located in Cappadocia, Anatolia, which is a well-known tourist area. In this area there are a lot of spring water and thermal water sites providing both drinking water and water for spas, which are used for therapeutic treatments of diseases and for health services. Therefore, it is necessary to quantify radon gas concentrations in the air of sites that use geothermal waters and spring water. Consequently, radon measurements were carried out using CR-39 detectors placed at different locations within each investigated thermal spa and spring water site. The results obtained indicate that, in the air of spring water at Helvadere, there is a high radon concentration. The average radon concentrations obtained for the air of Ciftehan and Ziga thermal spas were 12.5 ± 1.4 Bq/m 3 and 15.5 ± 2.1 Bq/m 3 , respectively, while in the air of Kemerhisar, Helvadere, and Okcu village spring water sites the average radon concentrations were 32 ± 4.2 Bq/m 3 , 265 ± 37.9 Bq/m 3 , and 35 ± 5.1 Bq/m 3 , respectively. The corresponding average effective doses were calculated both for patients and workers for Ciftehan and Ziga thermal spas, and for workers 0.09 and 0.11 mSv/year for Ciftehan and Ziga, respectively, were obtained. Doses for patients were 0.0007 and 0.0008 mSv/year for Ciftehan and Ziga, respectively. It is concluded that based on the measured radon concentrations and corresponding effective doses no radiation protection measures must be implemented., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this paper, we report the results of seasonal variations of indoor radon and thoron concentrations, equilibrium factors for gas progeny, and radiological risks to dwellers in the hilly area of Guwahati City, Assam, India. Twin-cup dosemeters with LR-115 (II) nuclear track detectors were used in this study. The findings show that values vary significantly, with winter having the highest values and summer having the lowest, with spring and autumn having moderate values. In winter, radon concentrations range from 61.6 ± 11.2 Bq m -3 (Mud) to 115.3 ± 34.3 Bq m -3 (AT), with geometric mean values of 69.2 ± 13.8 Bq m -3 and 109.4 ± 27.9 Bq m -3 , and in summer, they range from 21.1 ± 5.9 Bq m -3 (Mud) to 28.4 ± 8.3 Bq m -3 (AT), with geometric mean values of 22.7 ± 6.3 Bq m -3 and 26.1 ± 7.1 Bq m -3 , whereas thoron concentrations range from 13.1 ± 5.1 Bq m -3 (Mud) to 58.8 ± 12.6 Bq m -3 (AT), with geometric mean values of 27.6 ± 7.0 Bq m -3 and 52.9 ± 10.1 Bq m -3 in winter, respectively, and in summer, from 8.8 ± 2.3 Bq m -3 (Mud) to 13.0 ± 5.5 Bq m -3 (Mud), with a geometric mean value of 1.87 ± 1.29 Bq m -3 . Radon and thoron progeny levels are reported to vary from 4.1 ± 0.3 mWL (Mud) to 15.1 ± 4.3 mWL (AT) and 2.6 ± 0.9 mWL (Mud) to 14.3 ± 4.2 mWL (AT) in winter and from 1.5 ± 0.7 mWL (AT) to 3.0 ± 2.5 mWL (Mud) and 0.9 ± 0.3 mWL (AT) to 2.7 ± 0.5 mWL (Mud) in summer, respectively. The equilibrium factors for radon and its progeny have been reported to range from 0.23 ± 0.1 (Mud) to 0.51 ± 0.3 (AT) in winter, whereas from 0.23 ± 0.1 (AT) to 0.48 ± 0.4 (Mud) in summer, respectively. The equilibrium factors for thoron and its progeny have been estimated in the range of 0.02 ± 0.01 (Mud) to 0.09 ± 0.06 (AT) in winter, whereas 0.02 ± 0.02 (AT) to 0.07 ± 0.05 (Mud) in summer, respectively. The inhalation dose rates differed from house to house, having values in the range of 1.2 ± 0.2 mSv year -1 (Mud) to 4.6 ± 1.3 mSv year -1 (AT) in winter, whereas 0.5 ± 0.3 mSv year -1 (AT) to 0.9 ± 0.5 mSv year -1 (Mud) in summer, respectively. The effective doses (EDs) due to the exposure of radon and thoron in the study area have been found to range from 2.5 ± 0.3 mSv (Mud) to 9.1 ± 2.7 mSv (AT) in winter and 0.9 ± 0.4 mSv (AT) to 1.8 ± 1.3 mSv (Mud) in summer, respectively. The levels of radon and thoron in similar types of construction were found to be significantly different from one house to another. The estimated radon and thoron concentrations in the houses of that region during winter are found to be substantially higher than the global averages as reported by UNSCEAR., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

After smoking, indoor radon is the main contributor to lung cancer in many countries. The European Union (EU) Directive 2013/59/Euratom establishes a maximum reference level of 300 Bq/m 3 of radon concentration in the workplace, and an effective dose limit of 20 mSv per year for workers. If the radon concentration in a workplace exceeds the reference level, constructive mitigation applies. When constructive mitigation is not feasible, we propose to keep workers' effective dose below 6 mSv per year (category B of exposed workers) by controlling occupancy time. Setting the maximum annual dose at 6 mSv protects workers' health and eases the regulatory requirements for employers. If multisite workers are present, each worker has to be monitored individually by tracking the time spent and the radon concentration at each worksite. This paper shows a software tool for employers to perform this complex tracking in an accurate, conservative, and transparent manner, and in compliance with the EU by-laws.

Soil gas radon and indoor radon measurements have been carried out in Mayo-Louti and Benoué Divisions in northern Cameroon. Concentrations of radon in soil have been measured using Markus 10 at the depth of about 1 m. Radon concentration in soil varies from 0.9 to 13.8 kBq m -3 with a mean value of 4.6 kBq m -3 . Average daily indoor radon concentrations measured with RadonEye+ 2 detectors vary from 7 to 60 Bq m -3 with an average of 17 Bq m -3 . Indoor radon concentrations measured with passive RADTRAK detectors range between 15 and 104 Bq m -3 with a geometric value of 38 Bq m -3 and a geometric standard deviation of 1.5. This geometric value is lower than the value of 30 Bq m -3 given by UNSCEAR. Indoor radon inhalation dose ranges between 0.28 and 1.97 mSv a -1 with geometric value of 0.72 mSv a -1 (at 0.03 standard deviation). Outdoor radon inhalation ranges between 0.02 and 0.26 mSv a -1 with a mean value of 0.09 mSv a -1 . The total annual effective dose due to indoor and outdoor radon exposure for this study area is 0.81 mSv a -1 , less than 1.15 mSv a -1 the world average value given by UNSCEAR. There is no significant radiological risk for the inhabitants.

This work is a follow-up study on the exposure to indoor radon levels in Portuguese thermal spas. The previous research involved 16 thermal spas, where radon measurements in air and thermal mineral water were performed twice a year, from 2012 to 2016. These studies revealed concerning radon concentrations both in air and water. Therefore, a follow-up study on long-term radon measurements was conducted to estimate the year-round average radon exposure. The closer the long-term measurement is to 365 days, the more representative it will be of annual average radon levels. Continuous measurements over 1 year for the indoor radon levels are now presented for three of the 16 previously studied thermal spas, together with a time-series analysis of the gamma dose rates registered within the facilities of these thermal spas (TS). An attempt to identify possible patterns in the variation of gamma dose rates was made. Hourly gamma dose rates were modelled and forecasted using the Box-Jenkins seasonal time series models (SARIMA). The results showed that between December 2018 and November 2019, the indoor radon concentration varied from 202 to 1941 Bq/m 3 (TS1), from 52 to 191 Bq/m 3 (TS2), and from 937 to 1750 Bq/m 3 (TS3). Approximately 60% of the obtained values for radon concentration in the indoor air exceed the reference level of 300 Bq/m 3 . Gamma dose rates were continuously measured with GAMMA SCOUT® detectors for hourly readings (µSv/h) between 83 and 229 days. On average, the results are similar in all considered locations and range between 0.169 and 0.264 µSv/h, although variations are different in winter and summer. The calculated effective doses ranged between 3.49 and 18.65 mSv/year (TS1), between 1.37 and 2.53 mSv/year (TS2), and between 13.89 and 22.97 mSv/year (TS3). For occupational exposure purposes, workers would be classified as category A in nine locations (out of 20), as the exposure is liable to exceed an effective dose of 6 mSv/year. For the time-series analysis, the obtained models captured the dynamics of the time series data and produced short-term forecasts. Their accuracies have been quantified by minimizing the root mean square error, the mean absolute error due to the actual forecast, and the mean absolute scaled error. The current results corroborate the conclusions of previous research and give continuous data on occupational exposure to radon for three Portuguese thermal spas. For TS1 and TS3, the indoor radon levels are much higher than the reference level. Under this circumstance, mitigation measures must be implemented to reduce the radon levels accordingly with the Euratom Directive 2013/59 and the Decree-Law No. 108/2018. In general, the gamma dose rates were below 1 μSv/h and, therefore, the contribution to the annual effective dose is not significant. Nevertheless, the variation of the gamma dose rates showed a coherent behavior with the radon progeny build up in closed spaces, as when the considered facilities were closed for certain periods. The time series analysis made it possible to fit some models to the gamma dose rate variation, and although the produced models cannot forecast exact gamma dose rates, they can provide valuable information to build sound planning and decision-making strategies in occupational exposure., (© 2022. The Author(s).)

The concentrations of radon, thoron and terrestrial gamma radiation were measured to evaluate the outdoor effective dose. The outdoor radon activity concentration ranged from 5.79 to 5110 ± 46.36 Bq m -3 , with a mean of 320.03 Bq m -3 which is higher than the EPA level of 14.8 Bq m -3 . The range of the thoron activity concentration outdoor was from 0.00 to 4226.7 ± 58.5 Bq m -3 , with a mean of 226.1 Bq m -3 which was above the UNSCEAR recommended level of 10 Bq m -3 . The terrestrial gamma radiation dose rates range was from 98.31 to 3769.71 nGy h -1 with a mean of 446.27 nGy h -1 . The effective dose contribution from radon exposures in the study was estimated to be 3.2 ± 0.5 mSv y -1 is about 84% total annual effective dose received by the population in those areas. The estimated thoron and gamma dose contributions (15%, and 1% respectively) were not significant. The outdoor doses for thoron and gamma were lower than the ICRP (2007) value of 1 mSv. The total annual outdoor effective dose with an occupancy factor of 1825 h (5 h day -1 ) was estimated to be within the range of 0.30-551.41 ± 0.65 mSv, with a mean of 3.75 mSv which is a little higher than the world average of 2.4 mSv., (Copyright © 2021. Published by Elsevier Ltd.)

This paper provides a new approach that simplifies the monitoring of 214 Pb activity concentration on aerosols in the atmospheric surface layer. The approach allows obtaining data on 214 Pb activity concentration with the discreteness of 2 h. The experimental setup described in the paper made it possible to achieve a minimum detectable activity level of 0.4 Bq m -3 . Using this approach, the data on the diurnal variability of 214 Pb activity concentration in the atmosphere of Sevastopol city for a period of 18 months were obtained. The 214 Pb activity concentration varied from < 0.4 (less than 1% of the data series) to 8.9 Bq m -3 , mean value 2.0 ± 1.0 Bq m -3 . The analysis of the temporal variability of 214 Pb activity concentration on different time scales (diurnal, seasonal) was carried out. Annually averaged diurnal variation curve of 214 Pb activity concentration showed a peak at 6:00 local time and a minimum at 18:00. The maximum variability in the seasonal averaged diurnal cycle of 214 Pb activity concentration is observed in summer (± 30% of the daily average value) and the minimum in winter (± 13%). The maximum seasonal average value of 214 Pb activity concentration is observed in winter (2.5 Bq m -3 ) and the minimum in summer (1.4 Bq m -3 ). A quantitative estimate of the annual effective dose due to exposure to outdoor radon was obtained by using 214 Pb data, and it was 0.03 mSv a -1 ., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Introduction: New and renovated energy efficient buildings with minimised ventilation rates together with increased building airtightness are often associated with higher indoor radon concentrations compared to the concentrations in existing buildings. The purpose of our study is to analyse the problem associated with the increased radon concentration and ventilation requirements and recommendations in schools. The radon concentration was critically assessed by varying the design ventilation rates (DVRs) within fifteen cases according to legislative requirements and recommendations. The case study is a branch primary school in western part of Slovenia situated in a radon prone area., Methods: Radon ( 222 Rn) concentrations were simulated in the classroom, using CONTAM 3.2., Program: For validation, measurements were performed on 8 measuring days in September and 6 measuring days in March. The simulated and measured 222 Rn concentrations are well correlated for all measurement days, with the simulated/measured ratio of 0.85-1.39. In order to define optimal DVRs in terms of dosimetry, the effective dose and its ratio to the worldwide average effective dose at workplace, received by radon progeny in 950 h (expected effective dose, 0.13 mSv/y), were calculated for each case., Results: Simulations showed that the highest radon concentrations were observed in case 1 with a DVR of 79.6 m 3 /h (621 Bq/m 3 ) and case 4 with a DVR of 69.4 m 3 /h (711 Bq/m 3 ), both defined by national regulations. The calculated values in both cases exceeded the national reference value for radon (300 Bq/m 3 ) by 2.1 times and 2.4 times, and the WHO guideline value (100 Bq/m 3 ) by 6.2 times and 7.1 times, respectively. The simulations are in line with the results of radon dosimetry. Both DVRs correspond to the highest effective doses, 1.88 mSv/y (about 14-fold higher than expected effective dose) for case 1 and 2.15 mSv/y (about 17-fold higher than expected effective dose) for case 4. Case 11&#95;Cat I with a DVR of 1999.7 m 3 /h defined by EN 15251: 2007 resulted in minimal Rn concentration (35 Bq/m 3 ) and corresponds to the lowest effective dose 0.11 mSv/y and its ratio to the expected effective dose 0.8., Conclusions: Ventilation is an immediate measure to reduce radon concentration in a classroom and it must be performed in line with other holistic measures to prevent and control radon as a health risk factor., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

In the present study, 222 Rn activity concentrations in a newly formed underground tourist route under Książ castle, Poland, were investigated for periods undisturbed and disturbed by construction works. This preliminary assessment is based on the almost 3-year long continuous measurements (28 Oct. 2016-02 Jul. 2019) done with an SRDN-3 instrument. In detail described are radon concentrations for periods of renovation (11 Aug. 2018-10 Oct. 2018), opening (15 Oct. 2018-10 Apr. 2019) and operation and monitoring (11 Apr. 2019-02 Jul. 2019) of the facility. It was observed that after the termination of construction work, when natural ventilation returned to the state preceding this work, the absolute values of radon activity concentration decreased. The mean annual radon concentrations were higher than the reference level of radon concentration in underground spaces recommended by IAEA, ICRP, and by the EU Council Directive for workplaces. They reached 1179 Bq/m 3 and 943 Bq/m 3 in 2017 and 2018, respectively. Cyclically recurring daily changes in radon concentrations occurred only in April and October (so-called transitional periods) and only outside the period of construction work. The results confirmed; however, that these changes need not be considered when planning the work in the tunnel. The minimum effective dose rate from radon exposure occurs in colder periods of the year, from November to the end of March, where the mean effective dose rate value was found to be 0.0003 mSv/h. In contrast, the maximum dose rate of 0.014 mSv/h was observed from April to August.

Poorly ventilated environments such as residences can accumulate radon gas to levels that are harmful to humans and thus produce a public health risk. To assess the risk from natural radiation due to indoor radon exposure, 222 Rn measurements, using an alpha RAD7 detector, were conducted in Timóteo, Minas Gerais state, southeastern Brazil. Indoor radon concentrations, along with meteorological parameters, were measured every 2 h during both wet and dry seasons in 2017 and 2018. The mean concentration of indoor radon varied between 18.0 and 412.8 Bq m -3 , which corresponded to an effective annual dose of 1.2 and 7.6 mSv y -1 . Average radon concentrations were significantly higher during the winter dry season, and there was a strong positive correlation with humidity in both wet and dry season. Furthermore, concentrations showed an inverse correlation with atmospheric pressure, wind speed, air temperature, and solar radiation. The radon levels are generally above the limits recommended by international standards, meaning that mitigation measures are needed to improve air quality to reduce human exposure and risk. Finally, through the statistical analysis, it was possible to determine the differences and similarities between the sampling points concerning the geology of the place and the geographical location.

Radon (Rn), thoron (Tn), and thoron progeny (TnP) were measured in seven inhabited areas of the uranium and thorium bearing region of Lolodorf, located in southwestern Cameroon. Then the equilibrium factor (F Tn ) between thoron and its progeny was determined in order to show the importance of direct progeny measurements for correct estimation of effective dose due to radon, thoron and their progenies. A total of 220 RADUET detectors were used to measure indoor radon and thoron and 130 TnP monitors for thoron progeny indoors. The arithmetic and geometric mean concentrations of Rn, Tn, and TnP were 103 and 89 Bq m -3 , 173, and 118 Bq m -3 , 10.7, and 7.4 Bq m -3 , respectively. Total effective dose determined from radon, thoron, and their progenies was estimated at 4.2 ± 0.5 mSv y -1 . Thoron equilibrium factor varied according to seasons, the type of dwelling, building materials and localities. Thoron (Tn and TnP) contribution to effective dose ranged between 3 and 80% with the average value of 53%. Total effective dose estimated from the world average equilibrium factor of 0.02 given by UNSCEAR was 2.7 ± 0.2 mSv y -1 . The effective dose due to thoron varied greatly according to the different values taken by F Tn and was different from that determined directly using TnP concentrations. Thus, effective dose due to thoron determined from the equilibrium factor is unreliable. Therefore, the risk of public exposure due to thoron (Tn and TnP) may therefore be higher than that of radon (Rn and RnP) in many parts of the world if F Tn is no longer used in estimating total effective dose. This is not in contradiction with the UNSCEAR conclusions. It is therefore important to directly measure the radon and thoron progeny for a correct estimate of effective dose., (Copyright © 2020 Bineng, Saïdou, Tokonami, Hosoda, Tchuente Siaka, Issa, Suzuki, Kudo and Bouba.)

This work consists of the detection and quantification of the concentration levels of radioactive gas radon-222 (222Rn) of natural origin, as well as the determination of the critical points and the estimation of the effective dose absorbed by the tourists and guides inside the Jumandy cavern in Napo, Ecuador. According to the feasibility map of uranium of Ecuador, the study area is located in one of the top-priority areas for obtaining uranium, suggesting possible radioactivity in this unstudied region. The measurements were carried out from July to October of 2017, in three different monitoring points inside the cavern. The average radon concentrations measured in the cavern exceeded the maximum recommended environmental level by a factor of 28, and the effective dose absorbed by the guides exceeded the recommended maximum by a f actor of 10. Meteorological parameters such as temperature and relative humidity have an impact on the 222Rn concentrations in different parts of the cave., (© The Author(s) 2019. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.)

A continuous passive measurement of indoor and outdoor radon R222n, concentration is carried out in the nearby residential areas surrounding a high capacity gas-fired power station. The mean value for indoor measurements was 26.5 ± 1.75 Bq/m 3 that is below the worldwide indoor mean of 40 Bq/m 3 and for outdoor was 39.4 ± 4.04 Bq/m 3 which is higher than the worldwide average outdoor radon concentration of 10 Bq/m 3 . The annual estimated effective doses were found to vary from 0.54 to 1.05 mSv/y with an average value of 0.67 ± 0.04 mSv/y for indoor dose and from 0.23 to 0.57 mSv/y with an average value of 0.37 ± 0.03 mSv/y for outdoor dose with an overall mean annual effective dose of 1.03 mSv/y. Furthermore, the measured and modeled radon excess levels due to plant operation, both, show that the effect of power plant emission on atmospheric radon levels in the surrounding region is not significant., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The practical implementation of the International Commission on Radiological Protection's (ICRP) system of radiological protection requires the availability of appropriate methodology and data. Over many years, ICRP Committee 2 has provided sets of dose coefficients to allow users to evaluate equivalent and effective doses for radiation exposures of workers and members of the public. The methodology being applied in the calculation of doses is state-of-the-art in terms of the biokinetic models used to describe the behaviour of inhaled and ingested radionuclides, and the dosimetric models used to model radiation transport for external and internal exposures. This overview provides an outline of recent work and future plans, including publications on dose coefficients for adults, children, and in-utero exposures, with new dosimetric phantoms in each case. For the first time, ICRP will publish dose coefficients for intakes of radon isotopes calculated using dosimetric models. Committee 2 is also working with Committee 3 on dose coefficients for radiopharmaceuticals, and leading a cross-committee initiative to provide advice on the use of effective dose. The remit of Committee 2 has now been widened to include all data requirements for the assessment of doses to humans and non-human biota.

In this study, indoor and outdoor radon ( 222 Rn) surveys were carried out in the summer and winter seasons in homes of one hundred lung cancer patients in the year 2013-2014. The aim was to investigate the relationship between radon and cancer patients. Lung cancer patients completed a questionnaire concerning their living environment, various physical parameters and living habits. Pearson correlation and t tests revealed no meaningful results between radon concentrations, on one hand, and environmental and personal living habits, on the other hand. Consequently, the BEIR VI model was adapted and 222 Rn exposure was estimated to be responsible for about 12% of the lung cancer incidences in the winter season and around 5% in the summer season in the Rize Province. However, due to the limited number of data and numerous parameters that could lead to lung cancer, the estimations done with the model should be taken very lightly. The annual effective doses due to inhalation of indoor and outdoor 222 Rn were estimated to be, respectively, 1.43 and 0.94 mSv y -1 . The indoor and outdoor annual effective doses were, respectively, close and below the world annual effective dose (1.3 mSv y -1 ). At the district level, the indoor annual effective dose equivalent in the İyidere district was 4.52 mSv y -1 , which was 3.5 times greater than the world average. The number of patients in the majority of the houses in this district was more than one.

The current study was performed to review the conducted studies regarding the concentration of radon 222 in the tap drinking water; furthermore, by estimation of ingestion and inhalation effective dose, the health risk assessment in the adults and children using MCS technique was assessed. All related studies published among January 1990 to October 2016; were screened in the available databases such as Web of Science, PubMed, Science Direct, Scopus, SID, and Irandoc. The total effective dose was estimated by calculating E ing (Effective dose of ingestion) and E inh (Effective dose of inhalation) by Monte Carlo simulation (MCS) method. The range of ND ─ 40.9 Bq/L for radon 222 in water resources was proposed after evaluation of data collected from 13 studies with 1079 samples. The overall concentration of radon 222 in drinking water in Iran was 3.98: 95%CI (3.79 ─ 4.17 Bq/L). Also, the effective ingestion dose of radon 222 in adults age groups was 1.35 times higher than children. The rank order of drinking water resources based on the concentration of radon 222 was Spring > Spring and Well > Well > Spring and Qanat > Tap water. The overall concentration of radon 222 in drinking water in Iran was lower than WHO and EPA standard limits. Also, the rank order regarding area studied based on the concentration of radon 222 was Gillan > Mashhad > Mazandaran > Kerman > Yazd > Tehran > Kermanshah > Golestan > Hormozgan. The effective ingestion dose of radon 222 to consumers in the Gillan, Mashhad, Mazandaran, and Kerman were higher than WHO guidance (0.1 mSv/y). Also except consumers in the Hormozgan, inhalation effective dose radon 222, in the other investigated areas were higher than WHO guidance (0.1 mSv/y). Therefore, it is recommended to conduct the required programs regarding control and elimination of radon 222 concentration in Iranian drinking water supply., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: determining the integral value of annual effective dose from 222Rn for workers of the granite mining industry and assessment for the expected life effective dose from 222Rn., Materials: Materials were the results of measurements of external exposure dose of radiation measurements equiv alent equilibrium volume activity of 222Rn in workrooms and workplaces of major groups of granite quarry workers Mykolaiv region, studies EROA 222Rn air premises of these workers, research content 222Rn in drinking water., Results and Conclusions: Granite quarry workers receive double radiation exposure of 222Rn due to exposure in the workplace and at home. The load in the workplace due to inhalation of 222Rn the air was (2.1 ± 0.2) mSv / year (vari ation 0.9-5.9) in a residential area - (4,1 ± 0,2) mSv/year (variation 1.8-5.9). The total annual effective dose from internal exposure from air flow and working premises and drinking water was on average (6,5 ± 0,2) mSv/year, equal to a maximum value of 20 mSv/year. The expected life for the chronic exposure dose of technological naturally occurring radioactive sources for people who work in the granite quarries and, while living in high risk from radon is in the range of 0.16-1.12 Sv. The research results indicate that in assessing the effects associated with exposure due to radon 222 contingents persons such surveys must take into account all sources of this radionuclide dose., (L. Сrygorieva, Yu. Tomilin.)

The risks and dose conversion coefficients for residential and occupational exposures due to radon were determined with applying the epidemiological risk models to ICRP representative populations. The dose conversion coefficient for residential radon was estimated with a value of 1.6 mSv year -1 per 100 Bq m -3 (3.6 mSv per WLM), which is significantly lower than the corresponding value derived from the biokinetic and dosimetric models. The dose conversion coefficient for occupational exposures with applying the risk models for miners was estimated with a value of 14 mSv per WLM, which is in good accordance with the results of the dosimetric models. To resolve the discrepancy regarding residential radon, the ICRP approaches for the determination of risks and doses were reviewed. It could be shown that ICRP overestimates the risk for lung cancer caused by residential radon. This can be attributed to a wrong population weighting of the radon-induced risks in its epidemiological approach. With the approach in this work, the average risks for lung cancer were determined, taking into account the age-specific risk contributions of all individuals in the population. As a result, a lower risk coefficient for residential radon was obtained. The results from the ICRP biokinetic and dosimetric models for both, the occupationally exposed working age population and the whole population exposed to residential radon, can be brought in better accordance with the corresponding results of the epidemiological approach, if the respective relative radiation detriments and a radiation-weighting factor for alpha particles of about ten are used.

This paper presents indoor radon concentrations and specific activities of natural radionuclides measured in soils of Kosovo and Metohija. The measurements of radon concentration were performed during two consecutive 6-month periods in two rooms of 63 houses using CR-39 detectors. The annual radon concentration ranged from 30 to 810 Bq m -3 with the average value of 128 Bq m -3 . Almost 15% of the houses had radon concentration higher than 200 Bq m -3 . The difference between radon concentrations measured in the two 6-month periods was analyzed, showing, as expected, a slightly higher radon concentration in the "winter period" than in the "summer period". The variation between different rooms of the same houses was also analyzed, showing that 20% of the dwellings had a significantly higher radon concentration (>100 Bq m -3 ) in one room compared to the other (the coefficient of variation ranged up to 96%). The specific activities of natural radionuclides in the nearby soil were determined by gamma spectrometry. The estimated average value (and standard deviation) of 226 Ra, 232 Th, and 40 K specific activities were 32 (13), 35 (16), and 582 (159) Bq kg -1 , respectively. The correlation between indoor 222 Rn and 226 Ra content in soil was investigated. Only a weak correlation was found (Spearman's rho = 0.220) indicating that other factors might affect diffusion and accumulation of radon indoors, as confirmed also by the high variability between the rooms of the same houses.

Objectives: Radon concentrations for 31 Polish underground tourist routes were analyzed. The equivalent dose to the lung, the effective dose and the relative risk were calculated for employees of the analyzed routes on the grounds of information on radon concentrations, work time, etc., Material and Methods: The relative risk for lung cancers was calculated using the Biological Effects of Ionizing Radiation (BEIR) VI Committee model. Equivalent doses to the lungs of workers were determined using the coefficients calculated by the Kendall and Smith. The conversion coefficient proposed by the International Atomic Energy Agency (IAEA) in the report No. 33 was used for estimating the effective doses., Results: In 13 routes, the effective dose was found to be above 1 mSv/year, and in 3 routes, it exceeded 6 mSv/year. For 5 routes, the equivalent dose to lungs was higher than 100 mSv/year, and in 1 case it was as high as 490 mSv/year. In 22.6% of underground workplaces the risk of developing lung cancer among employees was about 2 times higher than that for the general population, and for 1 tourist route it was about 5 times higher. The geometric mean of the relative risk of lung cancer for all workers of underground tourist routes was 1.73 (95% confidence interval (CI): 1.6-1.87). Routes were divided into: caves, mines, post-military underground constructions and urban underground constructions., Conclusions: The difference between levels of the relative risk of developing lung cancer for all types of underground tourist routes was not found to be significant. If we include the professional group of the employees of underground tourist routes into the group of occupational exposure, the number of persons who are included in the Category A due to occupational exposure may increase by about 3/4. The professional group of the employees of underground tourist routes should be monitored for their exposure to radon. Int J Occup Med Environ Health 2017;30(5):687-694., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm -3 . This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices - including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) - were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm -3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The general public spends a major portion of their time in an indoor environment and hence receives a considerable amount of radiation. Knowledge about indoor radiation is important in order to arrive at the actual effective dose received by residents. The indoor radon, thoron, and progeny concentrations observed in the present study were found to vary with seasons of a given year. The highest and lowest indoor average radon, thoron, and progeny levels were observed during winter and summer seasons, respectively. The concentrations of indoor radon, thoron, and progenies were found to vary with the type of houses. The highest 222 Rn, 220 Rn, and progeny concentrations were observed in mud houses and the lowest values were recorded in wooden houses. The indoor 222 Rn concentration correlated well with concentration of its grandparent 238 U in underlying soil with a correlation coefficient of 0.87. The correlation between indoor 220 Rn and 232 Th in the underlying soil was found to be 0.64. The estimated effective doses received by the general public in the present study due to indoor radon and thoron were 1.49 ± 0.49 and 1.30 ± 0.53 mSv/year, respectively. The annual effective doses due to radon and thoron progenies were estimated as 0.76 ± 0.27 and 0.47 ± 0.23 mSv/year, respectively. The contributions from 222 Rn, 220 Rn, and corresponding progenies to the annual effective doses received were 37, 32, 19, and 12%, respectively. The general public living in the study area receives an inhalation dose of 4.02 mSv/year due to indoor radon, thoron, and progenies, which were found to be less than the action limit of ICRP 2009.

A survey was conducted to measure natural radioactivity in spa waters from the Kłodzko Valley. The main goal of this study was to determine the activity concentration of uranium, radium and radon isotopes in the investigated groundwaters. Samples were collected several times from 35 water intakes from 5 spas and 2 mineral water bottling plants. The authors examined whether the increased gamma radiation background, as well as the elevated values of radium and uranium content in reservoir rocks, have a significant impact on the natural radioactivity of these waters. The second objective of this research was to provide information about geochemistry of U, Ra, Rn radionuclides and the radiological and chemical risks incurred by ingestion of isotopes with drinking water. On the basis of results obtained, it is feasible to assess the health hazard posed by ingestion of natural radioactivity with drinking waters. Moreover, the data yielded by this research may be helpful in the process of verification of the application of these waters in balneotherapy. In addition, annual effective radiation doses resulting from the isotopes consumption were calculated on the basis of the evaluated activity concentrations. In dose assessment for uranium and radium isotopes, the authors provided values for different human age groups. The obtained uranium content in the investigated waters was compared with the currently valid regulations concerning the quality of drinking water. Based on the activity concentrations data, the activity isotopic ratios (234)U/(238)U, (226)Ra/(238)U, (222)Rn/(238)U, (222)Rn/(226)Ra and the correlations between radionuclides content were then examined. In brief, it may be concluded on the basis of the obtained results that radon solubility is inversely proportional to radium and uranium dissolution in environmental water circulation. The presented study allows conclusions to be drawn on the radionuclide circulation among different environmental biota: from lithosphere through hydrosphere to biosphere., (Copyright © 2016 Elsevier B.V. All rights reserved.)

At Vila Pouca de Aguiar area, northern Portugal, crops out a post-tectonic Variscan granite pluton, related with the Régua-Vila Real-Verín fault zone, comprising three types of biotite granites. Among these granites, PSG granite yield the highest average contents of U, probably due to its enrichment in accessory U-bearing minerals such as zircon. In the proximity of faults and joints, these granites are often affected by different degrees of hydrothermal alteration, forming reddish altered rocks, commonly known as "episyenites". These altered rocks are probably associated to the occurrence of hydrothermal processes, which led to uranium enrichment in the most advanced stages of episyenitization. In these granites, both average gamma absorbed dose rates in outdoor and indoor air are higher than those of the world average. Furthermore, even in the worst usage scenario, all these granites can be used as a building material, since their annual effective doses are similar to the limit defined by the European Commission. The geometric mean of radon activity of 91 dwellings located at the Vila Pouca de Aguiar pluton is 568Bqm(-3), exceeding that of other northern Portuguese granites. Measurements carried out during a winter season, indicate that 62.6% of the analysed dwellings yield higher indoor radon average values than the Portuguese legislation limit (400Bqm(-3)), and annual effective doses due higher than the world's average value (1.2mSvy(-1)). The interaction of geogenic, architectural and anthropogenic features is crucial to explain the variance in the geometric mean of radon activity of dwellings from Vila Pouca de Aguiar pluton, but the role of geologic faults is probably the most important decisive factor to increase the indoor radon concentration in dwellings. Hence, the development of awareness campaigns in order to inform population about the incurred radiological risks to radon exposure are highly recommended for this specific area., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In this study, measurements of indoor radon ((222)Rn), thoron ((220)Rn) and their equilibrium equivalent concentration (EEC) were carried out in 96 dwellings from 22 different villages situated in Hamirpur district, Himachal Pradesh, India, by using LR-115 type II-based pinhole twin cup dosimeters and deposition-based progeny sensors (DRPS/DTPS). The annual average indoor (222)Rn and (220)Rn concentrations observed in these dwellings were 63.82 and 89.59 Bq/m(3), respectively, while the average EEC (attached + unattached) for (222)Rn and (220)Rn was 29.28 and 2.74 Bq/m(3). For (222)Rn (f Rn) and (220)Rn (f Tn), the average values of unattached fraction were 0.11 and 0.09, respectively. The equilibrium factors for radon (F Rn) and thoron (F Tn) varied from 0.12 to 0.77 with an average of 0.50, and from 0.01 to 0.34 with an average of 0.05, respectively. The annual inhalation dose due to mouth and nasal breathing was calculated using dose conversion factors and unattached fractions. The indoor annual effective doses for (222)Rn (AEDR) and (220)Rn (AEDT) were found to be 1.92 and 0.83 mSv a(-1), respectively. The values of (222)Rn/(220)Rn concentrations and annual effective doses obtained in the present study are within the safe limits as recommended by the International Commission on Radiological Protection for indoor dwelling exposure conditions.

Radon is a radioactive gas, abundant in granitic areas, such as in the city of Porto at the north-east of Portugal. This gas is a recognized carcinogenic agent, being appointed by the World Health Organization as the leading cause of lung cancer after smoking. The aim of this preliminary survey was to determine indoor radon concentrations in public primary schools, to analyse the main factors influencing their indoor concentration levels and to estimate the effective dose in students and teachers in primary schools. Radon concentrations were measured in 45 classrooms from 13 public primary schools located in Porto, using CR-39 passive radon detectors for about 2-month period. In all schools, radon concentrations ranged from 56 to 889 Bq/m(3) (mean = 197 Bq/m(3)). The results showed that the limit of 100 Bq/m(3) established by WHO IAQ guidelines was exceeded in 92 % of the measurements, as well as 8 % of the measurements exceeded the limit of 400 Bq/m(3) established by the national legislation. Moreover, the mean annual effective dose was calculated as 1.25 mSv/y (ranging between 0.58 and 3.07 mSv/y), which is below the action level (3-10 mSv). The considerable variability of radon concentration observed between and within floors indicates a need to monitor concentrations in several rooms for each floor. A single radon detector for each room can be used, provided that the measurement error is considerably lower than variability of radon concentration between rooms. The results of the present survey will provide useful baseline data for adopting safety measures and dealing effectively with radiation emergencies. In particular, radon remediation techniques should be used in buildings located in the highest radon risk areas of Portugal. The results obtained in the current study concerning radon levels and their variations will be useful to optimize the design of future research surveys.

Indoor radon concentrations were measured in dwellings of the Puglia region in Southern Italy using LR-115 passive detectors. The results show that the radon concentrations varied from 15 ± 2 to 2166 ± 133 Bq/m³ with a geometric mean of 114 Bq/m³ and a geometric standard deviation of 2.3. An analysis on the factors affecting radon concentration such as age of the dwellings, floors, and stories, was performed. The mean effective dose to inhabitants has been calculated and found to be 8.2 mSv/y. Finally, for estimation of cancer risks, the lifetime risk and lung cancer cases per years per million have been calculated.

The surveys of radon concentrations in the Underground Tourist Route "Coal Mine" were carried out using passive and active measurement techniques. Passive methods with application of Solid State Nuclear Track Detectors LR115 were used at 4 points in years 2004-2007 and at 21 points in year 2011. These detectors were exchanged at the beginning of every season in order to get information about seasonal and spatial changes of radon concentrations. The average radon concentration noted in this facility was 799 Bq m(-3) and is consistent with radon concentrations noted in Polish coal mines. Seasonal variations, observed in this underground tourist route, were as follows: the highest radon concentrations were noted during summers, the lowest during winters, during springs and autumns intermediate but higher in spring than in autumn. The main external factor that affected seasonal changes of radon concentrations was the seasonal variation of outside temperature. No correlation between seasonal variations of radon concentrations and seasonal average atmospheric pressures was found. Spatial variations of radon concentrations corresponded with air movements inside the Underground Tourist Route "Coal Mine". The most vivid air movements were noted along the main tunnel in adit and at the place located near no blinded (in the upper part) shaft. Daily variations of radon concentrations were recorded in May 2012 using RadStar RS-230 as the active measurement technique. Typical daily variations of radon concentrations followed the pattern that the highest radon concentrations were recorded from 8-9 a.m. to 7-8 p.m. and the lowest during nights. The main factor responsible for hourly variations of radon concentrations was the daily variation of outside temperatures. No correlations were found between radon concentration and other meteorological parameters such as atmospheric pressure, wind velocity or precipitation. Additionally, the influence of human factor on radon concentrations was noticed. As human factor, we consider open entrance door during restorations works carried out inside the underground facility. Comprehensive surveys of radon concentrations in the Underground Tourist Route "Coal Mine", which included hourly, seasonal and spatial measurements, have revealed that radon can be the excellent tracer of air movements inside the underground facilities that are not equipped with mechanical ventilation system. The main external factor that affects hourly, seasonal and even spatial changes of radon concentrations inside Underground Tourist Route "Coal Mine" is the variation of outside temperature. The maximum effective dose received by employees during 2000 working hours in a year was 5.8 mSv y(-1) and the minimum was 3.5 mSv y(-1). Tourist guides, who usually spend underground about 1000 h y(-1), received effective dose from 1.7 mSv y(-1) to 2.3 mSv y(-1). According to Polish Law, employees, receiving effective dose for occupational exposure higher than 1 mSv y(-1) but below 6 mSv y(-1), are allocated to category B of workers and the level of radiation in their place of work should be controlled and continuously monitored. The radiation monitoring system in the Underground Tourist Route "Coal Mine" does not exist. None of Polish tourist routes or caves has installed radiation monitoring system although effective doses received by employees, in some of them, exceed values defined by law. Effective dose received by tourist during one trip was lower than 0.001 mSv y(-1) and risk of cancer induction was lower than 0.00001%. The probability, that tourists inside the Underground Tourist Route "Coal Mine" receive effective dose exceeding allowable annual limit for members of the public of 1 mSv y(-1) does not exist. The Underground Tourist Route Coal Mine is a safe place for tourists from radiological point of view., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Castañar cave contains the highest radon gas ((222)Rn) concentration in Spain with an annual average of 31.9 kBq m(-)(3). Seasonal variations with summer minimums and maximum values in fall were recorded. The reduction of air-filled porosity of soil and rock by condensation or rainfalls hides the radon exchange by gas diffusion, determining this seasonal stair-step pattern of the radon activity concentration in underground air. The effective total dose and the maximum hours permitted have been evaluated for the guides and public safety with a highly detailed radon measurement along 2011 and 2012. A network of 12 passive detectors (kodalphas) has been installed, as well as, two radon continuous monitoring in the most interesting geological sites of the subterranean environment. A follow up of the recommended time (max. 50 min) inside the underground environment has been analysed since the reopen to public visitors for not surpassing the legal maximum effective dose for tourists and guides. Results shown that public visitors would receive in fall a 12.1% of the total effective dose permitted per visit, whereas in summer it is reduced to 8.6%, while the cave guide received a total effective dose of 6.41 mSv in four months. The spatial radon maps allow defining the most suitable touristic paths according to the radon concentration distribution and therefore, appropriate fall and summer touristic paths are recommended., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

This study involves continuous radon monitoring during the academic year 2023/2024. An Airthings Corentium Home radon detector placed in the basement laboratory of a faculty building in Kosovska Mitrovica (N 42.897°, E 20.867°) was used for continuous measurements. The average radon concentration was 303 Bq/m3, and a seasonal pattern during the measuring period was observed. For the first time, the results were grouped by week, excluding non-working days, to present a real case scenario with the aim of assessing the radon exposure of students, teachers, and employed persons. The inhalation dose from radon (1.54 mSv) was very high considering that exposure occurred in both semesters. Another aspect of continuous radon monitoring was to explore the relationship between indoor radon measurements and the occurrences of earthquakes in the Balkan region. Daily variations in radon (peaks and differences) were analyzed at the monitoring site by using both empirical laws and taking into account the earthquake data set provided by the Seismological Survey of Serbia. The analysis revealed that the events chosen to confirm a clear association between earthquake occurrence and enhanced radon activities in the air(as a precursor of seismic activities) did not meet the required criteria but most likely reflected external meteorological conditions. [ABSTRACT FROM AUTHOR]

This study aims to measure radon gas concentration, calculate the annual effective dose, and calculate excess lung cancer risk in KufrKhal-Jerash north of Jordan. Radon is a radioactive gas located everywhere and contributes more than 40% of people's total dose from natural radiation. The Risk concerns have resulted from the increase in mortality due to lung cancer in KufrKhal. About 117 well-calibrated dosimeters were among the study area's districts (Hill 1, Hill 2, Hill 3, and village center). Each dosimeter consists of a plastic cup with known dimensions and a piece of solid state nuclear track detector (SSNTD) type CR-39 fixed in the inner bottom of the cup. After 90 days, the retrieved detectors were chemically etched, and the track density (tracks.cm−2) was determined. The results showed that the average radon concentrations drastically varied between the districts of KufrKhal (17.1–128.8 Bqm−3). However, the mean radon values in different districts are closely related (64.4–75.5 Bq.m−3). The lowest concentration (17.1 Bqm−3) was found in the Hill 1 district, and the highest value (128.8 Bqm−3) was found in the village center. However, the overall radon concentration in KufrKhal was approximately 69.2 Bqm−3. This value is within the range of the national average level (43.2 – 77.4 Bq.m−3) and way below the national action level (200 Bq.m−3). Furthermore, the corresponding values of the annual effective dose (AED) and the excess lung cancer risk (ELCR) for dwellers in this village were calculated to be 1.8 mSv.y−1 and 0.2%, respectively. These values, according to Jordan's national regulations are acceptable. [ABSTRACT FROM AUTHOR]

Hydrothermal resources are used for health prevention and treatment worldwide based on drinking, bathing, and immersing in thermal mineral waters. In some places, 222Rn inhalation is also present. In Brazil, several locations apply thermal and hydrotherapies integrated into the Unified Health System as in Águas de Lindóia and Thermas Antonio Carlos in Poços de Caldas Town. The effective dose due to 222Rn inhalation by the public and balneary workers, as well as the chemical and radiological characterization for these spas were evaluated. 222Rn activity concentration was measured by using CR-39, elemental water composition by neutron activation, and radionuclides, by gamma espectrometry. Results showed that the 222Rn activity concentration varied from 21 to 71 Bq m−3 in the public areas of the balnearies and from 407 to 16,451 Bq m−3 in the closed springs. Effective doses varied from 0.01 to 0.02 mSv y−1 for the public, from 0.10 to 0.33 mSv y−1 for works and from 0.03 to 4.95 mSv y−1 for maintenance. No risk occurs for members of the public and workers due to radon inhalation, but care must be taken on behalf of the maintenance workers from Águas de Lindóia balneary. The water, for both balnearies, do not exceed the recommendation for drinking water for gross alpha and gross beta activities. Chemically, the water from Águas de Lindóia is classified as hypo saline and the water from Poços de Caldas, as low mineral content. [ABSTRACT FROM AUTHOR]

Understanding radon‐prone areas is vital to prevent radon‐related health problems, enhance public safety, and ensure adherence to regulations aimed at minimizing radon exposure. We conducted a comprehensive review of cross‐sectional studies reporting on residential radon exposure in Iran. Our review encompassed studies published until February 13, 2022. Out of the 966 articles initially identified, 37 studies were included in our analysis, which measured indoor radon levels in a total of 3480 residential buildings in Iran. Notably, the highest residential radon levels (Bq.m−3) were found in Mazandaran province, with the most hazardous recorded levels in Talesh Mahalleh (3235), followed by Ramsar (1299). Conversely, Tehran, the capital city of Iran, had the lowest recorded levels of residential radon, at 11.0 Bq.m−3. Remarkably, indoor radon concentration exceeded both the reference levels recommended by the World Health Organization (WHO) and the standard levels set by the U.S. Environmental Protection Agency (US.EPA), with approximately 51% and 26%, respectively. The mean effective doses received by Iranian residents were 5.0 mSv.y−1 (0.3–81.7). Moreover, the mean excess lifetime cancer risk (ELCR) associated with indoor radon exposure was determined to be two per 1000 people. The annual incidence of lung cancer cases (LCCs) per million people attributed to indoor radon exposure in Iranian residential buildings ranged from 5.00E − 06 to 1.47E − 03. The included studies addressed a wide range of variables affecting radon levels, but they did not cover all factors comprehensively. These factors encompass the meteorological parameters, geological characteristics, building construction materials, building type, window type, occupancy information, and ventilation rates in enclosed spaces. The potential health risks associated with indoor radon exposure necessitate the implementation of effective control measures. These should include raising public awareness, revising construction regulations, enhancing ventilation systems, identifying high‐risk areas, and conducting more comprehensive studies to better understand the factors that influence radon concentration. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this research, the radon gas concentration was measured for samples from the water of the Euphrates River in the Hindia district of Karbala governorate. The selected collection locations were 30 different local ones on the river between the ancient and modern bridges, heading north and south, respectively; the distance between locations was 100 meters. The concentrations and effective dose of radon were measured using the RAD7 device technology. The highest value was for sample 21, where the effective dose was (0.00001752 Bq/m³). The same value for the effective dose was of sample 7. The lowest value was in sample 27, where the effective dose was (0 Bq/m³), the same value of sample 3. It was observed from the study that the remaining values of the samples ranged from sample 1 as the lowest value of the effective dose (0.0799 Bq/m³) and also for sample 2 and sample 15. The highest value was for samples 29 and 23, where the value of the effective dose was (0.00001314 Bq/m³). However, from observing the results, these values are within the internationally permissible limits according to the recommendations of US Environmental Protection Agency, which is 11 Bq/L. [ABSTRACT FROM AUTHOR]

Environmental monitoring of external and internal radon is very important for public health. To assess the possibility of respiratory cancer, the study dealt with collecting (81) samples of sludge produced as waste from the oil industry from oil fields in Maysan Governorate, southern Iraq. The aim of the study was to determine the concentrations of radon gas ( 222Rn) and the concentration of radium, and the effective dose resulting from the release of radon gas on the body and lung tissues was calculated. CR-39 trace detector technology was used to accomplish this work. It was found that the Fakka fields contain a high concentration of radium, the main cause of radon, while it was lower in the Bazargan fields. In all samples, the concentration of radium (226Rn) and the radon gas released from it was much higher than the permissible dose level recommended by the International Commission on Radiological Protection. [ABSTRACT FROM AUTHOR]

The study assesses environmental background radiation from radon, thoron, and thoron decay products across distinct geological settings in the Garhwal Himalaya region by using RADUET, CR-39 plastic track detectors, and deposition-based thoron (220Rn)progeny detectors. The measurements were conducted indoors throughout the winter, summer, and rainfall seasons during the year 2013. The annual inhalation doses from 220Rn progenies ranged between 0.83 and 2.99 mSv y−1, averaging 1.94 mSv y−1. The annual effective dose (AED), reflecting biological radiation impact, varied from 0.58 to 2.78 mSv y−1, with an average of 1.75 mSv y−1. [ABSTRACT FROM AUTHOR]

In this work, the indoor radon concentration and radiation dose risks were studied in dwellings within the Greater Accra region, using CR-39 detectors. The indoor radon concentrations ranged from 36.1 ± 2.7 to 92.0 ± 5.2 Bq m−3 with an annual average of 50.8 ± 3.4 Bq m−3. The annual mean effective dose was estimated as 1.3 mSv year−1. Excess lifetime cancer risk and lung cancer cases were assessed with 5% annual lung cancer deaths due to radon was realized. Indoor radon maps created with ArcGIS software over a 5 × 5 km2 grid showed radon prone areas in the region. [ABSTRACT FROM AUTHOR]

Background: Inhaling radon is the most common way that humans are exposed to this radioactive gas. Radon can seep into buildings and homes, where it can accumulate to levels that can be harmful to human health. According to the World Health Organization, radon is the second most common cause of lung cancer. Materials and Methods: The radon concentrations, effective dosage and lung dose were assessed in construction building materials of sand, cement, and bricks in Al-Shatra City, Dhi-Qar Governorate, Iraq using solid state nuclear track detector CR-39. Results: The average radon concentrations in sand were 92.766 ± 46.518 Bqm-3, while in bricks was 198.256 ± 87.64 Bqm-3 and cement was 69.897±46.903 Bqm-3. According to this study, there was difference in the concentrations of radon, and the largest amount was found in the bricks. An annual effective dose was 2.34 mSvy-1, 4.99 mSvy-1 and 1.76 mSvy-1 for sand, bricks and cement, respectively. On the other hand, the lung dose was determined to be 3.71, 7.92 and 2.795 for sand, bricks and cement respectively. Conclusion: The concentrations of radon gas in building materials were consistent with recommended by the International Commission on Radiological Protection (ICRP) 200- 300 Bqm-3 except the bricks materials. [ABSTRACT FROM AUTHOR]

The objective of this work is to give a holistic overview of the groundwater quality in Qatar in terms of its radon levels and provide a radiological risk assessment of elevated radon levels on human health. This study covered the analysis of groundwater collected from various locations throughout Qatar and maps using ArcGIS followed by a radiological risk assessment of radon in Qatar. There is no extensive study reported to investigate radon activity levels in groundwater across Qatar and their health effects. The radon level measurements of the Qatari groundwater ranged between 2.7 ± 0.2 and 60.7 ± 13.4 Bq/L with a mean value of 20.6 Bq/L, which is greater than the US EPA's maximum contamination level (11 Bq/L). About 65% of the studied samples exceeded the US EPA's MCL guidelines. The mean total annual effective dose due to radon inhalation and ingestion was 0.056 mSv/y, which is below the WHO reference level of 0.1 mSv/y. The radon radiological risk study through inhalation and ingestion clearly revealed that the contribution of the inhalation dose was higher than the ingestion dose. [ABSTRACT FROM AUTHOR]

Introduction: Radioactive contamination by uranium and its emissions, such as alpha particles, is considered one of the most critical issues affecting the human race and its existence. The study investigated the high ionization capacity number of alpha particles in whole blood samples from cancer patients because these particles have the most significant impact on the shape and function of living cells, modifying them into malignancies. Material and Methods: The TASLImage solid nuclear trace detector CR-39 was used to measure the effects of alpha emitters in the whole blood samples from 40 cancer patients for five types of cancer (breast, uterus, prostate, kidney, and colon) collected from a government hospital at Karbala/Iraq and compared with ten healthy samples. Moreover, the research investigated whether smoking and gender variation affect the outcomes. Results: The radon concentration in whole blood samples from patients and healthy individuals was significantly different (p< 0.05), and it was slightly higher in males with (22.82254±7.38794 Bq/m3). Women with colon cancer had higher blood levels of radon (32.13787±5.79261 Bq/m3) than men with the same malignancy (18.80531±5.63747 Bq/m3), regardless of gender. While the age factor had no noticeable impact, the smoking element had a considerable effect (p< 0.05). Conclusion: All alpha levels were within the (ICRP) usual ranges. Women with colon cancer had the most significant alpha values. In contrast, men with the same disease had the lowest values despite cancer patients' blood levels being higher than those of the healthy group.

This study is aimed at the analysis of perspectives of provision of radiation safety from natural sources of ionizing exposure on the territories included into the Russian Federation in 2022. The study contains comparison of the requirements of legislative acts and regulations on the radiation safety that were active in 4 new subjects of the Russian Federation (Donetsk and Lugansk republics, Zaporozhye and Kherson regions) on the time of their integration with their Russian equivalents. The results indicate the lack of harmonization between acting radiation safety sanitary acts of the Russian Federation and the Ukraine with recommendations of the international organizations. The study contains results of the surveys on the exposure of the public of the Donbass republics and Zoporozhye region by natural sources of ionizing exposure, analysis of the perspectives of the provision of radiation safety of the public of these regions and the Kherson region. Additionally the study includes the evaluation of the existing legislative base on the protection from natural sources of ionizing exposure in the Russian Federation and perspectives of harmonization with the recommendations of international organizations.

Systematic studies on natural radioactivity in the groundwater of Kodagu district, India were carried out. LED fluorimetric technique to measure uranium activity and emanometric technique to measure 222Rn activity in groundwater samples were used. The concentration of U and 222Rn in the water samples was observed to vary from 0.44 to 8.81 µg L-1 with a geometric mean of 2.04 µg L-1 and 1.54 to 9.61 Bq L-1 with a geometric mean of 3.59 Bq L-1, respectively. The estimated concentrations of uranium and radon in groundwater were within the recommended standard limits. The radiation dose due to U and 222Rn in groundwater was estimated and the total dose due to these radionuclides was found to vary from 4.51 to 30.28 µSv y-1 which was below the prescribed safe limit of 0.1 mSv y-1 by the WHO. [ABSTRACT FROM AUTHOR]

In this paper, the evaluation of the Rn-222 radioactivity content in drinking water samples from the Calabria region, southern Italy, is reported as a case study. The Rn-222-specific activity in the analyzed groundwater samples for human use was evaluated by using the PerkinElmer Tricarb 4910 TR setup and compared with the parameter value (100 Bq L−1) reported in the reference Italian legislation, i.e., D.Lgs. 28/2016, derived from the European Directive 2013/51/Euratom. The radiological health risk for the population of the investigated area, due to the ingestion and inhalation of Rn-222 dissolved in water, was then evaluated by calculating the total annual effective dose, only in those cases where the parameter value was exceeded. The obtained results represent a main reference for the investigated area and are useful for determining any possible radiological health risk for human beings related to the ingestion of the investigated radionuclide. Moreover, they can also be used as a baseline for future investigations regarding background radioactivity levels. [ABSTRACT FROM AUTHOR]