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The performance of continuous radon monitors (CRMs) is usually evaluated under controlled conditions in a radon chamber during calibrations or intercomparison exercises. The impact of thoron on CRMs response is rarely evaluated; in case the evaluation is performed, it is carried out in a controlled atmosphere with relatively constant, homogeneous, and generally high thoron concentrations and very low radon levels. In a real indoor environment, both radon and thoron concentrations are extremely variable, so the thoron interference evaluations reported in the literature are generally not applicable to CRMs used to measure radon concentration indoors. For this reason, an experimental study was carried out with four different CRMs in an indoor environment (an office room) where medium-to-high concentrations of both radon and thoron were expected. Thoron concentration has been separately evaluated throughout two different active monitors. Three CRMs resulted in overestimations of radon concentration by about 10% due to thoron interference, whereas such interference results were negligible for the fourth CRM. However, the thoron interference can also be used to assess thoron concentration by using CRM not specifically designed to do so. Based on the results of this study, an indirect method to assess thoron concentration is indeed proposed, relying on the combination of two identical monitors (one placed right close to the wall and the other one far enough from there).

To address the issue of residential radon risk we conducted two distinct experiments actively monitoring radon in 25 apartments in Rome and suburban areas for two weeks, and in 3 apartments in the historic center for several months. The action levels of 300 and 100 Bq/m3 are overcome in 17% and 60% of the cases, respectively, and these percentages rise to 20% and 76% for average radon measured overnight (more relevant for residents’ exposure). Active detectors allowed us to identify the seasonal behavior of radon, strongly dependent on the gradient of indoor-to-outdoor temperature, and of the way it travels from the ground to upper floors. High levels of radon are not limited to the lowest floors when the use of heating and ventilation produces massive convection of air. The importance of these factors is also evidenced by the very different values of gas concentration measured at different floors of the same building or in distinct rooms of the same apartment, that cannot be ascribed to the characteristics of the premises. However, the finding that high residential radon levels tend to concentrate in the historic center proves the significant influence of building age, typology, construction materials, and geogenic radon.

Bulgaria is rich in geothermal water. The radon level in spas buildings depends on soil underneath, thermal water and the ventilation conditions. The aim of the paper is to analyses influence of ventilation system on indoor radon in air in the spa buildings. Direct measurements of radon in the air were performed in treatment rooms (treatment with thermal water and without) and mineral pools. A statistically significant difference was found between the indoor radon levels in treatment rooms using water and those without water, located in branches with high radon concentration (MW, p = 0.032). The spectra of the rooms for 24 hours were considered for analysing the indoor radon daily variations. The radon arithmetic mean value in rooms with operating ventilation system was 148 Bq /m3, and in those without - 756 Bq /m3 and the statistically difference is significant (MW, p

This paper presents an analysis of indoor radon measurements carried out in municipality of Zubin Potok, northwestern part of Kosovo and Metohija. Annual measurements in two rooms of each house were performed by solid state nuclear track detectors commercially known as Gammadata. Average indoor radon concentration in different type of houses varied from 29-326 Bq/m3. A different year of house's construction including various types of building materials were selected for survey. A detail analysis showed that the differences in radon concentration occur between various building materials used for construction, flooring level, type of room and behavior of inhabitants. It was found that building materials in some houses contribute additionally to indoor radon.

In the present study, we aimed to determine the changes of indoor radon concentrations depending on various environmental parameters, such as the outdoor temperature, relative humidity, and air pressure, in university building premises of different applications and heights. The environmental parameters and indoor radon concentrations in four different premises were measured each working day over an eight-month period. The results showed that the indoor radon levels strongly depended on the outside temperature and outside relative humidity, whereas the weakest correlations were found between the indoor radon levels and indoor and outdoor air pressures. The obtained indoor radon concentration and environmental condition correlations were different for the different premises of the building. That is, in two premises where the ventilation effect through unintentional air leakage points prevailed in winter, positive correlations between the radon concentration and outside temperature were obtained, reaching the values of 0.94 and 0.92, respectively. In premises with better airtightness, negative correlations (R = &minus, 0.96 and R = &minus, 0.62) between the radon concentrations and outside temperature were obtained. The results revealed that high quality air isolation in premises could be an important factor for higher indoor radon levels during summer compared to winter.

WOS: 000440121800044 PubMed: 29879534 In this study, indoor (air) and tap water Radon (Rn-222) measurements were performed at various campus areas of Giresun University. The measurement and analysis results were compared with the values recommended by international and national organizations and those reported in literature studies. The measured and calculated values were found to be under the recommended limits. Also, annual effective dose values were evaluated to determine the annual radon exposure of an individual working in the measurement area. Indoor radon concentration values measured by CR-39 detectors were in the range of 76 Bq/m(3)-504 Bq/m(3) and the mean concentration value was obtained as 193.7 Bq/m(3). The radon concentrations in tap water samples were found to be in the range of 0.98 Bq/L-27.28 Bq/L. The annual mean effective doses (E-wig) of drinking water samples were calculated in the range of 9.9-150.4 (mu Sv/y) for ingestion and 0.97-14.84 (mu Sv/y) for inhalation calculations. Excess life time cancer risk (ELCR) was estimated as 0.54%. Radon dose rate in terms of mean annual working level month was calculated as 0.246 WLM/year. The study was performed with a view to contribute to further studies in the related field and constitute a basis for the measurements conducted in this area. Giresun University Research Fund [FEN-BAP-A-140316-50] This work is supported by Giresun University Research Fund project under the project no FEN-BAP-A-140316-50. The authors gratefully acknowledge the approval of Giresun University Administration for locating the detectors in the units, the valuable helps of Giresun University personnel, and the technical support of TAEK (Turkish Atomic Energy Authority). The valuable helps of Dr. Yelda Bingol Alpaslan and Dr. Nuri Ozturk are also acknowledged.

A comprehensive grid-based study of indoor Rn concentration in all accessible urban areas of the Republic of Cyprus, where 67.3% of the population resides, is presented. During the years 2004-2012, a total of 407 measurements of indoor Rn in the four highly-populated urbanised areas of Lefkosia, Lemesos, Larnaka, and Pafos districts were conducted, using high-sensitivity active Rn portable detectors. The four districts were subdivided into 189 grid cells, each of 1km2 in area. The grid cell mean indoor Rn concentration is in the range of 1.7 to 86.4Bq/m3, with an overall geometrical mean of 14.3±10.0Bq/m3, and a median of 14.3±3.9. The Rn mean in Cyprus is almost two-and-a-half times lower than the estimated world average of 39Bq/m3. The equivalent annual effective dose rate for each measurement was also calculated and compared to the corresponding world value. The spatial distribution and variation of Rn concentration values are also shown on maps of the urban areas of these districts. The conclusion of the present extensive and systematic Rn survey is that the Rn risk in the highly populated areas of Cyprus is low. © 2015 Elsevier B.V. 159 20 32

Results of indoor radon survey in the dwellings of district Bhimber are presented. Current study is continuation of our preceding studies aiming to setup baseline indoor radon data for the state of Azad Jammu & Kashmir, Pakistan. In this context, 60 representative houses were carefully selected and CN-85 based box type radon detectors were installed in bedrooms and living rooms of each house. The detectors were exposed to indoor radon for 90 days. After etching CN-85 detectors in 6M NaOH at 70?C for 3 hours, the observed track densities were related to the indoor radon concentration using calibration factor of 0.0092 tracks cm2/h per Bq/m3. The measured indoor radon concentration ranged from 29 ? 11 to 58 ? 8 Bq/m3, 40 ? 9 to 60 ? 7 Bq/m3, and 29 ? 12 to 66 ? 7 Bq/m3 in the regions of Bhimber, Samani, and Barnala, respectively. Excess relative risk factors were calculated using measured indoor radon concentrations, by using the risk model reported in the Biological Effects of Ionizing Radiation (BEIR VI, 1999) report. Excess relative risk was calculated for age groups of 35 and 55 years. Using local occupancy factor, average excess lung cancer risk for the population group of 35 and 55 years of age was found to be 0.42 ? 0.09 and 0.34 ? 0.08. The mean annual effective dose for Bhimber, Samani, and Barnala regions were found to be 1.05 ? 0.17 mSv, 1.09 ? 0.17 mSv, and 1.16 ? 0.17 mSv, respectively. These values are within in the safe limits recommended by the international organizations.

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration.

Using high-sensitivity radon (222Rn) portable detectors (passive electronic devices of the type RADIM3), the airborne 222Rn concentration in the interior of various Cypriot buildings and dwellings was measured. For each preselected building and dwelling, a calibrated detector was put into a closed room, and the 222Rn concentration was registered in sampling intervals of 2 to 4 h for a total counting time of typically 48 h. 222Rn activity concentrations were found to be in the range of 6.2 to 102.8 Bq m-3, with an overall arithmetic mean value of (19.3±14.7) Bq m-3. This value is by a factor of two below the world average (population-weighted) value of 39 Bq m-3. The total annual effective dose equivalent to the Cypriot population was calculated to be between 0.16 and 2.6 mSv with an overall arithmetic mean value of (0.49±0.37) mSv. © 2003 Elsevier Science Ltd. All rights reserved. 68 2 159 169 Cited By :29