Radon Concentration In Houses Research Articles

Assessment of radiation exposure in the phosphate mining area of Gafsa (Southeastern Tunisia)

ABSTRACT This study investigates the radiological health implications of sixty-three (63) samples of soil, food, and drinking water collected from the phosphate mining area of Gafsa in Southeastern Tunisia. Additionally, it assesses the exposure to radon concentrations in houses located around the phosphate mining sites. The activity concentrations in soil samples were found to be 382.1, 36.1 and 16.3 Bq kg−1 respectively for 40K, 232Th and 226Ra. The average activity of 232Th was higher than worldwide average value of 30 Bq kg−1. Eleven (11) radiological hazard parameters were computed based on various exposure scenarios including external gamma dose rate (GDR), annual effective dose (AED) and risk assessment (RA). The calculated GDR values were of 3.2 nGy h−1 in food and 45.4 nGy h−1 in soil samples, while the average AED values were of 3.9 µSv y−1 in food and 83.5 µSv y−1 in soil samples. Internal AED due to ingestion of radionuclides was found to have a mean value of 0.1 µSv y−1 in soil, 264.4 µSv y−1 in food and 10 µSv y−1 in drinking water samples. The AED values due to inhalation of soil-dust and radon were assessed to be 2.1 and 1.2 µSv y−1, respectively. The RA average values in food and drinking water samples were found to be 3 × 10−5 and 2.4 × 10−4, respectively. Based on the exposure pathway, inhalation of radioactivity through soil and radon resulted in highest total AED values, which remained below the reference limit. This was followed by internal exposure, with total AED values of 274.5 µSv y−1.

Analysis of radon concentration and gamma dose rate in residential houses of Ambon and Seram Islands, Maluku

Radon concentration analysis in the residential houses on Ambon and Seram Island - Maluku through the passive method using the CR-39 nuclear track detector has been studied. The CR-39 nuclear track detector was installed inside the residential houses for 3 months. After finishing the exposure, the detector was taken and etched using 6.25 N NaOH solution. The nuclear track of radon in the CR-39 was read by a microscope with 400 times magnification. From the results of reading the track, determination of radon concentration in the houses was calculated. The results of the analysis showed that radon concentrations in the residential houses of Ambon and Seram Islands, Maluku at the low level were in the range of 2.56 ± 0.18 Bq/m3 to 59.65 ± 4.22Bq/m3 with an average value of 28.42 ± 1.98 Bq/m3. The average concentration of radon is still below the average radon concentration in the world of 50 Bq/m3. The value of dose received by the population due to exposure of radon and gamma radiation in the range of 0.90-1.44 mSv/year. There is a positive correlation between radon concentration value and total radiation doses received by the population for a year. This data can be used in the study of radiation safety for the Ministry of Health and as a contribution to Indonesia in the international community about monitoring environmental radiation from radon concentrations in residential houses

Influence of climate, building and residential factors on radon levels in ground-floor dwellings in Montenegro

After year-long measurements with CR-39 detectors, nationwide radon survey was performed in 953 homes ? 0.5 % of all permanently inhabited dwellings in Montenegro. Influence of 11 factors (area, climate, type of house, year of construction, basement, foundation slab, number of stories, building materials, window frames, heating, and smoking) and 35 their 35 categories on the radon concentrations in 732 ground-floor dwellings was analyzed using descriptive, univariate and multivariate methods. Univariate analysis dropped influence of the two factors: heating and smoking. It reveals that, on average, radon concentrations in ground-floor dwellings differ at 95 % confidence level in urban and rural areas, in family houses and apartment buildings, in houses with and without basement, and in dwellings with window frames made of wood and PVC/Al. In Cf climate zone they differ from those in Cs and Df zones. Only two pairs of construction periods differ in mean radon concentrations in dwellings: 1980-1999 with 1900-1944, and with 1964-1979. Houses with one, two or three stories have almost equal average radon levels, which are higher than in buildings with more than three stories. Mean value of radon concentrations in houses made of stone are higher than in houses made of concrete, or bricks, or wood. Multivariate analysis revealed that six of the analyzed factors: area, climate, type of house, presence of basement, number of stories, and building materials simultaneously have significant relationships (p < 0.05) with radon concentrations in dwellings on ground floor in Montenegro.

Radon in houses of Kowary – Sudety Mountains, Poland

Abstract The presence of uranium makes the Kowary area characterized by an increased concentration of radon in the air and the living houses. Measurements of periodic radon concentrations in dwellings of Kowary were carried out three times in the last 20 years. It can be observed that 20 years ago level of radon concentrations in houses of Kowary were lower than today. Measurements carried out in Kowary over 20 years have shown that residents are exposed to radon concentrations, which often exceed 300 Bq m−3 – a reference level recommended by the European Union. The present geometric mean of radon concentration in houses of Kowary (260 Bq m−3) exceeds the geometric mean of radon concentration of buildings in the rest of Poland (142 Bq m−3).

Indoor Radon Measurement in Dwellings of Khorramabad City, Iran

Introduction: Exposure to indoor radon increases the risk of lung cancer. This study examined the level of indoor radon in dwellings of Khorramabad city, by using passive alpha-track detector (CR-39) during winter of 2016. Materials and Methods: In the present study, we detected the concentration of indoor radon in 56 dwellings. A passive sampling instrument (alpha-track detector with CR-39 polycarbonate films) was utilized to measure indoor radon gas concentration. The distribution map of indoor radon concentration was prepared using Arc GIS software.  Results: Radon concentration in the dwellings varied from 1.08 to 196.78 Bq/m3, with a mean value of 43.43±40.37 Bq/m3. The average annual effective dose received by the residents of the studied area was estimated to be 1.09 mSv. Our results showed a significant difference between the average radon concentrations in houses and apartments, with a higher level in houses. Conclusion: Indoor radon concentration in 10.1 of the dwellings was determined to be higher than the limit (100 Bq/m3) recommended by the World Health Organization.

Natural radiation due to radon. Case study: radon concentration in houses from Apuseni Mountains

Natural radiation due to radon. Case study: radon concentration in houses from Apuseni Mountains

DETERMINATION OF RADON CONCENTRATIONS IN DWELLING IN ACEH

Abstract. Determination of radon concentrations in dwelling in Aceh region by using a passive method has been conducted. In this research, area considered was divided into several sections called grid. Each grid represents an area of 60 km x 60 km in which, depend on public response, 6-10 passive radon monitors were installed. The number of passive radon monitors installed in Aceh is 200 units, and they can be taken back as many as 191 units or 95.50 %. The passive radon monitors have stayed in dwelling for 3-4 months and after period of the exposure, those radon monitors were taken back and brought to laboratory for further process, and then the track were read and the radon concentrations were calculated. Furthermore, data of radon concentration in dwelling and GPS location were put into MapInfo Software v.10.5 to create a map of radon concentration. The results of the analysis of the radon concentration in dwelling in Aceh demonstrate that the concentrations are in the range of 3.32 ± 0.23 Bq/m3 up to 68.30 ± 4.83 Bq/m3. This result was lower than the radon reference level determined by UNSCEAR, which was 300 Bq/m3. The data are useful in the regional extension and development plans, as well as the basis for health policy analysis due to the existence of radon in Indonesia. Furthermore, these data will become the contribution of Indonesia in the international world through UNSCEAR, IAEA and WHO. The data obtained can be used as partial data in creating a map of radon concentration in residents’ houses in Aceh, as a part of the map of radon concentration in Indonesia. Keywords: radon concentration, dwelling, Aceh, passive methodREFERENSI UNSCEAR, 1996, Natural Radiation Exposures, Forty Fifth Session, VienaIAEA, 2005, Radiation, People and the Environment, Viena.Bunawas, Emlinarti, M. Affandi, 1996, Penentuan laju lepasan radon dari bahan bangunan menggunakan metode pasip dengan metode jejak nuklir, Prosiding PPIKRL, PSPKR-BATAN, 20-21 Agustus 1996, pp. 16-21.Sutarman, L. Nirwani, Emlinarti dan A. Warsona, 2005, Penentuan konsentrasi gas radon dan thoron menggunakan detektor film LR-115 di DKI Jakarta dan sekitarnya, Prosiding PPI–PDIPTN P3TM-BATAN, Jogjakarta, p. 212-221.M. Affandi, D. Iskandar, dan Bunawas, 1996, Radon di Kompleks Perumahan BATAN, Presiding PIKRL, PSPKR-BATAN, p. 262-265Wahyudi, Kusdiana and D. Iskandar, 2016, Mapping of Indoor Radon Concentration in Houses Located in South Sulawesi Province, 2nd International Conference on the SERIR2 14th Biennial Conference of the SPERA, Bali, CTRSM-BATAN, p. 35-38.E. Pudjadi, Wahyudi, A. Warsona and Syarbaini, 2016, Measurement of Indoor Radon-Thoron Concentration in Dwellings of Bali Island, Indonesia, 2nd International Conference on the SERIR2 14th Biennial Conference of the SPERA, Bali, CTRSM-BATAN, p. 186-192.M.H.Magalhães, et al., 2003. Radon-222 in Brazil: an outline of indoor and outdoor measurements. Journal of Environmental Radioactivity, 67(2), pp.131–143.F.S. Al-Saleh, 2007. Measurements of indoor gamma radiation and radon concentrations in dwellings of Riyadh city, Saudi Arabia. Applied Radiation and Isotopes, 65(7), pp.843–848.

Radon in the soil air of Estonia

Several investigations in Estonia during 1996¬-1999 have shown that permissible level (200 Bq/m3) of radon (222Rn) in indoor air is exceeded in 33% of the inspected dwellings. This makes Estonia one of the five countries with highest radon risk in Europe (Fig 1). Due to correlation between the soil radon risk level and radon concentration in houses, small scale radon risk mapping of soil air was carried out (one study point per 70–100 km2). It turned out that one-third of Estonian mainland has high radon risk potential, where radon concentration in soil air exceeds safe limit of 50 kBq/m3.In order to estimate radon content in soil air, two different methods developed in Sweden were used simultaneously. Besides measuring radon content from soil air at the depth of 80 cm with an emanometer (RnM), maximum potential content of radon in soil (RnG) was estimated based on the rate of eU (226Ra) concentration in soil, which was acquired by using gamma-ray spectrometer.Mapping and following studies revealed that simultaneously measured RnG and RnM in study points may often differ. To inspect the cause, several monitoring points were set up in places with different geological conditions. It appeared that unlike the RnG content, which remains close to average level in repeated measurements, the RnM content may differ more than three times periodically. After continuous observations it turned out that concentration of directly measured radon depended on various factors being mostly controlled by mineral composition of soil, properties of topsoil as well as different factors influencing aeration of soil.The results of Rn monitoring show that reliable level of radon risk in Estonian soils can only be acquired by using calculated Rn-concentration in soil air based on eU content and directly measured radon content of soil air in combination with interpreting specific geological and geochemical situations in the study points.

Measurement of indoor radon concentration and assessment of doses in different districts of Northern Rajasthan, India

Radon (222Rn), the immediate decay product of radium, is a causative agent of lung cancer. The seasonal indoor radon concentration in houses with different floorings, walls and roofs has been measured in Northern Rajasthan, India. The measurements were made in 100 houses using LR-115-type II plastic track detectors over four successive three-month periods (winter, spring, summer and autumn). The mean values of indoor radon concentrations in winter, spring, summer and autumn were determined to be: 176 Bq m−3, 131 Bq m−3, 120 Bq m−3 and 151 Bq m−3, respectively. The annual average indoor radon concentrations in the dwellings were found to vary from 117 to 215 Bq m−3 with an average of 144 Bq m−3. In ∼10% of the dwellings the indoor radon activity concentration values lies in the range of action level (200–300 Bq m−3) recommended by International Commission on Radiological Protection. The annual effective dose received by the residents of the study area varied from 2.0 to 3.67 mSv with an average of 2.46 mSv. The seasonal variation in indoor radon reveals the maximum value in winter and minimum in summer. The influences of the factors linked to building characteristics in relation to radon measurements were examined.

Estimating the importance of factors influencing the radon-222 flux from building walls

Radiation hazard in dwellings is dominated by the contribution of radon-222 released from soil and bedrock, but the contribution of building materials can also be important. Using a simple air mixing model in a 2-story house with an attic and a basement, it is estimated that a significant risk arises when the Wall Radon exhalation Flux (WRF) exceeds 10×10−3Bq·m−2·s−1. WRF is studied using a multiphase advection–diffusion 3-layer analytical model with advective flow, possibly induced by a pressure deficit inside the house compared with the outside atmosphere. To first order, in most circumstances, the WRF is proportional to the wall thickness and to the radon source term, the effective radium concentration ECRa, which is the product of the radium-226 concentration by the emanation coefficient E. The WRF decreases with increasing material porosity and exhibits a maximum for water saturation of about 50%. For ECRa=10Bq·kg−1, in many instances, WRF is larger than 10×10−3Bq·m−2·s−1 and, therefore, ECRa=10Bq·kg−1 can be considered as the typical limit not to be exceeded by building materials. An upper limit of the WRF is obtained in the purely advective regime, independent of porosity or moisture content, which can thus be used as a robust safety guideline. The sensitivity of WRF to temperature, due to the temperature sensitivity of ECRa or the temperature sensitivity of radon Henry constant can be larger than 5% for the seasonal variation in the presence of slight pressure deficit. The temperature sensitivity of ECRa is the dominant effect, except for moist walls. Temperature and moisture variation effects on the WRF potentially can account for most observed seasonal variations of radon concentration in houses, in addition to seasonal changes of air exchange, suggesting that the contribution of walls should be considered when designing remediation strategies and studied with dedicated experiments.

Radon concentration in houses over a closed Hungarian uranium mine

High radon concentration (average 410 kBq m − 3 ) has been measured in a tunnel of a uranium mine, located 15–55 m below the village of Kővágószőlős, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m − 3 . Significantly higher radon concentrations (average 667 Bq m − 3 ) were measured in houses within ± 150 m from the surface projection of the mining tunnel + 50 m, compared with the houses further than the 300-m belt (average 291 Bq m − 3 ). The average radon concentration of the soil gas was 88.8 kBq m − 3 , the average radon exhalation was 71.4 Bq m − 2 s − 1 and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m − 3 ) may influence the radon concentration of the houses over the mining tunnel.

Effect of moving air and variable radon concentration on the response of charcoal canister

The calibration curves for standard EPA open face and diffused barrier charcoal collectors were extended for moving air environment applications. The response of charcoal to variable radon concentration at different temperature and humidity was studied using a radon chamber. The average radon concentrations were measured in two different districts of different soil natures in Cairo, using simultaneously activated charcoal and AB-5 active monitor. The measurements show that the average radon concentration in houses constructed on limestone nature soil is higher than in those constructed on clay nature soil. The active monitor data showed that radon concentration increases during nighttime and decreases during day.

Airborne and waterborne radon concentrations in houses with the use of groundwater

A preliminary survey of airborne and waterborne radon concentrations was conducted in an area where groundwater is used as a source of public water supplies. An average of waterborne radon concentrations was 58.4 Bq l −1 for public water supplies and that of airborne radon concentrations was 18 Bq m −3 for 10 houses.

Indoor radon concentration survey in Mexico

Indoor radon evaluations in specific regions of the country have been performed in an effort to assess the magnitude of the radon problem and its public health consequences. The survey of this paper covers four large non-tropical regions of north and central Mexico, and reports the results of measurements of indoor radon concentrations in houses of towns with between 100,001 and 500,000 inhabitants. The measurements were done by using passive detectors, namely, the closed-end-cup system with CR-39 polycarbonate chips as detector material. The measurements were performed throughout the two coldest seasons (between 5 and 20°C), winter and spring, in integration periods of 28 days covering the six month cycle. The results show a moderate average radon concentration below 200 Bq·m−3 with occasional higher values. This is very probably due to the climate conditions and the traditional habits of open door and window ventilation. The IFUNAM (Instituto de Fisica, Universidad Nacional Autonoma de Mexico) Laboratory, where the closed-end cup system for radon was developed, has gained experience though this survey and is willing to share it for future surveys at regional or national levels.

Radon concentrations in houses around the Plomin coal-fired power plant

Investigation of radon activity concentration in houses around the Plomin coal-fired power plant (Istrian Peninsula) started in the winter of 1990 upon the assumption that certain old houses in this region were built using mortar and plaster prepared from slag and ash. This paper presents the results of a preliminary investigation carried out in the winter of 1990 and spring of 1991, when the difference between radon levels in old and newly built houses was first noted, and the subsequent data obtained by radon measurements in 40 selected houses in the period from 1992 to 1994. The average annual radon activity concentrations in the old houses ranged from 55 Bqm −3 to 426 Bqm −3 (mean value 146 ± 91 Bqm −3) and in more recently built houses from 16 Bqm −3 to 67 Bqm −3 (mean value 36 ± 13 Bqm −3). The average annual effective doses from inhalation of radon progeny for the inhabitants living in the old and newly build houses were estimated to be 2.7 mSv and 0.7 mSv, respectively.

97/00661 Radon concentrations in houses around the Plomin coal-fired power plant

97/00661 Radon concentrations in houses around the Plomin coal-fired power plant

96/06512 Heat recovery in ventilation systems with exhaust air humidification

Radon is the largest source of risk to human health caused by an indoor pollutant in the industrial countries. Subslab ventilation (SSV) is one of the most effective and common methods of reducing indoor radon concentrations in houses with a basement. In this paper, the impact of SSV on the air exchange rate is quantified, through numerical modeling of a prototype house with basement for a range of permeabilities of soil and subslab aggregate and various sizes of the cracks in the basement floor. We show that a SSV system can increase the air exchange rate by as much as a factor of 4.5. Then the energy and capital costs of a subslab depressurization (SSD) system are compared with those of direct ventilation of the basement which is required to lower the indoor radon concentration to an acceptable level for a Chicago climate. We show that (1) an exhaust ventilation cannot significantly reduce the indoor radon concentration and may even increase it, and (2) a balanced ventilation with heat recovery is only effective for low premitigation radon concentrations. However, both SSV and balanced ventilation systems are probably too expensive to be recommended in houses with low premitigation radon concentrations. A SSD system is the most cost-effective technique for reduction of high radon concentrations.

Criteria for indoor radon concentration — an experimental study considering especially the Leipzig-Halle brown coal area

The project is supported by the EU-programme Human Capital and Mobility. The project intends to improve the understanding of the specific behaviour of the radon gas. The research will consequently focus on parameters or effects affecting radon concentration levels and their variation in buildings as a function of existing and previous variations of radon in the underground, in addition to the radon component from the building materials and environmental artificial radon sources coming from industrial processes like mining and metallurgy. The programme is to carry out an intercomparisonal experimental survey Lund-Kiel-Leipzig-Montpellier-Barcelona-Rome including both regular dwellings and instrumented “test houses” under various meteorological, geological and environmental conditions including the habits of the inhabitants. The radon levels will be measured indoors and in the subsoil using both track films and electronic devices. This should lead to a general model pertinent to variations of the radon concentration in houses.

Influence of Shallow Mine-Workings on the Radon Concentrations in Houses: A Problem of Old Mining Regions

Abstract In some regions of the German New Federal Lands, residues from early mining characterise the radiological situation and can also influence the radon concentration in buildings. Construction on waste rock with increased radium concentration, the use of waste rock as building material and construction above shallow mine shafts and adits are important in this connection. In Saxony, for instance, one has to reckon with probably hundreds of buildings that may be influenced by radon from shallow mine workings. Very short-term changes of radon concentrations in buildings over several orders of magnitude was well as their close temporal correlation with the underground airflow clearly indicate influences from underground. In Schneeberg and Schlema, fluctuations of radon concentration in buildings of several 10,000 Bq.m-3 within one hour were observed. In Schneeberg, the old mine was ventilated artificially by installing a ventilator with an output volume of 500 m3min-1. Thus the radon concentration in buildings of the central city area has been reduced. In Schlema, the radon rich shafts of early mining are ventilated at present by the still active ventilation system of the suspended uranium ore mining. In 1992, during the first six months, 4.5 x 109 m3 of mine air with a radon activity of 6.3 x 1014Bq were extracted from the mine. If the mine ventilators are switched off, radon concentration in buildings over mine shaft increases sharply by two orders of magnitude.

Radon Sources, Radon Ingress and Models

Abstract Information available 20 years ago suggested that unusual soil conditions were needed to produce high radon concentrations in houses. Based on this belief, simple models were developed to predict house radon concentrations based on estimates of soil radium concentration and soil type (related to permeability). Recent radon-in-housing surveys show that clay soils, which cover much of North America, are radon-prone. The permeability of these soils is not controlled by the soil type, but by the fracture patterns that develop as the soil dries out. Realistic prediction models must take the macroscopic soil structure into account. They must also deal with the effect of the rapid variations in driving force produced by wind velocity variations. The interaction between house and soil is complex, and simple models cannot give realistic results. Many people live in apartment buildings, and are exposed to radon released from building materials. Better models are needed for this source to help develop better controls. Many radon-prone areas have been identified by house surveys, so modelling is now needed only to explain what we know. The priority task today is not prediction, but encouraging production of low-radon dwellings in known high-radon areas.