Radon concentration in air, hot spring water, and bottled mineral water in one hot spring area in Thailand

Hot springs are famous as spa resorts throughout the world. However, these areas usually have high natural radioactivity from radon gas. In this study radon concentrations in air, hot spring water, and bottled mineral water produced in a spa area of Suan Phueng district, Ratchaburi province, Thailand were measured. Radon concentrations in air were in the range of 10–17 and 11–147 Bq/m³ for outdoor and indoor, respectively. Committed effective dose from inhale of radon were assessed and found to be in the range of 0.004–0.025, 0.25–0.6, and 1.134 mSv/y for visitor, local people and resort workers, respectively. These doses were in the range of 1.2 mSv/y regulated by UNSCEAR for the general public. Radon in hot spring water ranged from 2–154 Bq/L. Radon in bottled mineral water produced from the hot spring water were in the range of 17–22 and 0.2–0.3 Bq/L for those that stored for 7 and 90 days, respectively, after production. Radon concentration levels were in the range of the US Environmental Protection Agency reference level for radon in air which is 148 Bq/m³ and alternative maximum concentration limit (AMCL) for raw water which is 150 Bq/L. However, when considering the USEPA (Maximum concentration limit), 11 Bq/L, for radon in drinking water, the mineral water should be stored for at least 8–9 days after bottling before selling to the market.     

Fast determination of indoor radon (<Superscript>222</Superscript>Rn) concentration using liquid scintillation counting

The indoor ²²²Rn radionuclide was directly absorbed in typical 20 ml glass scintillation vials by passing ?3 dm³ of ambient air through 16 ml of water-immiscible non-volataile scintillation cocktail Ultima-Gold F for 10 min. The activity of radon and its two α-emitting daughters: ²¹⁸Po and ²¹⁴Po, was determined with the BetaScout low-background liquid scintillation counter. The limit of ²²²Rn detection is 9 Bq/m³, and the quantification limit with 20% relative accuracy is 28 Bq/m³. The results of the indoor Rn measurement in different houses showed good consistency with results obtained from a Sarad EQF 3220 device.     

Radon in schools and dwellings of Osijek

Indoor radon concentrations were measured in 10 821 pupils primary schools of Osijek by means of the Radhome silicon detector. The values ranged from 15 to 300 Bq/m³ with the arithmetic and geometric means of 93.4 and 70.6 Bq/m³, respectively. Ten years continuous radon measurements performed with the LR-115 nuclear track detector in three houses of different construction and town area gave means of 27, 96 and 23 Bq/m³; the indoor Rn concentration for a heating period was a factor of 1.5 higher than for the warm season. The average effective dose equivalent for the primary school pupils was 2.8 mSv/y (with occupancy factors of 0.6, 0.2 and 0.2 for home, school and outdoors, respectively). For citizens of Osijek it was 1.7 mSv/y.     

Indoor radon measurement in Izmir Province,Turkey

In 2013, an extensive study was performed in a total of 117 locations in Izmir province and indoor radon levels were measured using the alpha track etch integrated method with LR-115 detectors. As the maps are more practical to interpret the results of radiological survey, the distributions of indoor ²²²Rn activities in four most densely populated districts of Izmir were mapped in detail. It is seen that the estimated average radon concentration level (210 Bq m^?3) determined in Izmir province was almost three times higher than the mean value for Turkey (81 Bq m^?3). Exposed annual effective dose equivalents for Izmir province were estimated in the range of 0.7 to 12.3 mSv year^?1 with a mean of 5.3 mSv year^?1. In this study, it is pointed out that indoor radon concentration was affected by the age of the building and height above the ground.     

Radiation dose contribution from coal-slags used as structural building material

A significant dose contribution on the population could be derived from coal slags used as isolation material. Extremely high natural activities are measured in the coal slag, derived from the region of the settlement Ajka, Hungary. In some buildings monitored, the elevated -doses were nearly 5–10 times higher than the world average ones. The annual average indoor radon concentrations from the slag exceeded 400 Bq/m³ and in some cases up to 1200 Bq/m³. Due to the elevated exposure and the radon concentrations in the dwellings the annual dose was estimated to 8–24 mSv/y more than 5–10 times of the world average one.     

Fast liquid chromatographic determination of radiochemical and chemical purity of [11C]methionine by UPLC technique

Salinity, water logging, high nitrate, fluoride and dissolved uranium concentration in drinking water of southwest Punjab has impacted the local population leading to health issues and additional burden on economy. Though it was known that both U and its daughter products especially Rn contribute to radiological dose to the population through drinking water, there were no correlation studies carried out between these radioactive elements in U impacted regions of southwest Punjab. In this study, an initiative has been taken to assess the doses due to dissolved radon in drinking water. In addition, the U–Rn couple is evaluated in detail along with other hydrochemical parameters. The radon concentration ranges from 360–1700 Bq/m³ for Faridkot and 140–1400 Bq/m³ for Muktsar for both seasons and the related average total dose due to radon for both season of Faridkot and Muktsar are 9.79 µS/year and 7.74 µS/year respectively. The total dissolved uranium is in range of 16–350 µg/L for Faridkot and 14–106 µg/L for Muktsar for both seasons. An inverse correlation was observed between Rn and U, which could be attributed to diverse geochemistry of U and Rn in groundwater.

     

Measurements of indoor radon concentration levels in Kilis,Osmaniye and Antakya,Turkey during spring season

The fact that 50% of the natural radiation dose to which humans are exposed is caused by radon gas makes indoor radon measurements important. In this study, levels of indoor radon gas were measured in 204 houses in Kilis, Osmaniye and Antakya using passive nuclear track detectors. Cr-39 radon detectors were left in the living rooms of participants’ houses, then analyzed at the Radon Laboratory of Health Physics Department in Çekmece Nuclear Research and Training Center (ÇANEM) of Atomic Energy Agency of Turkey (TAEK). Average indoor radon activity concentrations for Kilis, Osmaniye and Antakya were 50 Bq/m³ (1.26 mSv/y), 51 Bq/m³ (1.29 mSv/y) and 40 Bq/m³ (1.01 mSv/y), respectively.     

A study of indoor radon in greenhouses in Mexico City, Mexico

Enclosed spaces in contact with soil, the main source of radon, like greenhouses have potentially high radon (²²²Rn) concentrations. Greenhouses are frequented by visitors and also are workplaces. The study of radon concentrations in greenhouses is, thus, a relevant concern for public health and environmental radiation authorities. For this study, the radon concentrations in 12 greenhouses in different locations within Mexico City were measured using nuclear track methodology. The detectors used for the study consisted of the well-known closed-end cup device, with CR-39 Lantrack^® as detector material. The measurements were carried out over a period of one year, divided into four three-month sub-periods. The lowest and highest annual mean radon concentrations found in individual greenhouses were 17.0 and 45.1 Bq/m³, respectively. The annual mean averaged over all 12 greenhouses was 27.3 Bq/m³. No significant seasonal variation was observed. Using the highest annual mean radon concentration found in an individual greenhouse, and an equilibrium factor of 0.4, the effective dose from ²²²Rn and its progenies was calculated to be 339.9 nSv/h. This corresponds to an annual dose rate of 679.8 μSv/y (0.057 WLM/y) for a worker spending 4 h a day, 5 days a week, 50 weeks a year, inside the greenhouse. For a visitor spending 12 h a year inside the greenhouse the annual dose is 2.469 μSv/y. The study of indoor radon concentrations in closed buildings such as greenhouses, which are both workplaces and open to visitors, is an important public health consideration.     

Calibration technique for a CR-39 detector for soil and water radon exhalation rate measurements

The calibration factor of 0.029 ± 0.0002 track cm^?2 per Bq d m^?3 for radon concentration measurements was determined using CR-39 and RAD7 detectors. The ²²²Rn concentration varied from 2,225 to 9,950 and 12 to 1,002 Bq m^?3 in soil and water, respectively. The highest radon exhalation and gamma dose rates were found in Acid and undifferentiated granitic rocks and Miscellaneous soils.     

Gamma radiation and radon levels in Mexico City dwellings

Gamma exposure rate and radon levels were measured in 75 single-family dwellings in Mexico City in order to correlate them with local environment. Radon monitoring was performed both indoors and outdoors using a continuous working level monitor for short-lived radon decay products; the gamma exposure rate was measured using CaSO₄: Dy+PTFE. The results obtained show a log-normal distribution. The mean indoor radon concentration is lower than 45 Bq/m³ and the mean indoor gamma exposure rate was 11.29 R/h.     

An unusual case of indoor air radon contamination: An unusual method for effective mitigation

In the course of routine surveillance for indoor radon in Austria, concentrations above 10,000 Bq/m³ were found in a house in the province of Carinthia, Austria. Multiple 3-day-measurements in all the rooms of the house were carried out for the next 21 months. All rooms of the house had elevated radon concentrations but radon levels decreased systematically from east to west within the house. Moreover, radon concentrations in one room of the building were found to be below 300 Bq/m³ in winter but above 12,000 Bq/m³ in summer. After installing a medium sized fan, operated only during the summer season, the semiannual summer radon levels dropped from approximately 8,000 Bq/m³ to 250 Bq/m³ at ground floor level. Note: The paper reflects the personal opinions of the authors.     

Radon survey in office room and effective dose estimation for staff

This study aims to: (1) Acquire the radon level in closed office rooms, providing radon exposure data for preliminary health risk assessment of office-working population. (2) Pre-analyze the relationship between radon concentration and indoor temperature, relative humidity. (3) Estimate seasonal, annual and total radon effective dose for ordinary office-working population. The results show that the 24-h or 8-h average radon concentrations in closed office rooms were about 32.0 Bq/m³ and 29.5 Bq/m³ during detection period, and the estimated effective doses in office rooms calculated by using 24-h and 8-h average radon concentrations were all far below that in residential environment.

     

Exposure to underground radon in and around Kolkata Municipal Corporation area: an exhaustive study

Air radon survey was carried out at different underground locations at Kolkata using radon monitor. Average radon concentration for basements was found to be 22.70 ± 1.12 Bq/m³ with maximum 59.00 ± 7.18 Bq/m³ and minimum 8.50 ± 3.14 Bq/m³. Average level for sub-ways was 23.05 ± 2.59 Bq/m³ fluctuating between maximum 39.00 ± 1.24 Bq/m³ and minimum 13.50 ± 1.78 Bq/m³. In comparison, open air background at basement entrance was 19.44 ± 1.06 Bq/m³ and subway entrance was 18.58 ± 1.14 Bq/m³. Annual effective dose was calculated to assess probable health risk. Radon concentration level and annual effective dose were found well below safe levels recommended by International Agencies WHO and UNSCEAR.

     

Radon measurements in groundwater

A device was developed for the collection, containment, and bubbling of radon from groundwater samples to facilitate concentration measurements in the field without the need for fragile glassware. Wellwater supplies were collected in high-potential areas of New York State in a comparison of the device with traditional methods (liquid scintillation and laboratory-based Lucas-cell counters). Waterborne radon levels to 4100 Bq L^–1 reveal the potential contribution to indoor air from everyday water use in a home, as levels of 1500 Bq L^–1 contribute about 150 Bq m^–3 (the EPA-recommended limit) to indoor-air radon levels. With a Geographic Information System (GIS), spatial coordinates from each site are used to correlate concentrations with bedrock geology.     

Enhanced indoor radon concentration by using radon-rich well water in a Japanese wooden house in Fukuoka, Japan

Summary Radon measurements were carried out in a Japanese wooden house built on granitic geology, where radon-rich well water is used. Atmospheric radon concentrations were measured over one year with passive integrated radon monitors. The monitors were distributed at several locations in the house and were replaced every two months. In order to confirm the diurnal variation and heterogeneous distribution of radon, short-term measurements were carried out accordingly. Radon, its decay products and terrestrial gamma-radiations were measured in this survey. From the long-term measurement, the radon concentration in the house ranged from 14 to 184 Bq^. m^-3with an arithmetic mean of 45 Bq^. m^-3. A radon concentration of 184 Bq^. m^-3was observed in the bathroom in spring (March-May) though the radon level was normal in the living room and bedroom. In order to characterize the house, similar measurements were conducted in several surrounding houses. There was a significant difference in radon concentration between the investigated houses. There was a spatial distribution of the radon concentration and the highest value was found in the bathroom. Radon and its decay products concentrations varied with time, which increased from midnight to morning whereas they decreased during daytime. Although the radon concentration in tap water was 1 Bq^. l^-1, a high level of 353 Bq^. l^-1was found in the well water.While well water was being used, the indoor radon concentration near the bathroom increased rapidly with a maximum value of 964 Bq^. m^-3. It is clear that the use of well water enhanced the radon level around the bathroom.     

Assessment of Summer Trends of Tropospheric Radon Isotopes in a Coastal Antarctic Station (Terra Nova Bay)

This work reports the first results of atmospheric radon measurements performed at the Italian Antarctic station located at Terra Nova Bay (74.69°S; 164.12°E) during summer campaigns of 1995-96, 1996-97 and 1997-98. Mean²²²Rn concentrations was 0.51 - 0.43 Bq m^m3 (median = 0.37 Bq m^m3), and ranged from 0.01 to 2.74 Bq m^m3 . On the average, these values were considered high, in comparison to results reported for other sites in Antarctica at equivalent latitudes. This could be explained by two causes: radon data for Terra Nova Bay were only for the summer period, when the ice-free area is at its maximum and thus the radon emission to the atmosphere; and by the larger ice-free area at Terra Nova Bay compared, for example, to measurements taken at another Antarctic site by the same technique (Ferraz station - 62°05'S; 058°23.5'W). The mean ²²²Rn to ²²⁰Rn activity ratio was 4.4 - 4.2, ranging between 0.1 and 45.3. The highest ratios indicated that some of observed surges of concentration of ²²²Rn could be attributed to not local sources. Lower radon concentrations were observed during katabatic wind events. The diurnal radon variation followed the general trend observed for continental areas located at lower latitudes.     

Radon concentrations in kindergartens of Osijek and Ljubljana

Indoor radon concentrations in the kidergartens of Osijek, Croatia, have been measured with -scintillation cells, LR-115 nuclear track detectors, as well as a Radhome semiconductor detector. Average values of 50.2, 43.7 and 47 Bq m^–3 were obtained, respectively. Under the worst conditions, the annual radon effective dose equivalent was 10 mSv y^–1. Using bare and filtered LR-115 detectors, the average equilibrium factor was assessed as 0.36 indoors. Measurements of the -dose rate in the kindergartens did not show any significant correlation with the radon concentration. Indoor radon concentrations in the kindergartens of Ljubljana, Slovenia, measured by scintillation cells had an arithmetic mean and standard deviation of 228 and 143 Bq m^–3, respectively.     

The daily radon dose in body organs caused by drinking milk and water

Milk is considered as the richest nutrition, being used by people. When drinking milk or water the radon gas will transfer from air to them rapidly. Since milk is majorly composed of water, probably radon existence in livestock consumable water could be the main cause of its presence in milk. Different portion of milk changed by radon gamma ray and consumption of radon included water or milk has its effects on the human body. For investigation the effect of radon in water or milk on human organs, this study has been done in two phases with MCNPX software. In the first phase, the dose rate of absorbed gamma ray by different portion of milk which is indoctrinated by 1 Bq/m³ of radon during a day is calculated. Moreover, the effects shown by milk and its components in radon gamma spectrum, which is demonstrator of milk absorption spectrum, are also surveyed. In the second phase as well, according to the human body phantom, the absorbed gamma dose caused by daily consumption of indoctrinated water or milk with 1 Bq/m³ radon is calculated. The production rate of free radicals in milk and its different components are derived according to escape data of MCNPX code.     

Ground level ozone (O3) associated with radon (222Rn) and particulate matter (PM) concentrations in Bucharest metropolitan area and adverse health effects

The aim of this paper is to contribute with new information in the application of ground based radon (²²²Rn) observations to atmospheric research, namely its relation with air pollution due to ground-level ozone (O₃) and particle matter in two size fractions (PM10 and PM2.5) for Bucharest metropolitan area in Romania. During January 1–December 31, 2011, ground levels of radon, ozone and particulate matter (PM) have been continuously monitored in synergy with the main meteorological parameters (air temperature, humidity and pressure), and daily global air quality indices. A systematic analysis of surface ozone observations of ground level radon, ozone and PM is presented. Observational results indicate the following yearly daily mean ground level concentrations: 40.26 ± 7.54 Bq/m³ for radon, 90.51 μg/m³ for ozone, 35.96 μg/m³ for PM2.5, and 40.91 μg/m³ for PM10. The assessment of the results showed the influence of local and meteorological conditions on the daily mean radon, ozone and PM concentrations. However, in densely populated metropolitan area of Bucharest the mean daily values of ozone, PM2.5, PM10, and attached ²²²Rn are sometimes higher than European Community limit values leading to serious public concern during the last years. Due to the high risk of increased levels of O₃, PM2.5, PM10, and attached ²²²Rn on human health respiratory function (especially for children and older persons), and urban green, the results are very useful for atmospheric, radiological protection, epidemiological and environmental studies.     

Use of 222Rn to trace submarine groundwater discharge in a tidal period along the coast of Xiangshan, Zhejiang, China

²²²Rn is one of the operative tracers for submarine groundwater discharge (SGD), which plays a significant role in the land–ocean interaction of the estuarine and coastal regions. By the distribution pattern of ²²²Rn in atmosphere, groundwater and surface seawater, in a full tidal period (25 h) in March 2012, SGD was estimated along the coast of Xiangshan, Zhejiang, China. ²²²Rn activity in Xiangshan coast was in range of 2.4 × 10⁴–1.7 × 10⁵ Bq/m³ with an average of 9.6 × 10⁴ Bq/m³ for groundwater; 0.2 × 10²–2.8 × 10² Bq/m³ with an average of 1.1 × 10² Bq/m³ for surface seawater. ²²²Rn activities in groundwater were much greater than those in surface water, suggesting that the major source of radon came from coastal groundwater discharge. Rn fluxes of atmospheric emissions, sediment, and of ²²⁶Ra in situ decay can be negligible in this study, but the tidal effects play a crucial role in Rn fluxes. Using a radon inventory equilibrium model, we estimated that the average SGD was 13.2 cm/day and the average terrestrial SGD flux was 1.8 × 10⁸ m³/day. Furthermore, SGD may have a vital impact on the composition and structure of nutrients in seawater, and contribute to eutrophication events occurring in spring season along the coast of the East China Sea.