Radon in well waters in the Kraków area

Dose assessment from exposure to uranium and radon in groundwater in Safi province, Morocco

In this study we evaluate the uranium and radon concentrations in groundwater from the Province of Safi. The samples were collected from 58 wells across five communes and analyzed using the LR-115 type II detector. Results indicate that uranium concentrations ranged from the Limit of Detection (LLD) to 3.73 µg/l, with a mean of 0.72 µg/l, well below the World Health Organization's safe limit of 30 µg/l. Radon levels varied from LLD to 2.39 Bq/l, with an average of 0.60 Bq/l, also below the United States Environmental Protection Agency's limit of 11 Bq/l. The estimated total annual effective dose due to uranium and radon ranged from 3.47 to 18.84 µSv/y, with an average of 7.54 µSv/y, which is significantly lower than the European Commission's recommended limit of 100 µSv/y. This investigation represents the first study of uranium and radon levels in groundwater in the Province of Safi, providing valuable data for future research and public health.

Estimation of the annual effective dose from exposure to radon in drinking water in Croatia

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.

Occurrence of 222Rn and 226,228Ra in underground water and 222Rn in soil and their mutual correlations for underground water supplies in southern Greater Poland

European Union Council Directive 2013/51/EURATOM recently sets out so-called indicator parameters for: radon, tritium and indicative dose of water intended for human consumption. The aim of this research was to elaborate an effective procedure for determination of radon and radium ^226,228Ra isotopes (which are potentially the main contributors to the internal dose from drinking and cooking water) and to find the possible relationships between these radionuclides in underground water reservoirs and ²²²Rn concentration in the soil gas in their vicinity. The research was performed by applying a non-volatile and water-immiscible scintillation cocktail based on a pure diisopropylnaphthalene (Ultima Gold F: UGF), which allow for efficient radon extraction from 0.5 dm³ of water samples to 20 cm³ of scintillation phase and its direct determination with a detection limit of 5 × 10^-3 Bq dm^-3. The further preliminary concentration of 3 dm³ of crude water samples by evaporation to 0.5 dm³ samples led to the removal of all unsupported ²²²Rn activity and allowed the ²²⁶Ra determination via equivalent ²²²Rn detection after one-month samples storage using a low-background Triathler liquid scintillation counter in the α/β separation counting mode. Together with determination of ²²⁶Ra isotope in water samples, the simultaneous measurements of ²²⁸Ra and ²²²Rn radionuclides concentrations in water as well as ²²²Rn activity in the soil gas around the water supply sites were performed. The achieved limit of ²²⁶Ra detection was at a very low level of 10^-3 Bq dm^-3. The measured values of ²²⁶Ra concentration in 50 public underground water supply units for the Kalisz district of Poland were relatively low and ranged from below detection limit to 28.5 × 10^-3 Bq dm^-3 with arithmetic mean and median values of 12.9 and 12.2 × 10^-3 Bq dm^-3, respectively. Weak correlations were observed between activity concentrations of ²²⁶Ra and ²²²Rn in the crude water samples (R² = 0.31) and ²²²Rn in water and its concentration in the nearby soil gas (R² = 0.48).

A method for long-term high resolution 222Radon measurements using a new hydrophobic capillary membrane system

Radon (R86222n) as a hydrological tracer offers a method for studying short to medium term groundwater - surface water interactions. These high frequency processes play an important role in wetland hydrology and biogeochemistry and may influence their contribution to the global carbon cycle. Therefore, there is a definite need for robust methods to measure high resolution ²²²Rn time series in-situ. In this study we adapted and improved a membrane system to measure ²²²Rn continuously with a primary focus on a rapid response time and low power consumption. The membrane system was constructed using a hydrophobic capillary membrane and laboratory experiments were conducted to quantify the systems' response time to predefined ²²²Rn pulses. It was then deployed in a stream draining a riparian wetland. The new membrane system could reduce the response time by ≈ 60 % in comparison to the established silicone membrane. We could identify the behaviour of the system in response to dynamically changing ²²²Rn activities and suggest a new method using simple linear regression to quantify the systems' response when the response time concept is inapplicable. Finally, we were able to measure high temporal resolution ²²²Rn activities reliably over an extended field deployment (68 d). We conclude that the improved system fills a gap ensuring high temporal resolution while maintaining extended maintenance intervals. This allows the user to study high frequency hydrological processes in remote areas. This new membrane system can be used to detect fast changes in ²²²Rn activities improving the comprehension of the underlying hydrological processes.

Radioactivity measurements and risk assessments of spa waters in some areas in Turkey

The current study presents the results of the activity of radionuclides in spa waters, and evaluates their radiological influences on the population consuming these waters in the Central and Eastern Black Sea regions of Turkey. Since these waters are used for therapy and consumption purposes unconsciously, their radiological impact on the people was computed by taking into consideration the annual intake through ingestion of ²²⁶Ra, ²³²Th, ⁴⁰K, ¹³⁷Cs and ²²²Rn. The mean activities were estimated to be 11.35 for gross alpha, 6.23 for gross beta, 2.96 for ²²⁶Ra, 0.42 for ²³²Th, 0.069 for ¹³⁷Cs, 0.19 for ⁴⁰K, and 267 Bq L^-1 for ²²²Rn, respectively. The estimated effective doses from spa water were found to be 49.77 µSv a^-1 (²²⁶Ra), 5.95 µSv a^-1 (²³²Th), 0.07 µSv a^-1 (¹³⁷Cs), 0.83 µSv a^-1 (⁴⁰K) and 56.03 µSv a^-1 (²²²Rn). These values were evaluated and compared with related verified values from literature. Also, physico-chemical characterizations of spa water samples considered in the current study were investigated. This study would be useful for consumers and official authorities for the assessment of radiation exposure risk due to usage of the considered spa waters.

Radon Research in Poland: A Review

The article presents the most important results of radon research in Poland. Large-scale research, launched in this country in the early 1950s, was originally linked to using radon dissolved in groundwater in balneotherapy as well as to uranium ore exploration and mining. This early research focused on the area of the Sudetes and nowadays it is also south-western Poland where most radon research is being conducted. This is chiefly due to the geological structure of the Sudetes and the Fore-Sudetic block, which is propitious to radon accumulation in many environments. Radon research in Poland has been developing dynamically since the 1990s. A lot of research teams and centres have been formed, all of them using a variety of methods and advanced measurement equipment enabling research into radon occurrence in all geospheres and all spheres of human activity. The author presents the contribution of Polish science to broadening human knowledge of the geochemistry of radon, particularly of 222Rn isotope. The article also presents the ranges and mean values of 222Rn activity concentration measured in different environments in Poland including the atmospheric air, the air in buildings and underground hard-coal and copper mines, the cave air, the air in underground tourist sites and abandoned uranium mines, as well as soil air and groundwater.

Measurements of radon concentrations in waters and soil gas of Zonguldak, Turkey

The radon concentrations in soil-gas and water samples (in the form of springs, catchment, tap, thermal) used as drinking water or thermal were measured using a professional radon monitor AlphaGUARD PQ 2000PRO. The measured radon concentrations in water samples ranged from 0.32 to 88.22 Bq l(-1). Most of radon levels in potable water samples are below the maximum contaminant level of 11 Bq l(-1) recommended by the US Environmental Protection Agency. The calculated annual effective doses due to radon intake through water consumption varied from 0.07 to 18.53 µSv y(-1). The radon concentrations in soil gas varied from 295.67 to 70 852.92 Bq m(-3). The radon level in soil gas was found to be higher in the area close to the formation boundary thrust and faults. No correlation was observed between radon concentrations in groundwater and soil gas. Also, no significant correlation was observed between soil-gas radon and temperature, pressure and humidity. The emanation of radon from groundwater and soil gas is controlled by the geological formation and by the tectonic structure of the area.

Radon (222Rn) in underground drinking water supplies of the Southern Greater Poland Region

Activity concentration of the ²²²Rn radionuclide was determined in drinking water samples from the Sothern Greater Poland region by liquid scintillation technique. The measured values ranged from 0.42 to 10.52 Bq/dm³ with the geometric mean value of 1.92 Bq/dm³. The calculated average annual effective doses from ingestion with water and inhalation of this radionuclide escaping from water were 1.15 and 11.8 μSv, respectively. Therefore, it should be underlined that, generally, it’s not the ingestion of natural radionuclides with water but inhalation of the radon escaping from water which is a substantial part of the radiological hazard due to the presence of the natural radionuclides from the uranium and thorium series in the drinking water.

Determination of radon concentration levels in well water in Konya, Turkey

Radon ((222)Rn) measurements were undertaken in 16 samples of well water representing different depths and different types of aquifers found at the city centre of Konya, Central Turkey. The radon activity concentrations of the well water samples collected in the spring and summer seasons of 2012 were measured by using the radon gas analyser (AlphaGUARD PQ 2000PRO). The radon concentrations for spring and summer seasons are 2.29 ± 0.17 to 27.25 ± 1.07 and 1.44 ± 0.18 to 27.45 ± 1.25 Bq l(-1), respectively. The results at hand revealed that the radon concentration levels of the waters strictly depend on the seasons and are slightly variable with depth. Eleven of the 16 well water samples had radon concentration levels below the safe limit of 11.11 Bq l(-1) recommended by the United States Environmental Protection Agency. However, all measured radon concentration levels are well below the 100 Bq l(-1) safe limit declared by the World Health Organisation. The doses resulting from the consumption of these waters were calculated. The calculated minimum and maximum effective doses are 0.29 and 5.49 µSv a(-1), respectively.

Measurements of radon concentration levels in thermal waters in the region of Konya, Turkey

(222)Rn (radon) is one of the most important sources of natural radiation to which people are exposed. It is an alpha-emitting noble gas and it can be found in various concentrations in soil, air and in different kinds of water. In this study, we present the results of radon concentration measurements in thermal waters taken from the sources in the region of Konya located in the central part of Turkey. The radon activity concentrations in 10 thermal water samples were measured by using the AlphaGUARD PQ 2000PRO radon gas analyser in spring and summer of the year 2012. We found that radon activity concentrations range from 0.60±0.11 to 70.34±3.55 kBq m(-3) and from 0.67±0.03 to 36.53±4.68 kBq m(-3) in spring and summer, respectively. We also calculated effective doses per treatment in the spas for the spring and summer seasons. It was found that the minimum and maximum effective doses per treatment are in the range of 0.09-10.13 nSv in spring and in the range of 0.1-5.26 nSv in summer.

Determination of the minimum measurement time for estimating long-term mean radon concentration

Radon measurements, as do any measurements, include errors in their readings. The relative values of such errors depend principally on the measurement methods used, the radon concentration to be measured and the duration of the measurements. Typical exposure times for radon surveys using passive detectors [nuclear track detectors, activated charcoal, electrostatic (E-perm), etc.)] may extend from a few days to months, whereas, in the case of screening methods utilising active radon monitors (AlphaGUARD, RAD7, EQF, etc.), the measurements may be completed quickly within a few hours to a few days. Thus, the latter may have relatively large error values, which affect the measurement accuracy significantly compared with the former measurements made over long time periods. The method presented in this paper examines the uncertainty of a short-term radon measurement as an estimate of the long-term mean and suggests a minimum measurement time to achieve a given margin of uncertainty of that estimate.

Evaluation of radon concentration in well and tap waters in Bursa, Turkey

(222)Rn measurements in water samples collected from 27 wells and 19 taps that were supplied from the investigated wells were conducted using the AlphaGUARD PQ 2000PRO radon gas analyser at sites across several geologic formations within the city of Bursa, Turkey. The measured radon concentrations ranged from 1.46 to 53.64 Bq l(-1) for well water and from 0.91 to 12.58 Bq l(-1) for tap water. Of the 27 sites sampled, only 7 had radon levels above the safe limit of 11.1 Bq l(-1) recommended by the USEPA. In general, all determined concentrations were well below the 100 Bq l(-1) revised reference level proposed by the European Union. These values of radon concentrations in water samples are compared with those reported from other countries. Doses resulting from the consumption of these waters were calculated. The minimum and the maximum annual mean effective doses due to (222)Rn intake through water consumption were 0.02 µSv a(-1) and 1.11 µSv a(-1), respectively.

Measurements of radon concentration in drinking water samples from Kastamonu (Turkey)

Concentration of (222)Rn was determined in selected natural spring and tap water samples collected during spring and summer seasons from Kastamonu, Turkey. The aim of this work was to produce a map of the radon concentrations in water sources of the province and to determine any potential radiological risk for the local population. Radon measurements were performed by an AlphaGUARD radon gas analyser. The average radon concentrations were found to vary from 0.39±0.02 to 12.73±0.39 Bq l(-1) for natural springs and from 0.36±0.04 to 9.29±0.45 Bq l(-1) for tap water in spring, from 0.50±0.09 to 19.21±1.00 Bq l(-1) for natural springs and from 0.31±0.03 to 13.14±0.38 Bq l(-1) for tap water in summer. Furthermore, the results are compared with international recommendations and concentrations reported for other countries. Doses resulting from the consumption of these waters were calculated. The effective dose equivalents due to the intake of the (222)Rn present in these waters are expected to range from 0.93 to 32.54 μSv y(-1) in summer and from 0.80 to 49.09 μSv y(-1) in spring.

High natural radiation exposure in radon spa areas: a detailed field investigation in Niska Banja (Balkan region)

The measurement campaigns have been done in the rural community of Niska Banja, a spa town located in southern Serbia, to evaluate population exposure to natural radioactivity. After a screening survey in 200 houses, annual radon and thoron concentrations were measured in 34 houses, and in 2004 a detailed investigation was carried out at six houses with elevated indoor radon concentrations. The paper presents the results of these detailed measurements. The complementary techniques were applied to determine radon and thoron concentrations in indoor air, in soil gas, radon exhalation from soil, soil permeability, and indoor and outdoor gamma doses. Soil and water samples were collected and analysed in the laboratory. Indoor radon and thoron concentrations were found to be more than 1kBqm(-3) and 200Bqm(-3), respectively. Extremely high concentrations of soil-gas radon (>2000kBqm(-3)) and radon exhalation rates (1.5mBqm(-2)s(-1)) were observed. These results will be utilised to set up the methodology for a more systematic investigation.