Experimental and Monte Carlo simulation studies of open cylindrical radon monitoring device using CR-39 detector

Evaluation of radon gas concentration in indoor air of spas and in spring water in the central Anatolia region of Turkey

The present study aimed to determine the concentration of radon (²²²Rn) 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/m³ and 15.5 ± 2.1 Bq/m³, respectively, while in the air of Kemerhisar, Helvadere, and Okcu village spring water sites the average radon concentrations were 32 ± 4.2 Bq/m³, 265 ± 37.9 Bq/m³, and 35 ± 5.1 Bq/m³, 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.

Anomalous indoor radon concentration in a dwelling in Qatif City, Saudi Arabia

An indoor radon survey was carried out recently in nine cities of Saudi Arabia using nuclear track detectors (NTD)-based passive radon detectors. The survey included Qatif City in the Eastern Province of Saudi Arabia, where 225 detectors were collected back successfully. It was found that the average indoor radon concentration in the dwellings was 22 +/- 15 Bq m(-3). However, one of the dwellings showed an anomalous radon concentration of 535 +/- 23 Bq m(-3). This finding led to a detailed investigation of this dwelling using active and passive techniques. In the active technique, an AlphaGUARD 2000 PRQ radon gas analyser was used. In the passive technique, CR-39 based passive radon detectors were used in all the rooms of the dwelling. Radon exhalation from the wall and the floor was also measured using the can technique. The active measurement confirms the passive one. Before placing the passive radon detectors in all the rooms of the two-storey building, the inhabitant was advised to ventilate his house regularly. The radon concentration in the different rooms was found to vary from 124 to 302 Bq m(-3). Radon exhalation from the floor and the wall of the room with the anomalous radon concentration was found to vary from 0.5 to 0.8 Bq m(-2) h(-1). These low radon exhalation rates suggest that the anomalous radon concentration is most probably due to underground radon diffusion into the dwelling through cracks and joints in the concrete floor.

Application of the can technique and radon gas analyzer for radon exhalation measurements

A passive "can technique" and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bqm(-2)h(-1) with an average of 1.35+/-1.40 Bqm(-2)h(-1). The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.