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In selected kindergartens and schools, long-term average indoor air radon concentrations were measured by two-month exposure of etched track detectors. Short-term average concentrations were obtained from 7-10 day continuous radon recordings during the exposure of etched track detectors. Only in about 1/3 of cases both averages did agree within ±20%; otherwise they differ considerably. The assumption that short-term results can substitute for long-term data, which is sometimes made to correct radon exposure estimated on the basis of concentrations obtained by etched track detectors, should therefore be treated with caution. [ABSTRACT FROM AUTHOR]

The health risk from thoron (Rn-220) is usually ignored owing to its short half-life (55.6 s), but the generated thoron decay products can cause a significant dose contribution. In this study, altogether 51 Slovenian soil samples were investigated using an accumulation chamber technique to obtain information about thoron exhalation features. The obtained (massic) thoron exhalation results varied between 6.9 and 149 mBq·kg−1·s−1 (average: 55.2 mBq·kg−1·s−1). The Th-232 content was determined using HPGe gamma spectrometry. The Th-232 activity concentration ranged between 9.3 and 161.7 Bq·kg−1 (average: 64.6 Bq·kg−1). The thoron emanation features were also calculated from the obtained results (2.9 to 21.2% with an average of 8.6%). The thoron exhalation and emanation properties were compared with the radon exhalation and emanation features determined in a previous study. It was found that there was no correlation between the radon and thoron emanation features, according to the obtained data. This can be explained by the different Ra-224 and Ra-226 distributions in the soil grains. As a result, the thoron emanation factor cannot be predicted from radon emanation and vice versa.

Abstract: It is well known that Slovenia and particularly Hungary have vine regions, where most inhabitants are involved in vine production. The aim of the study was to identify the radon level differences between cellar types and to estimate the dose to the workers. [Copyright &y& Elsevier]

The Slovenian Radon Programme started in 1990. Since then, radon and radon short-lived decay products have been surveyed in 730 kindergartens, 890 schools, 1000 randomly selected homes, 5 major spas, 26 major hospitals, 10 major municipal water supply plants, and 8 major wineries. Alpha scintillation cells, etched track detectors, electret-based detectors and various continuously measuring devices have been used. On the basis of estimated effective doses, decisions were made on appropriate mitigation. In total, 35 buildings have been appropriately modified. The programme is displayed and results reviewed chronologically and discussed.

Due to the specific work regime in the Postojna Cave, which depends primarily on the daily number of visitors, and on seasonal variationsin air radon concentrations, an optimal methodology for radon and progeny measurement and dose calculation was sought. The program of measurement throughout the years was optimized, and now comprises 3-mo exposures of etched-track detectors, and twice a year, 8-10-d measurements using continuous monitors. Radon concentrations range from about500 Bq m-3 in winter to about 6,000 Bq m-3 in summer, and equilibrium factors range from 0.42 to 0.69 in winter andfrom 0.33 to 0.86 in summer. Radiation doses from radon decay products for employees in the cave were calculated according to the ICRP 65methodology. The basic input data are radon concentrations and equilibrium factors at two selected locations in the cave and the records of the time spent by a worker in the cave. Effective doses received by employees annually ranged from 0.02 to 8.4 mSv. [ABSTRACT FROM AUTHOR]