The average indoor radon concentration in Finnish flats is 80 Bq/m3. Typically walls have been madeusing concrete elements. Building materials are the dominant source of indoor radon. However, in theflats of the lowest floor, with a floor slab in direct ground contact, the main source of radon is oftenthe inflow of radon bearing soil air. The number of these ground contact flats is less than 10 % of thetotal number of flats. The average indoor radon concentration of these ground contact flats is 150Bq/m3.
Since 1994 the Radiological Protection Institute of Ireland has been conducting a pilot programme ofpersonal monitoring of workers in workplaces with high radon concentrations. Initially theprogramme involved staff employed by the operators of commercial show caves, but in January 1999it was extended to incorporate non-show cave workers when employees in aboveground offices in twosmall Departments in an Irish University were included.Personal monitoring of show cave staff confirmed the fact that employees in two caves receivedannual radiation doses in excess of 4 mSv.
A national radon survey is still lacking for Greece. Some Groups have done several more or lesslocal or extended radon surveys and valuable experience has been gained (Anagnostakis et al.1996, Papastefanou et al. 1997, Louizi 1997). After the first preliminary survey done by ourgroup (Geranios et al.
A preliminary indoor radon survey in Greece based on 258 passive detectors, to test the technique andthe statistics, is presented. This paper is an extension of an initial survey (Geranios et al. 1999). Themajority of the detectors were placed in schoolrooms and dwellings for a yearlong (June 1997-June1998). The part of our sample concerning the northern region of Greece tends to indicate higher radonconcentrations than the rest part of the country. The radon concentration distribution fits well to thetheoretically expected lognormal.
High concentrations of natural radionuclides in building materials result in high dose rate indoorsdue to radon and thoron exhalation and the ?-rays emitted from them. Among the naturalradionuclides contained in building materials, most attention has been given to 226Ra due to 222Rnexhalation and the subsequent internal exposure. In external dose calculations due to buildingmaterials it is usually assumed that there exists radioactive equilibrium among the radionuclides ofboth the uranium and thorium series.
The Megalopolis lignite field basin in southern Greece, with Megalopolis-A and B lignite-firedpower plants in operation (total 900 MW), has been repeatedly investigated during the past 25years by the Nuclear Engineering Section of the National Technical University of Athens (NESNTUA).The present work aims at an integrated radioenvironmental approach leading to the doseassessment to the public and to the plants staff.
According to the recommendations of the ICRP and the German Commission on RadiologicalProtection, areas should be identified where increased radon concentrations in buildings occur morefrequently than on the country-wide average. Such regions are characterized by an increased radonpotential of the building ground. The highest indoor concentrations were measured in old houses ofgranitic ground and in mining regions.The identification of such areas in the first step is based on a small-scale investigation of the geogenicradon potential.
Analysis of a comprehensive database containing all available indoor radon measurements which were carried out in Israel between 1989 and 1994 (total of 31,842 assays) coupled with Geographical Information System (GIS) capabilities and geophysical data, shows a significant correlation between indoor radon levels and its levels in the underlying bedrock.
In the last twenty years the interest of the international scientific community on naturally occurring radioactive materials (NORM) in the environment and industry has been ever growing. In particular, the use of gamma-ray spectrometry techniques for activity measurements of gamma emitters belonging to uranium and thorium decay series greatly contributed to these investigations.
A dwelling in M?traderecske in the Hungarian north-east region was selected to study the radon daughter (RD) behaviour in a family room with natural low ventilation under living conditions. The selected house is erected on a geology where a relatively high radon concentration with yearly average of 1KBq/m3 exists. The room is considered a natural radon chamber where the most convenient environmental conditions are. Radon concentration was measured continuously by a monitor (Atmos10, Gammatechnik Sweden and Pylon Electronics of Canada).
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