Investigations on the retrospective estimation of radon exposure in homes had already been carried outin international collaboration in the uranium mining regions of Germany since 1994. Following aConcerted Action named "Retrospectively Estimated Radon in Areas Affected by Uranium MiningActivities " was agreed upon.
The retrospective determination of radon exposure levels in dwellings by means of the measurement ofthe Po-210 surface activity is subject to various uncertainties. These result partly from the valuesassumed for the equilibrium factor F and for the unattached fraction f, and, more importantly, fromdifferences in the deposition velocities of short-lived decay products of Rn-222, caused by varyingconditions of turbulence.
The work described in this paper is based upon the results of the recently completed National Surveyof Radon in Dwellings [1] carried out by the Radiological Protection Institute of Ireland (RPII).Measurements were carried out in 11,054 dwellings, located in 832 10 km grid squares across thecountry.
This paper presents the results of the National Survey of Radon in Dwellings carried out by theRadiological Protection Institute of Ireland (RPII). Radon measurements were carried out in 11,319houses throughout the country. Indoor annual average radon concentrations ranged from 10 Bq/m3 to1924 Bq/m3. The measurement data were grouped on the basis of the 10 km grid squares of the IrishNational Grid System and used to predict the percentage of dwellings in each grid square which exceedsthe Reference Level of 200 Bq/m3.
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.
In the Bihor uranium district there are an operating underground mine and the closed down open pit mine. The open pit mine was operated by the Soviets between 1952-1964, the ore being "exported" to the Soviet Union. The mean content of the uranium ore was 2%. The "waste rocks" from the open pit mine were used by the natives in the foundations of detached houses in rural areas. The goal of the survey was to identify this houses and to make radon and gamma dose rate measurements to assess the annual effective doses incured by the public.
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.
Login