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The effect on fertility of chronic exposure of female Wistar rats in “Avram Iancu” uranium mine to high Radon-222 and Radon-222 progeny concentrations in air was investigated. Time variations of fertility index as well as the histological aspect of ovarie

The wind speed and wind direction affected concentration of indoor radon in seven houses, which arelocated in three region of southern Finland. In the case of houses (B - F) which are built on upperslope of a permeable esker, according to the analysis of covariance the highest concentration of indoorradon, 20 - 33% over grand mean, was observed when wind (v?0.4 m.s-1) direction was perpendicularthe esker, leading to increasing pressure of soil gas and consequently to increased radon entry andconcentration.

A survey of radon concentration in kindergartens in area of town Piekary ?l?skie, affected byunderground mining, have been performed. Measurements were done in cellars and classrooms on thegroundfloor. The highest value of radon concentration in the classroom during long-term monitoringwas of about 228 Bq/m3. During the survey we proved a correlation between concentrations of radonin soil gas and in buildings.

Nowadays augmented risk of a lung and larynx cancers as a result of the exposure on radon is not onlyknown fact, but also the most important effect of the influence of the natural radioactivity on thegeneral public. There is no doubt, that quite often miners are more endangered by enhanced radonexposures as other members of the society.Upper Silesia is the region of the extended underground mining industry, mainly of a hard coal, butalso the metal ore mining.

The effectiveness of various insulating materials for limiting radon entry into houses has beeninvestigated experimentally in 90 existing houses and in laboratory conditions. Each material hasbeen evaluated according to several aspects - placeability, durability, tear resistance and diffusionproperties. The results of the radon diffusion coefficients measurement in more than 80 insulatingmaterials are summarized. We have found out that great differences exist in diffusion properties,because the diffusion coefficient varries within four orders from 10-13 m2/s to 10-10 m2/s.

The article presents a part of the measurements around a closed coal mine in an area of 2 km2 where newbuildings are planned. Because of high content of natural radioactivity (U and 226Ra) in coal and fly ash inthis area, high radon concentrations were measured. Monitoring consists of measurements on the coal minerepository and around it. Values of radon exhalation rates were in the range from 9 x 10-3 to 4 x 10-1 Bqm-2s-1. On the areas rich with coal and coal ash, higher radon exhalation rates were determined during allperiods of the year.

Sub-slab depressurization (SSD) systems in the form of radon sumps are being considered as themost effective and the cheapest radon remedial measures for existing buildings. Detailedmeasurements were made in 17 family houses that had been remediated using this system.Measurements results indicate that the performance of SSD systems depends substantially on thesoil permeability and on the presence or absence of a drainage layer beneath the floors.

Legal regulations on the utilization of raws and materials assigned for construction are applied inPoland taking into account radiation protection. A qualification coefficient f2 = SRa, where SRa is the 226Ra concentration in the material expressed in Bq/kg, connected with the limitation of radium concentration in the product due to the emanation of 222Rn (in parallel with qualification coefficient f1 limiting whole-body exposure for gamma radiation) is used for the purpose of limitation of the 222Rn concentration in buildings assigned for permanent residence of people.

Epidemiological evidence of lung cancer risk from radon is based mainly on studies of menemployed underground in mines where exposures are relatively high in comparison to indoorexposure. Nevertheless direct evidence of risk from residential radon is desirable. In 1990, a studywas started comprising 12 000 inhabitants of an area with elevated radon concentrations. The meanlevel in the houses was higher than general mean of the country by factor of five. In the period1961-95, a total of 173 lung cancers were observed.

The Austrian Radon Project (ARP) is aimed to investigate and measure systematically the indoorradon concentration in about 0.5% of all Austrian homes. With the information from this surveyareas of enhanced indoor radon concentration can be identified and people living in such areasshould be encouraged to mitigate their homes. The radon potential is introduced by normalizingthe observed radon data to a standard situation. By mapping the radon potential an overview on thegeological risk for enhanced indoor radon concentrations will be available.