The maps of radon risk of the town's agglomeration Bratislava and Kosice

Author dealt with the factors which affect the penetrability of the minerals for the releasing of the radon-222 and which affects its volume activity (av) in by-surface layer. The evaluation of the radon risk in Bratislava and Kosice zone is founded on the methodic used in the Czech Republic and on the Decree No. 406/92 Col. of Ministry of Health of the Slovak Republic. The valuation of the penetrability of the earth is in accordance with former Czechoslovak norm 73 1001. In Bratislava region the maps of radon risk in the scale 1:25000 a 1:50000 were assembled. The value av in the depth 0.80 m was inquired, granulometric analysis by standard laboratory method were made. The density of radon observations is following: 3 reference areas per 1 km2, one reference area represents 20 measured point in the net 20 x 20 m. From the results of the radon exploration originates that 56.8% examined area lies in low radon risk, 37.6% in middle and 5.6% in high radon risk. Consequent long-range measurement of equivalent volume activity of the radon in the flats, localized in high radon risk, shows in some places highest values than slackens Slovak limit (Devinska Nova Ves, Marianka, Raca, Vajnory). The considerable partition of the territory with high radon risk lies in the area of young tectonic systems, especially in the place of its crossing. From the heretofore results of the radon observations in the Kosice region (project come to an end in 1999) originates that considerable partition of the territory lies in low and middle radon risk. The localities with high radon risk are few numerous and small in place