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MEASUREMENTS OF DOSE RATE AND RADON GAS CONCENTRATION IN SCHOOLS AND KINDERGARTENS CONSTRUCTED WITH USING COAL-SLAG AS BUILDING MATERIAL

Cs. NÉMETH*, J. SOMLAI**, B. KANYÁR**
*Department of Physics, University of Veszprém,
*Department of Radiochemistry, University of Veszprém,
8201 Veszprém, P.O. Box. 158 (Hungary)

Coals mined in some regions of the Transdanubian Middle Mountains in Hungary have elevated
concentrations of 226 Ra. The slags and ashes derived from these coals have been used as building
material for schools and kindergartens. As the 226 Ra reached up in these waste products of coal-firing
systems, the gamma dose contribution in the buildings, which contained them, was calculated. In these
places the absorbed gamma dose rate could be reach the sevenfold of the global average values – 80
nGy h -1 - but the annual effective doses are lower than 1 mSv due to the relatively short time of
occupancy even in the cases of highest level. The radon levels do not exceed the 102 Bq m -3 during the
period when the people are in the rooms because of the frequent airing therefore, the assumed annual
effective dose derived from radon not exceed 0.4 mSv.