Author/Editor		Križman, M; Stegnar, P; Miklavčič, V
Title		Mercury ore processing-a new source of technologically enhanced natural radioactivity
Type		članek
Source		Environ Int
Vol. and No.		Letnik 22, št. Suppl 1
Publication year		1996
Volume		str. S251-8
Language		eng
Abstract		Technologically enhanced natural radioactivity originating from mining and processing of mercury ore has not been reported. In Idrija (Slovenia), mercury ore has been excavated and processed for almost half a millennium, and the roasted residues were disposed of everywhere in the town of Idija and in the surroundings. Later, houses and other buildings were constructed on such locations. In the fifties, it was discovered that the ore contained uranium. Recent investigations confirmed higher levels of radioactivity in the groud in some parts of town. Outdoor gamma radiation was measured, and elevated values were found at all places where mercury ore residues had been deposited. The contents of natural radionuclides were determined, mainly in various samples of ignited residues and their mixtures with soil. The uranium content in such samples were 4-20 times enhanced compared to background levels. The levels of indoor radon in ground floors of houses were determined and confirmed expectations. Levels exceeded all previous indoor values obtained in other places in Slovenia. In an old mining apartment house, the radon concentration reached 7300-15000 Bq m-3. Maximal outdoor radon concentrations in the town centre reached up to 100 Bq m-3 on mornings with a temperature inversion. The levels of radioactivity in the mercury mine are considerable at some places and the miners should be considered radiation workers.
Descriptors		MERCURY SOIL POLLUTANTS, RADIOACTIVE AIR POLLUTION, INDOOR RADON MINING AIR POLLUTANTS, RADIOACTIVE URANIUM BACKGROUND RADIATION