The natural radioactivity of coals from Romania

Between 1980-1992 were investigated 85 underground coal mines for the assessment of exposure of workers to radon and its daughters. At the same time, coal, barren rock, (infiltration, drainage, drinking) water, soil and wild vegetation samples were collected. From these samples the natural uranium and radium 226 contents were measured using fluorimetry and radon emanation methods, respectively. By all 1,304 coal and barren rock, 173 water and 146 soil and wild vegetation samples were collected and analysed for their radioelement content. The mean activity concentrations of U nat. and 226Ra from coals are at the level of concentrations from soils. The mean activity concentrations of the same radioelements from different kind of water samples are under the maximum permissible concentrations (MPCs) for drinking water. There was no radioactive contamination of soil and vegetation samples collected around the coal mining site. (author). 5 refs, 6 tabs