1. Health Institute of the Uranium Industry, Příbram, Czech Republic
2. Department of Statistics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
3. Center of Epidemiological Studies, Příbram, Czech Republic
4. Westat, Inc., Durham, North Carolina, USA
5. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA