1. Federal Office for Radiation Protection (BfS), Oberschleissheim, Germany;
2. International Agency for Research on Cancer, IARC, Lyon, France;
3. Department of Radiation Oncology, University Hospital, LMU, Munich, Germany;
4. Radiation and Nuclear Safety Authority, STUK, Helsinki, Finland;
5. Research Unit Radiation Cytogenetics, Helmholtz Zentrum Muenchen, Oberschleissheim, Germany