1. Department of Radiation Protection, Swedish Radiation Safety Authority, Stockholm, Sweden
2. Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
3. Icelandic Radiation Safety Authority, Reykjavik, Iceland
4. Department of Radiography, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
5. Department of Radiation Protection and Measurement Services, Norwegian Radiation and Nuclear Safety Authority, Bærum, Norway
6. Radiation Protection, Danish Health Authority, Copenhagen, Denmark
7. Department of Health Sciences, Norwegian University of Science and Technology, Gjøvik, Norway