1. Department of Occupational Medicine and Epidemiology National Institute of Occupational Health Oslo Norway
2. Department of Dermatology Oslo University Hospital Oslo Norway
3. Department of Research Cancer Registry of Norway Oslo Norway
4. International Agency for Research on Cancer World Health Organization Lyon France
5. Finnish Cancer Registry Institute for Statistical and Epidemiological Cancer Research Helsinki Finland
6. Faculty of Social Sciences Tampere University Tampere Finland
7. Icelandic Cancer Registry Icelandic Cancer Society Reykjavik Iceland
8. Faculty of Medicine BMC, Laeknagardur, University of Iceland Reykjavik Iceland
9. Nykøbing Falster Hospital University of Copenhagen Denmark