1. Medical School, University of Tampere, Tampere, Finland
2. Department of Dermatology, Tampere University Hospital, Tampere, Finland
3. Department of Dermatology, Päijät-Häme Central Hospital, Lahti, Finland
4. Non ionizing radiation laboratory, Radiation and Nuclear Safety Authority, Helsinki, Finland
5. Unit of Primary Health Care, Helsinki University Central Hospital, Helsinki, Finland
6. Department of General Practice, University of Helsinki, Helsinki, Finland
7. Unit of Primary Health Care, Kuopio University Hospital, Helsinki and Kuopio, Finland
8. Finnish Meteorological Institute, Arctic Research Centre, Sodankylä, Finland
9. Aeronomy division, Sodankylä Geophysical Observatory, Sodankylä, Finland
10. Children’s Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland