1. Section of Environment, Occupation and Health; Aarhus University; Aarhus C Denmark
2. H.C. Andersen Children's Hospital; Odense University Hospital; Odense Denmark
3. Institute for Risk Assessment Sciences; Utrecht University; Utrecht The Netherlands
4. Department of Occupational and Environmental Medicine; Copenhagen University Hospital; Bispebjerg Denmark
5. National Research Centre for the Working Environment; Copenhagen Denmark
6. Department of Anaesthesiology and Intensive Care; Odense University Hospital; Odense Denmark