1. Department of Epidemiology Research Statens Serum Institut Copenhagen Denmark
2. Sydney Medical School Faculty of Medicine University of Sydney Concord Hospital Sydney NSW Australia
3. Department of Organic Psychiatric Disorders and Emergency Ward Aarhus University Hospital Risskov, Aarhus Denmark
4. The National Research Centre for the Working Environment Copenhagen Denmark
5. Department of Occupational Medicine Danish Ramazzini Centre Aarhus University Hospital Aarhus Denmark
6. Section for Environment, Occupation and Health Department of Public Health Danish Ramazzini Centre Aarhus University Aarhus Denmark