1. Childhood Cancer Research Unit, Department of Women's and Children's Health Karolinska Institutet Stockholm Sweden
2. Department of Social Work and Criminology, Faculty of Health and Occupational Studies University of Gävle Gävle Sweden
3. Clinical Epidemiology and Biostatistics, School of Medical Sciences Örebro University Örebro Sweden
4. Clinical Epidemiology Division, Department of Medicine Karolinska Institutet Stockholm Sweden
5. Department of Epidemiology and Public Health University College London London UK
6. Centre for Occupational and Environmental Medicine Stockholm County Council Stockholm Sweden
7. Unit of Occupational Medicine, Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden