1. Institute for Risk Assessment Sciences (IRAS) Utrecht University Utrecht The Netherlands
2. Department of Pediatric Pulmonology and Pediatric Allergology Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen Groningen The Netherlands
3. Groningen Research Institute for Asthma and COPD (GRIAC) University Medical Center Groningen, University of Groningen Groningen The Netherlands
4. Julius Center for Health Sciences and Primary Care University Medical Center Utrecht Utrecht The Netherlands
5. Centre for Nutrition, Prevention and Health Services National Institute for Public Health and the Environment (RIVM) Bilthoven The Netherlands
6. Department of Epidemiology University Medical Center Groningen, University of Groningen Groningen The Netherlands