1. Department of Bioanalysis, Faculty of Pharmaceutical Sciences Ghent University Ghent Belgium
2. The Generation R Study Group Erasmus MC, University Medical Centre Rotterdam The Netherlands
3. Department of Epidemiology Erasmus MC, University Medical Centre Rotterdam The Netherlands
4. Division of Respiratory Medicine and Allergology, Department of Pediatrics Erasmus MC, University Medical Centre Rotterdam The Netherlands
5. Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
6. Sachs’ Children's Hospital Södersjukhuset Stockholm Sweden
7. Centre for Occupational and Environmental Medicine Stockholm County Council Stockholm Sweden