1. Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
2. Department of Chronic Diseases and Metabolism (CHROMETA), Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven, Leuven, Belgium
3. Hospital VITAZ Sint-Niklaas, Sint-Niklaas, Belgium
4. Department of Respiratory Diseases, University Hospitals Leuven, Leuven, Belgium
5. Department of Pediatrics, Pediatric Pulmonology, University Hospital of Leuven, Leuven, Flanders, Belgium
6. Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium