1. Department of Public Health and Primary Care-Centre for Environment and Health; KU Leuven; Leuven Belgium
2. ISGlobal; Centre for Research in Environmental Epidemiology (CREAL); Barcelona Spain
3. University Pompeu Fabra (UPF); Barcelona Spain
4. CIBER Epidemiología y Salud Pública (CIBERESP); Madrid Spain
5. Hospital del Mar Medical Research Institute (IMIM); Barcelona Spain
6. Department Health Protection; National Institute for Health and Welfare; Kuopio Finland
7. Department of Public Health; University of Helsinki; Helsinki Finland
8. CIBER Respiratorio (CIBERES); Madrid Spain
9. Division of Environmental Epidemiology; Institute for Risk Assessment Sciences (IRAS); Utrecht University; Utrecht The Netherlands
10. Netherlands Institute for Health Services Research (NIVEL); Utrecht The Netherlands