1. Helmholtz Centre Munich; German Research Centre for Environmental Health; Institute of Epidemiology I; Neuherberg; Germany
2. Institute of Environmental Medicine; Centre for Allergy Research; Karolinska Institutet; Stockholm; Sweden
3. Department of Environmental Immunology; UFZ - Helmholtz Centre for Environmental Research; Leipzig; Germany
4. School of Population and Public Health & Department of Medicine - Atmospheric Science Programme; Faculty of Medicine; University of British Columbia; Vancouver; BC; Canada
5. Respiratory Medicine Division; University of British Columbia; Vancouver; BC; Canada
6. Institute for Risk Assessment Sciences; Utrecht University; Utrecht; the Netherlands
7. School of Social and Community Medicine; University of Bristol; Bristol; UK
8. Department of Epidemiology; University Medical Centre Groningen; University of Groningen; Groningen; the Netherlands