1. Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
2. Universitat Pompeu Fabra (UPF), Barcelona, Spain
3. Universidad Autónoma de Barcelona, Cerdanyola del Vallès, Spain
4. CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
5. Department of Genes and Environment, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
6. IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain