1. Center for Research in Environmental Epidemiology, Barcelona, Spain
2. Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona, Spain
3. CIBER Epidemiologia y Salud Pública, Spain
4. National Institute of Public Health, Athens, Greece
5. Laboratorio de Salud Pública de Guipúzcoa, San Sebastián, Spain
6. Universitat Pompeu Fabra, Barcelona, Spain