Department of Clinical Sciences and Education, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden; Sachs Children's Hospital, Stockholm, Sweden. Institute of Epidemiology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany. Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany. ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain; CIBER Epidemiología y Salud Pública, Madrid, Spain; Hospital de Mar Medical Research Institute, Barcelona, Spain. Research Institute, Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. MACVIA-France, Contre les Maladies Chroniques pour un Vieillissement Actif en France European Innovation Partnership on Active and Healthy Ageing Reference Site, Montpellier, France; INSERM U 1168, VIMA: Ageing and Chronic Diseases Epidemiological and Public Health Approaches, Villejuif, Université Versailles St-Quentin-en-Yvelines, Montigny le Bretonneux, France. Institute of Epidemiology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany; Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Munich, Germany; Allergy and Lung Health Unit, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia. University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Department of Pediatric Pulmonology and Pediatric Allergology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD (GRIAC), Groningen, The Netherlands. Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria. Institute of Epidemiology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany; Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Munich, Germany; Institute of Psychology, Jagielonian University, Cracow, Poland. Institute of Epidemiology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany; Division of Metabolic and Nutritional Medicine, Dr von Hauner Children's Hospital, University Hospital, LMU of Munich, Munich, Germany. Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria; Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia; National Research Center-Institute of Immunology FMBA of Russia, Moscow, Russia; Karl Landsteiner University of Health Sciences, Krems, Austria. Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden. University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD (GRIAC), Groningen, The Netherlands; Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. Centre for Clinical Research Sörmland, Uppsala University, Eskilstuna, Sweden. National Institute for Public Health and the Environment, Bilthoven, The Netherlands. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden. Electronic address: olena.gruzieva@ki.se.