Marina Vafeiadi, Inga Petraviciene, Sandra Andrusaityte, Norun Hjertager Krog, Gunn Marit Aasvang, Dagmar Waiblinger, Audrius Dedele, Mark J. Nieuwenhuijsen, Lydiane Agier, Line Småstuen Haug, Jose Urquiza, Xavier Basagaña, Oliver Robinson, John Wright, Martine Vrijheid, Rosemary R. C. McEachan, Cathrine Thomsen, Kristine B. Gutzkow, Rémy Slama, Montserrat de Castro, Charline Warembourg, Dan Mason, Valérie Siroux, Barbara Heude, Amrit Kaur Sakhi, Ibon Tamayo-Uria, Helle Margrete Meltzer, Leda Chatzi, Regina Grazuleviciene, Léa Maitre, Maribel Casas, Theano Roumeliotaki, Instituto de Salud Global - Institute For Global Health [Barcelona] (ISGlobal), CIBER de Epidemiología y Salud Pública (CIBERESP), Harvard University Statistics Department, Harvard University [Cambridge], Norwegian Institute of Public Health [Oslo] (NIPH), University of Southern California (USC), Université Grenoble Alpes (UGA), Institute for Advanced Biosciences / Institut pour l'Avancée des Biosciences (Grenoble) (IAB), Centre Hospitalier Universitaire [Grenoble] (CHU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Vytautas Magnus University - Vytauto Didziojo Universitetas (VDU), Equipe 6 : ORCHAD - Origines précoces de la santé du développement de l'enfant (CRESS - U1153), Université Paris Descartes - Paris 5 (UPD5)-Centre de Recherche Épidémiologie et Statistique Sorbonne Paris Cité (CRESS (U1153 / UMR_A_1125 / UMR_S_1153)), Institut National de la Recherche Agronomique (INRA)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Recherche Agronomique (INRA)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Bradford Teaching Hospitals NHS Foundation Trust [Bradford, UK] (BTHFT), Imperial College London, University of Crete [Heraklion] (UOC), European Project: 308333,EC:FP7:ENV,FP7-ENV-2012-two-stage,HELIX(2013), Centre Hospitalier Universitaire [Grenoble] (CHU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Siroux, Valérie, The Human Early-Life Exposome – novel tools for integrating early-life environmental exposures and child health across Europe - HELIX - - EC:FP7:ENV2013-01-01 - 2017-06-30 - 308333 - VALID, Harvard University, Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK (BIHR), and Medical Research Council (MRC)
Characterization of the "exposome", the set of all environmental factors that one is exposed to from conception onwards, has been advocated to better understand the role of environmental factors on chronic diseases. Here, we aimed to describe the early-life exposome. Specifically, we focused on the correlations between multiple environmental exposures, their patterns and their variability across European regions and across time (pregnancy and childhood periods). We relied on the Human Early-Life Exposome (HELIX) project, in which 87 environmental exposures during pregnancy and 122 during the childhood period (grouped in 19 exposure groups) were assessed in 1301 pregnant mothers and their children at 6-11 years in 6 European birth cohorts. Some correlations between exposures in the same exposure group reached high values above 0.8. The median correlation within exposure groups was >0.3 for many exposure groups, reaching 0.69 for water disinfection by products in pregnancy and 0.67 for the meteorological group in childhood. Median correlations between different exposure groups rarely reached 0.3. Some correlations were driven by cohort-level associations (e.g. air pollution and chemicals). Ten principal components explained 45% and 39% of the total variance in the pregnancy and childhood exposome, respectively, while 65 and 90 components were required to explain 95% of the exposome variability. Correlations between maternal (pregnancy) and childhood exposures were high (>0.6) for most exposures modeled at the residential address (e.g. air pollution), but were much lower and even close to zero for some chemical exposures. In conclusion, the early life exposome was high dimensional, meaning that it cannot easily be measured by or reduced to fewer components. Correlations between exposures from different exposure groups were much lower than within exposure groups, which have important implications for co-exposure confounding in multiple exposure studies. Also, we observed the early life exposome to be variable over time and to vary by cohort, so measurements at one time point or one place will not capture its complexities. This work was supported by the European Commission Seventh Framework Programme (FP7/2007–2013) [grant number: 308333–the HELIX project]. INMA data collections were supported by grants from the Instituto de Salud Carlos III, CIBERESP, and the Generalitat de Catalunya-CIRIT. KANC was funded by the grant of the Lithuanian Agency for Science Innovation and Technology (6-04-2014_31V-66). The Norwegian Mother and Child Cohort Study is supported by the Norwegian Ministry of Health and Care Services and the Ministry of Education and Research, NIH/NIEHS (contract no N01-ES-75558), NIH/NINDS (grant no.1 UO1 NS 047537-01 and grant no.2 UO1 NS 047537-06A1). The Rhea project was financially supported by European projects (EU FP6-2003-Food-3-NewGeneris, EU FP6. STREP Hiwate, EU FP7 ENV.2007.1.2.2.2. Project No 211250 Escape, EU FP7-2008-ENV-1.2.1.4 Envirogenomarkers, EU FP7-HEALTH-2009-single stage CHICOS, EU FP7 ENV.2008.1.2.1.6. Proposal No 226285 ENRIECO, EUFP7-HEALTH-2012 Proposal No 308333 HELIX, FP7 European Union project, No. 264357 MeDALL), and the Greek Ministry of Health (Program of Prevention of obesity and neurodevelopmental disorders in preschool children, in Heraklion district, Crete, Greece: 2011–2014; “Rhea Plus”: Primary Prevention Program of Environmental Risk Factors for Reproductive Health, and Child Health: 2012–15).