Maitre, LéaBont, Jeroen deCasas, MaribelRobinson, OliverAasvang, Gunn MaritAgier, LydianeAndrušaitytė, SandraBallester, FerranBasagaña, XavierBorràs, EvaBrochot, CélineBustamante, MarionaCarracedo Álvarez, ÁngelCastro, Montserrat deDedele, AudriusDonaire Gonzalez, DavidEstivill, XavierEvandt, JorunnFossati, SerenaGiorgis-Allemand, LiseGonzález, Juan R.Granum, BeritGrazuleviciene, ReginaBjerve Gützkow, KristineSmåstuen Haug, LineHernandez Ferrer, CarlesHeude, BarbaraIbarluzea, JesúsJulvez, JordiKarachaliou, MariannaKeun, Hector C.Hjertager Krog, NorunLau, Chung-Ho ELeventakou, VasilikiLyon-Caen, SarahManzano, CyntiaMason, DanMcEachan, RosemaryMeltzer, Helle MargretePetraviciene, IngaQuentin, JoaneRoumeliotaki, TheanoSabido, EduardSaulnier, Pierre JeanSiskos, Alexandros P.Siroux, ValérieSunyer, JordiTamayo, IbonUrquiza, JoseVafeiadi, MarinaVan Gent, DianaVives-Usano, MartaWaiblinger, DagmarWarembourg, CharlineChatzi, LedaCoen, MuireannVan den Hazel, PeterNieuwenhuijsen, Mark J.Slama, RémyThomsen, CathrineWright, JohnVrijheid, Martine2020-05-082020-05-082018Maitre L, de Bont J, Casas M, et al. Human Early Life Exposome (HELIX) study: a European population-based exposome cohort. BMJ Open 2018;8:e021311. doi:10.1136/ bmjopen-2017-0213112044-6055http://hdl.handle.net/10347/22133Purpose Essential to exposome research is the collection of data on many environmental exposures from different domains in the same subjects. The aim of the Human Early Life Exposome (HELIX) study was to measure and describe multiple environmental exposures during early life (pregnancy and childhood) in a prospective cohort and associate these exposures with molecular omics signatures and child health outcomes. Here, we describe recruitment, measurements available and baseline data of the HELIX study populationseng© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-usehttp://creativecommons.org/licenses/by-nc/4.0/HELIXBlood pressureAnthropometryRespiratory healthNeurodevelopmentEuropean populationjournal article10.1136/bmjopen-2017-021311open access