Exposome

We measured 91 environmental exposures in pregnancy and 116 in childhood, when children were between 6-11 years old. Exposures covered 18 families as shown in the figure. Exposure assessment tools included mass-spectrometry based measurement of biomarkers of chemical exposure in urine and blood, exposure monitors, remote sensing and geospatial methods, and questionnaire-based interviews.

Exposome list and codebook:

Omics

We performed in-depth multi-omics molecular phenotyping in the HELIX children at the age between 9-11 years, including measurement of blood DNA methylation, blood gene expression, blood miRNA expression, plasma proteins, serum metabolites, and urinary metabolites. While blood DNA methylation and transcriptomics were measured genome-wide, the other omics followed a semi-targeted or targeted approach.

^*Omics annotations can be downloaded from the DOWNLOAD tab

ExWAS

We systematically tested the association between each exposure variable and each molecular phenotype (Exposome-omics-Wide Association Analysis, ExWAS) by fitting linear regression models adjusted for cohort, child’s age, sex, body mass index (sex and age standardized), ethnic origin, maternal education and omics specific covariates.