Toward Capturing the Exposome: Exposure Biomarker Variability and Co-Exposure Patterns in the Shared Environment

53 BACKGROUND: Along with time, variation in the exposome is dependent on the location and 54 sex of study participants. One specific factor that may influence exposure co-variations is a 55 shared household environment. 56 57 OBJECTIVES: To examine the influence of shared household and partner’s sex in relation to the 58 variation in 128 endocrine disrupting chemical (EDC) exposures among couples. 59 60 METHODS: In a cohort comprising 501 couples trying for pregnancy, we measured 128 (13 61 chemical classes) persistent and non-persistent EDCs and estimated 1) sex-specific differences; 62 2) variance explained by shared household; and 3) Spearman's rank correlation coefficients (rs) 63 for females, males, and couples’ exposures. 64 65 RESULTS: Sex was correlated with 8 EDCs including polyfluoroalkyl substances (PFASs) (p < 66 0.05). Shared household explained 43% and 41% of the total variance for PFASs and blood 67 metals, respectively, but less than 20% for the remaining 11 EDC classes. Co-exposure patterns 68 of the exposome were similar between females and males, with within-class rs higher for 69 persistent and lower for non-persistent chemicals. Median rss of polybrominated compounds 70 and urine metalloids were 0.45 and 0.09, respectively, for females (0.41 and 0.08 for males), 71 whereas lower rss for these 2 classes were found for couples (0.21 and 0.04). 72 73 CONCLUSIONS: Overall, sex did not significantly affect EDC levels in couples. Individual, rather 74 than shared environment, could be a major factor influencing the co-variation of 128 markers 75 of the exposome. Correlations between exposures are lower in couples than in individual 76 partners and have important analytical and sampling implications for epidemiological study. 77 78 79 80 81 . CC-BY-ND 4.0 International license peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was not . http://dx.doi.org/10.1101/175513 doi: bioRxiv preprint first posted online Aug. 18, 2017;