Is Breastfeeding a Source of Non-Persistent Chemical Exposure in Infants?

Abstract

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background: Exclusive breastfeeding is the recommended practice for the first 6 months following birth. Previous studies have detected phthalates and phenols in breast milk, but the contribution of breastfeeding to an infant’s exposure to these chemicals is unknown. We hypothesized that breastfed children would have higher urinary phthalate metabolite and phenol concentrations compared with non-breastfed children. Methods: We used data from 295 mother-child pairs in the HOME Study (Cincinnati, Ohio, enrolled: 2003-2006). Research assistants assessed breastfeeding duration via maternal report when infants were approximately 12 months old. We also quantified concentrations of eight phthalate metabolites and three phenols (bisphenol A, triclosan, and benzophenone-3) in infants’ urine collected at the same time. We estimated geometric mean (GM) phthalate metabolite and phenol concentrations by breastfeeding status, after adjusting for sociodemographic and perinatal factors, as well as urinary creatinine. Results: Eighty-two (28%) infants were breastfeeding at age 12 months. After adjusting for covariates, GM phthalate metabolite and phenol concentrations were 4-25% higher in children who were breastfed at 12 months than those who were not being breastfed. However, the 95% CIs of these estimates included the null and were imprecise. For example, urinary concentrations of bisphenol A and di-2-ethylhexyl phthalate metabolites were 13% (95% CI: -12, 46) and 4% (95% CI: -18, 31) higher, respectively, in breastfed children compared to non-breastfed children. Conclusion: In this cohort, we found little evidence to suggest that breastfeeding is a major source of exposure to phthalates and phenols in nursing infants. Future studies could consider examining whether plastic feeding bottles or pumped milk are potential sources of phthalate and phenol exposures among infants.