Breastfeeding: A Potential Excretion Route for Mothers and Implications for Infant Exposure to Perfluoroalkyl Acids

Abstract

Background: The presence of perfluoroalkyl acids (PFAAs) in breast milk has been documented, but their lactational transfer has been rarely studied. Determination of the elimination rates of these chemicals during breastfeeding is important and critical for assessing exposure in mothers and infants.Objectives: We aimed to investigate the association between breastfeeding and maternal serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS). For a subset of the population, for whom we also have their infants’ measurements, we investigated associations of breastfeeding with infant serum PFAA concentrations.Methods: The present analysis included 633 women from the C8 Science Panel Study who had a child < 3.5 years of age and who provided blood samples and reported detailed information on breastfeeding at the time of survey. PFAA serum concentrations were available for all mothers and 8% (n = 49) of the infants. Maternal and infant serum concentrations were regressed on duration of breastfeeding.Results: Each month of breastfeeding was associated with lower maternal serum concentrations of PFOA (–3%; 95% CI: –5, –2%), PFOS (–3%; 95% CI: –3, –2%), PFNA (–2%; 95% CI: –2, –1%), and PFHxS (–1%; 95% CI: –2, 0%). The infant PFOA and PFOS serum concentrations were 6% (95% CI: 1, 10%) and 4% (95% CI: 1, 7%) higher per month of breastfeeding.Conclusions: Breast milk is the optimal food for infants, but is also a PFAA excretion route for lactating mothers and exposure route for nursing infants.Citation: Mondal D, Weldon RH, Armstrong BG, Gibson LJ, Lopez-Espinosa MJ, Shin HM, Fletcher T. 2014. Breastfeeding: a potential excretion route for mothers and implications for infant exposure to perfluoroalkyl acids. Environ Health Perspect 122:187–192; http://dx.doi.org/10.1289/ehp.1306613

Reliability of perfluoroalkyl substances in plasma of 100 women in two consecutive pregnancies

“…Additionally, Thomsen et al, reported a 46% depuration of PFOA and 18% for PFOS after 6 months of breastfeeding by analyzing repeated breast milk samples from Norwegian mothers, and these findings are comparable to our observed reductions on maternal concentrations attributed to breastfeeding (Thomsen et al, 2010). In two previous studies that used a multivariate model, the estimated reduction in maternal PFAS concentrations associated with breastfeeding was lower than in our study (Brantsaeter et al, 2013; Mondal et al, 2014). Nevertheless, our results might not be directly comparable to those in other studies due to differences in the definition of the breastfeeding variable (at least 6 months of exclusive breastfeeding vs. per month of breastfeeding).…”

Developmental toxicity of perfluorononanoic acid in mice

“…It is also interesting to note the general fall of PFNA levels of the nursing dams, perhaps reflecting clearance of the chemical through urinary excretion and lactational transfer, as previously shown with PFOA [68]. Indeed, although PFNA in mouse milk was not determined in the present study, this fluorochemical has been commonly detected in human and cow milk, along with other PFAAs [69][70][71]. Neither PFOS, PFOA, nor PFNA produced any overt maternal toxicity (such as weight loss), except at very high doses where pregnancy loss was observed.…”

Per- and polyfluorinated substances (PFASs): Environmental challenges

“…Numerous PFASs have been detected in breast milk, though in concentrations much lower than in the mother's blood plasma [58,67,77,93,178,[186][187][188][189][190][191]. Lactational transfer (and baby formulations [94]) can nevertheless be the primary source of exposure to PFASs, mainly PFOS, for infants [60].…”

“…Accumulation through breast-feeding can, after six months, lead to body burdens similar to (PFOS) or higher than (PFOA) those seen in adults [58]. PFOA and PFOS blood levels were seen to decrease markedly in mother while it increased in child during breast feeding [191]. Longer breast-feeding led to higher serum PFAA levels in young girls [77].…”