Per- and polyfluoroalkyl substances (PFAS) in breast milk and infant formula: A global issue

Abstract

Background: Per- and polyfluoroalkyl substances (PFAS) are transferred from mother to infants through breastfeeding, a time when children may be particularly vulnerable to PFAS-mediated adverse health effects. Infants can also be exposed to PFAS from infant formula consumption. Our recent literature-based scoping of breast milk levels reported that four PFAS often exceeded the United States Agency for Toxic Substances and Disease Registry (ATSDR) children's drinking water screening levels in both the general population and highly impacted communities in the U.S. and Canada. This work presents a comparison of global breast milk and infant formula PFAS measurements with the only reported health-based drinking water screening values specific to children.

Methods: We focused on four PFAS for which ATSDR has developed children's drinking water screening values: PFOA (perfluorooctanoic acid), PFOS (perfluorooctanesulfonic acid), PFHxS (perfluorohexanesulfonic acid), and PFNA (perfluorononanoic acid). Published literature on PFAS levels in breast milk and infant formula were identified via PubMed searches. Data were compared to children's drinking water screening values.

Discussion: Breast milk concentrations of PFOA and PFOS often exceed children's drinking water screening values, regardless of geographic location. The limited information on infant formula suggests its use does not necessarily result in lower PFAS exposures, especially for formulas reconstituted with drinking water containing PFAS. Unfortunately, individuals generally cannot know whether their infant's exposures exceed children's drinking water screening values. Thus, it is essential that pregnant and lactating women and others, especially those having lived in PFAS-contaminated communities, have data required to make informed decisions on infant nutrition. An international monitoring effort and access to affordable testing are needed for breast milk, drinking water and infant formula to fully understand infant PFAS exposures. Currently, our understanding of demonstrable methods for reducing exposures to emerging PFAS is limited, making this research and the communications surrounding it even more important.

Keywords: Children's drinking water screening values; Drinking water; Human milk; PFHxS; PFNA; PFOA; PFOS.

Figure 1.

Process for deriving Environmental Media Evaluation Guides (EMEGs), or “children’s drinking water screening values” (ATSDR 2021).

Figure 2.

International concentrations of PFOA in breast milk (white bars) and infant formula (gray bars), in comparison with the children’s drinking water screening value (dotted line). Bars represent the mean or median breast milk levels. Error bars represent maximum, 90th or 95th percentile concentrations. Missing bars indicate reported concentrations were below the limit of detection, or PFOA was not measured in the study. The X-axis is log-scale. N values are given in Tables 1 and 2. The ATSDR children’s drinking water screening value is 21 ppt (21 pg/mL) (ATSDR 2018).

Figure 3.

International concentrations of PFOS in breast milk (white bars) and infant formula (gray bars), in comparison with the children’s drinking water screening value (dotted line). Bars represent the mean or median breast milk levels. Error bars represent maximum, 90th or 95th percentile concentrations. Missing bars indicate reported concentrations were below the limit of detection, or PFOS was not measured in the study. The X-axis is log-scale. N values are given in Tables 1 and 2. The ATSDR children’s drinking water screening value is 14 ppt (14 pg/mL) (ATSDR 2018).

Figure 4.

International concentrations of PFHxS in breast milk (white bars) and infant formula (gray bars), in comparison with the children’s drinking water screening value (dotted line). Bars represent the mean or median breast milk levels. Error bars represent maximum, 90th or 95th percentile concentrations. Missing bars indicate reported concentrations were below the limit of detection, or PFHxS was not measured in the study. The X-axis is log-scale. N values are given in Tables 1 and 2. The ATSDR children’s drinking water screening value is 140 ppt (140 pg/mL) (ATSDR 2018).

Figure 5.

International concentrations of PFNA in breast milk (white bars) and infant formula (gray bars), in comparison with the children’s drinking water screening value (dotted line). Bars represent the mean or median breast milk levels. Error bars represent maximum, 90th or 95th percentile concentrations. Missing bars indicate reported concentrations were below the limit of detection, or PFNA was not measured in the study. The X-axis is log-scale. N values are given in Tables 1 and 2. The ATSDR children’s drinking water screening value is 21 ppt (21 pg/mL) (ATSDR 2018).