Exposure to perfluoroalkyl substances through human milk in preterm infants

Perfluoroalkyl substances (PFASs) are environmental contaminants that have been shown to exert toxic effects, which are dependent upon concentration, in animals and humans. No specific data on the exposure of preterm infants to PFASs are available. We aimed to quantify the potential exposure of preterm infants to PFASs through human milk (HM), to be compared to the exposure data recently reported for infants by EFSA. The amount of PFASs in ten preterm (PHM) and ten donor HM (DHM) samples was evaluated, and the expected daily intake (EDI) at full enteral feeding was calculated. This EDI was compared to the mean and the 95th centile dietary exposure ranges at the lower bound for infants issued by EFSA. The calculated median EDI for total PFASs was 20.72 ng/kg/day (range 10.72–107.84) for PHM and 17.92 ng/kg/day (range 6.4–28.96) for DHM, which were both higher than mean exposure ranges reported for infants (2.4–12.2 ng/kg/day). The calculated EDI for DHM was far more similar to the 95th centile (4.5–27.9 ng/kg/day) dietary exposure ranges. For PHM samples, higher EDI values were obtained, with 4 out of 10 samples exceeding the upper limit of the 95th centile range. Conclusion: The exposure of preterm infants to PFASs through HM feeding might exceed reference values reported for older and healthier infants. Given the immunological and developmental vulnerability of preterm infants, the risks related to their exposure to PFASs should be further investigated, also focusing on how maternal exposure and subsequent transfer through HM feeding can be reduced.What is Known:• Perfluoroalkyl substances (PFASs) are environmental contaminants that have been shown to exert toxic effects, which are dependent upon concentration, in animals and humans. The EFSA has recently issued reference values for PFASs exposure for different age groups.• Infants might be exposed to PFASs prenatally, as these substances can cross the placenta, and postnatally, through breastfeeding. No specific data about exposure of preterm infants through human milk (HM) feeding are currently available.What is New:• The exposure of preterm infants to PFASs through HM feeding might exceed reference values reported for older and healthier infants.• Given the immunological and developmental vulnerability of preterm infants, the risks related to their exposure to PFASs deserve further investigation. As HM represents the optimal feeding for preterm infants, it will be fundamental to focus on how maternal exposure and subsequent transfer through HM feeding can be reduced.