Emerging and Legacy Perfluoroalkyl Substances in Breastfed Chinese Infants: Renal Clearance, Body Burden, and Implications

Abstract

Background: Human breast milk is a primary route of exposure to perfluoroalkyl substances (PFAS) in infants. To understand the associated risks, the occurrence of PFAS in human milk and the toxicokinetics of PFAS in infants need to be addressed. Objectives: We determined levels of emerging and legacy PFAS in human milk and urine samples from Chinese breastfed infants, estimated renal clearance, and predicted infant serum PFAS levels. Methods: In total, human milk samples were collected from 1,151 lactating mothers in 21 cities in China. In addition, 80 paired infant cord blood and urine samples were obtained from two cities. Nine emerging PFAS and 13 legacy PFAS were analyzed in the samples using ultra high-performance liquid chromatography tandem mass spectrometry. Renal clearance rates ( ) of PFAS were estimated in the paired samples. PFAS serum concentrations in infants ( year of age) were predicted using a first-order pharmacokinetic model. Results: All nine emerging PFAS were detected in human milk, with the detection rates of 6:2 Cl-PFESA, PFMOAA, and PFO5DoDA all exceeding 70%. The level of 6:2 Cl-PFESA in human milk ( ) ranked third after PFOA ( ) and PFOS ( ). The estimated daily intake (EDI) values of PFOA and PFOS exceeded the reference dose (RfD) of recommended by the U.S. Environmental Protection Agency in 78% and 17% of breastfed infant samples, respectively. 6:2 Cl-PFESA had the lowest infant ( ), corresponding to the longest estimated half-life of 49 y. The average half-lives of PFMOAA, PFO2HxA, and PFO3OA were 0.221, 0.075, and 0.304 y, respectively. The of PFOA, PFNA, and PFDA were slower in infants than in adults. Conclusions: Our results demonstrate the widespread occurrence of emerging PFAS in human milk in China. The relatively high EDIs and half-lives of emerging PFAS suggest potential health risks of postnatal exposure in newborns. https://doi.org/10.1289/EHP11403

Invited Perspective: PFAS in Breast Milk and Infant Formula—It’s Time to Start Monitoring

“…Yao et al. 1 state that “further epidemiological studies are needed to demonstrate whether breastfeeding with contaminants has adverse health outcomes on newborns.” It is hard to disagree with the sentiment. For many legacy chemicals, we have several decades’ worth of epidemiologic studies on this subject.…”

“…However, in the case of PFAS and infant nutrition, the approach of waiting for robust epidemiological study results is unsatisfactory. Legacy PFAS have been detected in breast milk and drinking water at levels exceeding various guidance values 1 , 14 , 15 ; furthermore, emerging PFAS are commonly detected in breast milk. 1 The data are too sparse to make general statements about PFAS in infant formula.…”

“…Legacy PFAS have been detected in breast milk and drinking water at levels exceeding various guidance values 1 , 14 , 15 ; furthermore, emerging PFAS are commonly detected in breast milk. 1 The data are too sparse to make general statements about PFAS in infant formula. However, because some infant formulas require reconstitution with water, PFAS intakes above levels of concern cannot be ruled out.…”

“…The study by Yao et al. 1 in this issue of Environmental Health Perspectives advances our understanding of infant exposures to per- and polyfluoroalkyl substances (PFAS). They note that “it is essential to provide a national baseline of PFAS exposure in human milk … and to assess the risks of emerging and legacy PFAS exposure in exclusively breastfed infants.” It is impossible to argue with that point, and in fact for years my colleagues and I have made similar calls for national breast milk monitoring programs.…”

6:2 Chlorinated Polyfluoroalkyl Ether Sulfonates Exert Stronger Thyroid Homeostasis Disruptive Effects in Newborns than Perfluorooctanesulfonate: Evidence Based on Bayesian Benchmark Dose Values from a Population Study

“…1 Regulations have been implemented to restrict the production and application of specific PFASs, especially perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA). 2 Driven by increasingly stringent restrictions on PFOS, the metal plating industry in China has developed a novel replacement (F-53B) 3 which is a commercial mixture of chlorinated polyfluoroalkyl ether sulfonic acid (Cl-PFAESA). It has been reported that F-53B has been used as a mist suppressant in place of PFOS in China for decades, 4 but environmental occurrence, behavior, and health effects have not been a concern until recent years.…”