Maternal PFAS Transfer through Lactation: Dolphin Milk Reveals Routes of Early-Life Exposure

Area of Science:

• Environmental Science
• Toxicology
• Marine Biology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are increasingly prevalent environmental contaminants.
• PFAS bioaccumulate and biomagnify, posing risks to high-trophic-level species like marine mammals.
• Limited data exists on temporal trends of PFAS exposure through maternal transfer in marine mammals.

Purpose of the Study:

• To evaluate longitudinal trends in PFAS concentrations and profiles in dolphin breastmilk.
• To assess the contribution of lactation to early-life PFAS exposure in marine mammals.
• To identify emerging and precursor PFAS compounds in dolphin milk.

Main Methods:

• Analysis of dolphin breastmilk samples from a single mother over a two-year lactation period.
• Utilized liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) for PFAS detection.
• Employed non-targeted analysis to identify a broader range of PFAS compounds.

Main Results:

• Detected 36 PFAS, with 17 continuously present throughout lactation (103-706 days).
• Perfluorooctanesulfonic acid (PFOS) concentrations exceeded European and Australian food safety recommendations by 1,000-fold.
• Identified novel long-chained perfluorosulfonic acids and PFOS precursors like PFECHS and SAmPAP.

Conclusions:

• Dolphin breastmilk is a significant pathway for early-life PFAS exposure.
• Lactation plays a critical role in the transfer of long-chained PFAS to marine mammal offspring.
• The study underscores the need for monitoring emerging PFAS and their precursors in marine ecosystems.