Airborne Precursors Predict Maternal Serum Perfluoroalkyl Acid Concentrations

Area of Science:

• Environmental Chemistry
• Human Health Exposure
• Toxicology

Background:

• Persistent perfluoroalkyl acids (PFAAs) like PFOA, PFNA, and PFOS are widespread environmental contaminants.
• Human exposure routes include direct contact with PFAAs in food, water, air, and dust.
• PFAA precursors (PreFAAs), which biotransform into PFAAs, represent a potential, less-understood exposure pathway.

Purpose of the Study:

• To investigate the association between airborne PFAA precursors and human serum levels of PFAAs.
• To determine if residential air and dust concentrations of PreFAAs correlate with maternal serum PFAA concentrations.
• To identify specific PreFAAs that may contribute to human exposure of PFOA, PFNA, and PFOS.

Main Methods:

• Analysis of PFAAs in 50 maternal serum samples from Vancouver, Canada (2007-2008).
• Measurement of PFAAs and PreFAAs in paired residential bedroom air (passive sampler) and vacuum dust samples.
• Statistical analysis to identify associations between airborne/dust PreFAAs and serum PFAAs.

Main Results:

• PreFAAs concentrations were higher than PFAAs in both air and dust samples.
• Positive associations found between airborne 10:2 FTOH and serum PFOA/PFNA, and airborne MeFOSE and serum PFOS.
• Airborne MeFOSE was linked to significantly higher serum PFOS levels, and airborne/dust PFNA predicted serum PFNA.

Conclusions:

• Airborne PFAA precursors, specifically certain fluorotelomer alcohols and sulfonamidoethanols, are a significant source of human exposure to PFOA, PFNA, and PFOS.
• Residential air contamination by PreFAAs is a relevant pathway for internal PFAA dose.
• Further research into PreFAA biotransformation and exposure is warranted.