Atmospheric Concentrations of Per- and Polyfluoroalkyl Substances in Michigan's Ambient Air Using Passive Sampling

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Analytical Chemistry

Background:

• Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants.
• Understanding atmospheric PFAS concentrations is crucial for assessing their transport and impact on environmental media in Michigan.
• Existing monitoring methods may not adequately cover large geographic areas for atmospheric PFAS.

Purpose of the Study:

• To measure atmospheric PFAS concentrations across Michigan using accessible passive samplers.
• To identify relationships between PFAS levels and environmental factors like population and industrial density.
• To differentiate the atmospheric transport pathways of various PFAS compounds.

Main Methods:

• Deployment of passive samplers (polyurethane foam discs and radiello-XAD samplers) at 27 sites across Michigan for one month.
• Analysis of samplers for both ionic and volatile, neutral PFAS, including short-chain perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonic acid (PFOS).
• Statistical analysis to correlate detected PFAS concentrations with environmental variables.

Main Results:

• Short-chain PFCAs (PFPrA, PFBA) and PFOS were frequently detected.
• Atmospheric PFAS concentrations varied significantly, with ∑3PFAS up to 15.5 pg/m³ (PUFs) and 248 pg/m³ (radiello-XAD).
• 6:2 fluorotelomer alcohol showed positive correlations with population density (r=0.52) and industrial site density (r=0.48).

Conclusions:

• Passive samplers are effective tools for monitoring atmospheric PFAS across broad regions.
• PFOS predominantly exists in the gas-phase (captured by radiello-XAD), while PFBA is primarily particle-phase (captured by PUFs).
• Environmental factors like population and industrial density influence atmospheric PFAS distribution, necessitating targeted monitoring strategies.