GOALI: Gas Phase PFAS and Organofluorine Release from AFFF: Measurement, Identification, and Exposure Mitigation

Aqueous film-forming foams (AFFFs) are used primarily to extinguish fuel fires. AFFFs consist of mixtures of per- and polyfluoroalkyl substances (PFASs), chemicals that are toxic to humans. Their persistence in groundwater is well known, but less is known about their potential to become gasses and contaminate the air.

This Grant Opportunity for Academic Liaison with Industry (GOALI) project will study the potential for a wide variety of PFASs contained in commercial AFFFs to be transported in the gas phase from different sources. The research will also investigate potential human exposure pathways from the released PFAS gasses. Successful completion of this research will advance knowledge on the fate and transport of PFASs, as well as provide data for use by remediation professionals, regulators, public health professionals, and other stakeholders to better understand the health risks of PFASs.

Collaboration with the industrial partner will combine complimentary skillsets on PFAS fate and transport, provide test samples for laboratory study and model validation, as well as provide industrial training opportunities for student researchers. Additional benefits to society will result from outreach to families about chemical exposure through a partnership with a local non-governmental organization, thus increasing scientific literacy.

AFFFs contain large concentrations of PFAS compounds. Recent results by the research team have shown that many PFASs are rapidly volatilized to the gas phase. Although the human health risk from exposure to PFASs in water is well characterized, comparatively little is known about human exposure to PFASs from gaseous sources.

Such knowledge is critical to accurately assess exposure to population subsets such as firefighters that may be exposed to greater concentrations than the general population. The overarching goal of this GOALI project is to determine the release of gas-phase PFAS evolved from AFFF during handling, use, and from contaminated water. This research is guided by the underlying hypothesis that both volatile and aerosolized PFAS are released to the gas phase.

The specific research objectives designed to test this hypothesis are to: i) investigate PFAS volatility, Henry’s law constants, and PFAS fragmentation via mass spectrometry, ii) identify and quantify gaseous AFFF-associated PFAS by total organofluorine, nontargeted, and targeted methods, and iii) determine potential gas phase transport pathways and mechanisms of exposure. Successful completion of this research will provide fundamental measurements relevant to the broad field of environmental PFAS contamination.

The GOALI industrial partner, Geosyntec, will provide critical expertise and groundwater and vadose zone samples from active AFFF-contaminated sites to enable validation of gas-phase exposure predictions. The collaboration of academic and industry experts with complimentary expertise in PFAS occurrence, analytical chemistry, and vapor intrusion will greatly facilitate achieving the research objectives.

Additional benefits result from measuring Henry’s law constants for PFAS compounds. These data will enable Geosyntec and the broader remediation industry to produce vapor intrusion models to more accurately assess PFAS fate and transport. This is a key outcome for industry, which cannot otherwise model intrusion due to the complete lack of data.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.