Overview of Per-and polyfluoroalkyl substances (PFAS): History, Sources, Exposure Pathways, Analytical Challenges, and Resources Nathan Eklund, PMP Pace Persistent Organic Pollutants (POPs) Lab
Per-and Polyfluoroalkyl Substances (PFAS) History Sources Exposure Pathways Analytical Challenges Information Resources
Per-and Polyfluoroalkyl Substances (PFAS) Per-and polyfluoroalkyl substances are collectively referred to as PFAS and are terms used to describe a large group of organic fluorinated chemicals; including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) PFAS are anthropogenic chemicals and do not occur naturally in the environment PFAS are a group of chemicals that are comprised of a carbon backbone containing many carbon-fluorine (C-F) bonds the C-F bond is the shortest and strongest in nature Due to their unique chemical structure, PFAS are very stable in the environment and are relatively resistant to biodegradation
Per-and Polyfluoroalkyl Substances (PFAS) Perfluorinated substances are those in which all the hydrogens on the carbons are replaced by fluorine. Polyfluorinated substances apply to chemicals in which not all the hydrogens on the carbons of the molecule are replaced by fluorine. When referring to mixtures of perfluorinated and polyfluorinated substances, it is more correct to use the term per- and polyfluoroalkyl substances or PFAS.
PFAS - History
PFAS - Sources Aqueous Film Forming Foam (AFFF) These foams have been stored and used for fire suppression, fire training, and flammable vapor suppression at hundreds of military installations and civilian airports (Hu et al. 2016), as well as at petroleum refineries and storage facilities, and chemical manufacturing plants throughout the United States. DoD Knowledge Based Corporate Reporting System show that 594 DoD facilities have been categorized as Fire/Crash/Training Sites
PFAS - Sources Production and Manufacturing Facilities Textiles and Leather: factory and consumer applied coating to repel water, oil, and stains Paper Products: surface coatings to repel grease and moisture Metal Plating and Etching: corrosion prevention, wear reduction, surfactant, fume suppressant Wire Manufacturing: coating and insulation Pesticides, cleaning products, polishes, photo processing
PFAS - Sources Production and Manufacturing Facilities Due to the solubility and persistence of many PFAS, environmental release mechanisms associated with these facilities include: air emission and dispersion spills disposal of manufacturing wastes and wastewater Potential impacts to air, soil, surface water, stormwater, and groundwater are present not only at release areas but potentially over the surrounding area
GenX concentrations in rainwater 1-3 miles away from facility ranges from 5.2 ppt to 630 ppt. 25 ppt found in rainwater 70 miles away from facility. State health goal is 140 ppt for drinking water.
Waste Disposal (Landfills) PFAS - Sources PFAS production facilities waste disposal Secondary manufacturing sites waste disposal Facilities that incorporate PFAS into the manufacturing process Municipal Solid Waste Facilities Disposal of consumer goods coated with PFAS Leachate
PFAS - Sources Wastewater Treatment Consumer and industrial use of PFAS-containing materials, including disposal of landfill leachate and firefighting foam, results in the discharge of PFAS to waste water treatment plants (WWTPs). WWTP Operations Conventional sewage treatment methods do not efficiently remove PFAAs Conventional treatment processes can change PFAS concentrations Increase in PFAA due to transformation of precursor PFAS
PFAS - Sources Wastewater Treatment continued.. WTTP Biosolids PFAS have been found in domestic sewage sludge more than half of the sludge produced in the United States is applied to agricultural land as biosolids Application of biosolids as a soil amendment can result in a transfer of PFAS to soil PFAAs can enter the food chain through the use of biosolidsamended soil PFAS concentrations can be elevated in surface and groundwater in the vicinity of agricultural fields that received PFAS contaminated biosolids
PFAS - Sources
PFAS - Sources
PFAS - Sources
Oliaei 2013, Environ Sci Pollut Res PFAS Exposure Pathways
PFAS Exposure Pathways Best documented source is contaminated drinking water near industrial production facilities or waste disposal e.g., Cottage Grove, Minnesota; Parkersburg, West Virginia; Dalton, Georgia; Decatur, Alabama; Arnsberg, Germany; Osaka, Japan Food is also implicated in many studies, especially fish from contaminated waters, items contaminated by food packaging and breast milk House dust may also be an important route of exposure especially for children who ingest relatively higher levels of dust via hand-to-mouth activity Workplace exposures significant for some sectors: manufacturing or services making or directly using PFAS, apparel sales, waste treatment
PFAS Exposure Pathways
PFAS Exposure Pathways
PFAS Exposure Pathways
PFAS Analytical Challenges PFAS is an emerging contaminant PFAS
PFAS Analytical Challenges PFAS is an emerging contaminant EPA has a health advisory level, but not an action limit Low detection limits requirements Production analytical chemistry has been available for a short time (instrumentation, available standards, etc) Potential blank contamination (ubiquitous nature of PFAS)
PFAS Analytical Challenges Unregulated compound group Various compound lists (6, 14, 21, 24)
PFAS Analytical Challenges
PFAS Analytical Challenges Unregulated compound group Various compound lists (6, 14, 21, 24) Various state and federal certifications
PFAS Analytical Challenges
PFAS Analytical Challenges Unregulated compound group Various compound lists (6, 14, 21, 24) Various state and federal certifications Various state and federal standards for different matrices Drinking Water Surface Water Groundwater Soils
PFAS Analytical Challenges
GES as of 1/18/2018 PFAS Analytical Challenges
PFAS Analytical Challenges Unregulated compound group Various compound lists (6, 14, 21, 24) Various state and federal certifications Various state and federal standards (MN, NH, NJ, etc) Various analytical methods (537, 537 v1.1, 537M, ASTM D7979, QSM 5.1)
PFAS Analytical Challenges
PFAS - Information Resources Interstate Technology and Regulatory Council (ITRC) 1. Naming Conventions and Physical and Chemical Properties 2. Regulations, Guidance, and Advisories 3. History and Use 4. Environmental Fate and Transport 5. Site Characterization Considerations, Sampling Precautions, and Laboratory Analytical Methods 6. Remediation Technologies and Methods 7. Aqueous Film Forming Foam https://pfas-1.itrcweb.org/
PFAS - Information Resources National Groundwater Association (NGWA) EPA (CLU-IN) SERDP and ESTCP Agency for Toxic Substances and Disease Registry (ATSDR) National Institute of Environmental Health Sciences (NIEHS)
PFAS - Information Resources
PFAS The Pace Solution Pace Florida has analyzed over 8,000 PFAS samples for PFAS (UCMR3) Two instruments (LC-MS/MS) for the analysis of drinking water and soil Holds certifications for most states in the US (UCMR3) Pace Minnesota Two instruments (LC-MS/MS) for the analysis of drinking water, groundwater, surface water, soil/sediment, and tissue Minnesota Department of Health and A2LA certification 16 other state and DoD certifications pending GenX and ADONA analysis by isotope dilution (Chemours)
PFAS Sample Containers
PFAS Sampling Guidelines
Per-and Polyfluoroalkyl Substances (PFAS) Questions? Nathan Eklund, PMP nathan.eklund@pacelabs.com (612) 710-0151