Providing technical research support to identify and mitigate environmental health concerns from “forever chemicals”

What are Per- and Polyfluoroalkyl Substances (PFAS)?

Per- and polyfluoroalkyl substances (PFAS) are a class of human-made compounds that are rapidly becoming an emerging public health concern. Some PFAS compounds have been used for decades in common consumer and industrial products such as non-stick cookware, food containers and food paper wrappings, carpeting, upholstery, clothing, and firefighting foams. The use of per- and polyfluoroalkyl substances makes materials more resistant to grease, water, and oil. Although some PFAS, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are no longer produced in the United States, these compounds are extremely stable and therefore persist in the environment and human body for extended periods of time. Additionally, newer per- and polyfluoroalkyl substances have been used as replacements and the toxicity and persistence of these emerging contaminants is not fully understood.

RTI researchers discuss testing for per- and polyfluoroalkyl substances

RTI researchers discuss testing for per- and polyfluoroalkyl substances

Why are PFAS a Contaminant of Emerging Concern?

PFAS sources: Recent testing has identified per- and polyfluoroalkyl substances in the environment from various sources, including industrial discharges to air and water, aqueous film-forming foam (AFFF) used on military bases and fire stations, agricultural areas with biosolids applications, and urban areas with municipal wastewater treatment discharges.

PFAS in the human body: Data from the National Health and Nutrition Examination Survey (NHANES) demonstrate that most adolescents and adults have detectable levels of per- and polyfluoroalkyl substances in their blood (CDC, 2018). However, potential PFAS exposure pathways are not assessed as part of NHANES, and the correlation between environmental exposure and serum levels is not well understood.

PFAS in the environment: Sites with elevated levels of per- and polyfluoroalkyl substances in drinking water continue to emerge, and data on PFAS in air, food, and indoor dust are limited. PFAS compounds have been identified in drinking water derived from surface water and groundwater. The EPA has not issued any Maximum Contaminant Levels for PFAS, but in 2012, PFOS and PFOA were added to the third Unregulated Contaminant Monitoring Rule (UCMR 3), prompting testing requirements for all public drinking water systems.

PFAS toxicity: There is limited research on the potential toxicity of PFAS in humans. In 2016, the EPA issued a lifetime health advisory (LHA) for PFOS and PFOA of 70 parts-per-trillion (EPA 2016a; EPA 2016b). The Agency for Toxic Substances and Disease Registry (ATSDR) released an updated draft of the toxicological profile for 14 per- and polyfluoroalkyl compounds in June 2018, proposing much lower minimum risk levels for PFAS and PFOA (ATSDR, 2018b).

An RTI researcher conducts laboratory tests on water samples

An RTI researcher conducts laboratory tests on water samples.

How Can RTI Help Address Per- and Polyfluoroalkyl Substances?

RTI has more than 30 years of experience evaluating hazardous, industrial, and municipal waste management practices and assessing human health impacts from pollutants released in the environment. Our program in aerosol and exposure science, epidemiology and environmental exposure, exposure research analysis, environmental health registries, health and environmental risk assessment, and PFAS removal provide the comprehensive, scientific expertise needed to assess per- and polyfluoroalkyl substances exposure and its impact on communities. 

We have a large group of subject matter experts with a broad range of expertise on environmental health science, laboratory science, and policy analysis on PFAS compounds. Our experts can help with the following:

  • PFAS compound identificationRTI laboratories can detect per- and polyfluoroalkyl substances using state-of-the-science methods to pinpoint the differentiate the types and concentrations of PFAS compounds in various sample media. We use LC-MS/MS, UPLC-Q-TOF-MS, and 4000 QTRAP to characterize and quantify trace levels of newly-identified and legacy PFASs in wide array of matrices. RTI has expertise to develop new analytical methodologies or modify existing methods for related compounds at detection limits well below state and federal screening levels.
  • Exposure assessments—Our experts estimate exposure by evaluating available concentration data in geographic information systems with exposure models. We can link PFAS sources to potential exposure pathways and media.
  • Site assessments—Our staff have successfully managed a variety of site-specific assessment projects to characterize multimedia, multi-pathway environmental hazards.
  • Risk assessments—RTI risk assessors estimate exposure using per- and polyfluoroalkyl substances concentration data, use GIS to conduct data analysis, evaluate the toxicity of PFAS compounds, perform risk assessments, and make mitigation recommendations. In addition, we can quantify PFAS exposure routes and evaluate the association of PFAS exposures at identified sites on PFAS levels in humans, livestock and plants.
  • Hydrogeologic modeling—RTI has the tools, knowledge, and experience to apply effective groundwater flow and transport models to address water-resource and environmental needs. From managing and protecting drinking water resources to understanding and cleaning up environmental contamination, models can provide vital information to help solve a variety of groundwater challenges. Modeling capabilities include:
    • Groundwater resource and impact evaluations
    • Uncertainty analysis
    • Data management and processing
    • Three-dimensional visualization
  • Targeted community engagement and risk communication campaigns—RTI has on-the-ground experience creating community outreach and engagement campaigns for communities impacted by specific environmental exposures.
  • Risk perception research—RTI has the expertise and software to identify risk perceptions using publicly available information on social media that can detect spatial and temporal trends in citizen concerns.
  • Environmental exposure health registries and epidemiology—Through our environmental health registry work with the World Trade Center Health Registry and the Katrina and Rita Exposures Registry, we have collected important data from thousands of individuals on post-exposure and post-disaster health outcomes.
  • Biological and environmental sample collection and monitoring—Our staff are well versed in the unique protocols necessary to collect biospecimens (e.g., blood, urine) and environmental samples (e.g. air, water, soil, dust, food).
  • Risk mitigation and remediation—RTI has longstanding expertise in evaluating risk mitigation options and overseeing remedial planning, approval, and implementation actions. RTI has experience evaluating various site-closure strategies, including land-use controls with environmental restrictive covenants or engineered barriers.
  • Removal of PFAS from water supplies—RTI has worked with universities to develop innovative and reliable ways to remove per- and polyfluoroalkyl substances from water supplies. We also work with clients to understand the landscape of innovative treatment solutions and drivers impacting the adoption of those solutions.

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