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SYSTEMATIC EVIDENCE MAP FOR 345 PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) [POSTER]
Citation:
Shirke, A., E. Radke-Farabaugh, H. Hubbard, C. Lin, N. Vetter, C. Lemeris, R. Blain, AND L. Carlson. SYSTEMATIC EVIDENCE MAP FOR 345 PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) [POSTER]. 42nd International Symposium on Halogenated Persistent Organic Pollutants, New Orleans, LA, October 09 - 14, 2022.
Impact/Purpose:
This poster has been prepared for submission to the 42nd International Symposium on Halogenated Persistent Organic Pollutants in October 2022. The conference agenda includes many PFAS-specific topics including "toxicology and metabolism of PFAS an other fluorinated compounds." The results of our evidence mapping efforts are of great interest to this audience as it provides a current landscape of the available toxicological and epidemiological evidence for a large number of PFAS chemicals. By presenting this information, we hope that researchers and regulators can use this work as a scoping tool to help with future PFAS risk assessment needs.
Description:
Introduction: Per- and polyfluoroalkyl substances (PFAS) are an environmentally ubiquitous class of synthetic chemicals consisting of a fluorinated carbon chain. Thousands of unique PFAS are used across many industrial and consumer applications including textiles, personal care products, and food packaging. The widespread use of PFAS raises concerns about health effects stemming from exposure to these chemicals through use of PFAS-containing products or environmental contamination. This systematic evidence map (SEM) builds upon a previous SEM conducted by the US EPA and characterizes the toxicological and epidemiological evidence base for 345 additional PFAS representing a wide array of chemical structures. Materials and Methods: Systematic review methods were used to identify and screen references from both peer-reviewed and “gray” literature sources. A literature search of multiple scientific databases was conducted through December 2021. Intentionally broad Populations, Exposures, Comparators, and Outcomes (PECO) criteria were used to identify references most relevant to human health hazard identification. Screening was conducted using both manual review by subject matter experts and machine-learning software applications. After screening, PECO-relevant references underwent a focused data extraction to create a literature inventory of study details (e.g. health effect category, exposure route, exposure duration, species) and study quality evaluation. Results: Over 13,000 references were identified from the literature searches. Of these, 207 references (121 animal and 86 human) were included as PECO-relevant after full-text screening, Animal studies (available for 34 PFAS) were primarily of acute (<24 hour) or short-term (1-30 days) duration and route of exposure was mostly via oral gavage or vapor inhalation. Commonly reported health outcomes were whole-body, reproductive, nervous, and hepatic effects. The most frequently studied PFAS were (E)-perfluoro(4-methyl-2-pentene) (CASRN 3709-71-5), 2H,3H-decafluoropentane (CASRN 138495-42-8), perfluoro-2-methyl-3-pentanone (CASRN 756-13-8), and perfluorododecanoic acid (CASRN 307-55-1). Most animal studies were found to have an overall study confidence rating of “low” or “uninformative” indicating that the study designs or effects reporting was deficient in a way that could significantly impact the interpretation of study results or limit their use for hazard identification. Data extraction and evaluation of the human studies are currently in progress. Conclusions: Many of the 345 PFAS assessed in this SEM were data-poor. Further, many of the animal studies evaluated were of “low” or “uninformative” confidence. Together, this highlights the need for robust health information that can inform risk assessments of these PFAS chemicals. This SEM, along with published results from our prior SEM, provides researchers and regulators an overview of the current PFAS human health landscape including data gaps and can serve as a scoping tool to help address the public health challenges associated with PFAS exposure.