Expanded Systematic Evidence Map for Hundreds of Per- and Polyfluoroalkyl Substances (PFAS) and Comprehensive PFAS...

Area of Science:

• Environmental Health Sciences
• Toxicology
• Epidemiology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are widely used industrial chemicals detected globally.
• The US Environmental Protection Agency (US EPA) has outlined research strategies to address PFAS challenges.
• This study focuses on PFAS identified for toxicity testing and those of interagency interest.

Purpose of the Study:

• To systematically map and summarize epidemiological and mammalian bioassay evidence for 345 PFAS.
• To inform human health hazard identification for selected PFAS.
• To build upon previous evidence mapping efforts and identify data gaps.

Main Methods:

• Systematic Evidence Map (SEM) methods were employed, combining manual review and machine learning.
• Searched peer-reviewed and gray literature for mammalian bioassay and epidemiological studies.
• Developed interactive web-based inventories to summarize study designs and health endpoints.

Main Results:

• Over 13,000 studies were identified, with 121 mammalian bioassay and 111 epidemiological studies meeting criteria.
• Epidemiological evidence (12 PFAS) focused on reproductive, endocrine, developmental, metabolic, cardiovascular, and immune systems.
• Mammalian bioassay evidence (30 PFAS) commonly assessed reproductive, whole-body, nervous, and hepatic systems; 41 PFAS had evidence from both streams.

Conclusions:

• Evidence was lacking for the majority of the 345 PFAS investigated.
• A comprehensive PFAS dashboard integrates findings, highlighting data gaps and aiding research prioritization.
• This work supports the US EPA's efforts in PFAS risk assessment and research planning.