PFAS (PFOA/PFOS 'forever chemicals')
Emerging Contaminant · measured in ng/L (ppt)
A large family of synthetic 'forever chemicals' used for decades in nonstick, water-resistant, and firefighting-foam products. They persist in the environment and the body for years.
Common sources
Firefighting foam (especially near airports and military/training sites), industrial manufacturing discharge, and landfill leachate contaminating groundwater.
Health risks
Associated with increased cholesterol, reduced vaccine response and other immune effects, thyroid hormone disruption, pregnancy-induced hypertension, and increased risk of kidney and testicular cancer (PFOA). EPA's 2024 drinking water rule set enforceable limits of 4 ppt each for PFOA and PFOS.
Sources & further reading
- EPA — PFAS National Primary Drinking Water Regulation (2024)
- ATSDR — Toxicological Profile for Perfluoroalkyls
- Steenland K & Winquist A (2021), 'PFAS and cancer: A scoping review', Environmental Research, 194:110690
How ClearDive rates severity
Readings are bucketed for map color-coding using thresholds referenced from EPA regulatory limits where available. This is a simplified public-awareness scale, not a substitute for certified lab analysis.
How to test for it
No reliable field test exists at these trace (parts-per-trillion) concentrations — samples must be sent to a certified laboratory for LC-MS/MS analysis.