PFOS (Perfluorooctane Sulfonate)
Cities measured
87
Detected in
87 / 87
Elevated / alert
3
EU limit
100 ng/L
Highest
8.4 ng/L — Beirut
Overview
PFOS is a synthetic fluorosurfactant formerly used in firefighting foams (AFFF), textile water repellents (Scotchgard), and electroplating. 3M ceased production in 2002. PFOS is a Stockholm Convention persistent organic pollutant (POP) — virtually indestructible in the environment.
Health Relevance
PFOS causes thyroid disruption, immune suppression, liver toxicity, reproductive effects, and developmental neurotoxicity. It bioaccumulates in the liver and kidney. Studies show PFOS exposure reduces vaccine immune response — a finding confirmed in human cohort studies with direct public health implications.
Regulatory Limits
Drinking Water Directive 2020/2184
0.1 μg/L for sum PFOS isomers. EU Environmental Quality Standard (EQS) for surface water: 0.00065 μg/L.
Controversy & Contested Science
Military airfields, civilian airports, and fire training sites that used PFOS-containing AFFF have contaminated groundwater at hundreds of European sites. Swedish hot spots include Arlanda Airport (Stockholm), Landvetter Airport (Gothenburg), and multiple military bases. Stockholm's drinking water comes from Lake Mälaren, not from the worst-affected groundwater zones, but PFOS is detectable in most Swedish drinking water samples at low levels. Global PFOS remediation costs run into hundreds of billions of dollars — and no cost-effective large-scale PFOS degradation technology currently exists.