PFAS in your drinking water: how to find out, and what actually helps

PFAS, short for per- and polyfluoroalkyl substances, are a family of synthetic chemicals that repel water, stains, and grease. They are often called “forever chemicals” because they break down extremely slowly, in the environment and in the human body.

[TODO: Dr. Dahlgren to review; attach citations (ATSDR / EPA summaries are referenced in the draft)]

Where they come from

Nonstick cookware, stain-resistant fabrics, some food packaging, and firefighting foam, which is a major cause of groundwater contamination near airports and military bases. Of all these routes, contaminated drinking water is the one most worth checking, because it is something you can measure and do something about.

How to find out about your water

• Public water: ask your supplier for the latest Consumer Confidence Report. Many suppliers also publish PFAS results online.
• Private well: routine municipal testing doesn’t cover you. PFAS testing needs a laboratory, and it’s especially worth doing near airports, military sites, industrial sites, or landfills.
• Maps: the Environmental Working Group and the EPA both publish PFAS contamination maps that show documented detections.

What helps, and what doesn’t

If your water does contain PFAS, the most practical home measure is a point-of-use filter certified to NSF/ANSI 53 or 58, or a reverse osmosis system.

Boiling does not remove PFAS. As water evaporates it can concentrate them slightly.

What the evidence says about health

Findings that are consistent across many studies include effects on reproduction and pregnancy, the immune system, cholesterol, and the liver. Evidence grade: Established Links to thyroid and metabolic effects and to cognitive symptoms are less consistent. Evidence grade: Probable

Should you get a blood test?

Blood tests for PFAS exist but aren’t routine, and a detectable level indicates past exposure rather than a prediction of illness. A useful question for your doctor is: “Given my water, is testing appropriate, and what would we do differently based on the result?”