The Evidence Is in Our Hair — A Century of Proof That Environmental Regulation Works

University of Utah scientists have provided striking physical evidence that environmental regulation works.

By analysing archived hair samples spanning more than a century, they documented steep declines in lead levels following EPA regulations. Published in the Proceedings of the National Academy of Sciences (PNAS), the study provides visceral, tangible proof at a time when environmental rules face political headwinds.

Lead poisoning was one of the defining public health crises of the 20th century. The EPA's regulations on leaded petrol, paint, and industrial emissions are widely credited with one of the greatest public health achievements in American history — and now that achievement is literally locked in human hair.

Key Facts

• Hair samples spanning 100+ years analysed (ScienceDaily)
• Dramatic decline in lead levels post-EPA establishment
• Published in PNAS, February 2026 (Live Science)
• Lead researchers: Thure E. Cerling, Diego P. Fernandez, Ken R. Smith

Why This Matters

At a moment when environmental regulations are under political pressure globally, this study provides the clearest single dataset showing environmental policy success over a century. The evidence isn't abstract — it's locked in the physical bodies of the people who lived through it.

What We Don't Know Yet

The study focused on the US; global lead exposure patterns vary significantly. Hair analysis has methodological limitations including potential contamination. And environmental justice communities — particularly in cities like Flint, Michigan — still face elevated lead exposure today.

Sources: ScienceDaily · Live Science · SciTechDaily
Published 17 February 2026 · Category: Environment & Climate