Overview
- University of Utah scientists analyzed 47–48 archived and contemporary hair samples from the Wasatch Front spanning 1916–2024 using mass spectrometry.
- Measured lead concentrations peaked near 100 ppm in mid-20th-century samples, fell to about 10 ppm by 1990, and dropped to under 1 ppm by 2024.
- The timing of the decline aligns with the EPA’s creation in 1970, the phase-out of leaded gasoline, and the closure of nearby smelting facilities.
- Researchers stress that hair reflects overall environmental exposure rather than blood lead levels, and they note the study’s small, regionally focused scope.
- The authors warn that recent federal moves to weaken EPA authorities, including signals of looser enforcement of lead rules, could jeopardize the gains documented.