Overview
- University of Utah researchers used mass spectrometry to analyze archived and contemporary hair spanning roughly 1916 to 2024, publishing their findings on February 2.
- Measured lead concentrations fell from peaks near about 100 parts per million in the 1970s to around 10 ppm by 1990 and roughly 1 ppm by 2024.
- The decline coincides with the phase-out of leaded gasoline and the closure of local smelters following EPA regulatory actions, the authors report.
- Hair records environmental deposition and preserves it over time, providing a historical exposure archive, though blood better reflects internal dose.
- The study highlights the public-health benefits of pollution controls, as the authors voice concern over recent efforts to weaken EPA enforcement.