Former 3M scientist Kris Hansen was among the first to discover how widespread PFAS contamination in humans was in the late 1990s — and the company continually disputed her results, ultimately sidelining her from PFAS research altogether, she said.

Extensive reporting from ProPublica dug into the decades-long cover-up. Now an environmental consultant, Hansen joined MPR News Morning Edition host Cathy Wurzer to tell her story and share more about her research in light of the article.