Unfortunately PFOS was spread around the globe. No one knows how it spread.
3M voluntarily stopped manufacturing this chemical and gave-up about $300 million in sales.
The good news is levels are extremely low – way, way below any known health effects. 3M workers who worked with this chemical for a long time have shown no ill health affects.
30 years ago you couldn’t even measure the level of PFOS in the bluegills.