MADISON, Wis. (AP) — The state Department of Natural Resources is warning people to avoid eating livers of deer killed around Marinette to avoid being exposed to PFAS chemicals. DNR officials said Tuesday that a study of 20 deer harvested around the JCI/Tyco Fire Technology Center in Marinette found significant levels of PFAS in the animals’ livers. DNR and state health officials issued a do-not-eat advisory for livers of deer harvested within five miles of the JCI/Tyco facility. PFAS are human-made chemicals that research suggests can cause health problems in humans. The chemicals have been used for decades in firefighting foam and nonstick cookware.