A federal study tested the blood of participants from communities in eight states with known contamination from PFAS, substances often referred to as “forever chemicals” because they resist breaking down in humans and the environment. Study participants from Pennsylvania lived near the Horsham Air Guard Station and former Naval Air Station, Joint Reserve Base Willow Grove, and the Naval Air Warfare Center Warminster site. Levels for four different types of PFAS for these participants were higher than the general U.S. population. Test results are in nanograms per milliliter.