Per- and polyfluoroalkyl substanc…y sites of exposure.

PFAS chemicals—used in many cosmetics and industrial products—can weaken your immune system, particularly your vaccine response. The research links PFAS exposure to increased asthma, allergies, and inflammatory bowel disease in humans. These effects happen mainly through skin contact, inhalation, and ingestion, though scientists say we need more human studies to fully understand the risks.