Per- and polyfluoroalkyl substances (PFAS) are among the most persistent and widespread classes of synthetic chemicals detected in U.S. drinking water systems. Due to their chemical stability, environmental persistence, and bioaccumulative properties, PFAS exposure has emerged as a significant public health concern. This narrative review examines toxicological evidence, biomonitoring data, regulatory evolution, national detection patterns, and preventive mitigation strategies relevant to chronic low-dose exposure. While recent federal regulatory standards represent substantial progress, permissible limits do not equate to zero biological risk. A complementary public health framework emphasizing environmental literacy, exposure awareness, and decentralized preventive strategies may strengthen long-term national health resilience.