PFAS surveillance within a highly militarized island: a case study of Okinawa, Japan

Per- and polyfluoroalkyl substances (PFAS) are a resilient class of anthropogenic contaminants of emerging concern with over 12 000 individual compounds that have been noted for industrial applications, consumer goods, and food packaging materials. In general, the most common contributors to PFAS environmental pollution are aviation facilities, specifically those that use aqueous film forming foams (<i>e.g.</i>, at military bases and airports). In this study, we examined the presence of PFAS across Okinawa Island (Japan) due to its large-scale U.S. military presence throughout the island. Surface water was collected at 61 sites across the island to achieve maximum geographical coverage of the island while also collecting near suspected PFAS sources; 31 PFAS were monitored using a 12 min HPLC-MS/MS method. A total of 15 PFAS were detected and quantified around the island with a mean Σ₁₅PFAS of 16.3 ng L^-1 and a maximum site concentration of 164.3 ng L^-1. Region-specific PFAS profiles were observed across the island, including the overwhelming presence of PFHpA in the northern region of the island, revealing the possibility of multiple PFAS source points in Okinawa. The resultant data herein provides the first island-wide examination of PFAS "hotspots" across Okinawa and is a critical first step toward increasing PFAS awareness and action.