Occurrence of per- and polyfluoroalkyl substances (PFAS) in the Philippine groundwater using a risk-based approach

In the Philippines, particularly in rural and remote areas, groundwater is the primary source of drinking water. Despite its abundance, the quality and availability vary across regions, emphasizing the dependence on distribution through local water districts and private suppliers. However, the characteristics of this water are not consistently monitored, thereby contributing to health and environmental risks. This study examines the occurrence of per- and polyfluoroalkyl substances (PFAS), also called forever chemicals, which are a global environmental concern. Using a risk-based monitoring approach in selected sites in Laguna, Philippines, groundwater samples (n=5) potentially contaminated with PFAS were analyzed using Liquid Chromatography-tandem Mass Spectrometry (LC- MS/MS) method following solid-phase extraction (SPE). Risk-based monitoring showed that the highest total PFAS concentrations were detected in areas located near a firefighting training facility and industrial parks, with an average of 36.77 ± 12.96 ng/L and 41.22 ± 0.35 ng/L, respectively. The detected concentrations surpassed the U.S. Environmental Protection Agency’s Maximum Contaminant Levels (MCLs) of 4 ng/L, highlighting potential health concerns. These results underscore the importance of further research, integrated water resource monitoring and management, and the implementation of mitigation measures to minimize PFAS exposure in affected communities.