Unregulated and Regulated PFASs in Bottled and Tap Water: Occurrence, Co-Occurrence Patterns, and Implications for Human Health and Regulatory Frameworks.

The occurrence of per- and polyfluoroalkyl substances (PFASs) in drinking water remains a critical environmental and public health concern. This study examines the presence of both regulated and unregulated PFASs in twenty-one bottled water and twenty-four tap water samples, assessing their concentrations, co-occurrence patterns, and potential human health implications. Regulated PFASs accounted for 87% of total PFASs in bottled water and 92% in tap water, demonstrating the effectiveness of current EU regulations. However, unregulated PFASs were detected in both water sources, contributing to 13% and 8% of total PFAS concentrations in bottled and tap water, respectively. Principal Component Analysis (PCA) and Pearson correlation matrices revealed distinct clustering patterns, suggesting common contamination sources and potential cumulative exposure risks. The presence of emerging PFASs, such as 4:2 FTSA and HFPO-DA, raises concerns about gaps in regulatory oversight, as their long-term health effects remain largely unknown. Despite EU Directive 2020/2184 setting limits on select PFASs, this study highlights the need for expanded monitoring and stricter regulations to address the full spectrum of PFAS contamination. Given the persistence and bioaccumulative nature of these compounds, a comprehensive human health risk assessment is essential to safeguard public health and ensure the safety of drinking water sources.