Accumulation of PFAS in wine from a contaminated area: perfluorobutanoic acid (PFBA) as a molecular marker of PFAS groundwater contamination and implications of wine ingestion for human health

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants of global concern, with food and drinking water representing major exposure pathways. Despite the regional relevance of wine as an agricultural product, the relationship between PFAS occurrence in wine and natural waters has been scarcely investigated. This study assessed the presence and composition of PFAS in wines produced within and around a highly contaminated area in Italy, examined their relationship with PFAS in groundwater, and considered the potential implications for human exposure. Seventy-six wines were analysed by UPLC-MS/MS. At least one PFAS was quantified in seventy-three wines. Short-chain PFAS dominated the contamination profiles, with PFBA (perfluorobutanoic acid) quantified in 93.5% of samples (median concentration: 196 ng/L, maximum: 18,067 ng/L), followed by PFPeA and PFBS (quantified in 61.5%, and 51.3% of samples, respectively). Higher PFBA concentrations were associated with wines from production areas overlapping the contamination plume (p = 0.009). PFBA was highly correlated with the other most quantified PFAS in wine (PFPeA, PFBS, and PFHxA). In contrast to groundwater, long-chain PFAS were rarely detected in wine (<10%). Regression analysis revealed a significant positive association between PFBA concentrations in wine and the nearest groundwater point for vineyards within 75 m of the aquifer (+0.48% in PFBA concentration in wine for each +1% PFBA in groundwater, p = 0.001), suggesting spatially mediated transfer from contaminated groundwater, and identifying PFBA as molecular marker of PFAS contamination. Estimated dietary intakes indicated exceedance of the EFSA tolerable weekly intake for 1 wine under the highest consumption scenarios, and for 3-8 wines when relative potency factors were applied. For 3 wines, the estimated daily intake of specific PFAS exceeded the corresponding oral reference doses. These findings indicate that, in PFAS-contaminated areas, wine may act both as a bioindicator of groundwater contamination and as a potentially relevant dietary exposure pathway.