Drinking waters contamination by per- and poly-fluoroalkyl substances of the anthropized area of Fos-Berre, France.

Per- and poly-fluoroalkyl substances (PFAS) contamination and geographical distribution were studied in drinking water from the industrial harbor of Fos-Berre, a highly industrialized area in southern France. An analytical method for 38 PFAS was developed, using large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry. To minimize the risk of contamination during preparation, samples were directly injected onto a SCIEX Triple Quad 7500 system after dilution in acidified methanol. Method limits of quantification ranged from 0.081 to 2.2 ng L-1, except for 8:2 fluorotelomer unsaturated carboxylic acid and perfluoropentanoic acid (5.4 ng L-1). The method was applied to 28 tap waters and two groundwater from 28 stations on the Crau groundwater table and Durance River. Eighteen PFAS were quantified in at least one sample, with concentrations from 0.14 for linear perfluorooctane sulfonic acid (PFOS) to 62.85 ng L-1 for 6:2 fluorotelomer sulfonic acid. Short-chain carboxylic acids (perfluorocarboxylic acids) and sulfonic acids (perfluorosulfonic acids) were the most frequently quantified, with perfluorohexanoic acid showing the highest frequency (73%), followed by perfluorooctane carboxylic acid, branched PFOS, branched perfluorooctane hexanoic acid (PFHxS), linear PFOS and linear PFHxS. Total PFAS ranged from <0.081 to 126 ng L-1 and the sum of the 20 regulated PFAS remained below the 2020/2184 drinking water directive limit of 100 ng L-1 except for one sample (119 ng L-1). Contamination levels and profiles varied across sites, reflecting catchment location, surrounding industrial activities, and groundwater flow, with higher concentrations detected downstream.