Abstract
In recent years, 1,4-dioxane has emerged as a pollutant of increasing concern following widespread detection in the aquatic environment of several countries. This persistent contaminant with specific physical and chemical properties can be rapidly dispersed and transported to river banks, groundwater and drinking water. Given the limited data on its occurrence in France, it was considered necessary to assess the potential exposure of the French population to this compound in drinking water. An analytical method based on solid-phase extraction (SPE) combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed and validated during this study with a limit of quantification (LOQ) of 0.15 µg/L. Recoveries in natural water matrices ranged from 113–117% with a relative bias not exceeding 17%. This method was used for a nationwide campaign at almost 300 sites, evenly distributed over 101 French départements (administrative units), including some that were overseas. 1,4-Dioxane was detected mainly (63%) in raw and treated water from sites associated with historical industrial practices related to the use of chlorinated solvents. The maximum concentration of 1,4-dioxane found in a raw water sample was 4.80 µg/L. Drinking water treatment plants using ozonation, granular activated carbon and chlorination have limited effectiveness in the removal of 1,4-dioxane. The results of this study are the first step towards bridging the knowledge gap in the occurrence of 1,4-dioxane in France. Further investigations are needed with priority being given to several sites where 1,4-dioxane has been found in substantial concentrations (> 1 µg/L).