Cooking with water containing PFAS: an overlooked route of exposition?

People can be exposed to PFAS in a variety of ways. Consuming of drinking water and/or food is a relevant exposure pathway for certain PFAS. Various studies have been carried out to assess if the cooking methods may alter the PFAS concentration in food. However, at our knowledge, the possible contamination of food cooked with contaminated water has never been assessed. This is particularly of worthy for people who live in areas where groundwater is contaminated, and lacking in a connection to a public water aqueduct and thus in an access to clean tap water. In some cases, they were not appropriately informed and trained regarding the use of their private wells, they have been consuming bottled water for drinking but have been continuing to employ their own well water for cooking and watering their garden for growing of domestic vegetables. This study reports the contamination of different food boiled with real, highly contaminated well water that has been consumed for years as drinking water. Two vegetables (potatoes and carrots), two cereals and derivatives (pasta and rise) and meat were selected for the study. They were boiled with clean bottled water and well water containing about 30 μg/L of total PFAS. 24-legacy PFAS concentrations were measured in water (at the beginning and at the end of the cooking) and in the food cooked in clean and polluted water. The content of target PFAS in the boiled contaminated water increased due to the loss of water by evaporation. All the food cooked in contaminated water was very contaminated and for some of them the PFAS uptake is much higher than that predicted by water absorption alone. The case study represents an extreme scenario due to the usage of very highly contaminated water but it provides evidences to foresee the food contamination in boiled food with lower contaminated water. The proved adsorption of PFAS from cooking water to food rises concerns and suggests considering this additional way of exposure for human in risk assessment.