PFAS has multiple pathways into the human body, including food, water, breathing, and (rarely) skin contact. Originating from the industrial manufacturing sector and our environment by proxy, PFASs have found their way into our bodies, mainly through food and water that have been contaminated in a variety of ways.
health effects” Sunderland, 2018)
PFAS pollution is directly related to our dietary intake. PFASs in the environment find their way into animals and plants, where they persist long enough to enter our bodies via consumption. PFASs can also find their way into our bodies from food packaging itself. Because PFASs are valued for their stain-resistant nature, they have seen extensive use in disposable food containers. According to FDA studies, using PFAS-contaminated soil, water, or biosolids to grow food can also cause food contamination. Currently, it is difficult to concretely connect PFAS contamination levels to adverse health effects (that is, it is difficult to ascertain what level of PFAS will cause what effects), so the FDA uses the most up-to-date scientific literature to estimate hazards.
Just like for water, the FDA has created a liquid chromatography-mass spectrometry (LC-MS) method for 16 types of PFAS in food (specifically bread, lettuce, milk, and fish), called C-010.01. The FDA has reported that this method can detect PFAS in food from 7 to 901 parts per trillion, which is very suitable for detection levels of all kinds in food. C-010.01 is apparently commercially available, but I could not find any laboratories that advertised PFAS testing for food when researching online.
Sources
https://www.fda.gov/food/chemical-contaminants-food/testing-food-pfas-and-assessing-dietary-exposure
https://supplychain.edf.org/resources/testing-for-pfas-in-food/