Occurrence of perfluoroalkyl substances in canned tuna and their impact on food safety

Continued use for industrial purposes of ever-new compounds compulsorily leads to the possibility of food contamination and risk for the consumer. Among the legacy and emerging contaminants, perfluoroalkyl substances (PFASs), used in the mid-20th century and still being implemented, are molecules of particular concern for their toxicity as endocrine disruptors, immunodepressants, possible carcinogens and liver and kidney toxicity. The main sources of PFAS exposure are water and food, particularly fish. In the European Union, European Food Safety Authority (EFSA) aimed the focus on 4 PFASs: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS). In this study, canned tuna was the investigated matrix, as a highly consumed food. The study aimed to detect the presence of 18 PFASs in 75 paired batches of precooked tuna loins and canned tuna through ultra-high performance liquid chromatography-tandem high-resolution mass spectrometry (UHPLC-HRMS). Seven of the investigated PFASs were detected in the analyzed samples. Among them, just two of the four PFASs of which EFSA established a Tolerable Weekly Intake (TWI), i.e. PFOS and PFNA, were found in canned tuna. The risk characterization related to canned tuna resulted in an intake value much lower than the TWI for the average Italian consumer, but is a possible concern for high consumers, considering that canned tuna is not the only source of PFAS intake.