Per- and polyfluoroalkyl substances (PFAS) in Market Fish from Guangzhou, China: Co-exposure Profiling, Dietary Exposure Assessment, and Risk-Based Consumption Limits

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants, with fish consumption being a major human exposure route. This study analyzed 150 market-sourced fish (73 freshwater, 77 marine) comprising 46 distinct species from Guangzhou, China. This study quantified 16 PFAS, applied Frequent Itemset Mining (FIM) to identify dominant co-exposure patterns, assessed dietary exposure and risks of exceeding the safety threshold using local dietary data, and estimated species-specific maximum recommended consumption limits. PFAS were detected in 99.33% of samples, with 92.67% containing two or more PFAS. The total PFAS averaged 2.776 ng/g. FIM identified {PFDA, PFUdA, PFTrDA} as the most frequent ternary combination (support = 0.460). Based on the European Food Safety Authority (EFSA) tolerable weekly intake (TWI) of 4.4 ng/kg bw/week for the sum of PFOA, PFOS, PFNA, and PFHxS, the hazard index exceeded 1 for half of the species under high-consumption scenarios. Species-specific consumption limits were derived, ranging from high permissible intake (>121 g/day), to strict recommended intakes of less than 33 g/day. This study demonstrated widespread PFAS co-occurrence in market fish from Guangzhou, identified critical co-exposure patterns via FIM, and advocated for the integration of mixture-based analytics and targeted dietary guidance into ongoing regulatory monitoring frameworks.