Mass spectrometry imaging unveils intergenerational toxicity of a novel PFECA (C7 HFPO-TA) in zebrafish

2-[2-(Trifluoromethoxy)hexafluoropropoxy]tetrafluoropropanoic acid (C7 HFPO-TA), a novel perfluoropolyether carboxylic acid (PFECA) identified as a high-priority emerging PFAS in Taihu Lake (447 µg/L), has been widely adopted as a PFOA substitute. However, its ecotoxicological effects, particularly long-term exposure-mediated multigenerational toxicity in aquatic organisms, remain unknown. In this study, we systematically evaluated the multigenerational toxicity of C7 HFPO-TA in zebrafish at an environmentally relevant concentration (500 µg/L). Maternal exposure induced significant offspring malformations (p < 0.05), predominantly pericardial edema (41.32 % incidence) and spinal curvature (17.67 %). By airflow-assisted ionization mass spectrometry imaging (AFAI-MSI), we demonstrated for the first time that C7 HFPO-TA may undergo transovarian transfer and induce tissue-specific metabolic perturbations. C7 HFPO-TA accumulation in oocytes triggered severe downregulation of arachidonic acid (AA) and glycerophospholipid metabolites (p < 0.001) in larval spinal tissue, which could disrupt skeletal development. Suppressed purine and folate metabolism (p < 0.001) in pericardial regions correlated with oxidative stress, potentially impairing cardiac function. Notably, the metabolic disruptions persisted in F1 offspring despite reduced chemical burden. Our study integrates spatial pollutant imaging with spatial metabolomics, advancing mechanistic toxicity assessment for emerging PFAS. The findings underscore that C7 HFPO-TA may not be a safe PFOA alternative due to its transgenerational risks, urging stricter regulation of PFECAs in aquatic ecosystems.