Detoxification-associated polyvinyl chloride micro- and nanoplastics clearance and liver metabolomic responses in mice

Aged PVC (A-PVC) exhibits distinct surface chemistry from original PVC that may result in different toxicokinetic and toxicodynamic behaviors, yet relevant evidence remains limited. This study investigated the tissue distribution, excretion kinetics and liver metabolic responses of PVC and its debris A-PVC in C57BL/6J mice following acute oral exposure. Py-GC/QTOF measurement revealed that both particles rapidly accumulated in major organs of liver, spleen, heart and lung, and that the particle burdens in the measured organs declined substantially by 72 h, which was further verified by the multiple imaging analysis. Although histopathological and biochemical alterations gradually attenuated during recovery, small A-PVC elicited more severe acute biological responses, whereas large original PVC produced relatively sustained toxic effects characterized by oxidative stress, inflammation and endocrine disruption. These findings highlight aging-associated alterations in the kinetic behavior of PVC MNPs. Notably, the organ specific clearance patterns of 300-1300 nm aged PVC are consistent with a hypothesized non-biliary intestinal excretion pathway, which warrants further verification.