Microplastic entry into bloodstream via hemodialysis: A dual-simulation clinical study.

Microplastics have attracted considerable attention due to their impact on the potential risk in health. Humans can ingest microplastics through ingestion, breathing, and/or drinking. Medical procedures involving plastic devices, such as hemodialysis, may lead to microplastic entry into the bloodstream. The purpose of this study was to evaluate the impact of hemodialysis on microplastic abundances in patients' blood. Laser direct infrared (LDIR) imaging spectrometry was employed to measure microplastics in ultrapure water samples (5 groups) before and after dialysis and blood samples (9 patients) pre- and post-hemodialysis. We detected the microplastics in the four water samples after dialysis, with no microplastics in pre-dialysis. Most of microplastics had diameters ranging between 20 and 50 μm. Compared to pre-hemodialysis blood samples, the number of microplastics in the post-hemodialysis blood samples was significantly increased (46.11 [56.22] vs. 96.11 [68.32], p = 0.027). We found chlorinated polyethylene (CPE), ethylene vinyl acetate (EVA), polymethylmethacrylate (PMMA), polytetrafluoroethylene (PTFE), and polyurethane (PU) in post-hemodialysis blood samples, with no trace in pre-hemodialysis blood samples. No significant correlation was observed between the number of total microplastics (or individual microplastic types) and the total dialyzed blood volume (all p values > 0.05). The results indicated that dialysis is associated with increased levels microplastics to enter the blood. However, the relationship between microplastic numbers and single dialysis-duration was not a single linear "contact time-dose".