Microplastics Entry into the Blood by Infusion Therapy: Few but a Direct Pathway

Microplastic pollution is now ubiquitous in the environment, making human exposure to microplastics unavoidable. This results in the detection of microplastics in human bodies, including blood. However, the pathways through which microplastics enter the bloodstream still need to be clarified, despite the studies of several direct and indirect routes. Herein, the potential occurrence of microplastics in infusion therapy sets, including glass infusion bottles, plastic infusion bottles, plastic infusion bags, and plastic infusion tubes, was investigated. The results showed that a total of eight microplastics, ranging from 4 to 148 μm in size, were identified from three PP-bottled infusion, three PE-bagged infusion, and one glass-bottled infusion, consisting of PE, PA, PS, and PC, while no particles were detected in infusion tubes. The samples containing microplastics accounted for 11.66% of the total samples with 1–2 particles/unit. Although microplastics were detected in infusion solutions, microplastic exposure to the bloodstream via infusion therapy is minimal, owing to their low abundance. Nevertheless, these findings suggested that infusion therapy might be a direct pathway of microplastics entering the bloodstream, partially or fully explaining the presence of microplastics in human blood and tissues.