MPs Entering Human Circulation through Infusions: A Significant Pathway and Health Concern.

Human uptake of microplastic particles (MPs) is causing increasing health concerns, and there is mounting pressure to evaluate the associated risks. While MPs can be ingested, breathed in, or drank in, a very direct entrance channel is available through ingress into the bloodstream. Intravenous infusion usually proceeds from plastic bottles. Many are made of polypropylene (PP), and filtering is applied to limit particle contamination. In this study, we examined the MPs' content of filtrates using a combination of surface-enhanced Raman spectroscopy and scanning electron microscopy. We find that the number of PP particles is significant (∼7500 particles/L). The MP sizes range from 1 to 62 μm, with a median of ∼8.5 μm. About 90% of particles ranged between 1 and 20 μm in size, with ∼60% in the range 1 to 10 μm. We then discuss the potential number of such particles injected and the consequences of their presence in the bloodstream. We highlight the organs for potential deposition, and we discuss possible clinical effects. Our quantitative data are important to help evaluate the toxicity risks associated with MPs and to accurately balance those risks versus the benefits of using intravenous injections.