Microplastic injection? Identification and quantification of plastic particles in medical injections

Microplastics (MPs) mainly enter the human body through ingestion and breathing. Most of them are excreted through feces, and only a small amount can accumulate in human organs and tissues. In contrast, if intravenous injection contains MPs, it could directly enter bloodstream and maybe pose severe health risk. To verify this hypothesis, we collected two types of injection [0.9 % NaCl and 5 % Glucose] with three dominant brands in China, to analyze the possible MPs. The results indicated that the injection had an average abundance of 895 MP particles/kg, ranging from 140 to 1840 particles/kg. Furthermore, more MPs were found in NaCl than Glucose injection. The MPs encompassed 21 types of polymers with notable brand variations in distribution. Notably, polyisoprene chlorinated (61.77 % in NaCl, 61.23 % in Glucose) are most prevalent. Most polymers had small diameter, with 30.5 % and 44.2 % of particles measuring between 0 and 30 μm in NaCl and Glucose injection, respectively. These minute particle sizes contribute to the dispersal of MPs within human tissues. In terms of shape, most polymers are fibers/fragments, with some in bead form. Our study uncovered a previously unnoticed but important pathway for MPs enter the human body, emphasizing the need to evaluate health risks of infusion-related MP.