A study has identified and quantified plastic particles in human blood for the first time. Using double shot pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), researchers measured plastic particles ≥700 nm in 22 healthy volunteers. Four high production volume polymers—polyethylene terephthalate (PET), polyethylene (PE), poly(methyl methacrylate) (PMMA), and polymers of styrene (PS)—were detected in blood. The average sum quantifiable concentration of plastic particles in blood was 1.6 µg/ml, indicating the presence of plastic particles in the human bloodstream. The study demonstrated that plastic particles can be absorbed across biological membranes and may pose a public health risk. The findings highlight the need for further research to understand the exposure and potential hazards of plastic particles in humans. The study used a robust analytical method to detect and quantify plastic particles in blood, providing a unique dataset for human biomonitoring. The results suggest that plastic particles may be bioavailable and could accumulate in the body, raising concerns about their impact on human health. The study also emphasizes the importance of developing sensitive and accurate methods for measuring plastic particle exposure in humans. The findings contribute to the growing body of evidence on the presence of plastic pollution in the human body and the need for further research to assess its potential health risks.A study has identified and quantified plastic particles in human blood for the first time. Using double shot pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), researchers measured plastic particles ≥700 nm in 22 healthy volunteers. Four high production volume polymers—polyethylene terephthalate (PET), polyethylene (PE), poly(methyl methacrylate) (PMMA), and polymers of styrene (PS)—were detected in blood. The average sum quantifiable concentration of plastic particles in blood was 1.6 µg/ml, indicating the presence of plastic particles in the human bloodstream. The study demonstrated that plastic particles can be absorbed across biological membranes and may pose a public health risk. The findings highlight the need for further research to understand the exposure and potential hazards of plastic particles in humans. The study used a robust analytical method to detect and quantify plastic particles in blood, providing a unique dataset for human biomonitoring. The results suggest that plastic particles may be bioavailable and could accumulate in the body, raising concerns about their impact on human health. The study also emphasizes the importance of developing sensitive and accurate methods for measuring plastic particle exposure in humans. The findings contribute to the growing body of evidence on the presence of plastic pollution in the human body and the need for further research to assess its potential health risks.