Current methods using pyrolysis–gas chromatography–mass spectrometry cannot reliably identify microplastics like polyethylene or polyvinyl chloride in human blood because natural blood chemicals and...

We analyzed the available evidence and found that current methods using pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) cannot reliably detect polyethylene or PVC in human blood. The issue isn’t that the technique is broken—it’s that the chemicals naturally present in blood, along with the heat-induced breakdown products created during testing, produce signals that look very similar to those from these plastics. This overlap makes it impossible to say for sure whether what’s being measured is actual plastic or just background noise from the body’s own chemistry [1]. So far, 27 studies or assertions support this limitation, and none contradict it. This means the evidence we’ve reviewed leans toward the idea that Py-GC-MS, as it’s currently used, isn’t a trustworthy tool for spotting these specific microplastics in blood samples. The technique may still be useful in other settings, like testing water or soil, but in blood, the interference is too strong to overcome with today’s methods. What this means for someone trying to understand plastic exposure in the body is that we don’t yet have a clear, reliable way to measure polyethylene or PVC in blood using this approach. If you’re looking for evidence of microplastic exposure, other methods or improved versions of Py-GC-MS may be needed—but right now, we can’t say with confidence whether these plastics are present based on this test alone.