Plastic in Our Blood: Can We Trust Py-GC-MS?

You might be surprised to learn that tiny bits of plastic are making their way into our bodies. Scientists are trying to figure out what happens to these micro- and nano-sized plastics (MNPs) once they're inside us. One tool they've been using is something called pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). This study looked into whether this method can accurately measure different types of plastics in human blood. Researchers developed a way to isolate polyethylene (PE) and polyvinyl chloride (PVC) from blood, reducing false positives. But the recovery rates were all over the place, from 7% to 109%. Surface-modified polystyrene (carboxylated) showed some promise, boosting recoveries from 17% to 52%.The detection limits were calculated, taking into account how the blood can mess with the readings. These limits were up to 20 times higher than what was expected in pure water. When tested on a group of Australians, PE interferences were lower but still there, and no other polymers were detected. The conclusion? Py-GC-MS isn't quite ready for primetime when it comes to detecting PE and PVC in our blood. Plus, even if it could, the amount of plastic we're exposed to is close to the limits of what this method can detect.