Don’t toss that scratched-up, questionably stained, borderline EPA Superfund site, 12-year-old cutting board just yet! Your vintage fermentation lab with knife marks might not be so dangerous after all.
But some scientists are now scrubbing off that idea, with one researcher even calling studies sounding the alarms as “a joke.”
Recent high-profile reports claiming micro- and nanoplastics (MNPs) have infiltrated the human brain, arteries, and testes are facing a major scientific backlash. Experts are warning that many of these widely publicized findings may be the result of methodological errors, contamination, and false positives rather than actual plastic ingestion.
The technical heart of the dispute lies in Py-GC-MS, a process where samples are vaporized to identify molecules by weight. Environmental chemist Cassandra Rauert noted that this technique is currently unsuitable for identifying polyethylene or PVC in human tissue because molecules from human fat can mimic the signal of these plastics. Her research listed 18 studies that failed to account for these false positives. Furthermore, Rauert argued it is “biologically implausible” that the mass of plastic reported could end up in internal organs, as particles between 3 and 30 micrometers are unlikely to cross biological barriers.
Instead, the scientists suggested that rising obesity levels might explain health problems better than an increase in plastic accumulation.
Adding to the skepticism, Fazel Monikh, an expert in nanomaterials at the University of Padua, noted that particulate materials undergo biotransformation once they enter a living organism. He explained that even in the “highly unlikely scenario” that an intact particle reached a protected organ like the brain, it would not “retain the appearance shown in most of the reported data.” Consequently, many experts find the results and interpretations of these studies to be scientifically unconvincing.
Experts like Frederic Béen describe the study of microplastics in humans as a “super-immature field” where the race to publish has led to shortcuts and the overlooking of routine scientific checks.
These methodological shortcomings have real-world consequences, including “scaremongering” and the rise of expensive, unscientific treatments claiming to “clean” blood of plastics for fees as high as £10,000 (about $13,500). While the presence of plastics in the body remains a “safe assumption” for most researchers, they emphasize the need for robust, standardized techniques to accurately inform public health policy. In the meantime, experts recommend precautionary measures, such as using charcoal water filters and avoiding heating food in plastic containers.
For this story, Fortune journalists used generative AI as a research tool. An editor verified the accuracy of the information before publishing.
