Don’t throw away that 12-year-old cutting board that’s scratched, questionably stained, and on the verge of EPA Superfund site! After all, an old fermentation lab with knife marks might not be so dangerous after all.
Scientists have been warning for years that microplastics are in everything: from the food and drinks we consume to the clothes we wear and the cleaning products we use. These microplastics are accumulating in our bodies and posing new risks to our health – or so we are told.
But some scientists are now pushing back on that idea, with one researcher even calling the study that raised the alarm “a joke.”
Recent high-profile reports claiming that micro- and nanoplastics (MNPs) have penetrated human brains, arteries and testicles are facing a backlash from the scientific community. Experts warn that many of the well-publicized findings may be the result of methodological errors, contamination and false positives rather than actual plastic ingestion.
“The brain microplastic paper is a joke,” writes Dusan Materic, head of research at the Helmholtz Center for Environmental Research (UFZ). Materic is one of several scientists who claim that previous studies on the damage microplastics cause to the human body have been exaggerated.
Chemist Roger Kuhlman said the previous study, which provided more evidence than there are holes in your cutting board, amounted to a “bombshell”. guardian.
“This is really forcing us to reevaluate everything we thought we knew about microplastics in the body,” Kuhlman, a former Dow Chemical Company chemist, told the publication. “As it turns out, it’s not much. Many researchers make extraordinary claims without even providing ordinary evidence.”
The controversy centers on a series of studies that made headlines around the world, including one that suggested the average weight of MNPs in the human brain may be equivalent to the weight of a plastic spoon. However, by November, a group of scientists formally questioned the study in a “problem arises” letter, citing limited contamination controls and a lack of validation steps.
The technology at the heart of the controversy lies in Py-GC-MS, a process that evaporates a sample to identify molecules based on their weight. Environmental chemist Cassandra Rauert points out that the technology is currently not suitable for identifying polyethylene or PVC in human tissue because molecules from human fat can mimic the signals of these plastics. Her study lists 18 studies that failed to account for these false positives. Furthermore, Rauert considers it biologically “implausible” that the reported large amounts of plastic could end up in the gut, since particles of 3 to 30 microns are unlikely to cross biological barriers.
Instead, scientists believe rising obesity levels may explain health problems better than increased plastic accumulation.
Fazel Monikh, an expert on nanomaterials at the University of Padua, points out that particulate materials undergo biotransformation once they enter an organism, which fuels suspicion. He explained that even in the “extremely unlikely event” that an intact particle reaches a protected organ such as the brain, it would not “retain the appearance shown in most reported data.” As a result, many experts find the results and interpretations of these studies scientifically unconvincing.
Experts such as Frederic Bain describe human microplastic research as a “super immature field” where the race to publish leads to shortcuts and a neglect of regular scientific checks.
These methodological flaws have real-world consequences, including “scaremongering” and the rise of expensive and unscientific treatments that claim to “cleanse” plastic blood, costing up to £10,000 (approximately $13,500). While the presence of plastics in the body remains a “safe assumption” for most researchers, they stress the need for robust, standardized techniques to accurately inform public health policy. In the meantime, experts recommend taking precautions such as using a charcoal water filter and avoiding heating food in plastic containers.
For this story, wealth Journalists use generative AI as a research tool. Editors verified information for accuracy before publishing.
This story originally appeared on Fortune.com