We are accustomed to alarming headlines stating that microplastics have been found everywhere, in every human body system—in blood, lungs, brain, and even the placenta. The scale of the problem seems total. But a recent study from the University of Michigan has added an important, ironic nuance to this picture: a significant portion of these frightening findings may be the result of sample contamination... by the scientists themselves.
A team of chemists led by Madeline Clough and Anne McNeil discovered that the standard nitrile and latex gloves, which researchers wear precisely to "protect" samples from contamination, are themselves a source of microscopic particles.
During glove production, stearates—salts of stearic acid—are used as a release agent, allowing the finished product to be easily removed from molds. When a scientist wearing gloves touches a test tube, filter, or microscope slide, an invisible trace of these salts is left on the surface.
When using standard infrared and Raman spectroscopy, stearate particles are practically indistinguishable from real microplastics, such as polyethylene. Experiments showed that simple dry contact of a glove with a sample can generate an average of up to 2000 false positive "microplastic particles" per square millimeter.
Does this mean microplastics don't exist? Of course, the study's authors were the first to rush to the defense of their colleagues who have been scaling the problem for years. "This doesn't mean microplastic contamination doesn't exist," emphasizes Professor Anne McNeil. "We might be overestimating its volume due to this error, but it shouldn't be there anyway. There's still a lot of it, and that's the problem."
The discovery primarily concerns systematic errors in quantitative assessments, especially in atmospheric air, water, and soil samples, where particle concentrations are already low. If we talk about human tissues, then yes, protocols for collecting and analyzing biomaterials now require revision to exclude the "glove trace." But this, according to the scientists, does not nullify previous data, but merely requires them to be re-verified using new algorithms that the scientists have already developed to distinguish stearates from actual polymers.
This story is reminiscent of another incident. In the last decade of the previous century, at the Parkes Observatory (Australia), astronomers spent years registering mysterious short radio signals, dubbed "perytons," which, by their characteristics, corresponded to extraterrestrial impulses or the traces of merging neutron stars. The explanation turned out to be maximally down-to-earth: the signal was emitted by a microwave oven in the staff lounge, which was opened before the heating cycle was complete, causing a short burst of radiation at that frequency. The research instrument was working correctly. Scientists simply didn't account for a mundane factor in a high-precision system, and the cause was found where they didn't expect it.
The basic fact remains unshakable: humanity has indeed managed to leave its synthetic traces everywhere. It's just that now we know that sometimes these traces are left not only by global industry but also by the researcher themselves, who is investigating the consequences, wearing latex gloves.
