Life in plastic might be fantastic after all — or at least not as dangerous as we’ve been led to believe.
Ubiquitous in the environment, microplastics can be found in the clothes we wear, the cleaning supplies we use, the food we eat, the water we drink and even the air we breathe.
For years, scientists have warned that these pesky particles may be quietly building up inside our bodies, posing a threat to human health. But a new report in The Guardian is shaking up that narrative.
Several experts told the outlet that some of the alarming claims about microplastics may be exaggerated — with one calling the skepticism a “bombshell.”
“This is really forcing us to re-evaluate everything we think we know about microplastics in the body. Which, it turns out, is really not very much,” Roger Kuhlman, a chemist formerly at the Dow Chemical Company, told The Guardian.
“Many researchers are making extraordinary claims, but not providing even ordinary evidence.”
Tiny particles, big questions
One of the earliest findings suggesting that microplastics may have entered the human body dates back to 2018, when Austrian scientists analyzed stool samples from people in eight countries and found that every single sample contained them.
Since then, they’ve reportedly been found in nearly every organ and tissue, from placentas and testicles to kidneys, lungs and livers.
But The Guardian found that at least seven widely cited studies were later challenged by other scientists. A separate review flagged 18 more for overlooking a major problem: human tissue itself can produce signals that mimic plastic, leading to possible false positives.
That includes a headline-grabbing report last year claiming the average human brain may contain the equivalent weight of a plastic spoon in microplastics.
“The brain microplastic paper is a joke,” Dr. Dušan Materić, a German microplastics researcher who co-authored a letter challenging the study, told The Guardian.
“That paper is really bad, and it is very explainable why it is wrong,” he added. “Fat is known to make false positives for polyethylene. The brain has [approximately] 60% fat.”
The study’s lead author acknowledged the limitations of the study, but said the science is still in its infancy.
“In general, we simply find ourselves in an early period of trying to understand the potential human health impacts of MNPs (micro- and nanoplastics) and there is no recipe book for how to do this,” University of New Mexico professor Matthew Campen told the outlet.
Claims under fire
Some scientists have also raised doubts about studies reporting particularly high levels of micro- and nanoplastics in the human body.
“From what we know about actual exposure in everyday life, it is not biologically plausible that that mass of plastic would actually end up in these organs,” Dr. Cassandra Rauert, an environmental chemist who led the review of studies that failed to consider a key source of false positives, told The Guardian.
One of the studies her review called into question was a landmark 2022 paper that reported detecting microplastics in human blood for the first time.
Its lead author, professor Marja Lamoree of Vrije Universiteit Amsterdam, rejected accusations that the findings may have been tainted, saying the review had “incorrectly interpreted” the data.
“I’m convinced we detected microplastics,” she told The Guardian. “But I’ve always said that [the amount estimated] could be maybe twice lower or 10 times higher.”
Other experts say they’ve never actually seen the kinds of microplastics that some studies claim to have found in human bodies.
“When particulate materials enter a living organism, including the human body, they undergo biotransformation,” Dr. Fazel Monikh, an expert in nanomaterials at the University of Padua in Italy, told The Telegraph.
“Even if one were to assume the highly unlikely scenario in which an intact particle reaches a protected compartment, such as the brain, and is then successfully detected, it would not retain the appearance shown in most of the reported data,” he explained.
“For these reasons, most of the presented results and their interpretation are not scientifically convincing to me, nor to my colleagues who are experts in this field,” Monikh said.
Avoiding ‘scaremongering’
The Guardian report makes clear that plastic pollution is undeniably widespread, and the critics it cites don’t accuse anyone of malpractice.
Their concern, rather, is that the rush to publish, sometimes by teams with limited experience, may have led to shortcuts and routine scientific checks being skipped.
Improving the quality of these studies is crucial, Rauert said, since shaky data can fuel “scaremongering.”
“We get a lot of people contacting us, very worried about how much plastics are in their bodies,” she noted.
The worry is that microplastics can carry toxic chemicals that trigger inflammation and cell damage in the body. Over time, research suggests this may disrupt hormones, harm gut microbiomes, affect cognitive function, reduce fertility and raise the risk of chronic disease.
“We want to be able to get the data right so that we can properly inform our health agencies, our governments, the general population and make sure that the right regulations and policies are put in place,” Rauert said.
While the public waits for science to catch up, even some experts who criticized studies on microplastics in the body say there’s no reason to ignore potential risks.
“We do have plastics in us — I think that is safe to assume,” Materić said. “I take some precautions myself, to be on the safe side.”
That includes avoiding drinking from plastic water bottles and reheating food in plastic containers — two practices research shows are major sources of microplastics in our diet.
