Microplastics – tiny particles less than 5mm in diameter – have already been detected in several organs within the human body, including lungs, placentas, reproductive organs, livers, kidneys, joints, and even bone marrow. Now, new studies show that brain tissue has also fallen victim to this widespread contamination.
“Given the research findings, it is now imperative to declare a global emergency to deal with plastic pollution,” says Sedat Gündoğdu, a researcher from Cukurova University in Turkey who studies microplastics. His words reflect the urgency felt by scientists across the world as they discover microplastics in even the most protected tissues in the human body.
One of the latest studies, still under peer review, highlights a startling accumulation of microplastics in the human brain. The research examined the organs of deceased individuals and found microplastics in all the livers, kidneys, and brains analyzed. Astonishingly, the study revealed that brain samples contained significantly more microplastics than other organs, ranging from 10 to 20 times the levels found elsewhere. The 24 brain samples collected in early 2024 measured, on average, around 0.5% plastic by weight.
“It’s pretty alarming,” says Matthew Campen, a toxicologist from the University of New Mexico and the lead author of the study. “There’s much more plastic in our brains than I ever would have imagined or been comfortable with.” The study describes the brain as “one of the most plastic-polluted tissues yet sampled.”
Even more troubling is the fact that brains from individuals with dementia, including Alzheimer’s disease, contained up to ten times more plastic by weight than healthy brain samples. Although further research is needed to understand the implications, the findings suggest a potential link between microplastics and neurodegenerative diseases.
The concentration of microplastics in human organs seems to be rising. Campen's study indicates that brain samples from 2024 contained about 50% more microplastics than samples dating back to 2016. This rise appears to reflect the increasing levels of plastic found in the environment. “You can draw a line – it’s increasing over time,” Campen said. “It’s consistent with what you’re seeing in the environment.”
While microplastics are accumulating in human bodies, the mechanisms behind their infiltration into the brain remain unclear. Bethanie Carney Almroth, an ecotoxicologist at the University of Gothenburg, notes that the blood-brain barrier, which normally protects the brain from harmful substances, is not as impenetrable as once thought. “When it comes to these insidious particles, the blood-brain barrier is not as protective as we’d like to think,” she says.
As scientists uncover microplastics in more organs, they raise growing concerns about potential health impacts. While the full implications of microplastics in the human body are still being studied, emerging research suggests they may contribute to conditions such as oxidative stress, inflammation, and cardiovascular disease. Animal studies have also linked microplastics to fertility issues, cancers, endocrine and immune system disruptions, and cognitive impairments.
The Journal of Hazardous Materials published a groundbreaking study last month that detected microplastics in human bone marrow for the first time. The study analyzed 16 samples and found widespread contamination, including polystyrene and polyethylene, which are commonly used in consumer products. Similarly, a recent Chinese study discovered microplastics in the membranes of every hip and knee joint examined during surgeries.
Research has also found microplastics in the reproductive organs of both humans and animals. A May 2024 study published in Toxicological Sciences revealed microplastics in all 23 human and 47 canine testicle samples analyzed. The study found that higher concentrations of plastic particles were associated with lower testicular weights in dogs, raising concerns about the potential impact on fertility.
Similarly, an Italian study earlier this year discovered microplastics in placentas, and other research has found contamination in penile tissue during surgeries for erectile dysfunction. These findings have led scientists to sound the alarm about microplastics’ infiltration of even the most sensitive human tissues.
Despite the disturbing evidence of widespread contamination, the full extent of microplastics' health effects remains uncertain. The U.S. Food and Drug Administration (FDA) asserts that “current scientific evidence does not demonstrate that levels of microplastics or nanoplastics detected in foods pose a risk to human health.” However, researchers caution that these particles may act as carriers for toxic chemicals used in plastic manufacturing, such as phthalates, which have already been linked to cardiovascular disease and reduced lifespan.
Efforts are underway to address the issue on a global scale. In 2022, the United Nations Environment Assembly began negotiating a global treaty to reduce plastic pollution. Several reports from 2024 suggest that the Biden administration is now supporting measures to curtail plastic production, a crucial step in combating the microplastics crisis.
In the meantime, experts recommend that individuals take steps to reduce their exposure to microplastics. Simple measures, such as using fewer plastic containers, drinking tap water instead of bottled water, and minimizing plastic use during food preparation, can help lower the risk.
But while individuals can take some precautions, researchers emphasize that more systemic action is needed. “There’s nowhere left untouched from the deep sea to the atmosphere to the human brain,” Almroth says, highlighting the scale of the plastic pollution crisis.
As the evidence mounts, it is becoming increasingly clear that urgent global action is necessary to protect both the environment and human health from the pervasive threat of microplastics.
For more details, see the original Guardian article here.
