Study finds plastics entered human brains via the nose. Now, what have people been placing over their noses lately?
Microplastic, macroharm
Earlier this year, a study revealing the presence of microplastics in male reproductive organs alarmed many. Not everyone wants to have children, of course. But most people want to be able to function normally, and so a more recent study which revealed the presence of microplastics in the brain has alarmed many more.
Microplastics (MPs) are tiny shards of plastic, anywhere from around 5 millimeters wide to just 1 nanometer wide, meaning that they cannot be seen without a microscope. The authors of the study revealing their presence in the brain described “shard-like particles” of plastic in the internal organs of bodies they autopsied — in the liver and the kidneys, and in larger concentrations in the brain.
More specifically, the microplastics found in the brain were in the frontal cortex, the part of the brain thought to be responsible for “higher” human functions such as abstract thinking, creativity, and decision-making.
1/200 of your brain could be plastic
Professor Matthew Campen, the lead author of the study, told media that the concentrations of plastics he and his team discovered were around 4,800 micrograms per gram, meaning that they constituted around 0.5 percent of the brain. He noted that, over the past eight years, the amounts of plastics researchers have been finding have increased quite considerably:
Compared to autopsy brain samples from 2016, that’s about 50% higher. That would mean that our brains today are 99.5% brain and the rest is plastic.
Campen and his team didn’t speculate on how the plastics got into the brain, though they did note that the causes appeared to be either genetic, dietary, or due to lifestyle factors, because the amounts of plastics found in brains did not rise corresponding to the age of the person.
They also observed that the most common type of plastic found was polyethylene, which is widely used in packaging of all kinds — both hard plastics and soft ones, such as those used in bags.
And how did it get there?
A few months passed, and another study came out with a possible answer to the question of how plastics manage to enter the brain: via the nose.
New research by Professor Dr. Thais Mauad and Dr. Luis Fernando Amato-Lourenco from the University of Sao Paulo and Freie University Berlin led to the discovery of microplastics both in the nose and in the olfactory bulb, located at the base of the brain. This time, the researchers found that the most common plastic in the nasal passages was polypropylene, which, like polyethylene, is used for packaging and food storage in both hard and soft plastics.
Professor Thais Mauad linked the finding to breating while indoors:
This study finds that the olfactory pathway is a potential major entry route for plastic into the brain, meaning that breathing within indoor environments could be a major source of plastic pollution in the brain,
Plastic can play with your cells
The research team also noticed that the plastic fragments they found were quite large, some with a diameter of 10 microns, from which they concluded that the level of smaller nano-plastics which enter the human body is much higher than was previously thought.
With much smaller nano-plastics entering the body with greater ease, the total level of plastic particles may be much higher. What is worrying is the capacity of such particles to be internalized by cells and alter how our bodies function.
The researchers noted that it has long been known that microplastics can enter human cells, and added that the implications of this are most concerning when it comes to children, whose organs can potentially be affected.
Could eating less meat help?
The study mentioned above, which described the effects of microplastics in reproductive organs, noted that higher concentrations of plastics correlated with lower sperm counts. Others also claim that microplastics can disrupt the body’s chemistry with a damaging effect on reproduction as well as growth and metabolism, and that the presence of MPs is correlated with higher incidences of cancer and infertility.
However, there is very little research on what effect microplastics in the brain might have, although animal studies have observed behavioral changes due to MPs in mice and chicken, as well as an increased likelihood of brain hemorrhage.
But what can be done?
According to Dr. Britta Baechler, a marine biologist and Associate Director of Plastics Science at Ocean Conservancy, the answer is: next to nothing. An article in The Hill, which quoted Baechler, also stressed that many of the MPs we take into our body come via protein-rich foods such as meat.
Researchers are still debating how much plastic people inhale and ingest, with factors like diet, drink, and location playing a role.
They cite a study published in Environmental Pollution which claimed to find that 88 percent of meat, fish, and vegetarian meat substitutes contained some form of MPs.
Professor Tracey Woodruff of UCSF also highlights the impact of protein-rich food, and adds some other advice on keeping MPs out of our bodies, such as not microwaving plastic, because the “heat makes plastic release harmful chemicals like BPA.”
Government, save me!
Woodruff believes that getting government involved in keeping microplastics out of our bodies is vital:
I’ve learned that it’s really important to be engaged in holding the government accountable for these exposures because, for so many of them, you or I can’t do anything about them — only the government can regulate chemicals that make their way into our water, food and products we wear and put on our bodies.
We should be able to go into a store and purchase an item and know that the government has made sure it’s safe for us and our families. The burden can’t be on consumers to navigate all of this.
That’s why I also register to vote. That’s the other thing I do consistently.
It's the masks, stupid
Woodruff did not mention who she votes for. That might matter for a different reason from the one she has in mind, because certain politicians are more likely to mandate MP exposure than others. How so? By requiring people to wear face masks, to “protect against COVID.”
The study that found MPs in the brain ran between 2016 and 2024 with no particular comment on why those years were chosen. The researchers found that the presence of MPs in the brain increased significantly over these 8 years, without wondering whether there could be some reason why, in the years 2020 onward, people’s brains might suddenly be filling up with plastic — via the nose, as the other study mentioned earlier noted.
Fortunately, yet another study, published in a quite obscure journal (Ecotoxicology and Environmental Safety) in April, 2024, set out to examine the “potential of face masks for the content and release of inanimate toxins.”
This was quite an extensive piece of research as it reviewed 1,003 studies covering surgical, textile, and N95 masks. The researchers were very concerned at their findings:
Most studies (63%) showed alarming results with high micro-and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkylsubstances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate,DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.
Plenty of scientists knew that already, but they didn't tell you
The study conceded that masks do have their uses when it comes to filtering out large particles of dirt and other items people don’t want to inhale, but concluded that the risks of wearing them were considerable enough to be weighed against any benefit:
Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.
Specifically, they stressed that requiring people to wear masks meant that they were exposed to “potentially harmful” toxins which posed a significant health risk, especially as the toxins were right up against their noses and mouths:
Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.
They cited numerous other studies (most if not all of which have received no media attention) which have drawn similar conclusions with regard to a long list of toxins found in face masks of all kinds.
They also noted that such close-up and prolonged exposure to the toxins in face masks could cause bacteria to multiply and encourage antibiotic resistance:
Microplastics and microfibers released from face masks may also contribute to the dispersion of pathogens and antibiotic-resistant genes (ARG) in the environment, as the architecture of face masks (microscopic meshing) can provide a preferable base substrate for microbial communities, including antibiotic-resistant pathogens.
What could be wrong with wearing a damp and dirty rag on your face?
They pointed out that the “dead space” between the mask and the wearer’s face is an extremely unhealthy environment, even without the added presence of toxins:
Humans inhale emissions from a mask at nearly zero distance and swallow water droplets originating from the moist dead space enriched with mask ingredients. In this regard – theoretically – wearing a mask may exert a higher risk of exposure than many other environmental sources.
And they stress that the difficulty in breathing through a mask leads many people to breathe via the mouth instead of the nose, depriving the wearer of the immune protection of the nasal passages:
... we underscore the phenomenon of predominantly oral breathing while wearing a mask, in contrast to normal unimpeded breathing, which is largely via the nose, with greater filtration. Oral breathing increases the hazard of directly inhaling particles and toxins from the mask into the deeper airways.
Meanwhile, reputable and widely-read medical journals such as the British Medical Journal (BMJ) are still publishing studies on the benefits of wearing face masks and claiming that a difference in self-reported symptoms of illness of 3.2 percent is enough to prove their value.
