«PLASTIC AUTO-ACCIDENTS»: How Polyethylene Threatens Our Brain

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Modern civilization is rightly called «plastic». It boasts numerous remarkable achievements, and eliminating plastic from our lives would be akin to giving up electricity. However, there is also a downside to this «plastic civilization». A recent study conducted on mice found tiny pieces of plastic in their blood vessels. For the first time, scientists were able to track in real-time how microplastics fill immune cells, move through the bloodstream, and end up in the blood vessels of the brain.

THE EARTH HAS A «PLASTIC SPHERE»

t is believed that right before our eyes, a new layer is forming around Earth, or has already formed — the «plasticosphere». Microplastics are particles smaller than 5 millimeters that can be found everywhere: from the depths of the ocean to the Antarctic ice. And if our civilization is studied by future archaeologists thousands of years from now, they will rightly call it the microplastic era.

We inhale plastic particles daily and everywhere: in offices, on the streets, at home. The number of sources of microplastics is practically incalculable — household items, clothing, furniture, toys, flooring… Microplastics are present in water, soil, and plants.

In 85% of water samples from 59 of the most developed countries, the average concentration of microplastic particles is 0.55 particles per liter. And if you think that drinking water from glass bottles protects you from microplastics, you’re mistaken. The concentration in «glass» is by no means lower.

PLASTIC «OCCUPANTS»

We don’t even realize that we constantly «enrich» our food with microplastics when we eat from plastic dishes, drink from plastic bottles, or cut food on plastic boards.

Almost all modern medicine is also plastic, so plastic particles can enter our bloodstream directly through plastic medical devices. Studies show that they have long infiltrated our brain, liver, and kidneys.

However, only now are researchers starting to understand what happens to these plastic «occupants» and how they affect human health. For example, one study last year showed that people with micro- and nanoplastics in fat deposits in the main artery have a significantly higher likelihood of heart attacks, strokes, and even death.

«CAR CRASH» INSIDE THE BRAIN

A team of biomedical researchers from Peking University, led by Haipen Huang, set out to investigate how microplastics affect the brain. The results of their study were recently published in Science Advances.

First, the scientists created a kind of window, surgically implanted into the skulls of mice. This allowed them to observe in real time how microplastics move through the bloodstream. The animals were then given water containing fluorescent polystyrene spheres — the same type used to make packaging, toys, and devices.

About three hours later, immune cells known as neutrophils and phagocytes engulfed the bright plastic specks and became fluorescent themselves. Some of these cells, traveling into the narrow bends of the blood vessels in the brain cortex, caused what could be described as a car crash.

PLASTIC CLOTS

Sometimes, these events disappeared quickly, while at other times, they persisted throughout the entire four-week observation period. The occurrence often depended on the size of the particles. Smaller ones led to fewer «accidents». According to the researchers, these «car crashes» manifest like blood clots.

Mice that were given microplastics showed reduced blood flow to the brain, affecting overall mobility. This effect lasted for several days. Similar effects were observed in the hearts and livers of the mice, but results for these organs are still being processed and will be published later.

The scientists hope that the visualization method can be used for further study of how plastic behaves inside the body.

DANGEROUS FRAGMENTS

Of course, specialists are still uncertain whether humans experience the same plastic «car crashes» as rodents. However, it seems that they do. And the main culprits appear to be ubiquitous plastic bags. The results obtained by Chinese researchers generally match earlier data published in Research Square by Elian El Hayek from the University of New Mexico in Albuquerque.

American researchers found high concentrations of plastic fragments in the brain tissue of individuals who had died and donated their bodies for research. Most of these fragments were polyethylene — a very common microplastic used in packaging.

Original research: