Small particles of plastic are in every single place: within the soil where our food is grown, within the water we drink and within the air we breathe. They get there from the plastic we throw away, which results in landfill sites, rivers and oceans. There, plastic waste slowly breaks down, releasing tiny particles called microplastics and even tiny nanoplastics into the environment.
Microplastics are also increasingly found throughout the human body. We're unsure how they got there, though there are three possible routes. We can ingest microplastics once we eat and drink them, breathe them into our lungs, or absorb them through our skin. Another pathway has recently been suggested, through which microplastics rise from our noses and enter our brains.
For a protracted time, it was believed that the human brain existed in splendid isolation from the remainder of the body. The so-called blood-brain barrier, a special layer of cells, protects the brain from all types of pathogens and harmful substances. However, we now know that the blood-brain barrier may be breached because tiny particles of plastic have been present in the human brain.
New research suggests that there's a minimum of one weak spot within the blood-brain barrier where microplastics can enter the brain. This Possible entry point It was proposed by researchers from the Freie Universität Berlin and the University of São Paulo. This happens within the nose, where there are special nerves, the olfactory nerves, that detect odors.
The olfactory nerves run from contained in the nose, through the skull, after which on to a component of the brain called the olfactory bulb. The researchers suggest that microparticles inhaled through the nose may one way or the other travel along the olfactory nerve and into the brain.
The researchers reached their conclusions by analyzing tissue samples from residents of São Paulo who had died and undergone routine autopsies by coroners. They extracted olfactory bulbs from these brains and analyzed them using various techniques.
Eight of the 15 brains studied had microplastics within the olfactory bulb. However, between these eight samples there have been only 16 microplastic particles, which might be somewhat comforting.
The 16 plastic particles included flakes, spheres and fibers and were manufactured from polypropylene, nylon and other plastics. Some of the fibers could have come from clothing. This is sensible because Washing clothes Synthetic fibers are a vital source of microplastics within the environment.
MattLphotography / Alamy Stock Photo
Some of our plastic particles are missing.
The recent study is one among many which have reported the presence of tiny plastic particles within the human body. Most of those studies are about microplastics, that are particles as much as five millimeters in size. Few studies have explored nanoplastics within the human body.
Nanoplastics are lower than a thousandth of a millimeter in size – so small that they're difficult to detect without special equipment, and few scientists have quick access to such equipment.
The reason nanoplastics are essential is that, unlike microplastics, they're well-documented to be harmful to living cells. This is because nanoplastics are quite small. Go inside the cells. Once inside, they'll kill the cell.
Nanoplastics are shown. Kill cells in animal embryos. Can lead it Birth defects in animals If the fetus is exposed to high doses of nanoparticles.
Fortunately, there isn't a evidence that humans have experienced a serious increase in birth defects in recent times. The placenta may prevent microplastics and nanoplastics from reaching the fetus.
We have to know more concerning the presence of microplastics – and nanoplastics specifically – within the human body. And we want to understand how they get there in the primary place.
This makes the brand new Berlin-São Paulo study very interesting. This suggests a possible entry point into the brain through the nose. This begs the query: What are the potential risks to our health from microplastics and nanoplastics? The jury is out, but perhaps feeling a little bit more nervous than before.