Microplastics: How they enter our bodies and what they do to us

Plastic is everywhere. It's in the clothes we wear, the products we use, the food we eat and even the air we breathe.

Plastics break down into tiny pieces, too small to see but not too small to affect our health. This is not a dystopian scenario but a reality that we are facing right now.

According to a Science News report, microplastics, fragments of plastic that are less than 5 millimetres across, have been found everywhere, from the deepest place on the planet; the Mariana Trench, to the top of Mount Everest.

Items such as clothing, cosmetics, electronics, tires, packaging and more degrade over time due to weathering or friction and release microplastics into the environment. We can ingest them through food and water, especially seafood that may contain microplastics in their gut.

Microplastics can also be inhaled through the air as they can become airborne and enter our respiratory system.

Microplastics scientist Heather Leslie and colleagues found microplastics in blood samples from 17 of 22 healthy adult volunteers in the Netherlands.

In 2022, scientists from the Netherlands and the U.K. announced they had found tiny plastic particles in living humans in two places they hadn't been seen before: deep inside the lungs of surgical patients and in the blood of anonymous donors.

But what does it mean for our health? The answer is not so straightforward. The science is still evolving. There are big open scientific questions around this and reasons to be worried. A growing community of researchers believe inhaled particles might irritate and damage the lungs. Some contain chemicals that are known to interfere with the body's hormones.

The threat of microplastics is invisible but real as the different types of plastic materials in the market continue to increase. "There were around 3,000 (plastic materials) when I started researching microplastics over a decade ago. Now there are over 9,600. That is a huge number, each with its own chemical makeup and potential toxicity," says Leslie.