According to a 2019 study by the University of Newcastle (Australia), people ingest a large amount of mini-particles of plastic through food and drink. If you were to scrape together all the particles for a week, you would have enough to melt them down into a debit card. In a year, that amounts to a quarter of a kilogram of consumed plastic.
And then we’re not even talking about all the microplastics you breathe. According to a 2019 study by Aalborg University (Denmark), you inhale more than 200 pieces of plastic up to five millimeters in size in 24 hours. That all sounds quite worrying. How link is all that plastic in your body?
Microplastics in water
You excrete most of the plastic you eat, the rest ends up in your bloodstream. You breathe in microplastics, especially the smallest nanoplastics, smaller than ten millionths of a metre. They can also enter your bloodstream through the lungs. Every part of your body can then be reached via the blood.
Before entering your bloodstream, the plastic flakes are part of larger plastic, such as drinking water bottles or plastic containers. Wherever there is plastic, there is a high chance that microparticles will be released. The plastic breaks down and tiny particles are released. For example, plastic packaging ends up in the ocean, where it breaks up into small pieces and enters the food chain via fish. Even tap water contains microplastics, although you will find much more in bottled water.
They also float in the air, for example due to the wear and tear of synthetic rubber in car tyres, polymers in paint and fibers in synthetic clothing. Roel Vermeulen, professor of environmental epidemiology at Utrecht University, conducts research into nano- and microplastics. ‘Measurements show that these particles make up between one and ten percent of all particles in the air.’
It varies by place. For example, at busy intersections, where many cars brake and accelerate, the share will be higher. ‘So we know that we breathe them in fully. Just like other components of air pollution, you are also continuously exposed to it.’
Eight milligrams of plastic per Dutch person
How many microplastics can you expect in your body? Vermeulen: ‘A study from 2019 shows that we have two particles per gram of dry tissue in our lungs.’ Those are thousands of pieces of plastic, waiting to enter your bloodstream. In 2022, VU University Amsterdam examined the blood of 22 Dutch people. They had 1.6 milligrams of plastic per liter of blood, which would amount to an average of eight milligrams per Dutch person.
The plastics we carry around the most are polyethylene terephthalate (PET) and polyethylene, plastics from bottles and packaging materials. “These kinds of analyzes are still in their infancy and need to be repeated with larger numbers of donors.”
Where does your blood take all these particles? It can get dangerous there. Your body cannot break down the microplastics, so they stay in your body forever. Or you separate them in some way. Dick Vethaak, emeritus professor of water quality and health at VU University Amsterdam: ‘We investigate whether they leave your body via bile, for example, or whether they accumulate in certain organs or tissues. For example, nanoplastics can enter cells and damage DNA there. The question is whether this flyer for microplastics will also work.’
The risks of microplastics in our body
The amount of evidence that it is a link is growing quite quickly. ‘All kinds of experiments with laboratory animals, such as mice and aquatic animals, show that systematic high exposure causes inflammation and damage to the DNA.’ And that can lead to cancer.
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It may seem that a microplastic crisis is lurking, but according to Vethaak, the plastic soup is not eaten as hot as it is served. It is not yet clear whether microplastics are more harmful than other tiny muck that you ingest.
Vethaak: ‘We know that particulate matter is one of the biggest causes of death worldwide. It causes, among other things, respiratory diseases, heart failure and lung cancer, as a result of which millions of people die prematurely every year.’ Microplastics are part of this particulate matter. Vermeulen: ‘We know that microplastics don’t do you any good, but at the same time we also know that they only make up a small part of all the particles in the air.’
Science is not yet sure whether these microplastics behave in the same way as other particulate matter in your body. ‘But plastic can easily bind to chemicals and proteins,’ says Vermeulen. ‘Microplastics in your body can be the shopping carts for diseases and other troubles.’ In addition, they can end up in your cells, where they can theoretically cause a lot of misery.
The amount of plastic is increasing every year
Although there is no immediate reason for total panic, there is enough reason to act now. Vermeulen: ‘We have to make less plastic, there’s no question about that. In fact, we should start limiting now.’ The amount of microplastics in the environment is already alarmingly high. In 2021, oceanographers at Kyushu University (Japan) estimate that there will be a total of 24.4 trillion pieces of microplastic in the oceans alone, the equivalent of thirty billion half-liter plastic drinking bottles. The atmosphere also contains an unimaginable amount of plastic, although there is not yet a thorough estimate of the total.
Vethaak: ‘Even if we stop producing plastic today, the amount of microplastics will only increase, due to the decay of all the plastic that is already present.’ Production is still growing annually, by four percent. As a result, we burden the planet with about 300 million tons of plastic waste every year, which is the weight of 1.8 million jumbo jets. This mainly ends up in landfills.
Five to thirteen million tons flow into the ocean and join the already considerable plastic soup, which currently weighs between 100 and 200 billion kilograms. If you had that weight of plastic bags, you could cover the Netherlands 180 times with them. It remains to be seen, but if the amount of microplastics becomes much larger, this could lead to new, unforeseen health problems.
Microplastics are also in your food
Are Vermeulen and Vethaak worried about the future? Vermeulen thinks it is worrying how much plastic humanity has now introduced into the environment. “We haven’t noticed it has become so widespread.” Vethaak: ‘What I found a slightly shocking eye-opener myself is that when you leave food and drinks open and exposed on, for example, the kitchen counter, the microplastics in the air settle on them. It’s almost equal to the amount you inhale, but then you eat it.’
That all sounds alarming, but it will only become somewhat clear in the coming years how harmful microplastics really are. Vermeulen concludes: ‘The methods for measuring microplastics and nanoplastics have recently become available. That is why the number of scientific publications on the harmfulness of microplastics is growing rapidly. So in the coming years we will have to wait and see how knowledge about the impact of plastics on the body develops.’ And until then, we must above all ensure that the plastic soup becomes smaller and that the plastic mountain does not get any higher.
