Tanja Vasama, Helsingin Sanomat, 14 March 2024
“It’s important for everyone to reduce their intake of plastics,” says a Finnish professor and offers tips for everyday life.
We eat, drink and breathe tiny plastic particles in our everyday lives. Minuscule microplastics – and even smaller nanoplastics – have in recent years been found in all sorts of places: in blood, liver, lungs, the placentas of pregnant women, and in breast milk. Evidence of the possible dangers these particles pose to humans has, however, long been uncertain.
Now Italian researchers have found that microplastics are indeed linked to human health. They reported their finding in the New England Journal of Medicine, one of the leading journals in medicine. According to the results, people whose carotid arteries contained plaque with micro- or nanoplastic particles were more likely to suffer a heart attack or stroke, or to die prematurely, than those whose arterial plaque contained no such particles. “The result is highly significant, and the article appears in a very prestigious journal,” says Professor Arja Rautio from the University of Oulu, who has studied microplastics. Physician Robert Brook, who studies environmental impacts on cardiovascular health, called the study a milestone in an interview with Nature. Neither Brook nor Rautio participated in the research.
The results are based on data collected from 257 people. All participants had undergone some kind of procedure due to heart problems, and the researchers examined plaque build-up in their carotid arteries. Those whose arterial plaque contained plastic particles had, on average, more than four times the likelihood of a heart attack, stroke, or death during the almost three-year period following surgery. Their levels of inflammation markers were also higher. Nearly 60 percent of participants had either micro- or nanoplastics in their arterial plaque, observed Raffaele Marfella, Professor of Internal Medicine at the University of Campania, together with his colleagues.
Microplastics are defined as plastic particles smaller than five millimetres. When plastic breaks down to a size under 0.001 millimetres, it is called nanoplastic. The naked eye cannot see nanoplastics at all. These particles form as plastics degrade due to sunlight, water, and other factors. Microplastic exposure can come from items such as drinking bottles, toothpaste, cosmetics, synthetic clothing, and dust from car tyres. Some studies have found that workers in textile factories exposed to synthetic fibre dust have higher rates of lung disease. In food and drink, microplastics have been found in fish, seafood, salt, sugar, honey, rice, milk, and drinking water. “We are all exposed to these particles,” Rautio says. “They are a bit like Trojan horses – they somehow disguise themselves.”
Not all particles remain in the body, however. “About 90 percent of the particles that enter through food and drink are apparently excreted in the stool.” It is the very smallest nanoplastics that can pass through cell membranes. They also reach deeper into the lungs, while larger particles are coughed out. In their new study, Marfella and colleagues wanted to find out whether these particles accumulate in arterial fat deposits, as previous research has shown that lipid molecules attract microplastics. “Studies have shown that some types of plastics can attach to immune cells, while others attach to proteins, lipid particles, the lining of blood vessels, or even other plastic particles. They’re like Trojan horses that somehow mask themselves,” Rautio says. Chemical analyses by Marfella’s team showed that most of the plastic particles in plaque consisted of either polyethylene – the world’s most commonly used plastic – or PVC.
Should we now start limiting the use of plastics in everyday life for health reasons? According to Rautio, it is important for everyone to take measures to reduce their exposure to plastics. Beyond human health, the issue also concerns the health of the environment and animals.
Vessi’s comment: Researchers’ suggested ways to protect oneself from microplastics:
Do not heat food in plastic containers; do not use old, worn plastic containers; replace plastic containers in the kitchen; do not wrap food in plastic; wear only natural fibres against the skin; use an air purifier at home and at work. A very healthy gut, with plenty of fibre, fast transit time, healthy intestinal walls and a good amount of short-chain fatty acids, allows far less micro- and nanoplastic to pass into the body. Saunas and sweating help excrete microplastics. Expecting mothers and families with small children need to be especially careful at home.
