Over the past 10 years, the medical community has become increasingly alarmed by the ubiquity of micro- and nanoplastics, tiny plastic particles that have been found by the thousands in foods, bottled waterand increasingly in our own bodies.
Recent medical studies have detected the presence of plastic in samples of blood, breast milk, placental tissue and even in people’s lungs.
So when Raffaele Marfella, a surgeon and professor of internal medicine at the University of Campania Luigi Vanvitelli in Naples, and his colleagues conducted a study to study to examine plaques taken from the arteries of people with cardiovascular diseasethey were not surprised to find that half of the samples contained miniature plastic fragments.
But a closer look at the data indicated a worrying trend – all of the patients who had accumulated plastic in their arteries had much more advanced disease. By monitoring them over the next three years, they discovered that these people were four and a half times more likely to die or have an accident. non-fatal strokecompared to patients whose samples did not contain plastic.
Marfella believes that the presence of plastic could have actively accelerated the deterioration of health, causing inflammation in the arteries. “I can say with reasonable certainty that contamination by micro and nanoplastics causes changes in the health status of tissues,” she says.
It is one of the first studies to identify a link between plastic deposition and declining human health. But we still need to learn a lot more about how and why plastic can damage the human body and, most important of all, what to do about it.
What are microplastics and where do they come from?
Plastic particles capable of entering the human body are microplastics, less than 5 millimeters wide, or nanoplastics, less than 1 millimeter wide.
They are believed to originate from the constant degradation of products such as automobile tires, mass-produced synthetic clothing, and paints used to coat buildings and roads. However, many scientists believe that single-use plastics such as water bottles, plastic cutlery, food containers, packaging, cotton swabs, plastic bags and wet wipes are the biggest culprits.
“Disposable plastic bottles reduce the cost of [beverage] production and transport, but they are one of the main sources of micro- and nanoplastics”, says Dick Vethaak, professor emeritus of water quality and health at VU University Amsterdam and Utrecht University, in the Netherlands. “Banning them is an excellent idea, as alternative, safer and more sustainable materials already exist on the market. As consumers, many of us can make our own decisions about whether to use glass bottles or transport our drinking water in reusable containers.”
It is thought that we inadvertently consume these plastic particles through inhalation or ingestion. At the beginning of this year, a study of researchers at Columbia University in New York identified a quarter of a million nanoplastics in a single liter of bottled water. Another worrying paper found that babies fed milk formula prepared in bottles made from propylene are exposed to high levels of microplastics.
What do we know about the impact on human health?
There are over 10,000 different chemicals present in various plastics, including some that are known carcinogens and others that are capable of disrupting vital hormonal systems.
Because of this, some researchers have begun to question whether the accumulation of plastic over several decades could be a factor contributing to the increase in cases of colorectal cancer in people under 50. Last year, a group of bowel cancer and toxicology experts in New Zealand published an article pointing out that emerging research suggests that not all microplastics are excreted from the body and, as a result, some may remain in the colon, where they can break through the inner mucus layer. This is a fundamental barrier that protects the colon wall against bacteria and toxic chemicals and, they suggested, if this barrier is damaged by plastic particles, it could lead to colon cells being much more exposed to potential carcinogens.
While some of this is still speculative, more and more evidence is emerging that shows that plastic is actively harming our gut. In a 2021 study, microplastic levels were found to be much higher in stool samples from people with inflammatory bowel disease compared to healthy individuals. People with more severe illnesses had even higher amounts of plastic in their feces.
Matthew Campen, a professor at the University of New Mexico who has studied microplastics, isn’t convinced that plastics themselves are necessarily harmful, but rather their sheer quantity is more the problem.
“Plastics are relatively safe, but they simply seem to be at alarmingly high levels [in the environment] and getting worse,” he says. “We believe that the main route of entry into the body is through the intestine and this is an important issue that needs to be better understood.”
What do we still need to know?
There are many unanswered questions, ranging from whether some forms of plastic are more harmful than others, whether certain sizes or shapes are more likely to cause harm, and what this tells us about their origin.
“Many of the particles found in the human body appear to be less than 2 micrometers long and 200 nanometers wide, and are often much smaller,” says Campen. “They appear to have a fragmentary appearance, like very old, brittle plastics that have disintegrated over many years. We’re still not sure how this affects biological interactions.”
Vethaak predicts that in the coming years we will learn even more about how much plastic is in our bodies, where it goes and what it does.
“The doses of plastic particles in our blood and tissues are high enough to trigger or mediate [biological] responses that lead to disease?” he says. “This information will be critical for risk assessments, but this data may still be several years away.”
How can we eliminate them or reduce their impact?
Every year, humans produce more than 350 million metric tons of plastic waste, and experts believe the only solution is to find better, more effective ways to degrade it. In the future, certain microbes could help us design more useful waste disposal facilities, with several laboratory experiments suggesting that strains of Rhodococcus ruber and even E. coli could be used to digest common plastics such as polyethylene terephthalate and polyurethane.
Campen believes that governments need to invest more in burning plastics to generate energy and deal with the large quantities of plastic stored in landfills around the world, some of which end up in the oceans and water supplies.
“Globally, I think the best solution is to quickly move to waste-to-energy plants,” he explains. “The daily waste we generate as individuals is the tip of the iceberg compared to the plastics already buried in landfills. We need to consider active recovery and incineration of plastics. It seems like a bad idea from a global warming perspective, but ultimately it’s no worse than coal.”
Avoiding plastic entirely is virtually impossible as it is so ubiquitous in our lives, from food packaging to cling film, clothing and disposable wipes. Even some tea bags contain a type of plastic called polypropylene to seal them and prevent their contents from falling into the box and mug.
But microplastics experts like Vethaak say there are some important steps you can take to minimize the amount of plastic you ingest in your everyday life. In addition to avoiding bottled water, he particularly emphasizes avoiding heating food in Tupperware. This is because whenever you microwave something in a plastic container, the chemicals inside the plastic leak into the food, while the intense temperatures actively degrade the plastic on a microscopic level, releasing micro- and nanoplastics that end up in your body. .
Vethaak also recommends installing reverse osmosis water filters in your home, which are capable of removing some microplastics from tap water.
However, because plastic is so ingrained in our world, the scary truth is that there is very little many of us can do to avoid it. For example, 82% of baby bottles around the world are made from polypropylene, although some brands like Hevea have started to manufacture alternatives from glass and natural rubber.
“Basically, we need to replace plastics with alternative, safer and more sustainable materials and this must be done as quickly as possible to minimize health risks,” says Vethaak. “But in the meantime, avoid drinks and foods exposed to plastic as much as possible.”
