‘Our clothes are made of plastic,’ says Melgert. The realisation came as a eureka moment: much of the microplastics in our homes seem to come directly from the clothes we wear every day. She has been studying how lungs react to harmful substances for years and in 2018 received a grant to investigate whether microplastics play a role in that process. ‘I wondered: are there actually microplastics in the air? And if so, what do they do to our lungs?’
Microplastics are all plastic particles smaller than five millimetres, ranging from visible granules to invisible nanoplastics. They break off from furniture, packaging, toys, but especially from textiles. ‘Wearing clothes often releases more fibres than washing them,’ explains Melgert. ‘It also depends on how the fabric is made: woven fabrics tend to release fewer fibres than knitted fabrics.’
‘Cheap clothing from the fast fashion industry is often made from low-quality fibres. These are short, spun into longer threads and therefore fall apart more easily. But little thorough research has been done into how much difference this makes in practice,’ says Melgert.
To find out exactly what happens, Melgert and her team have developed so-called mini-lungs: small structures made from real lung cells that resemble lung tissue. ‘This model accurately mimics real lungs. We use it to see how lungs develop or recover after damage, for example from infections or polluted air,’ she explains. When they added small polyester and nylon plastic particles to the mini-lungs, nylon stood out in particular: it slowed down the growth of the airways.
It's not the particles themselves, but the chemicals that leak out of them
‘It's not the particles themselves, but the chemicals that leak out of them,’ says Melgert. ‘So far, we have identified about 140 of these substances, many of which are still unknown. It remains a huge puzzle.’ These substances affect the cells in the airways. They cause a specific protein in these cells to function differently. ‘The protein inhibits the development of these cells, preventing the airways from growing properly. If we block that protein, the airways grow normally again. We don't yet know which of the 140 substances causes this effect,’ says Melgert.
It is not yet entirely clear what these findings mean for our health in the long term. ‘We believe that children and people with existing lung problems may be particularly sensitive when exposed to high concentrations,’ says Melgert. ‘For them, the processes that enable the airways to grow and repair themselves are especially important.’ There are indications from older studies. In the 1970s and 1980s, extensive research was conducted in nylon factories. There, small fibres were processed into velvety fabrics. ‘In some factories, 30 to 40 percent of workers suffered from coughing and shortness of breath, and they also had an increased risk of lung cancer,’ says Melgert. ‘Those were much higher concentrations than you would inhale at home, but it shows that too much is never good.’
The difference with natural fibres such as cotton is that they are ultimately broken down by the body. ‘Plastic fibres are not. They remain behind and if you inhale too much of them, they can accumulate. That is the risk.’
Melgert wants her research to raise awareness of the problem and show that we can do something about it. ‘The problem with environmental issues like this, just like climate change, is that they can be paralysing. People think: what can I do on my own? But here you can take action, and that has a direct impact on your own living environment. That creates a more positive feeling and motivates people to make more conscious choices.’
You take action, and that has a direct impact on your own living environment.
Air and vacuuming already help to reduce the amount of microplastics indoors. ‘Indoors, the concentration is often much higher than outdoors, while many people think it's the other way around. Airing helps to get rid of the particles.’ Clothing also plays an important role. ‘Where possible, choose second-hand or natural fabrics; that way, fewer microplastics are released. And perhaps the most important step: take a critical look at your own consumption. Do you really need that new item of clothing, or can you alter or reuse something? Every purchase you don't make directly reduces the amount of fibres – and the impact on the environment.’
Melgert and her team are working on a large citizen science project. During workshops, they measure how much fibre different garments shed and which fabrics release the most. ‘This gives us more insight and allows people to see for themselves what their clothes leave behind. It's an accessible way to raise awareness and show people that their choices matter.’
Her team has also developed the game Pack Your Bags, in which you, as a player, lose your holiday suitcase and have to quickly find replacement clothing – without filling the holiday home with microplastics.
Then come to the European Researchers' Night at the Groninger Forum on Friday 26 September. Melgert and her team will be there with the game, a microscope to examine clothing fibres, and you can even submit a sample of your own clothing. This way, you can learn all about microplastics and contribute to the research yourself.
Does a scientist with a good idea really see the light in a single moment? Usually not. Most good ideas or inventions only come about when you collaborate with lots of smart people. In the EUREKA! section, researchers talk about the moments when they thought, “I've found it!” A new story appears every eight weeks.
