Barbro Melgert Photo by Reyer Boxem

Pioneering research into
synthetic fibres

We breathe in plastic

Barbro Melgert Photo by Reyer Boxem
We breathe in plastics every single day. Microscopic fibres from that soft fleece sweater, your nylon socks, or the plastic cups from the coffee machine at work, can enter our lungs. Barbro Melgert found out that this is not without risk.
12 April om 16:09 uur.
Laatst gewijzigd op 13 April 2021
om 11:09 uur.
April 12 at 16:09 PM.
Last modified on April 13, 2021
at 11:09 AM.

Door Christien Boomsma

12 April om 16:09 uur.
Laatst gewijzigd op 13 April 2021
om 11:09 uur.

By Christien Boomsma

April 12 at 16:09 PM.
Last modified on April 13, 2021
at 11:09 AM.

Christien Boomsma

Achtergrondcoördinator en wetenschapsredacteur Volledig bio » Background coordinator and science editor Full bio »

Barbro Melgert has made her choice. The lung researcher, who works at the pharmaceutics department at the UG, got rid of all her plastic spatulas. She drinks tea from a metal cup and heats up her leftovers in glass containers. Those still have plastic lids, but ‘at least those don’t touch the food’. 

Realistically, she knows we can’t avoid plastic altogether. But we can certainly limit our contact with it. She has been doing so since her own research into microplastics led her to new insights.  

The microplastics in our clothes can have a disastrous effect on developing or recovering lungs, a study that Melgert published last month revealed. ‘I was astonished at the results’, she recalls. ‘I had not expected them.’

As far as the Himalayas

Her research started approximately two years ago, when research financier ZonMw decided to subsidise exploratory research into the impact of microplastics on our health. It’s a known fact that microplastics, particles less than five millimetres in size, are a growing problem. ‘They’re everywhere from the top of the Himalayas to the bottom of the Mariana Trench in the Pacific Ocean, eleven kilometres down’, zegt Melgert. 

Particulate matter also occurs inside, when we’re cooking or burning wood

No fewer than sixty thousand kilograms a year, 16 percent of total annual pollution, comes from cloths, like the nylon in our socks, the polyester in those soft blankets we use for the couch, or the lycra from our T-shirts. The microplastics are released as we wear, wash, and dry our clothes, clogging up the filter in our dryer. ‘You know how much dust gathers when you don’t vacuum for a few days. A large part of that dust happens to be plastic.’

We eat these fibres, and we breathe them in, where they settle in our lungs in the form of particulate matter. Is this harmful, though? Not much is known about the effects of microplastics, since the research into them is still in its early stages.

But Melgert, who normally studies lung diseases, wasn’t satisfied. She knows how important the air quality is, not just outside, but inside our houses as well. ‘People don’t realise that particular matter can also occur inside our homes, like when we’re cooking or burning wood or candles’, she says. Because our houses are increasingly well-insulated, the air inside remains stale. Very few people still open a window. ‘They’re worried about the energy bill.’


If microplastics are floating around inside our houses, it’s essential to know what it’s doing to our lungs. Melgert jumped at the chance to get a grant from ZonMw. ‘Our lab has these artificial minilungs, as an alternative to animal testing’, she says. ‘They’re minuscule organoids, grown from the lung cells of mice or even human lungs.’ 

What if, Melgert thought, I put plastic fibres in those lungs to see what happens?

This research has opened my eyes

Fairly randomly, she picked polyester and nylon, substances that are everywhere in our environment. The manufacturer delivered the fibres in long threads, which she cut down to a size similar to what floats around in the air, and stepped back to see what happened. ‘I figured it wouldn’t be too bad’, Melgert admits. ‘But boy, was I wrong.’

The lungs that were fully developed weren’t particularly affected. But the impact on the lungs that were still developing was disastrous; the organs barely developed, if at all. ‘The nylon’s effects were the most inhibiting’, she says. ‘But the polyester had a negative impact, as well.’

To be fair, the quantities she used, a thousand to five thousand fibres per lung vessel, were much bigger than what floats around our house. ‘Still, those quantities aren’t unheard of’, she says. ‘They do occur in the nylon industry, leading to lung issues among its workers.’

Fuzz filter

She performed another test using ‘real’ fabric, which she bought at fabric store Jan Sikkes at the Boterdiep. She washed and dried them in a washer and dryer she’d purchased just for her experiments. She was shocked to see the same results: when she added the lint from the dryer to the culture vessels, the minilungs barely developed.

That is when she decided to ban plastics from her own environment as much as possible. She avoids synthetic clothing, she stopped using disposable plastic containers, and she’s become extremely aware of how to ventilate any room she’s in. Her own house has a great ventilation system, which cleans the air as best it can. ‘This research has opened my eyes.’

But she’s not there yet. While we know that plastics are harmful, we don’t know why yet. Is it the plastic itself? Or is it the substances that ‘leak’ from these fibres? ‘Manufacturers add all kinds of things to them’, Melgert explains. ‘Like substances that soften the fibres or make them less flammable.’

Smarter choices

Melgert thinks it’s probably the latter, although she doesn’t know which substance is responsible. There are many possible candidates and testing them each would be a lot of work. Oligomers, infamous plastic softener BPA, and UV stabilisers that make nylon able to withstand sunlight have already been ruled out.

I worry that there will be a lot of people suffering from lung fibrosis after covid

She’s trying a different route: she extracts genetic information from the cells that came into contact with the plastic fibres, checks which genes are and aren’t active within that sample, and compares that to the known effects of the substances she suspects are responsible. ‘We hope this will help us make better choices’, says Melgert. 

Her research could have quite an impact. Healthy adults might not be overly affected by plastic fibre, but babies, whose lungs still need to develop, might be. People who are still recuperating from a lung-related illness, potentially due to covid, might also be affected. ‘A viral lung infection, deep in the lungs, could lead to swelling of the alveoli, which makes it difficult to breathe’, Melgert explains. ‘It’s called fibrosis.’

The body can usually fix this on its own, but not if this process is disrupted by plastic fibre floating around. ‘I worry that after covid, there will be a lot of people who get lung fibrosis’, she says. She can’t prove this, since she hasn’t done any research into it. ‘But it is a fear, and you’d want the air you breathe to be as clean as possible.’