How to breathe in fewer microplastics in your home

The air throughout our homes is infused with microplastics. But there are things you can do to breathe less of them

Clouds of invisibly small microplastics concentrate in the air of our homes, and we could be breathing in hundreds of thousands to millions of them each year. A few small changes can help us reduce our exposure.

If you look at the labels of the clothes you threw on today, chances are at least some of them use synthetic fabrics. They're cheap, colourful and come in an endless array of textures, weights and degrees of stretch. But these convenient garments are also among of the main culprits infusing the air in our homes with invisible pollution: microplastics.

When you wash and dry your polyblend jumper, for instance, shake it out, pull it on over your head, or just go about your day wearing it, countless minuscule fibres are released into the air. Take a breath, and a cloud of these tiny particles can flow into your airways.

We're just beginning to unravel the breadth of airborne microplastic exposure and its effect on our health, but what's already known is raising concern.

Scientists believe the majority of our exposure to microplastics happens when we're indoors. The good news is there are things we can do about it in our homes, from reconsidering the clothes and furnishings we buy, to changing the way we wash our clothes and clean our houses.

"Microplastics are everywhere, and there's no way you can avoid them," says Dana Barr, an exposure science professor at Emory University in Atlanta, the US. "But there are ways that you can significantly reduce your exposure over time, and it's mostly from behavioural change."

The air in our homes

Invisibly small fragments of plastic are all around us. They're expelled from virtually every product made of plastic (over 460 million tonnes of new plastic is produced every year). They make their way into our bodies via the food and water we consume, the products we use on our skin and the tiny particles we inhale when we breathe.

Food and water was once thought to be the main way microplastics entered the body, but some scientists now believe that inhalation may in fact be the predominant route.

For instance, take a meal of filter-feeding shellfish like mussels, which can have high concentrations of microplastics. You're likely to inhale more plastics during the meal preparation than you eat from the food itself, according to one study. In countries where shellfish makes up a large part of the diet, you might expect to eat 4,620 particles per year. But you could be inhaling around three to 15 times more particles a year during mealtimes.

In developed countries, people spend about 90% of life indoors, which is one reason that the potential for microplastic inhalation is significantly higher compared to outdoors. A 2021 study examining airborne microplastics indoors and outdoors in China found that the concentration was eight times higher in indoor air. Even where natural fibres predominated over synthetics, and laundry – a considerable source of microplastics – was typically hung outside, microplastics were still at higher concentrations indoors.

"The fact that we're spending so much time indoors, and we're breathing the air indoors, means that we probably are vastly underestimating exposure," says Barr.

Dust laced with plastic

When tiny fragments of plastic settle from the air, they often end up in household dust. Even though dust settles, it can easily get kicked up into the air when disturbed by any sort of friction. Jeroen Sonke, a biogeochemist at the French National Center for Scientific Research, investigated the presence of small microplastics in the range of one to 10 micrometres, which penetrate deeper into the lungs than larger fragments.

Sonke found an average of more than 500 fragments in one cubic metre of air indoors, and more than 2,200 fragments inside the cabin of a car. For a baby crawling on the ground, their faces can be inches away from microplastic-filled dust. Sonke and his colleagues calculated the amount of microplastics an infant may inhale on an average day ranged between 19,000 and 75,000 particles. For adults, it was 28,000 to 108,000 particles a day.

Challenges and Solutions

It remains challenging for scientists to unequivocally measure the amount of microplastics in the air. Standard microscopes tend to have a lower limit of around 20 micrometres, though Raman microscopy is allowing researchers to get down to the 1 micrometre range. Contamination also complicates the picture, as the clothes scientists wear can release microplastics into their samples.

Microplastics come from textiles like clothes, upholstered chairs, sofas, and carpets. Domestic laundry dryers and washing machines are also considerable sources. To reduce exposure, experts suggest choosing natural fibers, improving home ventilation, and using specialized filters for washing machines that can reduce up to 90% of microfibres from wastewater.