‘They’re in the air, drinking water, dust, food …’ How to reduce your exposure to microplastics

No corner of the planet is free from minuscule fragments of plastic packaging, textiles or utensils. We ask scientists what this means for our health – and what we should do to protect it.

Invisible specks of eroded plastic from long-forgotten toothbrushes, sweet wrappers and stocking-filler toys are everywhere. They live in our laundry bins, the Mariana trench and the human bloodstream. Microplastic particles can be small enough to infiltrate biological barriers such as the gut, skin and placental tissue. We are all now partially plastic – but how worried should we be, and is there any way to minimise our exposure?

At the moment, says Stephanie Wright, an environmental toxicologist at Imperial College, London, a lack of epidemiological and in-human data means we don’t yet know the harmful effects of microplastics, but “I would say reducing particle exposure in general (including microplastic) is likely to be beneficial”. But avoiding the stuff is a tall order, considering it’s in the “air, drinking water, dust and food”.

Food and drink sealed in plastic has long been associated with cleanliness, purity and protection from contamination, but we now know that some of the highest exposures to microplastics, says Wright, “are likely to come from processed and packaged foods and drinks”. The shedding of plastic is increased when containers are exposed to heat. “Hot water in plastic-lined cups and takeaway containers also release micro- and nanoparticles, in some cases trillions per litre, although whether these are true plastic particles is unknown.”

Wright says that to reduce exposure to microplastics, “I would start by not heating anything in plastic, or consuming hot liquid that has come into contact with plastic”. This includes microwaving food in Tupperware or ready-to-heat products such as boil-in-the-bag rice and “food-grade nylon used for food packaging, as liners for baking pans in restaurants and commercial kitchens and in slow cookers in household kitchens”.

When it comes to water, she chooses tap over bottled: “Some bottled waters – including glass bottles – contain thousands of microplastic particles per litre.” And, ideally, she would take it filtered. When I mention filtering to Mark Taylor, chief environmental scientist at the Environmental Protection Authority in the Australian state of Victoria, he points out that home water filters are usually plastic, too: “Ultimately it will start to shed because it will degrade.”

Microplastics in a laboratory. Photograph: David Kelly/The University of Queensland

This gives me the perfect opportunity to gloat about my glass and stainless steel filter jug, but then I remember that the charcoal refills come in plastic pouches. When you start observing your plastic use, it’s hard not to spiral. “I think we can stress ourselves out over all of these things and put too much focus on it,” says Taylor. “The reality is people are living longer than they’ve ever lived before. Some people in a [global] population of 8 billion, of course, will be affected and may well die as a result of microplastics exposure.” The way forward, he says, is “balancing the risk of microplastics versus practical actions and lifespan”.

Having extensively studied microplastic exposure in homes – which is where Taylor says we absorb the most plastic contamination – he knows it’s impossible to avoid the stuff and so there’s no point worrying over every bit of plastic we meet. Instead, he says, “we can look at minimising inessential uses”.

At one end of the scale sits a plastic heart valve, which is essential. Whereas fruit sealed in plastic is unnecessary. “You can think about the furnishings and the clothes that you acquire, and buy more natural fabrics,” says Taylor. “Instead of having a polyester carpet, you could have a wool carpet.” Natural fibres are often more expensive, but second-hand is always an option, and if it’s not something you can change, don’t sweat it. “You can think about buying natural clothing – they do produce microfibres, but they’re not microplastics and they break down. If you’ve got kids, do you need to have plastic spoons and plates?”

On a personal level, he says, he makes choices based on unnecessary exposure, but also as an act of consumer protest – “every little action matters”. It is often hard to find out the composition of plastic products – they don’t come with ingredients lists like food – but he recalls looking for a new watch strap and discovering one contained perfluoroalkyl and polyfluoroalkyl substances (PFAS). “I went: well, I won’t be buying that. It is associated with testicular and kidney cancer, low birth weight in newborns and just a ton of things.” PFAS are among the many commonly used chemicals in plastics that are endocrine disruptors, which some scientists believe are to blame for declining global sperm counts.

He actively avoids buying food such as fruit and veg wrapped in plastic, or adorned with “those stupid little food stickers”. His household uses glass instead of plastic in the kitchen. “I wear predominantly, but not entirely, natural fibres, because my work jacket is made of polyester. But I prefer either cotton or wool.” He concedes, however, “I have a wooden floor with varnish, which I know will slough off.”

At our current rate, more than 10bn tonnes of mismanaged plastic waste will be dispersed in the natural environment by 2050. Photograph: Dotted Zebra/Alamy

Keeping a clean house is something anyone can do to reduce exposure. “The carpets, the curtains, the sofa, most of those are probably not made from fully natural fabrics, and they degrade, and their fibres accumulate,” he says. All that dust and fluff that balls up like tumbleweed under sofas, or twinkles in sunbeams after you plump a cushion, will contain plastic fibres. This is why the vacuum cleaner is about more than being house-proud.

He says: “It’s very clear, whether you’re dealing with microplastics or trace metals such as lead, zinc, cadmium and arsenic that migrate into a home, that regular vacuuming is really effective at reducing the load.” If you don’t vacuum, the dust remobilises and, adds Taylor, “deposits in open water vessels, on your fruit, on people’s hands, kitchen utensils”.

He recommends – if you can afford it – robot vacuum cleaners, “that go around the floor and just keep on top of the worst of it when you’re out at work. Or preferably, if you’ve got a hard floor, wet mopping.” With carpets, vacuuming has the added benefit of capturing loose fibres soon to be shed from everyday wear and tear.

Malcolm Hudson, an associate professor in environmental science at the University of Southampton, is very keen that we don’t panic about our current exposure to microplastics. Instead, he’d rather we divert that energy into helping to stop the planet accumulating yet more plastic. At the current rate of production, more than 10bn tonnes of mismanaged plastic waste will be dispersed in the natural environment by 2050.

He certainly isn’t panicking right now. “I’m sitting at home in my office and I’m probably breathing in some plastic fibres from the clothes that I’m wearing, and from the carpet on the stairs just outside my office,” he says. “And I’ve probably ingested some plastic in my lunch, which is an unsettling thought but it’s probably not doing me a great deal of harm,” he says. He doubts, at this point, whether trying to limit plastic exposure will make much difference to his health right now.

Hot water in plastic-lined cups releases micro- and nanoparticles. Photograph: Boy_Anupong/Getty Images

“We’ve evolved to deal with inhalation and ingestion of impurities,” he says. “That’s why we have complex respiratory systems and all sorts of trapping devices to stop particles going into our lungs. It’s why we have an immune system that’s set up to deal with small foreign bodies. It’s why we have a digestive system that doesn’t let larger impurities get into our system – they just pass through.”

But in another few decades, “if the environment continues to get more contaminated, I think you have got potentially a harmful issue.” This is partly due to the sheer volume of microplastics that will have accumulated by then, and we know that the greater the exposure, the greater the risk. “There was a study from a few years ago that showed that people who work in textile factories in Bangladesh have been exposed to very high levels of airborne microplastic fibres and they do get respiratory disease.”

The other reason the health risks will grow with time is because the older the particles are, the more toxic they can become. They can harbour pathogenic microbes and take on other pollutants such as heavy metals. “And then,” says Hudson, “if you swallow that microplastic, you’re swallowing a small dose of another harmful chemical as well.” These chemicals include, “polyaromatic hydrocarbons, plasticisers like phenol A that are used in things like furnishings and packaging – they can have hormone mimicking or carcinogenic properties. Heavy metals like copper, vanadium, mercury, lead. Cadmium contaminated sediments have already become associated with plastics.”

Meanwhile, avoiding traffic-heavy roads is always recommended, where microplastics are part of the toxic soup of pollution, although Hudson reckons they’re probably the least of your worries next to car fumes and tyre particles. Plastic comes off road markings and wears off brakes, says Hudson, “made from composite synthetic polymers”. Roads are, adds Wright, “a hypothesised source of microplastic particle emissions to the air due to litter being worn down and run over”.

But it’s hard and time-consuming to prove the effects of any one pollutant on health. “In a study, isolating the impact of microplastics versus all the other contaminants such as air pollution would be really difficult,” says Taylor. But rather than sit back and say there’s no hard evidence they cause harm to humans, he says he would rather, “apply the precautionary principle: in the history of environmental toxicology, early concerns were usually born out. So, let’s take an approach that minimises – I don’t think we can eliminate – the risk.”

Amy Fleming

Mon 10 Jul 2023

The Guardian