A sensible guide to microplastics and your health, by an expert

Plastic is an undeniable part of everyday life. It keeps our food fresh, lines disposable coffee cups, and even makes up a significant part of clothing and carpeting materials. But recently, concern has grown over microplastics, particles smaller than 5 millimetres that slough off plastic as it degrades, and the threats they pose to human health. Microplastics have been detected throughout the human body, including in the blood, saliva, liver, kidneys, and placenta. Investigators are probing how they get into other organs and tissues from the lungs and gastrointestinal tract. Microplastics smaller than 1 micrometre, known as nanoplastics, worry researchers the most because they can infiltrate cells. Dr Nathaniel Clark, a lecturer in physiology at the University of Plymouth, whose research interests include how micro/nanoplastics and nanomaterials affect environmental and human health, says: “Microplastics can enter our homes through a range of routes. They can be present in food and drinking water and released from plastic products through abrasion or degradation. However, detecting particles in a particular environment does not necessarily mean that they pose a significant health risk.” Shorts Clark says it is hard to establish what microplastic exposure means for human health at the concentrations and particle characteristics to which people are actually exposed: “Laboratory studies often use specific particle types, sizes and concentrations that may not reflect real-world exposure. The presence of microplastics in the body should not, by itself, be interpreted as evidence of harm.” Due to their small size, microplastics are nearly impossible to see and avoid completely. The average person consumes roughly 250 grams of microplastics a year – the weight of a heaped dinner plate, or about 5 grams a week (the weight of a credit card). If you want to cut down your microplastic exposure, Clark has some advice on what to look out for. Teabags Compelling evidence shows that exposing plastic to high temperatures or hot water releases microplastics, which has prompted concern over teabags. A study by McGill University in Canada in 2019 found that when a plastic teabag was steeped in a cup of water at 95°C, it released more than 11.6 billion microplastics into the cup – more than the estimated amount a person consumes in a year. Most teabags are made from natural fibres, but some have moved away from paper towards plastic. Clark says more evidence is needed to show that avoiding plastic teabags makes a difference to health, and says :“I would be cautious about saying that this means people should stop using them.” Some experts have also recommended avoiding drinking hot drinks in polystyrene cups. Containers Cling film is made from plastic, and some experts recommend storing food in ceramic or glass containers. Clark says, “we don’t currently have good evidence allowing us to say that avoiding cling film would make a measurable difference to someone’s health”. However, he says there is good evidence that heat and mechanical wear such as scratching can influence the release of microplastics and nanoplastics from some plastic food containers: “In particular, studies have shown that heating plastic containers, including in a microwave, can result in the release of particles, although the amount varies considerably depending on the type of plastic, the temperature, heating time and other conditions.” Importantly, these studies show particle release; they do not establish that microwaving food in plastic harms human health. “As a sensible precaution, I would avoid unnecessarily heating food in plastic containers, particularly at high temperatures. Where practical, transferring food to a glass or ceramic container before microwaving is a simple way of reducing an avoidable source of exposure. Similarly, replacing containers that have become heavily scratched, cracked or visibly degraded is reasonable,” says Clark. Water Microplastics have been detected in both bottled and tap water. Clark says whether filtering water is worthwhile depends on the filter type and what it is designed to remove. He explains: “Some water filtration systems can remove a proportion of particulate material, including some microplastics, depending on the technology and particle size. However, I would not recommend that everyone needs to filter their drinking water specifically because of microplastics. The evidence does not currently demonstrate that filtering household drinking water provides a meaningful health benefit for the general population.” The UK uses 10 million bottles of water a day, and one 2024 US study found hundreds of thousands of tiny plastic particles in bottled water, prompting experts to say they would avoid drinking from plastic bottles and drink tap instead. Chopping boards Experiments have shown that plastic chopping boards release microplastics during chopping, with the amount depending on the type of plastic and how the board is used. Visible cutting and abrasion provide an obvious mechanism for plastic loss, although the significance of this as a source of human exposure is not yet established. If you’re thinking of switching to wooden utensils, Clark says: “If the aim is specifically to reduce plastic particle exposure, wood avoids the potential generation of plastic particles, but there are also considerations around hygiene, durability and how utensils are cleaned and maintained. Stainless steel, glass and other non-plastic materials can also be practical alternatives where appropriate.” Sponges and cleaning products Many conventional kitchen sponges are made partly or entirely from synthetic polymers and undergo mechanical abrasion during use, making them a plausible source of plastic particles. Clark says: “In many cases, the abrasion will happen unnoticeably over time – we don’t have the data to know how fast this occurs.” If you want to reduce unnecessary plastic use, Clark suggests choosing a durable natural-fibre or cellulose-based alternative. Soft furnishings and clothing Synthetic textiles are an important potential source of plastic fibres in indoor environments, as Clark explains: “Wear and abrasion can release fibres, which can then become incorporated into household dust. Clothing and other textiles made from polyester, nylon, acrylic and other synthetic polymers are therefore potential contributors.” According to Clark, the amount of fibre released depends on the polymer, construction of the textile, age, washing conditions, mechanical abrasion and other factors. He says: “In general, ‘synthetic’ does not automatically mean that a particular item will shed more, and newer or more expensive clothing isn’t necessarily better from a shedding perspective. The construction and treatment of the fabric can be just as important as the polymer itself,” says Clark. If you want to reduce fibre release, practical measures such as washing clothes only when necessary, avoiding unnecessarily aggressive washing, and reducing mechanical abrasion through scratching, scuffing, or rubbing are probably more useful than simply throwing away existing synthetic clothing and replacing it. Plastic-associated chemicals Plastics can expose us to chemicals associated with their manufacture or use, including substances such as some phthalates and bisphenols, which can interfere with the body’s natural hormone systems even at low levels of exposure. “Many of these chemicals have established or suspected effects on human health, although our total exposure can come from multiple sources and it is often difficult to determine how much comes specifically from plastics,” says Clark. There is some recent evidence that reducing plastic exposure can reduce exposure to some of these chemicals quite rapidly. A 2026 randomised pilot trial involving 60 people found that a seven-day intervention using low-plastic food and, in some groups, plastic-free kitchenware reduced urinary concentrations of several plastic-associated chemicals, including some phthalates and bisphenol A. Clark says: “This study does not show that reducing plastic exposure improves health, but it does suggest that reducing plastic contact with food and other everyday products can reduce exposure to at least some plastic-associated chemicals. This could therefore be a reasonable additional reason for people who want to reduce unnecessary plastic use – alongside, but distinct from, the question of exposure to micro- and nanoplastics themselves.”