Surprising number of foods contain microplastics. Here’s how to reduce the amount you consume
The public is starting to understand that they can find microplastics in their food, particularly seafood, but exposure from other foods is far more common than most people realise.
Studies have shown that your daily intake of microplastics from food and drink is estimated to be anywhere from zero to 1.5 million microplastic particles per day. The biggest source is likely to be coming from bottled water.
Here are five of the more surprising sources of microplastics in your food and drink.
1. Chewing gum
When you chew gum, you are essentially chewing a lump of plastic. Most chewing gum is made from a gum base (plastics and rubber), to which sweeteners and flavourings are added. As you chew, the gum base releases microplastics. A single gram of chewing gum can release up to 637 microplastic particles.
Natural gums made with plant polymers are not much better. They release a similar number of microplastics as the synthetic gum. This suggests that microplastics aren’t just coming from the gum base but could be due to the introduction of microplastics during the production or packaging process.
Most microplastics were released within the first eight minutes of chewing, so to reduce your exposure, chew one piece of gum for longer, rather than constantly popping in fresh pieces.
2. Salt
Salt may seem like a pure, simple ingredient but studies have shown that 94% of salt products tested worldwide are contaminated with microplastics. The contamination is so widespread that sea salt has even been proposed as an indicator of microplastic pollution in the marine environment.
Contamination has been found to be higher in terrestrial salts, such as Himalayan salt, rather than marine salts. New technologies are being investigated to help clean up sea salt, however, it is likely that much of the contamination comes from production and packaging.
Your salt grinder might also be making things worse. Disposable plastic spice grinders can release up to 7,628 particles when grinding just 0.1g of salt using a plastic grinder. To minimise your exposure, switch to a grinder with a ceramic or metal grinding mechanism and store salt in non-plastic containers.
3. Apples and carrots
Microplastic contamination of fruit and vegetables has been identified in several studies. Nanoplastics, which are plastic particles smaller than 1,000 nanometres, can enter plants through the roots. Microplastics have also been found on the surface of a variety of fruit and vegetables.
One study found apples and carrots to be the most contaminated and lettuce the least. However, microplastic contamination remains relatively small when compared with more highly processed foods.
While we don’t yet know what the effects of the microplastics are, we do know that antioxidants in fruit and vegetables, such as anthocyanins, which give fruits and vegetables their red, blue and purple colours, keep people healthy, so do keep eating them.
4. Tea and coffee
Teabags are not the only source of microplastics in your hot beverage. Tea leaves, coffee and milk can all be contaminated with microplastics. The use of disposable plastic-lined takeaway cups is one of the biggest sources of microplastic contamination in hot drinks. High temperatures can cause the release of microplastics from the container into the beverage.
Hot drinks contain more microplastics than the iced equivalents so switching to a cold beverage can reduce your exposure. Buying milk in glass bottles has also been shown to result in a lower microplastic load. This doesn’t extend to all drinks, though. A study of bottled drinks demonstrated that soft drinks and beer stored in glass bottles had higher microplastic contamination than plastic bottles, possibly due to contamination from the painted metal bottle caps.
There are a few truly plastic-free teabags available – they use cotton rather than biodegradable plastics to seal their bags. Identifying these brands, however, can be tricky as there is no standard approach to labelling and not all companies are transparent about the composition of their product.
Overall, switching to loose leaf tea and using metal or glass reusable cups are good strategies for reducing microplastic contamination.
5. Seafood
While studies have shown that most seafood is contaminated with microplastics, what is perhaps most surprising about seafood is the amount of attention it receives compared to other food sources. One study showed the levels of microplastics in so-called “filter feeders”, such as mussels, was just 0.2-0.70 microplastic particles per gram. This is significantly less than the 11.6 billion microplastics released when brewing a single cup of tea with a plastic tea bag.
Other steps you can take
Storing food in plastic containers and eating highly processed food are both associated with high concentrations of microplastics in stool samples, so you could try and avoid these. Microwaving food in glass containers rather than plastic is also a good idea to prevent microplastics leaching into your food.
Finally, the single biggest source of microplastics in food and drink is likely to be bottled water with up to 240,000 particles per litre. Switching to tap water can help to significantly reduce your exposure.
While eliminating plastics entirely from our diets may be impossible, making these swaps should help to reduce your exposure.
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Catherine Rolph does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.