Made up of minute plastic particles produced by the breakdown of larger plastic items and commercial production, microplastic pollution is becoming a major issue.
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One study has estimated that there are around 24.4 trillion fragments of microplastics in the upper regions of the world’s oceans. Twelve different microplastic types were discovered during tests on humans and animals, according to the results of a study published in Toxicological Sciences. Scientists believe they pose numerous health risks and may be responsible for a range of issues including cancer, a weakened immune system and male infertility.
The problem is the particles are extremely tiny, enabling them to enter the human body with ease. Like plastics of every size, they don’t break down harmlessly for hundreds of years. In the meantime, they cause environmental damage and health issues for people and wildlife.
Plastic in food and water
Infiltrating food and water, plastic is ending up in our bodies. Often consumed by marine animals and fish, which are part of the food chain; every time you eat a fish or shellfish, you’re ingesting the plastics they have eaten in their lifetime.
Studies estimate each person consumes, on average, 53,864 microplastic particles every year just from the seafood they eat. This is enough plastic to make 17 credit cards!
Even a cup of tea, the staple of the British public, means we’re ingesting microplastics. Typically, tea bags contain plastics, so the hot water boiled up in the kettle can make the tiny particles melt at 95°C.
One study, conducted by researchers at McGill University in Canada, estimates that tea bags release billions of micro and nano plastics, smaller in diameter than a human hair, which is a tiny 75,000 nanometres across. Invisible to the naked eye, they end up in the boiled water in your teacup.
Scientists estimate this equates to 11.6 billion microplastics and 3.1 billion nano plastics being released into water worldwide. They suggest using less teabags, reverting instead to the more old-fashioned method of buying loose tea.
Fruit and vegetables are meant to be good for us and we’ve all heard of eating our “five a day”, but research suggests they too contain microplastic particles, absorbing them through their roots. The tiny plastic pieces can enter the leaves, seeds and flesh of the fruit. Carrots and apples are the most contaminated vegetable and fruit respectively, each containing more than 100,000 microplastic particles per gram, according to research.
Plastic in beer
If you enjoy beer, you may be consuming microplastic particles with your pint, as it’s manufactured from crops such as wheat, and water, both of which contain plastic particles. Scientific research published in 2022 suggested a pint of beer could contain up to 50,000 plastic fragments, with 90% of them being minute particles of polypropylene and polystyrene. Other beverages such as bottled mineral water, iced tea, soda and energy drinks also contain plastics, although not in as great a quantity as beer.
A separate study found almost every sample of salt contained microplastics, with 93% of brands tested being contaminated with various amounts. The report, Global Pattern of Microplastics in Commercial Food-Grade Salts, by the American Chemical Society, said it was difficult to determine how this had occurred, although natural sea salts were among those most contaminated.
It is estimated that an average adult ingests some 2,000 microplastic pieces annually from seasoning their food with salt.
What are the health risks?
Microplastics' effect on humans isn’t fully understood, but a body of research suggests they pose various risks.
The chemicals present in plastic have been linked to heart disease, cancer and poor foetal development. They can also disrupt the hormones and endocrine system that regulate our growth, metabolism, reproduction, energy levels and development.
Cell damage can lead to allergic reactions and inflammation, according to research carried out at the University of Hull, which analysed 17 earlier studies into the toxicological impact of microplastics. It compared the amount of microplastics consumed by people in water, salt and seafood to the levels that had caused cell damage in laboratory tests. The research found that people had ingested enough microplastics to cause allergic reactions, oxidative stress, damage to cell walls and cell death.
Evidence shows that as well as infiltrating human lungs and blood, plastic particles have found their way into reproductive systems too. A new study, published in May 2024, suggested microplastics may be responsible for an increase in male infertility by reducing the sperm count. Microplastic particles, including PE and PVC, have been found in male reproductive organs.
Scientists say more research is needed to determine the impact of microplastics on fertility, but believe initial studies suggest a high presence of microplastics may have a detrimental effect on testicular function.
What can be done to mitigate this problem?
Unfortunately, there is little that can be done to reduce our consumption of microplastics in what we eat, simply because research is in its early stages. Scientists are still investigating how the plastic particles get into the food chain and which products have the highest amount.
Despite the uncertainty, many nations are already taking action to reduce the microplastics being released into the environment. A resolution by the United Nations in 2017 discussed the need for new laws to reduce the hazard posed to our planet, wildlife and people’s health.
Members of the public are urged to sign the Global Plastics Treaty Petition launched by Earthday.org, urging the UN and governments to make a greater commitment to reducing plastics pollution by 60% by 2040.
In practical terms, everyone can do their bit, at home and at work, by recycling and reusing plastics. In addition, avoid single-use plastics, as they make up 89% of ocean pollution, according to data from the United Nations Environment Programme.