As far as our bodies are concerned, Planet Earth is now Planet Plastic.
Tiny plastic particles – microplastics – in the air we breathe, our food and water and many of the products around us pollute our bloodstream and organs, with potentially serious health consequences.
Previously the particles have been linked to lung disease, liver failure and fertility damage in men.
But now two new studies have shown something more alarming – that even our brains are being invaded with these plastic pieces, possibly raising our risk of dementia and Parkinson’s or causing developmental problems in children.
This invisible plague comes in the form of tiny particles classed as microplastics (as small as 0.0001mm) and nanoplastics (even tinier particles – as small as one billionth of a centimetre, 0.000000001cm).
On average we ingest about 5g of plastic particles every week – the same weight as a credit card – according to a 2019 World Wildlife Fund review of data from 50 previous studies. Over a year this adds up to 260g, or half a pound.
Numerous studies show that many of these plastics can be highly toxic.
Research reveals microplastics can lodge in our organs, causing dangerous inflammation. Microplastics may also transport infectious bacteria and viruses.
Tiny plastic particles – microplastics – in the air we breathe, our food and water and many of the products around us pollute our bloodstream and organs
Until now most scientists believed that our brains were safe from plastic invaders because they are protected by the blood-brain barrier, a layer of specialised cells that acts as a filter keeping out toxic substances and infections.
But the two new studies suggest microscopic plastic particles are small enough to slip past the blood-brain barrier and into the brain.
The first study, published in September in the journal Environmental Health, analysed the brains of 15 people who had died from various causes and found microplastic particles in eight of them, specifically in the olfactory bulbs.
This pair of rounded tissue masses at the bottom of the brain relays information about smells from the nose to the brain. Crucially this pathway is a weak spot in the blood-brain barrier.
Luís Fernando Amato-Lourenço, an environmental engineer at Berlin University who led the study, suggests that inhaled microplastics may bypass the blood-brain barrier by flowing up nasal mucus and becoming mixed in brain fluids around the olfactory bulbs, via tiny ‘perforations’ in bony structures found in this area.
The olfactory nerve, responsible for transmitting the smell information, is situated just below the front and prefrontal lobes – areas of the brain involved in thinking, judging and problem solving.
The most common type of plastic found was polypropylene, used in a wide range of plastic packaging, clothing and home accessories – suggesting ‘indoor environments as a major source of inhaled microplastics’, the researchers said.
Co-researcher Thais Mauad, an associate professor of pathology at the University of Sao Paolo in Brazil, warned: ‘What is worrying is the capacity of such particles to be internalised by cells and alter how our bodies function.’
The findings ‘should raise concern amid the increase in neurodegenerative diseases such as Parkinson’s’, the report said.
Experiments on mice have already shown how microscopic plastic particles can damage brains – for instance a 2022 study in the journal Chemosphere found that microplastics provoke chronic inflammation that damages brain cells.
Two years earlier, a study by Rutgers University in New Jersey in which pregnant mice inhaled microplastics found that the particles were being passed on to the next generation – in the organs and brains of the foetuses.
Another new study on humans suggests microplastics might also invade our brains via the food and drink we consume.
The researchers, led by Dr Matthew Campen, a professor of pharmacology at the University of New Mexico, examined brain, liver and kidney samples taken from 51 local men and women’s post-mortem examinations.
The scientists were surprised to find up to 30 times more microplastics – most commonly polyethylene – in brain samples than in the liver and kidney.
They theorised this could be due to high blood flow to the brain carrying plastic particles with it from organs such as the liver and kidney. It’s thought the particles accumulate there because the brain – which has the blood-brain barrier to protect it – is less efficient at ridding itself of toxics than other organs.
Professor Campen’s study, which has yet to be peer-reviewed, also found the amount of plastics in brain samples increased by about 50 per cent between 2016, when the first samples were taken, and 2024, potentially reflecting the rise in human exposure to environmental plastic pollution.
The view was echoed by Professor Richard Thompson, a plastics pollution expert at the University of Plymouth, who warned that environmental contamination (by microplastics and nano-plastics) could double by 2040.
Rather than waiting for further evidence of harm to humans, Professor Thompson says we should be cutting plastic contamination now.
A good place to start for most of us, he told the Mail, is in ‘single-use items such as plastic bottles’.
What other steps can we take to protect our brains from exposure to microplastics?
WEAR NATURAL FIBRES
Up to 65 per cent of all the microplastics floating in our household air may come from synthetic-fibre clothes, according to a 2020 study by the Organisation for Economic Co-Operation and Development (OECD).
This warns that the microscopic particles are shed every time we wear or dry clothes indoors that are made of plastics such as polyester, acrylic and nylon textiles.
Opting for clothing made with cotton, wool and silk could cut your risk
More than 80 per cent of fashion-brand clothes contain plastics, according to a 2021 analysis of 10,000 items by the Royal Society for the Arts.
Such clothing significantly contributes to the fact that indoor concentrations of microplastics can regularly be 60 times higher than outdoors, according to environmental researchers at the University of Portsmouth.
One potential risk is the effect of such fibres on the lungs.
Two years ago a study by the University of Hull of samples from living people found microplastics buried deep inside narrow airways in the lungs.
In separate research earlier this year Barbro Melgert, a professor of respiratory immunology at the University of Groningen in the Netherlands, found that synthetic fibres in textiles make it more difficult for lungs to recover from infection or injury.
It’s hard to avoid these materials altogether, but opting for clothing made with cotton, wool and silk could cut your risk.
CHOOSE WOODEN FLOORS AND WOOL RUGS
Carpets are an ‘important source of microplastics in indoor air’, warned a study this year by environmental scientists at the University of Birmingham, which examined plastic pollution in the air inside 30 homes in the city.
They found that having carpet was associated with a 20 per cent increase in airborne microplastics, compared with uncarpeted indoor areas – although a 2020 study put the figure higher, estimating that having carpets can double the amount of microplastic fibres in the home.
Research shows plastic fibres abound in most mass-market British carpets. Choose natural flooring products made from wool, sisal, jute or seagrass; wooden floors and natural rugs also don’t produce microplastics.
DITCH THE MICROFIBRE BEDDING
Microfibre or hollowfibre synthetic bedding is another significant source of indoor microplastic air pollution.
Cheap to mass-produce, these very fine synthetic fibres were created as a man-made equivalent to natural down.
The most common plastic found in bedding is polyester, and the most prevalent polyester in bedding is polyethylene terephthalate or PET. This is made from chemicals including substances extracted from oil and sometimes coal.
Plastic fibres from bedding, carpets and furnishings were the dominant type of microplastic found in the Birmingham University study which looked at plastics in the home, making up about 60 per cent of all the samples taken.
Try using sheets and covers made from natural fibres – and consider duvets filled with natural goose or duck feathers. An alternative to feathers is cellulose fibres processed from wood pulp.
BUY VINTAGE FURNITURE
Many modern furnishings have plastics in their coverings, as well as plastic-foam fillings.
Even furniture made from non-plastic material – such as leather – may nonetheless have cushions made of polyurethane foam that will ultimately produce microplastic dust.
Modern second-hand furnishings are similarly often made of microplastic-shedding materials, and impregnated with older fire-retardant chemicals associated with cognitive and fertility problems, as well as allergies.
One option is modern wooden items with plastic-free wool cushions. Alternatively, properly vintage and antique furniture made with horsehair can offer a plastic-free way forward.
DUST WITH A WET CLOTH
You can reduce microplastic dust and fibres in your home by regularly using a vacuum cleaner with HEPA or S-class filters and mopping and wiping down surfaces with a damp cloth (dry dusting flicks tiny particles back into the air).
DITCH PLASTIC CHOPPING BOARDS
Boards made from polyethylene or polypropylene could expose humans to up to 79.4 million microplastics each year
Reduce ingestion of microplastics by using wooden chopping boards in the kitchen.
Boards made from polyethylene or polypropylene could expose humans to up to 79.4 million microplastics each year, according to a study last year by scientists at North Dakota State University.
