Every day we ingest countless thousands of tiny particles of waste plastic from the air and water that surround us, as well from as the food we eat.
The damage these plastics may wreak inside our bodies is only now beginning to be understood fully.
Over the past decade scientists have become increasingly concerned that this plastic plague may be seriously poisoning our bodies and brains, with potentially lethal consequences in some cases.
Now a series of highly reputable studies are beginning to confirm one of medicine’s worst fears – that these particles, which can be as small as one billionth of a centimetre, may be fuelling a wave of cancers affecting people’s lungs, colons, bladders and prostate glands.
Some of the most worrying news comes from researchers at the University of California, San Francisco, who conducted an in-depth review of over 3,000 studies on microplastics.
Their report, published in December 2024 in the journal ACS Publications Environmental Science & Technology, starkly pronounced: ‘We concluded that microplastics are suspected to harm human reproductive, digestive and respiratory health, with a suggested link to colon and lung cancer.’
The paper is the first review of previous studies of microplastics to use ‘gold standard’ methods for this kind of research approved by the U.S National Academy of Sciences.
As Dr Antonis Myridakis, a lecturer in environmental sciences at Brunel University told the Mail, this approach involves amalgamating the most reliable results from a mass of studies, so that the overall conclusions are as authoritative as possible: ‘These results are strong.’
The colour of black plastics, derived from carbon black (carbon particles), is essentially a form of soot
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.
The tiny particles that invade our bloodstream and organs are classed as microplastics (as small as 0.0001mm) and nanoplastics (as small as one billionth of a centimetre, 0.000000001cm).
They are becoming ever more pervasive: each year companies worldwide produce nearly 460 million metric tons of plastic. That is projected to reach 1.1 billion by 2050.
Research has already shown how microplastics can lodge in our organs, causing dangerous inflammation.
And hazardous chemicals are often carried on the surface of these particles – these chemicals, used in their manufacture, include plasticisers – chemical additives that make plastics more flexible – which may mutate our DNA, raising the risk of cancers.
This fear has been significantly reinforced by the new California University report – this highlighted scientific evidence suggesting that plastic microparticles disrupt the mucus layer in the colon which normally protects its cells from damage, and thus ‘potentially promote tumour development’.
The researchers also warned that microplastic particles are suspected of killing intestinal cells and causing chronic inflammation, as well as harming the intestinal immune system, which again might cause cancerous changes.
The California researchers also reported on an association between inhaling microplastics and poor lung function. The particles can damage lung tissues and cause chronic inflammation that may damage cells and their DNA, ‘which can increase the risk of lung cancer’.
Lead author of the study Dr Matthew Cole warns that one of the worst things you can do is keep food in single-use plastic containers
Experts at the charity Breast Cancer UK say that while still unproven, ‘a link is feasible between microplastics and breast cancer risk’.
The charity explains: ‘Microplastics often contain mixtures of hormone-disrupting chemicals, which mimic the female hormone oestrogen. These may be particularly hazardous [as they are linked with causing cancerous changes in breast cells}. Ingestion of microplastics can cause inflammation and irritation. This may potentially lead to DNA damage and promote cancer.’
These findings come on the tail of other disturbing new research that warned of an association between ingesting microplastics and developing prostate cancer.
The study, published in the Lancet journal eBioMedicine last October, used high-tech scanning to identify microplastics in tissue samples obtained from 22 prostate cancer patients (with an average age of 67).
The researchers, at the Peking University First Hospital in Beijing, found a host of different plastic types inside the tumour tissue, including polystyrene, polyamide and polyvinyl chloride (PVC).
Levels of polystyrene microparticles alarmed the scientists most.
This plastic is commonly used in disposable food containers and the study showed that the more takeaways the patients had eaten, the more polystyrene was found in their tumours.
The scientists warned that microplastics carry toxic plasticisers that have ‘known hormone-altering, often carcinogenic properties’.
They are calling for large studies to be launched urgently to explore how takeaway packaging may be driving microplastic exposure.
Further concern comes from Australian research published last August, which revealed that microplastics have been found in the urinary tracts of more than two-thirds of patients with bladder cancer.
The study, by Bond University in Queensland, examined research data collated from 18 previous studies on patients in the US, China, Germany, Italy, the Netherlands, Pakistan and Taiwan.
While there is no direct proof that the microplastics caused the cancers, the researchers concluded that the evidence shows the toxic and inflammatory materials seriously harmed the human urinary tract cells in ways which might lead them to turn cancerous.
In 2019 the World Health Organisation published a report which concluded microplastics in drinking water did not present a threat.
But the Australian scientists said that their evidence ‘challenges the World Health Organisation’s assertion that microplastics pose no risk to public health’.
They added: ‘The documented toxic effects of microplastics, alongside their ability to induce inflammation and reduce cell viability, raise significant public health concerns relating to bladder cancer.’
Fears about the plastics that surround us in everyday life have further been intensified by research at Plymouth University into plastic cookware – and particularly black plastic cookware.
A study last year at Plymouth Marine Laboratory revealed that plastic cookware can release microplastics into food during food preparation.
The lead author, Dr Matthew Cole, a senior ecotoxicologist warned that plastic cookware may be contributing more than 5,000 microplastic pieces a year into homecooked food.
Black plastic utensils, a common sight in many households, may be particularly hazardous, previous research from the university suggests.
In a 2018 study published in the journal Environment International found that these utensils are often made from electronic waste and contain toxic flame retardants, lead and mercury.
The colour of black plastics, derived from carbon black (carbon particles), is essentially a form of soot. The study found toxic chemicals in 40 per cent of black plastic utensils, which tested up to 30 times above the level deemed safe.
As well as avoiding black plastic cookware, Dr Myridakis told the Mail that we can all reduce our exposure to microplastics by improving our household air quality.
‘Microplastic air pollution is significantly more abundant indoors than outside,’ he says.
‘Regularly vacuuming with cleaners that have high-quality air filters, as well as dusting and ventilating our homes, really can make a difference.’
He adds: ‘In the kitchen one of the worst things you can do is keep food and drink in plastic containers – particularly old, brittle and scratched ones. The other thing to ban from home is single-use plastic containers such as water bottles, as they use the cheapest forms of plastic that shed the most microparticles.’
