Paris: Small shards of plastic called microplastics are accumulated in human brains, but there is not enough evidence to say if this is damaging us, experts have said.
These usually invisible pieces of plastic are found everywhere, from the top of the mountains to the bottom of the oceans, in the air that we breathe and the food we eat. They are also discovered by crossing the whole human bodies, within lungs, hearts, placentas and even the blood-brain barrier.
The increasing omnipresence of microplastics has become an important problem in attempts to hammer the first plastic pollution treaty in the world, where the last round of the UN interviews will be held in Geneva next week.
The effects that microplastics and even smaller nanoplastics have on human health are not yet fully understood, but researchers have worked to find out more in this relatively new field.
The most prominent study that looks at microplastics in the brain was published in February in the Nature Medicine magazine.
The scientists tested brain tissue of 28 people who died in 2016 and 24 who died in the US state of New Mexico last year, and discovered that the amount of microplastics in the samples increased over time.
The study made the headlines around the world when the main investigator, the American toxicologist Matthew Campen, told the media that they detected the equivalent of a plastic spoon of microplastics in the brain.
Campen also said that he estimated that the researchers could insulate about 10 grams of plastic from a donated human brain – which compared those amounts to an unused chalk.
Speculation ‘Far outside the evidence’
But other researchers have since insisted on the small study.
“Although this is an interesting finding, it must be carefully interpreted pending independent verification,” said toxicologist Theodore Henry of the Heriot-Watt University in Scotland AFP.
“Currently, speculation is about the potential effects of plastic particles on health much further than the evidence,” he added.
Oliver Jones, Professor Chemistry at RMIT University of Australia, said AFP There were “insufficient data to draw fixed conclusions about the occurrence of microplastics in New Mexico, let alone worldwide”.
He also thought it was “rather unlikely” that brains could contain more microplastics than had been found in raw waste water – as the researchers had estimated.
Jones pointed out that the people in the study were completely healthy before they died, and that the researchers acknowledged that there were not enough data to show that the microplastics caused damage.
“If (and it is a big thing if I in my opinion) microplastics in our brains, there is no evidence of damage yet,” Jones added.
The study also contained duplicated images, the Neuroscience News website that the channel reported, although experts said that this did not affect the most important findings.
‘Can’t wait for full data’
The majority of research into the effects that Microplastics have on health has been observational, which means that it cannot determine the cause and effect.
One of such a study, published in the New England Journal of Medicine last year, showed that microplastics that built up in blood vessels was linked to an increased risk of heart attack, stroke and death in patients with a disease that hides arteries.
Experiments have also been conducted on mice, including a study in the science progress in January that detected microplastics in their brains.
The Chinese researchers said that microplastics can cause rare blood clots in the brain of mice by hindering cells – while emphasizing that the small mammals are very different from people.
An assessment by the World Health Organization in 2022 showed that “evidence is insufficient to determine risks to human health” of microplastics.
However, many health experts have cited the precautionary principle and say that the potential threat that microplastics could pose requires action.
A report on the health risks of Microplastics by the Barcelona Institute for Global Health that was published this week prior to the treaty discussions, said that “policy decisions cannot wait for full data”.
“By acting now to limit exposure, improve risk assessment methods and give priority to vulnerable populations, we can tackle this urgent problem before escalating in a broader crisis on public health,” it added.
The amount of plastic that the world produces has doubled since 2000 – and is expected to triple from the current rates by 2060.
