From World Economic Forum. Feb 19, 2025
There’s a growing body of evidence about how widespread microplastics have become – across land, sea and air – and the impact they could be having on human health. It is estimated that people inhale 68,000 microplastic particles every day and some experts believe we are in the midst of a plastic health crisis.
Microplastics have now been detected throughout the human body – including the blood, lungs, liver and even lower limb joints. Scientists have found evidence of microplastics in our brains, and further studies have revealed how these microplastics are accumulating and rapidly rising.
How do microplastics get into the food chain?
These tiny particles are often small enough to pass through water filtration systems, and we can then unknowingly ingest them.
Equally, research has shown that such microplastics can be transported in the atmosphere, spreading to even the remotest corners of the Earth.
In the ocean, these particles can be eaten by marine life – from fish to shellfish. A study in the US state of Oregon found microplastics in 98.9% of seafood samples, while a 2022 study found broken-down microplastics in blue mussels off the Australian coast. The research added to the findings of an earlier study that concluded, “if you eat mussels, you eat microplastics”.
And it’s not just marine life that could be affected. Microplastics have been found in foodstuffs including honey, tea and sugar, as well as in fruit and vegetables.
Microplastics are also making their way onto farmland through sewage sludge being used as fertilizer, according to a Cardiff University study. The BBC reports that much of this will then end up in waterways as a result of runoff from the top layer of soil.
Are microplastics harmful to human health?
While the full extent of the environmental and health impacts of microplastics are not yet known, a recent study found that nanoplastics and microplastics could be “emerging risk factors for cardiovascular diseases“; this research is backed by a 2024 study that points to the possibility that microplastics can increase the likelihood of heart attack, stroke or death. Another study, meanwhile, linked microplastics with inflammation and noncommunicable diseases.
In a 2025 study on mice, real-time imaging showed microplastics moving through their brains and blocking blood vessels. While the researchers said it would be “premature” to suggest that the process could replicate in human brains, the authors concluded that “the potential long-term effects of microplastics on neurological disorders such as depression and cardiovascular health are concerning”.
The link between air pollution and premature births has already been established, but a study in the US has found both microplastics and nanoplastics in higher concentrations in the placentas from premature births than in those births that went to full term. “Our study hints at the possibility that the accumulation of plastics could be contributing to the occurrence of preterm birth,” Professor Kjersti Aagaard told The Guardian.
Meanwhile, microplastics in the placenta may be affecting hormone levels in the developing foetus, according to a study just published in ScienceDirect.
At the other end of the age spectrum, micro- and nanoplastics in the brain might be causing cognitive decline and even Alzheimer’s disease, a US study recently found.
Some researchers say we’re in the lull before the storm and that “alarmingly, a turning point is expected in the future, signalling a significant microplastic pollution outbreak if effective measures are not taken to mitigate it”.