Microplastics in human blood: what are they, what do findings mean for health - and how widespread are they?

Plastic pollution is a major environmental concern, with microplastics - minuscule fragments of the material - found in rivers and oceans around the world, and even at the top of Mount Everest.

As with all plastic, microplastics are not biodegradable, and it can be hundreds of years until they are eventually broken down.

Now, microplastics have been found within human blood for the first time, sparking health concerns and revealing the true extent to plastic’s toxic grip on our world.

But what does it mean for our health?

Here is everything you need to know about it.

What are microplastics?

Microplastics are fragments of any type of plastic less than 5mm in length, according to the European Chemicals Agency.

They can include microfibers from clothing, microbeads, and plastic pellets (also known as nurdles), as well as fragments of water bottles, fishing nets, plastic bags, microwave containers, tea bags, and tires.

What’s been discovered?

Almost 80% of the people tested in the research funded by the Dutch National Organisation for Health Research and Development were found to have microplastic pollution in their blood.

Scientists analysed blood samples - taken with steel syringe needles and glass tubes to avoid contamination - from 22 anonymous donors and found plastic particles in 17 of them.

Half of the samples contained PET plastic found in drinks bottles, while a third contained polystyrene from food packaging, and a quarter contained polyethylene, from which plastic carrier bags are made.

Some of the blood samples contained two or three types of plastic.

“Our study is the first indication that we have polymer particles in our blood – ​it’s a breakthrough result,” said Prof Dick Vethaak, an ecotoxicologist at Vrije Universiteit Amsterdam in the Netherlands.

Following the findings, more research is needed; Vethaak has said the results might reflect short-term exposure to plastics right before samples were taken, such as drinking from a lined coffee cup or wearing a plastic face mask.

What does it mean for our health?

The full health implications of the discovery are not yet known, but the findings do show that plastic particles can travel around the body and may lodge in organs.

What is already known is that microplastics cause damage to human cells and air pollution particles cause millions of early deaths a year - so it’s unlikely to be good.

A separate recent study found that microplastics can latch on to the outer membranes of blood cells, limiting their ability to transport oxygen.

Vethaak told The Guardian it is “certainly reasonable to be concerned.

“The big question is what is happening in our body? Are the particles retained in the body? Are they transported to certain organs, such as getting past the blood-brain barrier? And are these levels sufficiently high to trigger disease? We urgently need to fund further research so we can find out.”

How widespread are microplastics?

The discovery of microplastics in human blood comes just days after the largest UK-wide, microplastic citizen science campaign to date revealed microplastics present in every UK waterway tested.

Plastics were also found almost 400 feet underground in a natural cavern near Castleton in the Derbyshire Peak District.

Led by national non-profit organisation We Swim Wild, over 100 Wild swimmers across the UK lent their support as ‘Waterloggers’ to collect water data using empty glass wine bottles.

Each four-litre sample was tested in laboratories, which confirmed microplastics present in every sample.

Calling for the UK Government to take urgent action on the results, We Swim Wild founder Laura Owen Sanderson said: “We now know that microplastics are infiltrating every aspect of our lives.

“We breathe in, drink and eat plastic particles every day; and little research has been done to establish what risk that poses to human health. This campaign provides a large and unique grassroots dataset for the UK government, as clear evidence that urgent action is needed now.”

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