Microplastics have been found in the blood of cows and pigs for the first time, sparking concern about how the particles might move through the food chain.
Scientists say the discovery could have serious implications for public health but warn that more research is needed to assess the level of toxicity and how much humans may be exposed to it.
Experts fear that microplastics could be deposited in organs or find a way into breast milk if they enter a person’s bloodstream.
New discovery: Microplastics have been found in the blood of cows and pigs for the first time, sparking concern about how the particles might move through the food chain (stock image)
The research, which involved 12 cows and six pigs, was led by Heather Leslie, of Vrije University in Amsterdam.
She said: ‘We have uncovered preliminary evidence of trace amounts of plastic particles in farm animals’ bloodstreams.
‘It is in the interest of animal and human health protection to further explore this nascent signal of plastic pollution exposure in the food chain.’
Leslie added: ‘We already know that hundreds of other animals also have microplastics in their bodies. But in cows and pigs, it had not been discovered before.’
The researcher presented her findings at a conference on microplastics in Amsterdam.
When asked what the potential risk was to humans, she replied: ‘If you want to assess the risks, you first have to know what the actual exposure is and how toxic it is.
‘If we are above the values that are still safe and responsible, then we have to do something about it.’
It is thought that microplastics in the soil could end up in the crops eaten by farm animals.
Previous research has shown that these particles cannot be broken down by the intestines and often end up in manure.
‘It has to be very fine particles that cannot be seen with the naked eye before it can enter the bloodstream,’ said Leslie.
Earlier this year scientists found plastic in sea turtles’ muscles for the first time, confirming that pollution is affecting marine life on a chemical level.
However, there may still be hope in the form of mussels.
In July, researchers at the Plymouth Marine Laboratory found that a cluster of 300 mussels, weighing 11lbs (5kg), could filter out 250,000 microplastic particles an hour.
The sea creatures excrete particles in pellets that sink.
Around 3,760 tonnes of plastic debris – the equivalent weight of eight jumbo jets – are currently floating in the Mediterranean, according to a study published earlier this month.
Researchers from the Hellenic Centre for Marine Research in Greece estimate that 17,600 tonnes of plastic enter the sea every year, of which 84 per cent ends up on beaches and 16 per cent in the water column or on the sea floor.
Microplastics are 5mm in length (the size of a lentil) or less and are formed as plastic breaks down into tiny particles.
The tiny particles are everywhere: they are produced from the breakdown of bags and bottles, the wear and tear of the soles on our shoes as we walk, and the tyres on our cars as we drive.
They are in our water, food and on surfaces we touch — and scientists are only just understanding their impact.
While our bodies are thought to clear some of the microplastics that build up inside us, according to a 2018 review by King’s College London, newer research suggests it’s possible for microplastics to pass from the airway or gut into the blood and to our organs.
The research, which involved 12 cows and six pigs, was led by Heather Leslie, of Vrije University in Amsterdam (stock image)
Microplastics are 5mm in length (the size of a lentil) or less and are formed as plastic breaks down into tiny particles
In theory, the plastic could then cause damaging inflammation or leach harmful chemicals.
In one of the latest studies, Italian scientists found microplastics in human placentas for the first time, which could affect foetal health and development.
Plastic in the gut also could affect the digestive system’s immune response or aid the transfer of chemicals and pathogens, researchers have previously said, adding that this may have implications for ‘patients with gastrointestinal diseases’.
While no conclusive link can yet be made with the risk to human health, scientists are concerned and say that more research is needed.