Many people like to start their day with a takeaway coffee, but a new study could convince you to reconsider your order.
Researchers warn that single-use disposable cups release millions of microplastic and even smaller ‘nanoplastic’ particles when exposed to hot liquid.
Although these cups are made primarily of paper, they often have a thin plastic inner layer to prevent them from leaking.
In a new study, experts warn that this liner is a ‘previously overlooked’ source of microplastic pollution.
Experts compared two types of disposable cups: one lined with fossil fuel-based polyethylene (PE), and the other lined with biodegradable polylactic acid (PLA).
While it may seem like a greener option, the biodegradable PLA-lined cups actually release twelve times more microplastics than their PE-lined counterparts.
Co-author Dr Elvis Okoffo, an environmental health scientist from the University of Queensland, said: ‘This doesn’t mean people should necessarily stop using paper cups, or that PLA is inherently unsafe.
‘But the impact of plastic particles on human health is unclear, and we know that the chemicals in plastic are not intended to be consumed.’
Researchers warn that single-use disposable cups release millions of microplastic and even smaller ‘nanoplastic’ particles when exposed to hot liquid (stock image)
Although these cups are mainly made of paper, they often have a thin plastic inner layer to prevent them from leaking. This is made of fossil fuel-based polyethylene (PE) or biodegradable polylactic acid (PLA).
Microplastics are small pieces of plastic with a diameter between one micrometer and five millimeters.
Nanoplastics, meanwhile, are even smaller: they are about a thousand times thinner than a human hair.
Together, these microscopic plastic pollutants have been found almost everywhere on Earth. also in the human body.
Because microplastics and nanoplastics are so small, they can sometimes pass through the barriers in our intestines, lungs and skin.
From there, the plastics enter the bloodstream and hitchhike on the red blood cells, travel through the body and settle in our organs.
Although they now come from many different sources, what we eat and drink does an important way in which these plastics enter our bodies.
In their new study, published in ACS Food Science and Technologythe researchers investigated whether disposable cups could be another possible source of pollution.
The researchers exposed plastic-lined paper cups to hot water, just as you would while making a cup of tea, and analyzed the water after a short soak.
Biodegradable PLA-lined cups (red) release 12 times more microplastics than their PE-lined counterparts (blue)
They found that water in a PE-lined cup contained 2.7 million plastic particles per milliliter.
Meanwhile, the water from the PLA-lined cup contained 4.3 million particles per milliliter, which is 12 times the total mass released by the PE-lined cup due to the larger particle size.
Dr. Okoffo says: ‘The materials used in food contact products should be assessed not only for their environmental sustainability, but also for their behavior in releasing particles during daily use.
‘Our results show that plastic-coated paper cups release significant amounts of micro- and nano-scale plastic material when exposed to hot water.’
Scientists are just beginning to understand what effects exposure to microplastics can have on our bodies, and whether they are likely to be harmful.
Microplastic particles have been found in multiple organs, including the brain, testiclesheart, stomach, lymph nodes and placenta.
There is now increasing evidence that this level of contamination can be harmful.
Studies conducted on animals and cells in the laboratory have linked microplastics to inflammation, a reduced immune system, deteriorating tissues, abnormal organ development and cell damage.
This comes after scientists from the Universitat Autònoma de Barcelona warned that a single tea bag could release billions of dangerous microplastics (pictured) into your body
A large-scale review of the evidence conducted by the University of California, San Francisco, suggested that microplastics can harm our reproductive, digestive and respiratory health.
The researchers even suggested a link with colon and lung cancer, while other papers have found a direct link between microplastic contamination and a higher risk of heart attack and stroke.
However, microplastic contamination is relatively new and data is still somewhat limited.
What scientists do know for sure is that many plastics contain toxic chemicals that can ‘leak’ into your bloodstream.
However, not all plastics contain these harmful chemicals and not all materials are equally susceptible to leaching.
While the researchers aren’t suggesting that customers have given up using paper cups yet, they are calling on regulators to implement safety guidelines or product warnings.
‘Nanoplastic releases should be part of the safety assessment of food contact materials, especially products designed for hot drinks,’ says Dr Okoffo.
‘Product manufacturers could also consider developing cup liners that release fewer plastic particles when exposed to hot liquid.’
