A single 1-litre bottle of water could contain 240,000 microscopic plastic particles. The health implications of ingesting plastic are unclear, but early research suggests such particles could travel into various organs within the body.
Millions of tonnes of plastic are produced every year as a result of human activity, such as the fishing industry and domestic waste. Most of this is made up of microplastics, which measure between 1 micrometre and 5 millimetres across.
Plastic fragments that measure under 1 micrometre across are known as nanoplastics and could present an even greater concern than microplastics. Their smaller size means they may be more likely to penetrate the body’s gut lining, the placenta and even the blood-brain barrier, says Yan.
The size of nanoplastics makes them difficult to detect, but now Yan and his colleagues have developed an innovative technique to do so.
The team took six 1-litre bottles of own-brand water from three unnamed US supermarkets and exposed them to lasers, which would vibrate when they encountered a plastic fragment. On average, each bottle contained around 240,000 plastic particles – up to 100 times more than previous studies found.
The size of the lasers’ vibrations indicated the type of plastic in the water, with around 90 per cent being nanoplastics. Only 10 per cent of these could be identified, but they included polyethylene terephthalate (PET), which the bottles were made from.
There is no reason why similar amounts of nanoplastics wouldn’t be in other US water bottles, as well as those from other countries, but this needs to be tested in its own study, says Yan.
Going forward, the researchers hope to refine their technique to identify more of the nanoplastics within water, he says.
Sherri Mason at Pennsylvania State University described the research as a “very impressive and ground-breaking study”.
“We know that plastics shed particles much like how people shed skin cells, continually, but being able to quantify and identify these plastic particles down to the nanoplastic range is critical to moving our understanding of the human health implications forward,” she says.