As humans continue to ingest microplastics from the environment, many researchers are investigating if this may have a negative effect on our health.

Making a cup of tea may sound perfectly benign, but researchers have used it to shine a light on the potential effects of tiny plastic particles on human health.

These particles, known as micro- and nano-plastics (MNPs), have been found everywhere in the environment – from the seabed to Antarctica, from fresh water to snow, ice and soil. They are present in the food chain and are directly ingested by humans – potentially at levels that could affect our health. While no causal link has yet been found between MNPs and disease, researchers say they have identified enough ‘red flags’ to be concerned.

Now back to that cup of tea. Researchers at the Autonomous University of Barcelona (UAB) in Spain have found – and characterised – MNPs from commercially available teabags made from nylon-6, polypropylene and cellulose. When infused in the normal...