Scientists have proven for the first time that viruses can survive and remain infectious by binding themselves to plastics in freshwater — raising concerns about the potential impact on human health.
Rotavirus, which causes diarrhoea and an upset stomach, was found to survive for up to three days in lake water by attaching itself to the surfaces of tiny beads of plastic pollution, called microplastics, according to researchers at the University of Stirling in the UK.
The study, published in the journal Environmental Pollution, is the first of its kind to explore the issue using water taken from the natural environment. Previous studies focussed only on the spread of such viruses in sterile hospital settings.
“We found that viruses can attach to microplastics, which allows them to survive in the water for three days, possibly longer,” said Professor Richard Quilliam, lead researcher from the varsity.
“Even if a wastewater treatment plant is doing everything it can to clean sewage waste, the water discharged still has microplastics in it, which are then transported down the river, into the estuary and end up on the beach. We weren’t sure how well viruses could survive by ‘hitch-hiking’ on plastic in the environment, but they do survive, and they do remain infectious.”
The researchers tested two types of viruses – those with an envelope, or “lipid coat” around them, such as the flu virus (they tested bacteriophage Phi6), and those without: enteric viruses, such as rotavirus and norovirus (they tested rotavirus strain SA11).
They found that in those with an envelope, the envelope quickly dissolved, and the virus was deactivated, whereas those without an envelope successfully bound to the microplastics and survived.
“Viruses can also bind to natural surfaces in the environment. However, plastic pollution lasts a lot longer than those materials,” said Quilliam.
“This research is very much a proof-of-concept for conducting more research into how long pathogens can survive by binding to microplastics, as we only tested for three days, and what happens to them next.”