Researchers discovered that dangerous viruses can survive in fresh water for up to three days by hitchhiking on plastic.
|Human enteric, or intestinal, viruses can survive for days on plastic particles that swimmers can easily swallow, according to Stirling University researchers. Images C: GJ Flick and DD Kuhn/Virginia Tech|
Rotavirus, an enteric virus that causes diarrhoea and stomach upsets, was discovered to survive in water by attaching to microplastics, which are tiny particles less than 5mm long. Researchers from the University of Stirling discovered that they are still infectious, posing a potential health risk.
Prof Richard Quilliam, the project’s lead researcher at Stirling University, stated, “We discovered that viruses can attach to microplastics, allowing them to survive in the water for three days, possibly longer.”
Previous research had been conducted in sterile environments, but this is the first study into how viruses behave in the environment, according to Quilliam. To determine whether viruses found on microplastics in water were infectious, he used standard laboratory methods.
“We weren’t sure how well viruses could survive by ‘ hitchhiking ‘ on plastic in the environment, but they do survive and remain infectious,” he explained.
The findings, which were part of a £1.85 million Natural Environment Research Council-funded project investigating how plastics transport bacteria and viruses, concluded that microplastics enabled pathogen transfer in the environment. The study was published in Environmental Pollution.
“Being infectious in the environment for three days is enough time to get from the wastewater treatment works to the public beach,” Quilliam explained.
He claimed that wastewater treatment plants were unable to capture microplastics. “Even if a wastewater treatment plant does everything possible to clean sewage waste, the water discharged still contains microplastics, which are transported down the river, into the estuary, and end up on the beach.”
These plastic particles are so small that swimmers could swallow them. “Occasionally, they wash up on the beach as lentil-sized, brightly colored pellets known as nurdles, which children may pick up and put in their mouths.” “It only takes a few virus particles to make you sick,” Quilliam explained.
While the impact of microplastics on human health is unknown, Quilliam believes that “if those bits of microplastics are colonized by human pathogens, then that could well be a significant health risk.”
The researchers tested two types of viruses: those with an envelope, or “lipid coat,” such as the flu virus, and those without, such as enteric viruses like rotavirus and norovirus. They discovered that the envelope quickly dissolved and the virus died in those with a coating, whereas those without an envelope successfully bound to the microplastics and survived.
“Viruses can bind to natural surfaces in the environment,” Quilliam explained, “but plastic pollution lasts much longer than those materials.”
The viruses were tested for three days, but future research will look into how long they can remain infectious.
Another study published last month by Quilliam’s team discovered that levels of fecal bacteria on wet wipes and cotton buds washed up on beaches posed a health risk. In 2019, they discovered sewage bacteria “hitchhiking” on plastic pellets on Scottish beaches for the first time.
Source: The guardian