LOOK TO THE LIGHT

New research from the University of Toronto has found that UV-LED lights can destroy coronaviruses. “We’re at a critical time where we need to use every single possible stop to get us out of this pandemic,” says study author, Assistant Professor Christina Guzzo. “Every mitigation strategy that can be easily implemented should be used.” UV lights kill viruses through radiation. Guzzo first tested the lights on bacterial spores notorious for their resistance to this radiation (known as Bacillus pumilus spores).

“If you’re able to kill these spores, then you can reasonably say you should be able to kill most other viruses that you would commonly encounter in the environment,” says Guzzo. Within 20 seconds of UV exposure, the spores’ growth dropped by 99 per cent. The researchers then created droplets containing coronaviruses, to mimic typical ways people encounter viruses in public, such as from coughing, sneezing and bleeding. The droplets were exposed to UV light and placed in a culture to see if any of the virus remained active.

After just 30 seconds of exposure, the virus’ ability to infect dropped by 93 per cent. UV-LEDs are cheap and can be retrofitted in existing light fixtures but repeated, prolonged exposure is harmful. Guzzo believes the lights should be used when public spaces are empty, such as vacated buses that have finished their routes, or empty elevators travelling between floors.