COMMENT:
Late yesterday, I tweeted a clip from Mevo, showing off a handheld UVC (ultraviolet C light) device it had bought to sterilise its rideshare cars in seconds (see below).
I should point out from the get-go that the UV "gun" is just one of a number of anti-Covid 19 measures that the car-sharing company will introduce as it resumes service next week under Level 3. There will also be wipes.
A Mevo message to customers says, "All contact surfaces in the vehicles are regularly sterilised with UVC technology (Ultraviolet C light, or Hard UV), which kills Covid-19 within seconds and used in hospitals around the world. Additionally, you can also find 70% isopropyl alcohol wipes in the centre console of every vehicle for your use while on-trip."
But it was the UV gun that, which a rep for the company said had been purchased for $2000, that got the most focus, and flak, when I tweeted.
"That video has my handheld bulls**t detector going off," said Dylan Reeve, in one of the politer comments. Others worried about health issues.
I put these concerns to Dr Simon Swift, an associate professor of microbiology and infectious disease with Auckland University's faculty of medical and health sciences.
Swift said yes, UV does work, but with a couple of important provisos.
• Covid19.govt.nz: The Government's official Covid-19 advisory website
"UVC will inactivate a wide variety of bacteria and viruses in a reasonably short time - say five to 10 seconds," Swift said.
"It is really good at hard flat surfaces. It isn't so good at fabrics or things that give shadows as these can mean the virus isn't exposed to the UV light."
Would the zapped viruses include the one that causes Covid-19?
"It looks like there isn't any peer-reviewed literature evaluating the dose required to inactivate the SARS-CoV-2 virus responsible for Covid-19," Swift said. "But there is plenty of literature showing effectiveness against other coronaviruses, and lots of other types of virus, so I think it is a safe assumption that UVC will be effective against SARS-CoV-2."
Swift noted that hospitals and transport operators in China use UVC, though often only for a limited set of surfaces, and often using robots rather than people with handheld devices.
"In some hospitals UVC robots are used just to sterilise floors, rather than rooms with beds and other furniture - so you have to be careful when considering the claims like 'used in hospitals around the world'," Swift said.
"The inside of a car can have lots of fabric and lots of opportunities for shadowing of areas we touch [cup holders, glove compartments and their latches, seat positioning levers etc..]. So I wouldn't be confident of the inside of a car being disinfected by UVC. I'd consider using plastic seat covers."
"UVC is the nasty UV that causes most sunburn and even short exposures can cause damage to eyes," Swift said.
"So the units need adequate testing, and operators need expert training on use and proper PPE.
"UVC can also degrade some plastics, which might not be good for fittings inside the car."
A spokesperson for Mevo said the company had seen the responses to its video on Twitter
The car-share operator responded, "The safety of members and staff is a top priority for Mevo. Ultraviolet germicidal irradiation [UVGI] is backed by numerous clinical studies and is one of the many additional measures that Mevo is implementing to maintain best in class health and safety practices as recommended by Government and the World Health Organisation."
• Covid19.govt.nz: The Government's official Covid-19 advisory website
Falls in Fletcher Building and F&P Healthcare drove the sharemarket lower.