A man wears a face mask as he looks at a COVID-19 information sign in Montreal, Sunday, Sept. 20, 2020, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes

Preliminary B.C. study results suggest mask mandates can lower COVID-19 spread by 25%

Study has not yet been printed or peer reviewed

Preliminary results from a study conducted by Simon Fraser University researches suggests that a mask mandate can lower the transmission of COVID-19 by 25 per cent each week.

Study results, released prior to peer review on Wednesday (Oct. 7), show that mandating masks indoors nationwide in early July could have reduced new weekly cases by 25 to 40 per cent in mid-August. That would translate approximately to 700 to 1,1000 fewer cases each week.

Researchers from SFU’s economics department focused on mask mandates brought in across Ontario’s 34 Public Health Units over the course of two months this year. Results from comparing units that went to mask mandates early, versus later, showed that earlier adoption was association with an average weekly reduction of 25 to 31 per cent, in July and August. There has been no mask mandate province-wide in B.C., although many government buildings, grocery stores and other businesses have brought in mask rules of their own.

ALSO READ: B.C. records 102 new COVID-19 cases, 2 deaths

The results of SFU’s study differed from an earlier one about mask mandates in the U.S., which found a nine to 10 per cent reduction in new cases.

“One possible explanation is that Ontario’s mask policy is more comprehensive: we evaluate the effect of universal indoor mask-wearing for the public rather than the effect of mask wearing for employees only in [the U.S. study]. Differences in the compliance rate may also contribute to this difference,” researchers noted.

An analysis of mask mandates across the country found a reduction in new cases of up to 46 per cent in the first weeks after adoption. Researchers also saw that mask mandates increased self-reported use by 30 per cent.

“Jointly, these results suggest that mandating indoor mask wear in public places is a powerful policy measure to slow the spread of COVID-19, with little associated economic disruption in the short term,” the study concluded.

Researchers also looked at COVID-19 restrictions and their effect on new cases. They found that the most stringent restrictions were associated with a decrease of 48 to 57 per cent in weekly cases.

Study authors noted that while the results are significant, “their sample period does not allow them to definitively say whether the effect of mask mandates persists or weakens beyond the first few weeks after implementation.”

ALSO READ: Anti-mask protest at Kelowna schools ‘disappointing,’ says superintendent


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

A section of the Trans-Canada Highway north of Lytton. The highway will be closed for eight hours starting at 10 p.m. on Oct. 22. (Photo credit: BC Back Country)
Highway 1 from Spuzzum to Cache Creek to be closed for eight hours starting Oct. 22

Ten-hour closure will allow work to be done on bridge at Spuzzum

(from l) Fraser-Nicola candidates Aaron Sumexheltza (BC NDP), Jonah Timms (BC Green Party), Mike Bhangu (Independent), Dennis Adamson (Independent), and Jackie Tegart (BC Liberals) physically distancing after the All Candidates Forum in Ashcroft on Oct. 15. (Photo credit: Barbara Roden)
Candidates face questions about health care, housing, and more

All five Fraser-Nicola candiates were at a forum in Ashcroft on Oct. 15

(front row, from l) Ashcroft and District Lions Club president Sue Peters; Joan Henderson of The Equality Project; Esther Lang from the Christmas Hamper committee; Trish Schachtel of the South Cariboo E. Fry Society food bank; and Tim Hortons manager Damian Couture with members of the Lions Club. (Photo credit: Gareth Smart)
Smiles all round as Lions raise money for three local groups

Equality Project, food bank, Christmas hamper fund all benefit from Tim Hortons Smile Cookie sales

Cache Creek Village office, date unknown. (Photo credit: Wendy Coomber)
Cache Creek council decides to change meeting nights, start time

Council also takes first, brief look at water meters, noting cost of installation

BC Liberal Party candidate Jackie Tegart says that her party has pledged a $2 million investment in developing the McAbee Fossil Beds east of Cache Creek. (Photo credit: Barbara Roden)
BC Liberals promise $2 million investment in McAbee Fossil beds

Site has potential as a centre for education, research, and tourism

Provincial health officer Dr. Bonnie Henry presents modelling of COVID-19 spread in B.C., March 25, 2020. (B.C. government photo)
B.C. sets another COVID-19 record with 203 new cases

up to 1,766 active cases in B.C., two more deaths

More and more electric cars are on the road, but one Chevy Bolt owner was shocked to see how much his BC Hydro bill skyrocketed once he started charging the vehicle. (Black Press file photo)
Lower Mainland man sees significant spike in BC Hydro bill after buying electrical vehicle

An increase should be expected, but Brian Chwiendacz experienced a 200-plus per cent hike

The Anonymous YVR is an Instagram page that reviews restaurants and other establishments around B.C. based on how well they adhere to COVID-19 rules. (Instagram)
Anonymous Instagram page reviews COVID-19 safety measures at B.C. businesses

There are a number of public health orders various types of establishments must follow to slow virus’s spread

Jordan Naterer, an electrical engineer from Vancouver, was last seen Saturday Oct. 10. (Facebook photo)
Search efforts to resume for missing Manning Park hiker; Trudeau speaks on case

PM says he’ll do what he can to ‘nudge’ efforts to find Jordan Naterer, yet has little leverage locally

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Smartphone showing various applications to social media services and Google. (Pixabay photo)
National media calling for level playing field with Google, Facebook

In Canada, Google and Facebook control 80 per cent of all online advertising revenues

École de L’Anse-au-sable. (Google Maps)
B.C. records first COVID-19 outbreak at school, six weeks after students return to class

Three cases of the virus have been identified at École de L’Anse-au-sable

Green Party leader Sonia Furstenau is seen as she leaves media event during a campaign stop in West Vancouver, B.C., Tuesday, October 20, 2020. THE CANADIAN PRESS/Jonathan Hayward
B.C. Green leader hopes voters see value in minority government

The Greens received nearly 17 per cent of the popular vote in 2017 yet received just three seats

Most Read