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

Alberta’s chief medical officer of health, Dr. Deena Hinshaw, confirmed more than 1,000 cases over the weekend Monday afternoon. File photo
COVID-19: Central zone active cases up Monday

‘We’ve now crossed the tipping point,’ says Hinshaw

Right, Ambassador of Hungary to Canada, Her Excellency Dr. Maria Vass-Salazar, lays a wreath at St. Michael’s RC Cemetery in Manfred, Ponoka County on Oct. 25. (Emily Jaycox/Bashaw Star)
Wreath laying ceremony held in Manfred

Ceremony marks 64th anniversary of Hungarian revolution, honours settlers

Alberta has 3,651 active cases of COVID-19. (File photo)
432 new COVID cases sets another record Friday

Central zone holds steady at 126 active cases

B.C. Liberal leader Andrew Wilkinson, B.C. NDP leader John Horgan and B.C. Greens leader Sonia Furstenau. (Black Press Media)
VIDEO: One day until B.C. voters go to the polls in snap election defined by pandemic

NDP Leader John Horgan’s decision to call an election comes more than a year ahead of schedule and during a pandemic

Cases in Ponoka (East Ponoka County) as of Oct. 27. (alberta.ca)
Diagnosed cases of COVID-19 at three Ponoka businesses

Town ‘strongly encouraging’ residents to wear non-medical masks in public

Prime Minister Justin Trudeau provides an update on the COVID pandemic during a press conference in Ottawa on Tuesday, Oct. 27, 2020. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau says pandemic ‘really sucks,’ and that Christmas gatherings are up in the air

The prime minister encouraged residents to continue to follow the advice of local health authorities

The Williams Lake Indian Band is stipulating no-go zones for mushroom picking in areas burned by last summer’s wildfires. 100 Mile Free Press photo
Who controls mushroom harvesting on Indigenous lands?

‘We don’t necessarily know where the mushrooms grow, how old the stands need to be, those types of things.’

Canadian and American flags fly near the Ambassador Bridge at the Canada/USA border crossing in Windsor, Ont. on Saturday, March 21, 2020. THE CANADIAN PRESS/Rob Gurdebeke
U.S. election results one factor that could impact immigration to Canada next year

The survey polled 1,523 Canadians between Oct. 23 and Oct. 25

Alberta’s provincial flag flies on a flag pole in Ottawa, Monday July 6, 2020. The Alberta government is hoping to get more Albertans employed by moving to limit the number and type of temporary foreign workers it allows into the province. THE CANADIAN PRESS/Adrian Wyld
Alberta to limit temporary foreign worker program to save jobs for Albertans

Temporary foreign workers already in the province won’t be affected

Submitted
Montana First Nations councillor gives back to youth

Has pledged 10 per cent of his salary for youth programming

Royal Alexandra Hospital front-line workers walk a picket line after walking off the job in a wildcat strike in Edmonton, on Monday, October 26, 2020. THE CANADIAN PRESS/Jason Franson
Alberta labour board orders health-care staff who walked off the job to go back to work

Finance Minister Travis Toews said in a news release that he was pleased with the labour board’s decision

Wetaskiwin Hospital staff join AUPE walk outs across the province Monday Oct. 26, 2020. Shaela Dansereau/ The Pipestone Flyer.
City of Wetaskiwin health-care workers strike in protest of province-wide cuts

Wetaskiwin Hospital staff join other front line hospital workers across the province in walk-outs.

Most Read