Canada has quietly revised its guidelines on how COVID-19 spreads to include the risk of aerosol transmission, weeks after other countries and international health organizations acknowledged the airborne threat of the coronavirus.
The Public Health Agency of Canada (PHAC) updated its guidance without notice this week, making mention of the risk of transmission from aerosols — or microscopic airborne particles — for the first time.
“SARS-CoV-2, the virus that causes COVID-19, spreads from an infected person to others through respiratory droplets and aerosols created when an infected person coughs, sneezes, sings, shouts, or talks,” the updated guidance said.
“The droplets vary in size from large droplets that fall to the ground rapidly (within seconds or minutes) near the infected person, to smaller droplets, sometimes called aerosols, which linger in the air under some circumstances.”
The federal agency’s guidelines previously said the virus spreads only through breathing in respiratory droplets, touching contaminated surfaces and common greetings like handshakes and hugs.
PHAC did not immediately respond to CBC’s request for comment on the changes to the guidelines.
Change to guidelines ‘pretty major,’ aerosol expert says
“This is pretty major,” said Linsey Marr, one of the top aerosol scientists in the world and an expert on the airborne transmission of viruses at Virginia Tech. “The big difference now is that ventilation is important — distancing alone is not enough.”
CBC News pressed the federal agency last month on why it still made no mention about the risk of aerosols despite other international agencies doing so.
The U.S. Centers for Disease Control and Prevention (CDC) updated its guidelines in early October to include that COVID-19 can sometimes be spread by airborne transmission, after mistakenly posting and later removing a draft version of guidelines in late September.
The World Health Organization also came under fire in July after 239 scientists from 32 countries wrote an open letter calling on the United Nations agency to update its messaging on the risk of airborne transmission of the coronavirus.
The update to PHAC’s guidelines came after Canada’s Chief Public Health Officer Dr. Theresa Tam recommended the use of three-layer non-medical masks Tuesday to prevent the spread of COVID-19 ahead of winter weather that could bring more people together indoors.
“This is an additional recommendation just to add another layer of protection. The science of masks has really accelerated during this particular pandemic. So we’re just learning again as we go,” she said Tuesday.
“I do think that because it’s winter, because we’re all going inside, we’re learning more about droplets and aerosols.”
Marr said that updated PHAC guidance on three-layer non-medical masks was in line with the threat of aerosol transmission.
“If we were only concerned about large droplets, then pretty much almost any piece of single layer of fabric would work,” she said.
“But because we are concerned about aerosols, then we do need to think about the quality and fit of our masks and we know that having multiple layers improves the filtering performance of masks.”
WATCH | Linsey Marr speaks in July about evidence the coronavirus could be airborne:
A signatory of the letter urging the WHO to change its recommendations around COVID-19 airborne transmission says it would be wise to do as much as we can to slow down the virus. 6:00
Tam said Tuesday public health officials also wanted to emphasize that the public should wear a mask indoors when not with people in their household, another significant update to its guidance.
“That will help prevent droplets or aerosols more so than if you were just relying on the two metre distance,” she said. “Again, adding another layer.”
PHAC previously told CBC News in a statement on Sept. 24 that it was not updating its guidance on airborne transmission — even though it said there “have been situations where aerosol transmission in closed settings has occurred.”
Studies of superspreading events, such as a choir practice in Washington state, a call centre in South Korea and a restaurant in China, have supported the conclusion that some degree of transmission is occurring through the air. (Evan Mitsui/CBC)
The agency said at the time its guidance would remain the same: limit time spent in closed spaces, crowded places and close contact situations, while maintaining physical distancing, hand-washing and mask-wearing.
Addressing aerosol transmission requires many measures
“Distancing helps, masks help, ventilation helps — no one of these things is perfect,” Marr said.
Aerosol transmission, she said, would not be addressed by focusing on just one of these measures alone. “But when we combine all these things, we haven’t seen any outbreaks.”
PHAC also said in September that it was reviewing evidence on the topic and acknowledged that aerosols could be suspended in the air and infect others nearby, but it wasn’t known at what rate that happens and under what conditions.
“It’s important for the public health agencies to acknowledge this so that the public can now take appropriate steps to reduce transmission,” Marr said. “And there’s a lot of organizations like schools and businesses that look to the public health agencies for guidance.”
She said the updated PHAC guidelines would make it harder for these types of organizations to ignore the threat of aerosol transmission.
Studies of superspreading events, such as a choir practice in Washington state, a call centre in South Korea and a restaurant in China, have supported the conclusion that some degree of transmission is occurring through aerosols.
Virus particles were also found in the air at a nursing home outbreak in May in Montreal, where a faulty ventilation system may have been a source of transmission that infected 226 residents and 148 employees.
An outbreak at a spin studio in Hamilton, Ont., saw at least 85 people infected and prompted the city to announce new, enhanced guidelines for gyms and fitness centres including mandatory masking.
“The gym followed all the guidelines: they had distancing, they did hygiene, they had people wearing masks before and after,” Marr said, “but if it were just all large droplets, then the distancing and hygiene would be sufficient — but obviously, it wasn’t.”
“Because aerosols do play an important role in transmission and if you just distance and just do hygiene, that’s not enough.”
VANCOUVER – Contract negotiations resume today in Vancouver in a labour dispute that has paralyzed container cargo shipping at British Columbia’s ports since Monday.
The BC Maritime Employers Association and International Longshore and Warehouse Union Local 514 are scheduled to meet for the next three days in mediated talks to try to break a deadlock in negotiations.
The union, which represents more than 700 longshore supervisors at ports, including Vancouver, Prince Rupert and Nanaimo, has been without a contract since March last year.
The latest talks come after employers locked out workers in response to what it said was “strike activity” by union members.
The start of the lockout was then followed by several days of no engagement between the two parties, prompting federal Labour Minister Steven MacKinnon to speak with leaders on both sides, asking them to restart talks.
MacKinnon had said that the talks were “progressing at an insufficient pace, indicating a concerning absence of urgency from the parties involved” — a sentiment echoed by several business groups across Canada.
In a joint letter, more than 100 organizations, including the Canadian Chamber of Commerce, Business Council of Canada and associations representing industries from automotive and fertilizer to retail and mining, urged the government to do whatever it takes to end the work stoppage.
“While we acknowledge efforts to continue with mediation, parties have not been able to come to a negotiated agreement,” the letter says. “So, the federal government must take decisive action, using every tool at its disposal to resolve this dispute and limit the damage caused by this disruption.
“We simply cannot afford to once again put Canadian businesses at risk, which in turn puts Canadian livelihoods at risk.”
In the meantime, the union says it has filed a complaint to the Canada Industrial Relations Board against the employers, alleging the association threatened to pull existing conditions out of the last contract in direct contact with its members.
“The BCMEA is trying to undermine the union by attempting to turn members against its democratically elected leadership and bargaining committee — despite the fact that the BCMEA knows full well we received a 96 per cent mandate to take job action if needed,” union president Frank Morena said in a statement.
The employers have responded by calling the complaint “another meritless claim,” adding the final offer to the union that includes a 19.2 per cent wage increase over a four-year term remains on the table.
“The final offer has been on the table for over a week and represents a fair and balanced proposal for employees, and if accepted would end this dispute,” the employers’ statement says. “The offer does not require any concessions from the union.”
The union says the offer does not address the key issue of staffing requirement at the terminals as the port introduces more automation to cargo loading and unloading, which could potentially require fewer workers to operate than older systems.
The Port of Vancouver is the largest in Canada and has seen a number of labour disruptions, including two instances involving the rail and grain storage sectors earlier this year.
A 13-day strike by another group of workers at the port last year resulted in the disruption of a significant amount of shipping and trade.
This report by The Canadian Press was first published Nov. 9, 2024.
The Royal Canadian Legion says a new partnership with e-commerce giant Amazon is helping boost its veterans’ fund, and will hopefully expand its donor base in the digital world.
Since the Oct. 25 launch of its Amazon.ca storefront, the legion says it has received nearly 10,000 orders for poppies.
Online shoppers can order lapel poppies on Amazon in exchange for donations or buy items such as “We Remember” lawn signs, Remembrance Day pins and other accessories, with all proceeds going to the legion’s Poppy Trust Fund for Canadian veterans and their families.
Nujma Bond, the legion’s national spokesperson, said the organization sees this move as keeping up with modern purchasing habits.
“As the world around us evolves we have been looking at different ways to distribute poppies and to make it easier for people to access them,” she said in an interview.
“This is definitely a way to reach a wider number of Canadians of all ages. And certainly younger Canadians are much more active on the web, on social media in general, so we’re also engaging in that way.”
Al Plume, a member of a legion branch in Trenton, Ont., said the online store can also help with outreach to veterans who are far from home.
“For veterans that are overseas and are away, (or) can’t get to a store they can order them online, it’s Amazon.” Plume said.
Plume spent 35 years in the military with the Royal Engineers, and retired eight years ago. He said making sure veterans are looked after is his passion.
“I’ve seen the struggles that our veterans have had with Veterans Affairs … and that’s why I got involved, with making sure that the people get to them and help the veterans with their paperwork.”
But the message about the Amazon storefront didn’t appear to reach all of the legion’s locations, with volunteers at Branch 179 on Vancouver’s Commercial Drive saying they hadn’t heard about the online push.
Holly Paddon, the branch’s poppy campaign co-ordinator and bartender, said the Amazon partnership never came up in meetings with other legion volunteers and officials.
“I work at the legion, I work with the Vancouver poppy office and I go to the meetings for the Vancouver poppy campaign — which includes all the legions in Vancouver — and not once has this been mentioned,” she said.
Paddon said the initiative is a great idea, but she would like to have known more about it.
The legion also sells a larger collection of items at poppystore.ca.
This report by The Canadian Press was first published Nov. 9, 2024.
