Joe Allen thinks a lot about the air. More specifically, the air we breathe indoors.
According to the Harvard professor, founder of the university’s Healthy Buildings Program, our building design and public health officials have ignored indoor air systems for too long—i.e. A covid pandemic hits.
But then it was too late. That lack of attention has contributed to tens of thousands of COVID cases, Allen says. He believes rethinking the building’s design is critical to preventing the spread of COVID and other potentially deadly respiratory infections in the future.
“Think of the public health gains we’ve made in the last hundred years. We’ve made improvements to water quality, outdoor air pollution, our food safety; we made sanitation improvements: absolute fundamentals of public health,” he said. “Where was the indoor air in this conversation? It is completely forgotten. And the pandemic showed what a blatant mistake that was.”
One of the earliest superpropagators
By March 2020, COVID was spreading in the US
This month, the Skagit Valley Chorale gathered at a church in Washington for a rehearsal. Half the choir members showed up, including board members Debbie Amos and Coysie Bettinger.
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“We just thought about hand sanitizer, wash your hands often, you know, don’t hug because it’s touching,” Bettinger said.
None of it was good enough. Chorus members start to get sick after a few days. In total, COVID struck 53 of the 61 people in the church that night. Two of them, both in their 80s, died.
Skagit County health officials concluded that members of the choir had “intense and prolonged exposure” to surfaces and possibly airborne particles called “aerosols” containing the virus.
The conclusion caught the attention of Virginia Tech professor Lynsey Marr, who specializes in aerosol science. Although the medical community was focused on droplets, surfaces and handwashing, Marr and his colleagues firmly believed that COVID was primarily an airborne disease.
Marr uses a portable fogging device to explain how so many choir members could have gotten sick.
“When they sing, they are constantly releasing viral particles into the air,” she said.
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The choir was in the church for more than two hours, and all that time virus particles were floating around, reaching other people, she said.
“You can imagine that after that long, other people would inhale enough of them to get sick,” Marr said.
As far as Mar knows, the building’s heating, ventilation and air conditioning were not working that night. The researchers suspect that it most likely turned off automatically because the choir members generated enough heat on their own.
Understanding the progress of building ventilation
Analysis of the probable superdispersion event led to one of the most significant papers on the importance of ventilation published during the pandemic. Then, last year, a study in Italy went further. Using school fans and ducts to exchange indoor air with outdoor air five times per hour has been found to reduce the risk of COVID infections by at least 80%.
In the US, it took until last May for the Centers for Disease Control and Prevention to recommend an air exchange rate at all.
“If you look at the way we design and manage buildings – I mean offices, schools, local coffee shops[s] – we didn’t design for health,” Allen said. “We have minimum standards.”
Improving the level of filtration in a building is an easy and inexpensive change that can do more than just protect against COVID. It can also reduce the incidence of flu and protect against smoke from a forest fireoutdoor pollution and allergens, according to Allen.
“Covid has changed everyone’s thinking”
Some companies are now focusing on indoor air for the health of their workers as well as the health of their bottom line.
Allen diagnoses problems in air quality systems and proposes solutions for clients, including CBS parent company Paramount. He has also worked with commercial real estate firm Beacon Capital Partners and Amazon. Allen advised Amazon before it opened a 22-story office building in Arlington, Va., last May.
The top floor of Amazon’s new offices is a maze of pipes and ducts. It’s part of a $2.5 million HVAC system that starts with massive roof vents and dampers.
“Covid has changed everyone’s thinking in terms of air quality, in terms of contagious or infectious diseases,” said Katie Hughes, Amazon’s director of health and safety.
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JPMorgan Chase says its new headquarters in New York will have state-of-the-art air quality control systems. Another skyscraper in New York, One Vanderbilt, already has a modern HVAC system.
Having “healthy” buildings can bring workers out of their homes and back into offices, Allen said.
“All else being equal, which building will you go to? You have a choice right now: this building that puts healthy building controls, or this building that’s designed the way we’ve always designed buildings and tends to be a sick building?” Allen said.
Learning lessons
It’s not just companies that are changing. Skagit Valley Chorale rehearsals are now held in another church with a new HVAC system. The doors remain open to let fresh air in, regardless of the season. There are even portable carbon dioxide monitors to track ventilation. Board member Debbie Amos said they learned lessons from the aerosol study after people’s traumatic experience.
“Now we’re continuing in a way where we can still sing, but in a safer way,” she said.
As new strains of COVID continue to emerge and flu season is just beginning, Allen isn’t worried that people are forgetting the importance of building air systems. He sees fundamental changes in the scientific and medical communities as companies pay attention to what building design means for the health of their employees
“I don’t think we’ll ever forget those lessons,” Allen said. “We’d better not do that.”