“To create safe schools,we need to focus on safe air because airflow is a key factor in reducing the risk of COVID transmission,” said occupational hygienist and scientist Kate Cole,speaking on behalf of the group.
She said this should include high-efficiency particulate air (HEPA) purifiers,which work by mechanical filtration to remove tiny virus particles from the air. They have been introduced in some overseas jurisdictions and are being scoped by some private schools.
Education Department deputy secretary Ruth Owenlast week told parents in a webinar the department would focus on natural ventilation,and there was “no one with any scientific or medical qualifications” showing evidence that air purifiers or filters would help with ventilation any more than windows or doors.
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But Ms Cole said she and her colleagues from OzSAGE supported using air purifiers when natural ventilation was not sufficient to improve airflow.They include leading epidemiologist Tony Blakely and Professor Lidia Morawska,who waslast week named amongTime magazine’s 100 most influential people of 2021 for her work on aerosol transmission of COVID-19.
“While opening windows is good,that doesn’t always prevent the build up of contaminated air effectively,” Ms Cole said. “There are some very simple strategies that can be used to check this,including the use of CO2 monitors[to see how much carbon dioxide is building up in those spaces]. It’s a really fantastic surrogate for us to understand if a space is a high risk,or if it’s a low risk.”
Experts suggest carbon dioxide concentrations indoors should be below 800 parts per million. If it is above that level,and there is no other way of getting fresh outdoor air into the space,”that would be the point we recommend the use of things like portable HEPA[high-efficiency particulate air] purifiers”,Ms Cole said.