When Lidia Morawska goes out for dinner near her home in Brisbane, she takes with her all the essentials: keys, phone, mask — and her carbon dioxide monitor. She puts the device on the table next to her wine glass and waits anxiously for a reading.
The monitor essentially measures how much breath there is in the air. We exhale CO2, so a higher reading indicates more breath, acting as a proxy measure of ventilation and the potential transmission of airborne viruses, including Covid-19.
Even in a busy room, Morawska, a pioneering aerosol scientist at Queensland University of Technology, says good ventilation results in a CO2 reading close to background levels — the amount you’d expect to be there if there weren’t