The Green Flag Association has urged the government and businesses to emphasise clean air rather than clean hands to reduce the risk of coronavirus transmission, saying public messaging needs to urgently shift gear before the next surge of infections.
Green Flag is a nonprofit organisation lobbying for greater awareness around ventilation.
SA is currently registering a seven-day moving average of only 286 cases a day, but experts anticipate a fourth wave is likely in December.
Scientists’ understanding of how the virus is transmitted has evolved since the onset of the pandemic more than 18 months ago and it is now widely accepted that inhaled aerosols pose a far greater risk than touching contaminated surfaces, yet the government, schools and businesses continue to prioritise hand and surface hygiene at the expense of improving ventilation, said Green Flag adviser Gary Kantor, assistant professor at Case Western Reserve University, Ohio, in the US.
Green Flag is campaigning to raise awareness about the importance of good air quality in public spaces, an area it says remains neglected in SA’s efforts to manage the coronavirus pandemic.
“There is a large amount of convincing evidence that SARS-CoV-2, like other respiratory viruses, spreads through the air,” said Kantor. “Very few — if any — cases have been reported that resulted from touching contaminated surfaces,” he said.
In poorly ventilated indoor spaces, the concentration of virus particles rapidly builds up, turning them into high-risk environments. “We can improve ventilation by opening doors and windows, and make sure [ventilation] systems work properly,” he said. Air-conditioning systems needed to draw in sufficient fresh air to prevent a build-up of stale, exhaled air, he said.
Taverns, bars and restaurants were all potentially risky environments, because they were filled with unmasked people speaking loudly, as were taxis that kept their windows closed, he said. “Taxis are confined environments where up to 16 people sit closely together. If windows are not opened, a simple trip to work or to the shops can become a superspreader event.” he said.
The World Health Organisation has acknowledged that Covid-19 is an airborne disease, but SA’s Covid-19 public health messaging does not adequately reflect this, said the Green Flag Association. “Social distancing and wearing a mask are still important because the tiny floating aerosols that contain the coronavirus can be transmitted both up close and at a distance. But without ventilation, the distancing is much less effective. At the same time there is ongoing, misplaced expenditure on temperature scanning, fumigating and physical barriers, which can actually trap the vital flow of air,” said Green Flag adviser Sean Chester, APEX Environmental technical director.
“Many people still believe that surface and hand sanitation guarantee the prevention of Covid-19, even though it is an airborne disease,” Chester said.
While numerous cases of super spreader events in poorly ventilated indoor settings such as restaurants and bars have been reported globally, only a few have been documented in SA. These include the Tin Roof nightclub in Cape Town and the post-matric festival Rage, which both sparked a surge in cases in 2020.
Poorly designed buildings with inadequate ventilation were a major contributor to the spread of Covid-19 and older, draughtier buildings built before the 1970s were better for their occupants health than more modern designs that recirculated air to be more energy efficient, said Kantor.
Improving indoor ventilation could not only reduce the risk of transmitting Covid-19 but also slow the spread of other airborne disease such as tuberculosis and influenza, and reduce hospital-acquired infections, he said. In 2019, TB killed an estimated 58,000 people in SA, and influenza killed another 10,000.
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