As South Africa officially enters its fifth wave of Covid-19, dominated by the highly infectious omicron subvariants, the primary threat to health from shared indoor air – but not the only one – is its contamination with the airborne coronavirus.
According to Gareth Kantor, an anaesthetist and health systems expert with an interest in ventilation, and Jennifer Stearns, a professor who specialises in design at the New School, a university in New York city, Covid-19 joins tuberculosis (TB), influenza and many common colds as airborne diseases acquired mainly by breathing the air in crowded indoor settings such as offices, factories, schools, restaurants, clinics and public transport. Not from surfaces.
The deadliest effects of Covid are hugely reduced by vaccination. But only 40% of South Africans have had the jab, less than 10% get an annual flu shot, and effective TB and cold vaccinations aren’t yet available. Properly worn, high quality masks (such as N95, KN95, KF94) are effective in reducing transmission of airborne disease. But many people are not willing to continue wearing masks at this phase of the pandemic and not enough people are coming forward to get vaccinated.
Outdoor air may be significantly polluted. But outdoor exposure is not, in most cases, how you get Covid or the other airborne diseases, unless you spend prolonged periods up close to someone infected. Prevention measures should therefore focus on cleaning indoor air. Dirty air is invisible, but a real threat to health, also to the economy.