Across Belgium public venues from restaurants to swimming pools are being fitted with sensors that display how much air customers are sharing with others in an attempt to combat further surges of Covid-19 into the autumn and winter.
The carbon dioxide monitors, which cost about €70, indicate whether windows or doors should be opened to increase the circulation of fresh air and prevent the transmission of coronavirus.
Pedro Facon, Belgium's Covid-19 commissioner, compares the way the virus spreads in the air to cigarette smoke: if someone infected is in an enclosed space, infectious particles spread from their breath through the air in the room and are then inhaled by other people.
“I think the importance of air quality and ventilation has been long underestimated,” the commissioner told The Irish Times. Focus has centred on surfaces and droplets from coughing and sneezing, he said, overshadowing the role of shared air.
“Even if there were some experts already in summer of last year that pointed to the importance of ventilation, there were a few policies, or decisions, with regard to it,” he said.
This is now changing in Belgium, where authorities decided that this summer’s reopening of hospitality, gyms and entertainment venues had to be accompanied by ventilation requirements.
Belgium’s indoor hospitality reopened in June, with precautions such as a limit of eight people per table, social distancing, face masks and mandatory 1am closing times. Bar service is banned and discos and nightclubs are closed.
Gyms, cinemas and theatres are open with limits.
All such businesses are now required to display a carbon dioxide monitor in a location visible to the public, so customers can check whether the fresh air is at a safe level.
“Businesses were happy with this because it meant they could reopen, and it’s a small investment that costs €60 or €80 depending on the type of sensor,” Mr Facon said.
The amount of carbon dioxide reflects how much of the air that individuals are breathing in has already passed through the lungs of others.
If the sensors show carbon dioxide levels of 900-1,200 parts per million, venues are required to take action to improve it, and anything above that level is a safety breach. It will be enforced by inspectors who will issue warnings if they find sensors are not displayed, and after a three-month phase-in period will begin issuing fines to businesses that do not comply.
The measure is adapted from existing workplace safety regulations which already set out maximum carbon dioxide levels, which were in place because a high level of carbon dioxide is poor for concentration and overall health.
This month Mr Facon will put forward proposals to extend the measures throughout the education system in advance of the new school year.
“There is a lot of protest, or lack of support from especially the education system with regard to the idea of putting CO2 meters in each classroom, because this has a certain cost,” he said.
“However, it is not that much. In Flanders it would cost about €5 million. It’s not that much if you see what we have invested in disinfectant gels and surface cleaning, it’s only a small amount.”
Some buildings including some old schools, certain catering establishments, and some sports infrastructure will not be able to comply with the carbon dioxide limits due to their design. Such venues will have the option instead of installing air filters that disinfect the air.
“The carbon dioxide can be too high, but if there is filtration and disinfection, that’s okay from a Covid-19 perspective,” Mr Facon said. “It’s not really okay from an overall wellbeing perspective, but that’s something we would need to address in the more long term.”
Belgium suffered one of the world’s highest death tolls in the first wave of the pandemic, a situation that Mr Facon said was down particularly to unpreparedness in nursing homes, a depleted stock of protective equipment, sparse testing facilities and a national team of only about 20 contact-tracers for a population of 11.5 million.
But the country rallied and faced the second and third waves better, and it now has the highest rate of vaccination of almost any EU country. It is set to surpass Israel in the percentage of people who have at least one jab.
Mr Facon does not expect a new wave to be as severe as those that came before due to the high rate of vaccination. But the more infectious Delta variant is now thought to make up more than half of new cases, and caution will prevail.
“We must be prudent, because even further new variants could emerge,” he said. “We need to be ready, and that is why we are putting a lot of effort into testing, isolation, quarantine, on outbreak management and also on ventilation. Because we are not sure what could happen, and we want to be prepared.”