DO YOU THINK about the air quality when you enter an indoor space?
It’s estimated that we spend 90% of our time inside buildings, yet until the COVID-19 pandemic, we have given little thought to the quality of the indoor air. It’s so critical that in July, 239 of the top scientists from 32 countries wrote an open letter to the WHO urging them to revise their recommendations to include airborne transmission of COVID-19. Most scientists agree airborne transmission is the primary source of transmission, and the key to fighting this disease is to clean the indoor air to prevent person-to-person transmission.
The most recent example of airborne transmission was in a small restaurant in restaurant in Jeonju, a city in southwestern Korea. Epidemiologists were stumped because the city hadn’t had a coronavirus case in two months. It was later learned that a traveling sales person, who was infected but asymptomatic, had also been at the restaurant. But the two were only in the same space for 5 minutes and were seated more than 15 feet apart. A careful study of the event that included cell phone data, virus genomic testing, and airflow patterns from the air conditioning system concluded the infection was caused by the airborne SAR-CoV-2 pathogen carried by the air flow in the room. Yet, people with their backs to the airflow did not get infected.
Heating and cooling systems are not designed to clean indoor air. They have focused on thermal comfort and, to a lesser extent, humidity control. For many buildings, the only option to bring fresh air into a building is either by opening windows, or filtering the indoor air.
In New England, bringing in outdoor air is not feasible half of the year due to excessive outside temperature and/or humidity. Further, most heating and cooling systems are managed and maintained by the building owner, whose motivation is to keep costs down. The cost to modify HVAC systems to bring in high amounts of outside air are expensive to implement and operate.
Small businesses that lease space have little control over the heating and cooling system, yet they are responsible for the health of their employees and customers. Face masks are effective, but if we want to get back to the “good old days” of enjoying life without wearing a face mask, local air filtration will be required to lower the risk of airborne transmission, while instilling public confidence. Economic incentives need to be created to encourage indoor clean air objectives to be met, especially for our small businesses.
The good news is a vaccine has been developed and distribution is underway. Although COVID-19 is the most recent virus to impact our society, it will likely not be the last. COVID-19 has raised our collective awareness around airborne disease transmission and the need for effective solutions to address this challenge. The idea of possible airborne pathogens has been firmly planted in our collective memories, and will not be easily forgotten.
We need to consider improving indoor air quality as an important way to proactively reduce the risk of disease transmission for all airborne pathogens, which includes the flu, chickenpox, measles, tuberculosis, influenza, and the common cold.
The last major outbreak of influenza occurred in 1918 and was responsible for the death of 50 million people. Influenza outbreaks are cyclical and some epidemiologists are predicting we are due for another outbreak with death expectations in the millions. Reducing the ability for these pathogens to spread within indoor spaces can significantly reduce these numbers, and the technology to do this is well understood and can be delivered at a reasonable cost.
Government needs to shift the focus from treating the symptoms of the disease, to providing incentives to prevent it.