Airborne Transmission – Ventilation

Angie Szumlinski Health, Studies

Although airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been recognized, the condition of ventilation for its occurrence is still being debated. A study was published in Science Direct that identified that although droplet spread is the most common way to contract COVID-19, airborne spread is also a risk in poorly ventilated spaces.

The research team analyzed an outbreak that occurred in Guangzhou which was linked to three unrelated families. Local health officials learned that the families at lunch at the same restaurant on Chinese New Year’s Eve on January 24, 2020. The research team obtained a video recording and seating arrangement from the restaurant and looked at the restaurant’s air conditioning system across five zones of the establishment. Using the original table setup, they tested the dispersion of a warm tracer gas, which acts like exhaled virus droplets, to simulate the spread of droplets in the restaurant. They found that the measured ventilation rate was 0.9L/s per person, which is lower than recommended standards.

Ultimately, the researchers concluded that the contaminated recirculation bubble can’t solely explain the outbreak. The low ventilation, lack of outdoor air supply, and close distance between the tables appeared to contribute to the droplet dispersion among those who were infected. Lots of great information! Do we stay home and not dine in restaurants? The jury is out, we do what we are comfortable doing and use precautions that are known to be effective. Stay well, mask up and stay tuned!