It sounds like there's increasing evidence that in indoor environments with sustained occupancy, aerosol transmission becomes significant for COVID-19. If so, it becomes useful not just to avoid such environments, but also to flush the air continuously as a precaution.

There's increasing evidence that in indoor environments with sustained occupancy, aerosol transmission becomes significant for COVID-19. If so, it becomes useful not just to avoid such environments, but also to flush the air continuously as a proxy for air quality in general (other aerosols, VOCs, etc.), and CO2 monitors are relatively inexpensive. Would there be value in deploying CO2 monitors in grocery stores in order to confirm there are sufficient air changes per