Since airborne transmission has been considered as a possible infection route for the novel coronavirus in addition to contact and droplet infection routes, ventilation is an important measure against airborne route. In this paper, we describe the history of setting regulatory standard values and the interpretation of CO2 concentration as a measure against infectious diseases. Although the standard value of 1,000 ppm is not intended originally for infection control, it is practically useful as a guide value for potential infection risk management.
At the 2020 annual meeting of The Society of Risk Analysis Japan, we hosted a special session focusing on novel coronavirus disease (COVID-19) as an emerging risk. In the context of the COVID-19 pandemic, the regulatory science perspective is very important as countermeasures have to be decided in a very limited time and without sufficient scientific knowledge. The objective of the session was to discuss the contribution of risk science to countermeasures against COVID-19. The topics were as follows: (1) science and policy under the risk governance; (2) risk assessment at mass gathering events; (3) regulatory science of the infection risk management and the regulatory framework issue; (4) comparison of mortality risk and economic impact.