This simple-to-use tool, released as a Beta version, allows users to estimate a group-wide relative exposure to SARS-COV-2 associated with various activities. The tool facilitates understanding of the relative importance of factors that contribute to increased exposure. It incorporates both scientific principals and recent findings regarding virus characteristics to assess relative exposure based on the key mechanistic and epidemiological factors.
Factors Assessed by Tool
1) the emission rate of virus, 2) viral aerosol degradation and removal, 3) duration of activity/exposure, 4) inhalation rates, 5) ventilation rates (indoors and outdoors), 6) volume of indoor space, 7) HVAC filtration removal efficiency, 8) mask use and effectiveness, 9) distance between people, 10) group population’s adherence to public health guidance, 11) size of the group, and 12) prevalence of infection (including variants) and immunity in the population. The nomogram model can be broadly applied to many situations (i.e., worker safety, public events, and schools). The model’s results are aligned with the United States Occupational Safety and Health Administration (US OSHA) classifications of exposure risks, by benchmarking the exposure calculations to a baseline scenario that is considered high risk by US OSHA. We define the baseline scenario to represent a person (i.e., medical worker) who is exposed in close proximity to a COVID-19 infected person.