Post by Andrew Maynard (scientist & author, expert on socially responsible and ethical innovation), published in his personal blog the 28th of June 2020, and updated afterwards to improve the risk estimations and to provide more information on the calculation approach taken.
Calculations are based on a model developed by Dr. Jose Jimenez from University of Colorado Boulder
Modeling personal COVID19 infection risk in university classes can help inform effective risk reduction strategies
If you’re a student or instructor facing the prospect of in-person classes in the fall, and worrying about what the risks are of being infected by COVID19 as a result, you’re not alone.
Like many, I’ve been grappling with the potential risks of in-person teaching in the light of COVID119, and wondering just how effective measures being discussed are going to be.
Most universities are working hard to reduce the risks through measures like temperature screening, mask-usage, reduced occupancy and hybrid in-person/online teaching models. Yet without a clear sense of where these measures are backed up by evidence, I find myself finding it hard to get a good feel for what the personal risks might be.
And that’s speaking as a person who studies risk for a living!
Paying attention to ventilation in classrooms
Modeling in-class COVID infection rates
Modeling of Personal Risk of Becoming Infected
Preparing the Model
---- Risk versus room occupancy
---- Masks versus no-masks
---- Increasing room size while keeping occupancy fixed
---- Varying Ventilation Rates
---- Expanding Risk Reduction Scenarios
---- Variable community infection rates
Proceed With Caution
Figure 1. Personal risk estimates for a 900 square foot class room as a function of occupancy.
Figure 2 Personal risk estimates for a 250 square foot class room as a function of occupancy.
Figure 3 Personal risk estimates while varying room size for a fixed number of occupants
Figure 4. Estimating personal risk in a 900 square foot classroom for a range of air exchange rates.
Figure 5. Estimating personal risk in a 250 square foot classroom for a range of air exchange rates.
Figure 6. Estimating personal risk in a 900 square foot classroom for four different scenarios.
Figure 7. Personal risk estimates as a function of infection rates amongst students attending class