The viral inoculation load is a key gap in our knowledge base for testing and policy. I struggle with test interpretation not knowing at what level a test should be positive since the question is not if the virus is present but rather: A. if the illness is caused by COVID-19 and if the person is infectious. Something I think about daily.
It probably has to do with testing how much passes through the mask. Then you know what viral load you need to get infected. That probably has a probability curve. So you can then look at that probability curve and find a percent chance of catching the virus.