Can anyone explain to me why the numbers can change over time on the maps on https://data.wastewaterscan.org/? This is a screenshot from last week, and that # on the same date today now shows in the 600s. Assuming it has something to do with the ‘PMMoV Normalized’… like it’s averaging? I’m very obviously not super knowledgeable about how this data works.
Anytime you're doing this type of analysis you have to have an internal standard to compare to. Basically, you tell whatever equipment you're using "here's a standard amount to compare to" if that makes sense. I'm trying to oversimplify a bit, but hopefully it helps.
A little quick research on this tells me that PPMoV(Pepper mild mottle virus) turns out to be the most abundant RNA virus in human feces and is found in roughly the same concentrations year round. So that means they can basically tell their equipment "here's a standard to normalize the data with."
