That map makes it looks like the borders of Missouri were decided based on radon risk. Which is not what I think actually happened when they drew those borders.
The granularity of the map seems to be at the county level, so I will guess that the EPA did not gather this data by itself, but rather, rely on self-reported data from each county from each state. A county is a political boundary, so the state of Missouri probably had different testing regulations and methodologies than its neighbors like Iowa and Illinois.
>> so the state of Missouri probably had different testing regulations and methodologies than its neighbors like Iowa and Illinois
Then the map doesn't show risk of radon. It's worthless for that purpose.
"Different political institutions have different standards for what is a radon risk."
It's a map of different political institutions then. That's fine. Just don't try to sell a map of political institutions as a map of radon risk when that is obvious bullshit. I mean it's completely obvious from the boundary.
Radon Risk is well established. If it’s higher than a specific limit you need to mitigate. This map just indicates where it is likely to be higher on average based on geology.
So, no, don't believe your map.