Dirty Bomb'd Areas

So after poking through the spoiler-rific thread Here I’ve realized something…

Dirty Bombs would take more than a few days to “wear off” as a result, I move to suggest that either some cities spawn with a high level of radiation perhaps with a center crater tile (It’s not exactly realistic but it’s the only way I can think of to indicate it other than finding yourself vomiting after wandering about cities.)

As things stand there are periodically spawned square patches of radiation, which I suspect to be a dirty bomb detonation site, but these patches of radiation are completely randomly placed, which doesn’t make any sense.