Share this on Facebook
download .zip with all pictures
That’s a good observation, but if the rain was a significant source, then the surrounding area and objects would have been reading similarly high like the vehicles (well, the area was reading higher than normal places, but not by a lot – a few times normal background).
My understanding is that, yes, rain brings down stuff that is floating around, but this is outweighed by its cleaning effect (washing stuff away), and in the Exclusion Zone it’s better to stay on concrete than grass because the rain continually washes dust off the concrete but washes it into the ground where it accumulates in the soil and plants.
An interesting example – next to that famous decaying ferris wheel is a large expanse of concrete fairground, with a drainage grate in the center. The city is fairly far from any seriously contaminated areas, and the grate is clogged with moss, so the rain is constantly cleaning any dust off the large area of concrete… but then filtering it all through a small area of moss.
Consequently, the area reads low (for the Exclusion Zone)… except for that small patch of moss, which was far and away the most radioactive thing I saw in that particular part of the city.
(Normally in a “clean” area the readings on grass or dirt is only about two or three times higher than the level I would read when stepping a few meters away onto concrete, but this little patch of moss was something else.)
That’s something I didn’t really understand about the Exclusion Zone until I was there – the radioactivity is *very* unevenly distributed. So many events and processes, both natural and artificial can cause contamination to have been spread or concentrated or moved in different ways that one area can be completely safe, while only a short distance away, it can be dangerously radioactive (far more radioactive than those vehicles).
That’s why the Exclusion Zone is so big and some people claim it’s ok to live there – large areas *are* mostly safe (though not by everyone’s standards), and the guide mostly keeps to those areas, but you can walk into a dangerous area anywhere and never even know it unless you have a Geiger counter with you, so it’s not exactly the kind of neighbourhood you’d want to be in!
A lot of areas seem randomly haphazardly marked with a radiation signs on posts, a bit like a street sign in the middle of a field. That doesn’t mean “duh, just in case you forgot you’re in the exclusion zone, which is radioactive” it means “stay away – we know that it’s much much worse over here”, though not every hotspot is marked. :-/