Re: Radioactivity

Elton N. Kaufmann - Cycloid Fathom Group (cycloid@cycloid-fathom.com)
Mon, 24 Nov 1997 00:00:48 -0600

It's not just fallout. There is natural potassium 40 (I think that's the
one) in concrete that one can pick up with a scintillation counter. Other
thorium isotopes are also in some structural materials (yes some release
radon, but they also emit their own emanations). If you're really getting
fallout radiation (not cosmic rays), there would likely be some
strontium-90 in it - long-lived bad stuff. The levels must be very low
unless you're near Kiev or other accident zones. If you live or work where
the walls would dose your film as much as one airport x-ray would, move out
now. You've got a bigger problem than fogged film!
EltonK

At 05:57 PM 11/23/97 -0500, SCHRAMMR@WLSVAX.WVNET.EDU wrote:
>Yes, Luis brings up an interesting point. Not only are some homes built
>in locations where there are more natural deposits of radioactive materials
>but there is more radiation inside a brick house than a wood frame house.
>The reason for this is that bricks are made from clay which contains some
>naturally occuring radioactive isotopes. Now I know that sounds like an urban
>legend but my research advisor told me that and I did not believe him at
>first so I actually ran a test to see if it was true. My research work was on
>natural fallout. I used a device that drew large volumes of air through a
>filter. The filter would capture all sorts of stuff including the decay
>products of radon gas which itself is a decay product of uranium. After
about
>30 minutes of air sampling, the filter was placed in a scintillation counter.
>I tried putting the air sampler next to a brick wall. The result was a
>sharp increase in the amount of radiation that accumulated on the filter.
>I also learned that fallout is a function of weather. During hot muggy days
>when there is a temperature inversion, the fallout level climbs and sometimes
>reaches a surprising level. After a rain or snow, the air is "washed" clean
>and the fallout level drops dramatically.
>
>Now before someone complains that this has nothing to do with alt photo
>process, let me say that the point is that one should store film in a
>wood structure rather than a brick structure so it will last longer.;-)
>
>Bob Schramm
>
>
>
Exhibiting fine-art and editorial photography
Cycloid Fathom Gallery
Elton N. Kaufmann, Chairman
P. O. Box 8129
Downers Grove, Illinois 60517-8129
USA
cycloid@cycloid-fathom.com
http://www.cycloid-fathom.com/gallery/
ftp.cycloid-fathom.com/group/uploads/