Cs-137 in soil

[Gary Schroeder <schroede@mail.sep.bnl.gov>]

>Is CS-137 left over from the above ground weapons testing?
>Yes.  About 50 % of the original fallout still remains, although it has 
>been redistributed to a certain degree.  It is still possible to find 
>137-Cs in surface soil samples, especially in undisturbed locations 
>such as untilled pastures and graveyards.
>Les Fraley

Les, it's most certainly observable in locations other than untilled fields
and graveyards!  Besides, natural erosion mechnisms like wind and rain are
far more influential than tilling when you're considering a time scale of
decades.  Go grab a few hundred grams of dirt from your back yard.  It may
be less than a pCi/g, but you'll find it with a high efficiency HPGe detector.


===============
Gary L. Schroeder
Brookhaven National Laboratory
gs1@bnl.gov