Cs-137 in soil -Reply

[Dave Speed <dspeed@well.com>]

As usual, my learned colleague, Dr. Frame is a wealth of good information.

I would add another $0.01, however.

The *distribution* of Cs in the soil is highly variable, dependant upon the
mechanism of deposition (and by this time, transport factors).  I remember 
one site where we ran hundreds of samples and saw approx 1 in 12 peak by 
some largish (10 - 30x) factor.  And this was in a small area - the 
deposition in a larger area can vary even more.  See the old TransStat
issues if you can find them.

Processing the samples at too high of a temperature can vaporize the Cs.
When we backed off of a protocol which had us drying the soils at 400 deg C, 
our Cs levels went up.

When attempting to determine if the soils are contaminated, it may be useful
to analyize a background population and then compare its distribution
against the data in question.  We had a lot of success with this techinque
in the 1970's.

Email me if you need more.

Dave