No Subject

[Mike Baker <baker@groves.neep.wisc.edu>]

The following was posted to the riskanal discussion list.  Someone
in this forum may be better able to answer his question.

Mike Baker ... baker@groves.neep.wisc.edu

----------------------------------------------------------------------
Originator: riskanal@listserv.pnl.gov
----------------------------------------------------------------------

Date: Mon, 06 Jan 1997 16:45:10 -0800
From: DJeffrey@EMCONINC.COM (Jeffrey, David)
Subject: Chernobyl radionuclide risk reality chec


Here's a little quiz for you rad risk buffs out there.  I recently got my 
hands on some
slides used in a presentation at, I believe, the recent SETAC meeting in 
Washington.  In flipping through the slides, which were given to attendees 
as a handout, I found an interesting figure showing concentrations of 
cesium-137 in soil as a function of distance and location with respect to 
the exploded reactor site.  This figure shows surface concentrations on the 
order of hundreds to even thousands of "kBq/m2".

I was curious about just how bad/high these levels were, so I did a little 
unit conversion math and found a PRG-like value of 0.017 pCi/g to protect 
against external radiation from cesium-137 in soil for a target cancer risk 
of 1E-07.

The thing that bothers me about my computation is that, if my math is right, 
and if these surface levels of cesium-137 are right, these levels of 
cesium-137 are completely "off the chart" riskwise. Can some more 
knowledgable rad risk person out there check my numbers.  I have assumed a 1 
cm mixing depth, in order to be able to relate a surface concentration with 
a 'per mass' soil concentration.

Incidentally, this data is for cesium-137 measured on 1/1/95, so even though 
the this isotope has a fairly short half-life (30 years), at these levels, 
if they're right, that's not much consolation. And if the data and my 
computations are correct....remind me to stay the heck away from the Ukraine 
and Belarussia, at least for the next several hundred cesium-137 halflifes!

Oh, one more thing....I DO NOT apologize in advance for any steenking 
cross-postings, so there. We all have 'delete' buttons.
------------------------------