Re: Environmental Epidemiology and Toxicology- K-40 Thread

[RadiumProj@cs.com]

Radsafers:

FYI. On the subject of interesting sidelights related to K-40 is the issue of 
KCl salt "Quickmelt" commonly sold each winter in bulk 50 pound containers 
anywhere in the Northern US. 

KCl has a K content of about 500 g/kg and a K-40 concentration of over 
400,000 pCi/kg  of KCl. Do the math. Years ago after seeing a display of KCl 
next to the checkout counter at a local Sams' Club consisting of a palet of 
KCl containers [50 pounds each] about 10 deep by 7 wide by 5 high [7945 kg], 
I did a quick calculation that indicated a gamma dose rate from K-40 photon 
flux would be  about  0.2 mR/hr in the middle of the display.

I went back with a DigiDose meter and placing it in close proximity got a 
dose rate of about 0.1 mR/hr, or more than 10 times background. Interesting.

I have a photo of a mother with her small child waiting in the checkout line 
next to this KCl salt display. 

The irony is  KCl is being mined in bulk and the radiation producing 
technologies want  to put nuclear waste into salt mines. Nuclear waste will 
eventually decay away with a half life of tens of years to thousands of years 
for the major components of a nuclear plant or weapon's  mix. For KCl the 
K-40 has a half life of more than a billion years. Go figure.

Nevertheless this does make an interesting point on a natural radiation 
source being brought into commerce which delivers a dose rate and person-rem 
to real people that will far exceed that which nuclear waste storage could 
ever deliver in the offsite environment to real people.

Stewart Farber
172 Old Orchard Way
Warren, VT 05674
email: radiumproj@cs.com



In a message dated 4/5/00 11:20:40 PM Eastern Daylight Time, sjd@swcp.com 
writes:

<< On April 5, Frank R. Borger asked, "Can anybody out there come up with an
 estimate of the amount of radioactivity released per year through bananas
 shipped thru New York?"
 
    This finding (below) is not exactly an answer to the question, but
 presents an interesting sidelight. >>

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