Re: K40 in dead sea

["Raymond A Hoover"<TOBEOR@inel.gov>]

Using MicroShield and the information below, I estimate the exposure rate
at 5 cm above the water to be about 3 uR/hr (assuming no errors of course).




maay100@bgumail.bgu.ac.il on 02/18/98 11:40:14 AM

Please respond to radsafe@romulus.ehs.uiuc.edu


To:   radsafe@romulus.ehs.uiuc.edu
cc:    (bcc: Raymond A Hoover/TOBEOR/LMITCO/INEEL/US)
Subject:  K40 in dead sea




        This is a continuation of the string on radiation exposure from
K40.
        The Dead Sea contains contains 16 grams K per liter (approximately
8 times the average concentration in humans). At a risk of affecting our
tourist trade, I would like to ask what the estimated radiation exposure
would be to a bather floating say for 1/2 an hour in that saturated
solution.

                                Mike Quastel
                                Soroka Medical Center and
                                Ben Gurion University of the Negev
                                Beer Sheva, Israel
                                Fax: +972-7-6400765
                                Email: maay100@bgumail.bgu.ac.il


>Specific activity of K-40 is 853 pCi/g K or about 30 Bq/g K according to
>Eisenbud (p. 407 in Environmental Radioactivity, 1987) and there is
>about 140 g K in 70 kg man or 4400 Bq of K-40.  Therefore, 20 MBq is too
>high as is the claim for C-14 (specific activity = 6.1 pCi/g C = 0.23
>Bq/g C).
>
>I still agree with Franz.
>
>Lauri Kaihola
>Wallac Oy
>POB 10
>FIN-20101 Turku
>Finland
><lauri.kaihola@wallac.fi>
>http://www.wallac.fi
>
>
>
>> I totaly agree with Franz:
>> One should not create problems where there are none.
>>
>> By the way:
>> A typical adult (70 kg) contains about 20 MBq natural K-40 in their
>> muscles.
>> There are almost as much C-14.
>> (see: http://kermaosf.medphysics.wisc.edu/~empw/)
>>
>> Is this then also a problem?
>>
>> Urban