Re: Thorium in urine

["Christoph Hofmeyr" <Christoph_Hofmeyr@NNR.CO.ZA>]

RADSAFERS,

Isn't Thorium-232  one of the radionuclides which miraculously has lost a

lot of its radio-toxicity between ICRP 54 and ICRP 68, a factor of almost

30, if I am not mistaken (ALI of 40 Bq for 50 mSv went to 470Bq for 20

mSv)?

Chris Hofmeyr

chofmeyr@nnr.co.za





Previous messages:





                                                                                                     

                    brian.keele@SWEC.COM                                                             

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                                                   Subject:     Re: Thorium in urine                 

                                                                                                     

                    2001/04/04 16:08                                                                 

                    Please respond to                                                                

                    brian.keele                                                                      

                                                                                                     

                                                                                                     





The thorium in urine background is highly variable.  The ICRP 23 value is

0.1

ug/day.



P.Roth et. al., Journal of Radioanalytical and Nuclear Chemistry, Vol. 226,

1997

is a reference.  They report:



Background Urinary excretion of Th-232  average: 47+/-27 uBq/day with a

range

between 9 and 121 uBq/day.  One person varied between 26 and 167 uBq/day

over a

15 day period.



P Roth also refers to several studies, including:

H. Dang, Health Physics, 1989:   16+/-6 uBq/day

Minoia, Sci. Tot. Environ., 1990:  0.35+/- 0.16 mBq/liter with a range from

0.04

to 2.9 mBq/liter.



>From my own experience, I am reasonably certain that there are a number of

individuals (in the U.S.) with much higher levels of ambient thorium in

their

urine and that the levels fluctuate for even more dramatically than what

has

been published.



Of course, all thoughts are entirely my own and do not necessarily reflect

that

of my employer or clients.



Brian Keele, CHP







BLHamrick@AOL.COM on 04/03/2001 11:34:34 PM



Please respond to BLHamrick@AOL.COM





 To:      radsafe@list.vanderbilt.edu



 cc:      (bcc: Brian Keele/Contract/SWEC)





 Subject: Thorium in urine





Does anyone have a reference for an average (i.e., background value) of

thorium in human urine?



Thank you,

Barbara L. Hamrick

BLHamrick@aol.com













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