Re: Sr Biological Half-Life

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

ICRP 53, @ pg. 169, reads:
According to the ICRP model, a fraction of 0.82 of intravenously
administered strontium is initially distributed in soft tissues and is
largely removed with a half-time of about 2 d, although a fraction of about
0.15 is retained for a much longer time. The strontium initially lost from
soft tissues is partly excreted and partly taken up by the skeleton, which
reaches a maximum content of 0.25 of the administered Sr, with the cortical
bone content exceeding that of the cancellous bone by a few percent of the
administered amount. In accordance with the ICRP bone model concerning the
radioactive half-lives of bone-seeking radionuclides (ICRP 1979), both Sr-85
and Sr-89 are assumed to be distributed throughout the volume of mineral
bone, and Sr-87m is assumed to be distributed over bone surfaces, at all
times following their deposition in the skeleton. A urinary to faecal
excretion ratio of 4:1 is assumed for intravenously administered Sr.

I hope that this isn't too qualitative to be useful to you. I can fax you
the tabulation of biokinetic data, if that would be helpful.

chris alston
alstonc@odrge.odr.georgetown.edu








At 10:40  03/06/98 -0600, you wrote:
>Does anyone have any info on the excretion fraction of Sr 
>administered by injection?
>