Re: "Normal" concentration of tritium in urine

[Andy Hull <hull@mail.sep.bnl.gov>]

Rick,
While I'm not sure what you are looking for, I assume that the "normal"
concentration of tritium in urine should be comparable to that of
precipitation(unless influenced by some proximate local source.
since the recent concentrations of tritium in precipitation are much less
than 100 pCi/l, they are not detectable by straightforward LSC analysis. The
current "normal" concentration would be far lower than could be detected by
standard LSC analysis, but would require prior enrichment.

The most authoritative data on tritium in precipitation is published every
four years by the IAEA in its Technical Reports Series on Environmental
Isotope Data, of which the most recent in out Research Library is No. 10,
Technical Reports Series No. 371.(1988-91).  Following the early 1960s
thermonuclear atmospheric tests, the U.S. concentrations reached about 6,000
pCi/l. Extrapolating from the 1988-91 levels,  the current concentrations on
the Eastern seaboard of the U.S. are probably around 25 pCi/L. These are not
appreciably different from the few pre-testing levels reported by  Okada and
Momoshima in "Overview of Tritium Characteristics, Sources and Problems",
Health Physics 65:6 (1993).