Uranium in Urine - Background Levels

["Carbaugh, Eugene H" <gene.carbaugh@pnl.gov>]

Jeff & any others interested (sorry, tried to e-mail directly and
message bounced back.  I didn't keep the original request and don't have
Jeff's last name or company)

Generally, you will find that environmental uranium in urine will
demonstrate a log normal distribution.  Here at Hanford, we use 0.2 ug/d
excretion rate as a general screening level (with a mean background down
around 0.06 ug/d).  We do have areas where individuals can come in well
above 0.2 ug/d just from their environmental sources. I don't know how
far back you want to go.  I have a couple of extended abstracts which
were published in the proceedings of the Annual Conference on Bioassay,
Environmental, and Analytical Radiochemistry in the 1990-94 era.  We
also have published some information in our Technical Basis for Internal
Dosimetry at Hanford (PNL-6866 Rev. 1).  We published data plots and the
conclusions, but not the raw data themselves.  The Bioassay Conference
extended abstract included plots of Hanford (Eastern Washington) and
Pantex (Texas panhandle) data.  Quite different situations.
Uranium monitoring has been a real pain to us over the years.  It was a
snap when we were processing soluble uranium and had biweekly or monthly
schedules.  Then we could set screening levels well above the
environmental noise.  Also, the few places where we had insoluble
uranium, we could handle quite nicely assuming chronic or random
intakes...as long as we were dealing with annual internal doses.  When
we switched to the committed dose system in 1993, things got a lot
uglier for insoluble uranium.  
E-mail or give me a call and we can discuss it more, if you like.  
	Gene Carbaugh
	Internal Dosimetry
	Pacific Northwest National Laboratory
	(509) 376-6632
	gene.carbaugh@pnl.gov