90~r_90y ~od

~urdcn ~li~tor

Curves for Former Bikini Residents

A statistical analysis, based on demonstrated variance in the Bikini
resident’s urine activicy concentrations and on the small-~ample size,
indicated that a 60-70% confidence level applies to the estimated true
value for the mean body burden for adult”population groups. Children
and adolescent mean body burdens were estimated at the 40-50% confidence
level. In addition, post departure urine samples required a 20-fold
Inrli.vidual
sample
increase j.nradioactivity measuremcntrs
ensitivity.
processing indicated 40% of the samples were below the minimum detection
limit. Increased sensitivity was aci>ievedby c.ompositingthe samples.
The ran~e of the post departure body burden estimate was derived from the
individual urine sampl.cmeasurements and the minimum detection limit of
the composite. Due to the uncertainty in measurement, the small sample
size and the normal variance in urine ac~ivi.tyconcentrations, the post
departure estimated true value for mean body burden does not correlate
well with the expected value for adult female and child/adolescent groups.

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