106
(1972) have measured the 2289, /226p, concentration ratio in a coral at (as
high as) 0.2.
Thus, the maximum alpha radioactivity contribution from
members of this decay chain is in the neighborhood of (0.2 X 1,06 x 5)=1.06
pCi/g.
The most likely candidate for the majority of the measured excess
total alpha radioactivity, assuming that these numbers are real, are artificially concentrated and/or bomb produced radionuclides.
contributors is large.
The list of potential
The approximately 16 pCi/g values which can be attribu-
ted to these "unknown" radionuclides is a significant (13%) portion of the
alpha radioactivity burden which was measured spectrometrically in this sediment and should be investigated further.
5.5 Reliability of the Data
The degree which the radionuclide concentrations measured are
representative of the true areal distribution of radionuclide concentrations
measured in the sediments are dependent on several considerations, including:
(1) the error in the analytical measurement, (2) the reliability of the
laboratory (within sample) subsampling procedures, and (3) the field sampling
"bias" or error.
parts.
In this study, the field sampling error consists of two
One is the (within station) variance introduced by sampling from the
distribution of concentrations present in the small area designated as a
“sampling station.”
This problem was viewed as the jn situ homolog to the
laboratory subsampling problem noted in No. (2) above.
The second field
sampling uncertainty concerns completely missing larger areal concentration
distributions by inadequate sampling.
In this regard, the 30 stations
sampled in the lagoon were certainly not enough to detail all the Jocal variations and more sampling is necessary to adequately evaluate the several bio-
erentmma
geochemical problems of interest.
The error in the analytical measurement was dealt with in sections 4.2-3