piggies,
aeRee
‘
a
Bobb. -cosg ac
8 pee
Tap at et apier overs othe’ sn 1
:
. . The sol] and- sand. samplesincludedthose fromthe islands —
meme mare 7
:
‘proper, fromthe beach, and fromthe lagoon bottom. - The radio-
activity of a sample taken from the top inchof soil on |
Labaredj-Isiand March 26, 1954, wae 6.3 microourles per gran,
which is equivalent te one curle per .325 pounds. of top soll.
Phe activity ofthis sample ten months later, January 29, 1955,
_was one thirtieth its original value, t.e., 1¢ had passed
throughnearly five half~Lives. .The deeayrate fer this period
4s expressedby the formula, r= ¢ 7/51, with March 1, 1954,
.as-the date of origin (Figure 12), Thisvate approximates the
mixed.fission product decay rate and in general approximates
the decay rate for many of the biological samples.
For these
ae
‘Péasons the decay faetor tor correcting counts back to the day
of colleation wea paged on the decay«ourveof a‘similarsoft
‘sample, |
“The decline in radioactivity of the soll samples ean ‘be
i ae
“Sbaervedfrom‘the figures in Appendix ‘TableXe ‘considerable’
oe
“variation in.‘the activity of soul samples trom ‘the same‘area on
TE
the game day ¢an be expected ‘because of the nature of the fall-
out:‘pattern and should be kept in ‘ind’wheninterpreting results.
“
“1954, but less from guly 1954 to ‘Jamuary1955. then the sample
pte
‘ofdecline is greater than the. decay rate ‘from‘aréh to saty’
“eounta fron all istands are ‘averaged,the ‘Felative¢decline an
Boncommre es SOE Gh
RETSTEoS
EEOTRRegreer
“If consideration 1s given to the Fabelle séupies only, ‘the rate
ceeikonaa-tiedesuicean egeivetot totty ene: