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Rongelap and Bikini Atolls
The wi85 content on Scaevola leaves at Rongelap Atoll
on August 8,
1958,
was higher than
that in the same species
at Nan Island (Bikini), Keith, Henry, and Leroy Islands
(Eniwetok), and Ujelang Atoll (Table 3).
These levels
suggest that Rongelap Atoll received a greater amount of fallout than did the above islands with the exception of Leroy
Island at Eniwetok Atoll.
The latter island was contaminated
heavily with fallout not containing wl85 as evidenced by the
comparative levels of Cet4i+l44_prl41+144 (429,000 a/m/z),
RYLOS+106_py103+106 (440,000 d/m/e) and Zr95-Nb95 (1,100,000
d/m/g) (Table 2) to those at Keith and Henry Islands.
wi85 accounted for 89 per cent of the total radioactivity
on Scaevola leaves collected at Rongelap on August 8,
1958,
(Table 3, Fig. 8) and 90 per cent on leaves of the same species
collected at Nan Island (Bikini) on August 28.
Thus, the con-
tamination on the plant leaves at both Bikini and Rongelap
Atolls may be assumed to be due to recent fallout.
from Nan Island,
total;
In topsoil
wi85 accounted for only 33 per cent of the
the isotope was not detected in soil from Rongelap
(Table 3).
The ratios of wi85 in the soil samples from Nan
Island and Rongelap Atoll indicate that a significant part
of
the contamination was
due
to
earlier fallout.