B83.
Yano, N.
FansrsLeveorgtosy
RADIOACTIVE DUST IN THis AIR.
g
ics ‘ (Tonys) 7, mc. 2, Yel (1956).
abdGeothys
An electric precipitator is
:sed to collect dust in
the air because its collection efficiency for radioe
active substances is up to 10 tines that cf the
impactor of filter-paper types.
About 10 cu. m. of
air is filtered duri:ig 5 hours, and the trapped dust
is :easured more than 24 hours after collection to
avoid the influences of naturally active substances.
ew
dl
The avezage radioactivity of the air is approximatee
ly 10749
c./ee. During the period of observation &
peaks occurred. The dates and maximum levels of
artificial activity, Respectively, are November
abd
4-10,
1
19
s
1-2 x
107
uc./l.}3
April
1l-13,
1955,
4.3 x 1079
uc./le3 November 25-8, 1955, _maximnm
unknown; and March 22-5, 1956, l= x 107? uc./l.
The presumed dates and pleces of detonation corres-
ponding to the peaks are October 31, 195% northwest
of Japan; March 29, 1955, Nevada, U. S. A;
November 22, 1955, near L. Baikal, U. S. S. R.3; and
March 13-15, 1956 unknown.
84.
Yatazawa, Michihike and Yanazaki, Yoshio
ABSORFTION OF FISGION PRODUCTS BY PLANTS (PART V)
ABSORPTION OF GROSS FISSION PRODUCTS. Soiland
Flant Food 2, 158-163 (1956).
85.
Yatazawa, Michihiko
RADIOACTIVE CONTAMINATION OF PLANTS IN JAPAN COVERED
WITH RAIN.OUT FROM H-BOMB DETONATIONS IN MARCH-MAY
195% AT BIKINI ATOLL, MARSHALL ISLAND.
(PART II)
a
RADIOACTIVE ELEMENTS OF CONTAMINATED PLANTS. Soi]
|
and Plant Food 1, 23-4
(1955).
Following a fallout estimated at 0.2 microcurie/l.
;
Trifolium repens, Astragalus sinicus, and Rumex
japonicus were harvested and analyzed for radio=
activity. Most of the radioactivity (2300 - 4%700
counts/min./50 g. plant ash) was associated with
oxalate precipitate.
A small amoung of activity
ir. the Zn BEpup is attributed to Zn
produced by
>
recetion 2n°?
(n,y) from Zn employed in the mech-
@nical parts of the borb.
Sr-Ba radioactivity was
C.l that of the rare earth group.
Distribution of
the radisactive ele:ents was nearly the same as
that found or tre No. 5 Pukuryueharu.e
-2he