168
DREVINSKY AND PECCI
30
1
25
TTTtTy
TTT TIT
TT TTT
YT
TTT
-
—
20
—
=
x
iw
215
=
-
2
—
TROPOPAUSE —=
x
10
—
A
X
@
©
5 kL
0
10°
30
fogash
10!
>0.15 p RADIUS
0.02 TO 0.15 p RADIUS
<0.02 » RADIUS
TOTAL
tt
107
~]
Popp dite
pe
TOTAL B, NET COUNTS/MIN x G/M? (S.T.P.)
TTT
y
103
104
TTT
25
~
20
be
—
#15 --
_
=
ww
ws
5
—
=
z
TROPOPAUSE—t =X
10
_
5K
_]
0
197!
fo} pt td
10°
on
oe
10!
Jott tt
5+ CONCENTRATION, DIS/ MIN PER CUBIC METER(S.T.P.)
Fig. 4—Radioactivity data for impactor —filter collections over Minneapolis, Minn. (45°N 93°W), on May 16, 1963.
102