30
TT TTT
l
TT
177
TTTTT
25
_
20 --
—
2 15;
~
s
—
T
T
_l
Af
-_
=
—_/
£10
d > 0.15 p RADIUS
5
0
10!
30
val
4
X 0.02 TO 0.15 p RADIUS
® < 0.02 p RADIUS
po
107
fo
=
tt
M4ce/%S- ACTIVITY RATIO
!
10°
TT rt ry
ae
!
a
ALTITUDE, KM
_|
10
aa
5/L
_
0
10°
30
\
L
tyre
r
TT
l
10!
57 -/9S- ACTIVITY RATIO
TTToty
Lot
put
107
TTT TTTT
Lao
= 20 f—
=
Mw
ut
S15
}he
am
_
|
4
10
4
4
3 f—
0
1077
l
a
ft
10°
957-/\4Ce ACTIVITY RATIO
| [yyy
10!
Fig. 7—Activity ratios for impactor—filter collections over Minneapolis, Minn. (45°N 93°W), on May 16, 1963.