Evening star. [volume] (Washington, D.C.) 1854-1972, 1959-05-06

high into the air. how II circ
howit comes back 10 earth and
where II falls.
Until yesterday this informa-
ton has been a matter OF pub
lie dispute by scientists and
sometimes bitter. partisan de-
bate IN Congress and Federal
a9encies.
This leaves one more vast
ARIA. Of uncertainty. however.
before the true hazard OF radio
active fallout can be assessed.
That area is the biological eff
feet Of fallout-its effect on
people.
Five-Polnt Summary
To sum up. the new picture
Of fallout. now generally ac-
cepted by all the scientists in
volved, is TINS:
First the radioactive debris
from atomic explosions equiv
alent to some 30 million tons OF
INT is now in the strato-
sphere. This is considerably
less than many previous
estimates. The significance is
that less remains to fall on us,
but less future testing can be
done without increasing the
level Of hazard.
Second. the material does not
fall uniformly on the worlds
Just and unjust. 1t is concen-
trated in the northern hemi-
sphere in the ATTITUDES which
include the United States. This
settles an old argument over
uniformity.
Third, the dangerous material
falls out rather quickly. A year
ago scientists thought it took
seven years for half Of the ma
tefdal to fall out. seven years for
half Of the remainder, and so
on After yesterday, the &C
cepted figure is two years half
residency for material blasted
upward near the equator and
one year for material sent up
near the Arctic. Therefore, the
far-north Soviet tests are the
most dangerous.
Hits Middle Latitudes
Fourth. the material does not
filter down evenly all over the
world through the tropopause
(the dividing line, about five
miles high, between the strato-
sphere, where the material rests
in the still, almost airless sky,
and the troposphere, the tur-
bulent lower area where the
weather isl. It comes through
that barrier only at breaks"
which exist at about 40 degrees
of latitude, north and south.
Up and down air currents
passing through these breaks
bring the radioactive material
down into the troposphere
where transforms carry it on
down to the surface Of the
earth.
This new concept accounts
for the concentration belt which
makes radioactivity in the
United States. particularly the
northern regions, high.
Fifth, there are seasonal var
iations in fallout. The spring
is heaviest. We are now headed
into the worst fallout spring
since the first A-bomb.
viii Study Effects
DR.. Frank Shelton, technical
director of the Armed Forces
Special Weapons Project, who
Just finished the heart Of the
definitive mechanism survey.
believes efforts of Government
scientists can now be turned
most profitably to a determine
ton of how human beings,
plants and animals are affected
by the fallout.
After another years double
check in the northern and
southern hemisphere Of the
fallout mechanism, DR.. Shelton
believes his own shop could stop
operations.
The radiation subcommittee
Of the Atomic Energy Commit
tee is holding a series of hear
ings under the Craftsmanship
of Representative Holif1eld,
Democrat of California, to bring
fallout information up to date
and to determine what can be
taken out Of the realm of con-
troversy and what can be pre-