- 23 =
melting snow has been found at times to contain levels of radicactivity
higher than that in the more usual sources.
In the event of nuclear
way with high levels of fallout, much, indeed moat, of it could be re-
moved by water softeners and ion exchange resins (21).
A few yeara ago, when the soil contained less fallout and the rate
of fallout was increasing, a major share of the Sr-90 in forace consumed
by livestock was from direct fallout on the vegetation.
Since the level
has increased in the soil, the indications are that most of the Sr-90
now gets into the plant by way of the soil and root uptake.
Experiments
with black-eyed peas, lima beans, and snap beans at Beltsville, Maryland,
during 1956 indicated that only a small part of the Sr-90 in the vegetation came from direct deposition on the plant surfaces.
In situations
such as that reported by Alexander of alfalfa which was grown on two
very sandy soils in Illinois and derived its calcium from high caloium
subsurface horizons rather than from the plowed layer, the uptake of
Sr-90 was very small in comparison to vegetation that obtains its calcium
largely from the plow depth, where the Sr-90 occurs.
# Thas and the following section are tased almost entirely on the
testimony of Dr. Lyle Alexande.’, Dr. Rubert Reitemeier and Dr. Alan
Seymour in The cature of radioactive fallout and its effects on man,
Hearings before the Special Subcommittee on Hadiation of the Joint
Committees on Atomic ‘nergy, Congress of the United Ctates, May 27, 22,
29, and June 3, 1957, Part 1, pp. 512-523,