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‘Appears to be the principal origin. Theoi ies which propose that the carbon skeleons of furfuryl alcohol and maltol of
‘heared milk derive from carbon atoms
(2 to 6 and 1 to 6, respectively, in the
‘glucose moiety of lactose remain attractive in light of these findings (/0)}.
S. Patron
ae
ey
R. J. Frrpsr
Department of Dairy Science,
Pennsylvania State University,
University Park
References and Notes
1,
2.
3.
4.
5.
6.
7.
8.
9.
10.
§. Patten and R. J. Fiipse, J. Dairy Sci, 36.
766 (1953).
S. Patton, ibid. 38, 457 (1955).
, ibid, 33, 904 (1950).
F, E. Potter and 8S. Patton, ibid. 39, 978
(1956); H. C. Sherman, Ind. Eng. Chem. 2,
24 (1910); J. Brand, Ber, deut. chem. Ges.
27, 806 (1894).
§. Patton, f. Dairy Sei, 33. 102 (1950).
According to I. A, Gould, [f. Dairy Sei, 28.
379 (1945)], 80 to 85 percent of the total volatile acid of heated milk is formic acid.
O, L. Osburn, H. G. Wood, C. H. Werkman,
Ind. Eng. Chem. Anal. Ed. 5, 247 (1933).
C. K. Claycomb, T. T. Hutchens, J, T. Van
Bruggen, Nucleones 7, 38 (1950).
[Isolated only as its naphthyl urethane.
Authorized for publication as paper No. 2134
in the journal series of the Pennsylvania Agricultural Experiment Station.
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8 March 1957
100
,
Gamma Rays from Local
Radioactive Sources
There is considerable interest at the
present time concerning the possible ceffects of man-made radiations on man
himself. Because one source of these radiations is of world-wide extent, the interest has also become world-wide. Although considerable literature nowexists
on the subject of man-made radioactive
contamination, on the one hand, and on
the biological effects of radiation, on the
other, the actual importance of the first
as far as the second is concerned has
often been obscure, It is thought desirable at this time to present some independent experimental data that will
allowindividuals to reach their own conclusions.
As early as 1928, R. A. Millikan be-
came interested in the gamma rays
emitted by local radioactive materials
in the soil and rock at: various localities
in order to determine the effect of these
radiations on the cosmic-ray measure-
ments in which he was primarily interested. These measurements extended
from California into the Rocky Moun-
tain area and on up to Churchill, Manitoba (1). They probably represent a
unique series of measurements, since they
were made before man-made contamination became widespread.
An ionization chamber measures directly the quantity of interest as far as
the biological effects of gamma rays are
1088
cv Man-made Contamination
O
—
we
ee
—_—
ee
ree
Fig. 1. “‘Noise level” of gamma rays and cosmic rays in the Western Hemisphere. Abscissas
roughly increase with increase of distance from Pasadena. The amount of man-made contamination is taken from the National Academy of Sciences report, Biological Effects of
Atomic Radiation (7). As is stated in that report, ... U.S. residents have, on the
ce
average, been receiving from fall-out over the past five years a dose which, if weapons
testing were continued at the same rate, is estimated to produce a total 30-year dose of
about 0.1 roentgen” (an average of 3 mr per year).
concerned, and this is the instrument
here employed. One of the instruments
Millikan made and calibrated is still in
good condition after 26 years and is very
convenient to use. A recent redetermination of the absolute value of the calibra-
tion (2) agrees with Millikan’s value to
0.3 percent. In this survey, Millikan’s instrument has been used for some of the
measurements, and a more modern jonization chamber (3) for others. The two
give essentially the same answer. Both
were used unshielded in the measure-
ments reported here.
In Fig. 1, most of the values taken
during the years have been entered. The
ordinates are in milliroentgens {mr} per
year, To convert into ion pairs per cubic
3
centimeter, per second in | atmosphere
of air, divide the ordinates by 15. The
various stations are plotted as abscissas
with the same increment from one to the
other. Roughly, the stations get farther
from Pasadena with increase in abscissa.
The chief reason for plotting in this manner was to bring out the variability of
‘ radioactivity from one station and region
to another.
Measurements were madeof the total
radiation at a given station; then the
known contribution from cosmic rays (4)
was subtracted to get the effect of the
gamma rays from local! radiation only.
In the Rocky Mountain region, the
local radiation is high, presumably because of the Seay ; which is known to
SCIENCE, VOL. 125