Evening star., 1949-03-09
Stars, Men and Atoms a
Ultraviolet Radiation
Held of Dubious Value
Potent Germ Killer Only in Labs,
u. S. Experimenters Report
Rv Thomas x. Henry


The value of ultraviolet radiation of liv-
ing quarters. offices and public gathering
places is very doubtful, according to results
Of two Government experiments Just re-
ported here.
The first was carried out over q period
Of six years. It was a cooperative project
Of the United States Public Health Service
and the Federal Bureau of Prisons. The
subjects were 400 teen-age boys confined for
Federal offenses at the National Training
School for Boys here.
Some OF the sleeping quarters were con-
stantly irradiated. Others were untreated.
During the last two years of the test five
times the amount of radiation was used as
is generally recommended. Comparison was
made of the incidence of respiratory diseases
In the two groups of boys.
Net Result Nil.
The net result, concludes the report, was
essentially nil. Among the boys sleeping
in the radiated quarters there were slightly
fewer cases of colds, influenza and the like.
The difference was not great enough, how
ever, to be significant Sometimes the sick
ness rate was considerably higher among
the boys from the radiated rooms.
The second experiment, continuing for
four years. was carried out by the Navy at
its recruit training centers at Sampson,
N. Y, and at the Great Lakes Barracks. Not
only were the living quarters of some recruit
regiments irradiated but also the mess and
assembly halls. Other regiments were kept
IN nonradiated surroundings. During part
OF the period floors and blankets were oiled
to reduce germ-carrying dust in the air.
The respiratory disease rates for the men
living in the sections treated with ultraviolet
were somewhat lower throughout the entire
period than for the others. Sometimes the
difference was as much as 20 per cent. At
other times, however almost the reverse was
true, the report states.
Works in Laboratory Conditions.
Ultraviolet light is known to be a potent
germ killer under laboratory conditions In
actual daily life, however there are appar-
emily too many complicating factors to make
1t worth the expense and trouble.
+ 4
Air war against flies is in prospect.
Cities can be fairly well fly sterilized by
spraying them with potent insect posons,
such as DDT. from low-fying planes, it Is
shown by study undertaken for the Pub
lie Health Service by Cornelius M. Kruse Of
Johns Hopkins University.
The efficacy of air spraying of mosquito
infested islands of the Pacific and domestic
forests threatened by insect pests has been
we'll demonstrated. The common house fly
and its close relatives. however. offered q
ing flight is made at height of only 20 to
80 feet. just before dawn. when there is a
downward movement in the atmosphere. 1t
is impossible to fly over city roofs at an
altitude much below $50 feet and the ideal
time for fly control is just after dawn when
air conditions are likely to be particularly
turbulent.
Home Sanitation Essential.
The tests showed, however, that high
degree of fly sterilization is quite practical
It is not to be considered, the report EN-.
phasizes, as a substitute for rigorous house,
hold sanitation to keep down the house fly
population. The major value would come
few times each summer when the fly
population of an urban area gets out Of
hand.
major problem was that of staining
of houses. laundry on lines. and the like,
by the fine spray dispersed from the planes.
This has required devising special mixtures
of poisons. One substance. hexachlorocyclo-
hexane, was found to be from i've to seven
times more effective than DDT and to have
little staining effect.
Tests showed the possibility of treating
about II acres per minute. Flies are killed
both by contact with particles of the spray
In the air and by coming to rest on surfaces
upon which the poison has fallen. Labora-
tory experiments were used to determine the
size of droplet necessary to kill chloro-
formed fy-supposed to stimulate normal
insect at rest or in the act of feeding.
The major value of the system, it is ex.
planned, would be in times of an epidemic
of fly-carried disease, major catastrophe,
or in time of war,