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ENVIRONMENTAL RADON CONCENTRATIONS
AN INTERIM REPO
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‘by Harold Glauberman and A.J. Breslin
Health and Safety Laboratory
New York Operations Office
U.S. Atomic Energy Commission
The Health and Safety Laboratory is investigating the variability in space
and time of natural radon concentration as a portion of its contribution
to the United Nations scientific endeavor. This is an interim report of
that work. Measurements were begun in late November 1956 and will continue indefinitely. One hundred and twenty samples have been collected
and analyzed to date. Most of the sampling has been done in and around
New York City; a few samples have been collected in New Jersey.
The present phase of the investigation is primarily a pilot study.
Attention is being directed to instrumentation, sampling technique and
semple variability, and the development of a systematic sampling program. Although the collected samples have yielded valuable data, they
are more important as a basis for designing an integrated pattern of
collection.
PROCEDURE
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The basic measurement is one of instantaneous radon concentration. A
grab-sample is collected in a one-liter glass flask ey analyzed in the
laboratory by a pulse counting fonization technique. \1 ) The results
are reported in curies/liter of elemental radon in air.
capacity is limited to six flasks per day.
The analytical
Whenever practicable, sam-
ples have been replicated so that the sampling error could be computed.
' When replicates have been obtained, individual successive samples have
been collected as rapidly as possible at a fixed location.
Measurements are also being made of the daughter products of radon.
At
each sampling location, the daughters are sampled for ten minutes by
drawing air at ten liters per minute through a one-inch diameter molecular filter disc. Alpha activity is measured in the laboratory with a
scintillation counter. Initially, we attempted to measure the daughter
decay as a function of time according to the method described by
Tsivoglou, Ayer, and Holaday. (2)
However, the counting statistics
:
proved to be too unreliable at the activity levels measured. Nevertheless, a means is being sought whereby the daughter activity can be used
to define the state of radioactive equilibrium of the decay products
‘with
radon.
“Oy
POS