health and safety laboratory - Digital Collections

t
81 others. These data were also reported "by Eiseribud and Harley.(4>5)
I The network since 1954 has been quite stable. In January 1959 it
A Nations.
consisted of 46 U. S. stations, 68 elsewhere in North America and overseas
and 64 maintained in cooperation with other countries through the United
As the approach to fallout problems became more sophisticated, it was
desirable to have a measure of individual radionuclides, particularly Sr^
and to have an estimate of the gamma dose delivered to the population in
M various geographic areas. Actual Sr^ measurements could best be performed
m on monthly samples but, because of the radiochemistry involved, this col
lection system grew very slowly. It was apparent that it would be very use
s© ful if a reasonable estimate of the Sr^ deposition could be made from the
total beta measurements on gummed film.
JH ,In the period before megaton weapons were fired, the radioactive debris
m stayed in the troposphere and was cleared out with an average life of about
t
one month. Thus, it was usually possible to attribute fallout to a single
QD
burst and to make reasonable estimates of the $r content based on total
beta measurements. It was also possible by a knowledge of the nuclides pro-
duced, to estimate the infinite plane gamma dose.
M The original calculations of Sr^ deposition from measurements of
total beta activity on ashed gummed-film samples>were performed as follows:
^3 1. The activity measured on a given sampling day was attributed to
the test immediately preceding that sampling day.
2. The measured activity on the counting day was extrapolated to a
fixed day^(usually the first day of the following year) by the
formula
I
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