health and safety laboratory - Digital Collections

I
total
p activity relation for routine pots and films was made. The total p
• ratio of pot/film for 1958 was found to be 2*25 rather than 1.6.
The change in collection efficiency factor does not account for the
m difference "between the computed values for pots and gummed film. It is not
M
possible to evaluate the numerous other factors, such as the use of a single
sampling date for a monthly collection; and no explanation is available.
• Data for pot-gummed film comparisons at locations other than New York
City are presented in Tables 6, 7 and 8.
Since the earliest results are for
m 1957, there is no* confirmation of the low estimates for 1954* As was the case
m for New York City, the 1957 comparison is better than that for 1958 and 1959.
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It has been found from the HASL pot network data that little of the
debris from the USSR tests in the fall of 1958 appeared far south of the
equator. The model would be expected to strongly underestimate the Sr in
the lower latitudes at the end of 1958 and in 1959.
and Pretoria in Table 7 seem to confirm this,
90
Soil analyses provide only cumulative Sr y
The data from Durban
deposition data, and not
• deposition rates. Since the inherent error (not including sampling) in soil
analysis is about 1Q%^ ', the subtraction of Sr soil values to obtain
£ deposition rate is not satisfactory. Thus, the only valid comparison of
m
gummed film data with soils is for accumulated deposition.
There is a factor not accounted for in the comparisons made here.
• Soil values are reported as of the time of collection, while the summed
l
i
l
l
gummed film values are as of their collection date.
These summed values are
therefore too high by about 3% per year, as no allowance has been made for
90
Sr decay after deposition.
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