DISCUSSION OF iM@SULTS
I,
Sr90 Surface iir Concentration Data
Larre air blower samples,collected over tine last several vears at tie Naval
Research Laboratory, “Iasnineton, D, C. by I, H. Blifford and associates, were
made available to us for Sr?0 assav,
Collections were made on irmy Chemical
Cerne T:-pe V filters of 200 square inches area and of heavy asbestos fiber
composition,
Collection volumes ranzed from about 1 to S million cubic feet
of air for collection neriods of one day to one week,
The large blower samples
vihieh were analvzed from Sr?0 were collected from four locations:
Washinston,
, Cog Kodiak, ‘leske; Port Lyautey, French Morocco; and Yokosuka, Janan,
4
summary of the Sr90 concentration data, together .:ith the location, collection
veriod and sample volume for each sanple, is presented in the last section of
this report,
The “fashineton, D. ©. Sr90 air concentration data are presented in Figure
1.
For these sarples, the volumes were cemputed from recorded flow rate data.
Figure 2 shows the variation in total flot with length of the collection due
to dust loedine of filtersat the Tasnin-ton, 0. C. station.
This curve was
obtained from ifr, Blifford at the Naval Research Laboratory, who indicated
quite large variations of individual collection volumes from the average
values sho-vm.
The data “or the three foreien stations are presented in Figure 3,
For
these, the collection volumes were not monitored and the volume of each sainple
wes estimated b* assuminr the effect of dust loading observedotpshington, B.C.
(Figure 2)
applied equally well et these other locations.
The necessity of
makint this essumption imposes a restriction on comparison of relative air
concentrations for the Jour locations but dces allov us to consider the change
in alr concentration zith time at each location,
SS