. -A a a wos SS . LSA aes, os aS > SD~ a oe ae Fog > A Sots A J BAT ONAL tek 8 ow a “ANE * > > ye “s & TAN. ne - “ss ~ . = we : > Summary at DL 7 2 1a fea ere The sets of data on fallow: frem the U. 3. soils, “ne Ta .t: Mle nevi. dust-fall and the pot and rainfall from New York City and Pittsburgh all indicate that the current gummed film estimates of Sr-90 deposition are in error. This is particularly true for activity attributed to tests in the summer of 1956, The actual Sr-90 measurements show the debris to be much older, and the gummed film data must be recalculated on this basis. It was not possible to recalculate the mass of data involved for this report, but this will be done. In the meantime, the gummed film estimates of Sr-90 must be considered as minimum values, subject to correction. Further samples and analyses on pot and soil samples are required before conclusions can be drawn as to the extent and uniformity of fallout outside the United States. Such work is in progress and will be reparted when the results are completed. - 19 -