: Q C ORECLEED SE REO S@CPEthSTP 0018933 _- ly in the stratornphere and the particle size, sithevgh not known, roust be very small, probably less then 0.1 micron, It ig dietributed by the etratospheric winds in the east-west or west-east direction, and thsre is also thought to be a slow circulation toward the poles, Movement into the troposphere can take place by slow settling or by ses.conal changes in the altitude of the tropopzuse, The exckirge may be most prevalent at the break in the trcopcpause near the middle latitudes, Once transfer from the stratosphere is completed, the material will be deposited relatively quickly in the eame manner as intermediate fsllout (Reference 23). 1.2.4 Procedures for the Determinztion of Fallout Partitien. The hazards cf nuclear wezpons testing are agsociated primarily with worldwide fallout, since local fallout can be controlled by selection of the test site and the proper winds aloft so that its arez of depesition will be of However, local fallout has local miner consequence to the population of the world, Introduction of radio; ecological consequences which are not neglibitie Aud 14 aad fuse Spat Lite 2 . . . : . - \ . ° muclides, such es sr79, into the human ervironment viz world-wide fallout his 2 potential effect on the whole population and their significance hes been studied in grezt detzil (Reference 24}, As a result ef theze studies, it has been concluded that certzin radionuclids levels at the sarth's sur. . . . . . Q eptsole limits by restricticas om the rate of nuclear testing. yy qn a face can be tolerated anc thet these levels can Fe mintzined within This is Ezsed on the concept thit a ecrdition of "equilibrium" is rezched in the 23 a cr fe A QuPA Atle t a “o~ wf