CLOSING REMARKS Eveerne P. Cronxire Dr. Cronxits. Dr. Dunving, Col. Maxwell, T certainly must admit that I accepted this rather reluctantly, not being by training and experience really qualified te interpret all of the different diverse disciplines and talents that have been discussed here, However, I did accept it, and if you will bear with me for afew moments, I will go over some ofthe things which I primarily looked at perhaps as a physician. The objectives were to try to get someidea of what should be done, some idea of what is actually well known, and where to go fromhere. I will try to take each section rather briefly. Thefirst topic on decay constants, weathering and shielding, produced some rather interesting facts that I had personally not appreciated. Dr. Nagler of the Weather Burcau outlined the input data for their model for the prediction of fallout which embraces the necessary physical paramcters that must be put into Stokes law. However, I detected a rather simple statement that he made as he went over this, that in reality they took past experience and fed past. experience into their machines, and then predicted the fallout, rather than used the actual mathematical model. This seems to indicate thatin this area, not only for the ratherdiffuse planar distribution of fallout material, but particularly to get practical information on drift, turbulence, piling up end inhomogencities that must certainly exist in areas, particularly in urban areas, if fallout should oceur, is really actually measured inside this aluminum build- ing seemed to be somewhat in conflict with the concepts that were later presented by Dr. Borg and Dr. Bond. It appears that many more empiric studies of this sort are indicated to try to bring together experiment and theory. Dr. Breslin pointed out the great effectiveness of simple types of washdown provided the conditions of wetting and adequate volame flow are maintained. The data presented by Dr. Zobel on the emission of fission products very carly after fission confirms the calculations of Borg and gives much further useful information that can be fed into the experimental models. Dr. Mather’s contribution was a most practical point. The spectrometry readings varied considerably with angle from the surface of the ground, and pointed out the practical problemsof shielding, and thatshielding is most effective against the horizon. Dr. Borg pointed out that the Spencer-Fano equations for gamma radiation can be used most effectively to define the spectrum at any point in space from a monoenergetic or polyenergetic source when the necessary factors are fed into the model. The meanor effective Dr. Graveson presented encoureging data on energy of a polyenergetic source is useless. The source mustbe treated as separate, discrete fragments, to study the behavior of each with distance using the appropriate buildup factors to describe the condition in space in which one is biologically interested. Hepointed out that the actual measurements in the field were initial radiation, and those is comparable in its dimensions to the average American home. It appeared that these measurements gave very significant protection, However, the diminution in the intensities method could be well applied to the analysis of the spectrum from afallout field, and in fact, preliminary calculations have indicated its an urgent field for further mathematical and practical study. theeffectiveness of shielding by a building that predicted by theory are veryclose, indecd. Dr. Borg further pointed out that a similar 233