8. Some concept of fraction of device which is meaningful in terms of relative gammaradiation hazard should be formulated. The total ionization from all products of a given device could, for example, be computed for a 4-7 ionization chamber. Decay-corrected measurement in the chamber of any fallout sample, whether fractionated or not, would then give a quantity representing a fraction of the total gamma-ray hazard. The definition of contamination index should also be expandedto include the concept of contamination potential at any point in the fal). out area. In addition to the effects of the fission-to-total-yield ratio of the device on the result. ant radiation field, the final value should include the effects of the particle characteristics anq chemical composition of the material as they affect chemical availability and decontamination, Ideally, the value should be derivable entirely from the parameters of the device and its environment, so that it could be incorporated in model theory and used as part of conventional pre. diction procedures. 9. Additional bias studies of collecting instruments and instrument arrays should be per\ formed. If possible, a total collector, an incremental coliector, and a standard collector array! should be developed whose bias characteristics as a function of wind velocity and particle terminal velocity are completely known. This problem, which can be a source of serious error in fallout measurements, has never been satisfactorily solved. To do so will require full-scale tests of operational instruments using controlled airflow and particles of known shape, density, and size distribution. Collectors should be designed to present the largest collecting areas possible, compatible with other requirements, in order to improve the reliability of subsequent analyses. 10. More-detailed measurements of oceanographic and micro-meteorological variables should accompany any future attempt to make oceanographic or aerial surveys of fallout regions if contour construction is to be attempted. It appears, in fact, that because of the difficulty of interpreting the results of such surveys, their use should be restricted to locating the fallout area and defining its extent and generai features. 11. Based on the results presented in this report, and the final reports of other projects, a corrected set of fraction-of-device contours should be prepared for the Redwing shots. These contours may represent the best estimate of local fallout from megaton detonations available to date; however, more-accurate estimates could be made in the future by collecting and analyzing enough total-fallout samples of known bias to permit the construction of iso-amount contours for various important radionuclides. 156