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BIOLOGICAL EFFECTS OF BLAST. Technical Progress Report

Description: The current state of knowledge relevant to biological blast effects was summarized in a selective manner. Initially, five problems of concern to those who would relate the environmental variations produced by nuclear weapons with biological response and hazard assessment were pointed out. Primary, secondary, tertiary, and miscellaneous blast effects were defined and selected interspecies experimental data of a physical and pathophysiological nature useful in estimating human response were presented. Tentative biological criteria defining safe levels of exposure were set forth as were survival curves for different conditions of exposure in Hiroshima. These were discussed along with the comparative variations in range of the free-field effects as they vary with explosive yield. The fundamental requirement for surviving seconds, minutes, and hours to abet survival for days, weeks, months, and years was emphasized along with the necessity for planning protective measures against all hazardous weapons effects as one attractive alternative for minimizing casualties and maximizing survival in the event of a nuclear war. (auth)
Date: December 1, 1961
Creator: White, C.S.
Partner: UNT Libraries Government Documents Department

TERTIARY BLAST EFFECTS: THE EFFECTS OF IMPACT ON MICE, RATS, GUINEA PIGS AND RABBITS. Technical Progress Report

Description: A total of 455 mlce, rats, gulnea plgs, and rabbits was subjected to lmpact at velocitles ranglng between 25 ft/sec and 51 ft/sec. The deslred velocities were generated by allowlng the anlmals to free-fall from various helghts to a flat concrete pad. The ventral surface of each anlmal was the area of impact. Problt analyses of the 24-hr mortallty data ylelded LD/sub 50/ lmpact veloclties with 95% confldence limits as follows: mouse, 39.4 (37.4 to 42.0) ft/ sec; rat, ft/sec; and rabbit, 31.7 (30.2 to 33.3) ft/sec. The LD/sub 50/ figures for the mouse and rat were slgnificantly higher, statlstically, than those for the gulnea plg and rabblt. The small spread ln the LD/sub 50/ values suggested little variation ln the tolerance of blologlcal systems to impact. Further, the steepness of the mortallty curves lndicated a narrow survlval range to lmpact. Extrapolatlon of the experimental data to the 70 kg anlmal yielded a predicted LD/ sub 50/ impact velocity of 26 ft/sec (18 mph). Literature relevant to the human case was revlewed and the tentative appllcabllity of the predlcted flgures to adult man ls discussed. (auth)
Date: February 28, 1961
Creator: Richmond, D.R.; Bowen, I.G. & White, C.S.
Partner: UNT Libraries Government Documents Department

DETERMINATION OF AERODYNAMIC DRAG PARAMETERS OF SMALL IRREGULAR OBJECTS BY MEANS OF DROP TESTS

Description: Drag coefficients were determined for various irregular objects such as glass fragments, stones, steel fragments, and spheres by means of drop tests for use in a mathematical model to correlate nuclear explosion blast experiments. Drop tests were also made on small laboratory animals and extrapolated to estimate the drag properties of man. A method was developed to estimate the average drag properties of man from his total surface area. (D.L.C.)
Date: June 1, 1960
Creator: Fletcher, E.R.; Albright, R.W.; Goldizen, V.C. & Bowen, I.G.
Partner: UNT Libraries Government Documents Department

EFFECTS OF OVERPRESSURES IN GROUP SHELTERS ON ANIMALS AND DUMMIES

Description: S>Relative biological hazards of blast were studied in two types of communal air-raid shelters during Shots 1 and 8. Dogs, restrained within the shelters during detonation, were studied pathologically and clinically for blast injuries. Two anthropometric dummies were test objects for displacement studies utilizing high-speed photography. Physical data included pressure vs time and air-drag determinations. During Shot 1, animals sustained marked blast damages (hemorrhages in lungs and abdominal organs), three dogs were ataxic. and the dummies were rather violently displaced. In Shot 8, however, no significant injuries were found in the animals, and the dummies were minimally displaced. Analysis of the physical data indicated that blast injuries and violent displacements may occur at much lower static overpressures than previously assumed from conventional explosion data. Furthermore, biological damage appeared to be related to the rate of rise of the overpressure and air drag, as well as the maximum overpressure values. (auth)
Date: September 1, 1953
Creator: Roberts, J.E.; White, C.S. & Chiffelle, T.L.
Partner: UNT Libraries Government Documents Department

MORTALITY IN SMALL ANIMALS EXPOSED IN A SHOCK TUBE TO "SHARP"-RISING OVERPRESSURES OF 3-4 MSEC DURATION. Technical Progress Report

Description: A total of 661 animals was exposed to sharp''-rising overpressures of 3 to 4 msec duration using a shock tube of novel design which produced a pressure pulse similar to that obtained with high explosives. The reflected shock overpressures associated with 50% lethality were 29.0, rabbit, respectively. Other observations included the time of death in mortally wounded animals and gross pathological lesions likely to contribute to mortality. Selected data from the literature bearing upon the influence of overpressure and pulse duration on lethality were reviewed. These included pulse durations ranging from less than 1 msec to 8 sec. The critical pulse duration, that duration shorter than which the overpressures required for mortality increases sharply, was noted to depend upon animal size and to be of the order of many hundreds of microseconds to very few milliseconds for smaller'' animals and a few to many tens of milliseconds for larger'' animals. (auth)
Date: June 15, 1961
Creator: Richmond, D.R.; Goldizen, V.C.; Clare, V.R.; Pratt, D.R.; Sherping, F.; Sanchez, R.T. et al.
Partner: UNT Libraries Government Documents Department

A STUDY OF THE TISSUE RESPONSE TO STERILE DEPOSITS OF PARTICULATE MATERIAL

Description: Thirty-seven sterile materials of common construction usage, common lubricants, and samples of wearing apparel were injected as finely divided particles into the subcutaneous soft tissues of guinea pigs, each in six different sites. At intervals of 3, 7, 14, 21, 30, 65, or 90 days, an inoculation site of each material was excised, in toto, fixed, and examined microscopically. In addition, ten selected materials were injected into the liver and spleen and deposited on the omentum and mesentery of four guinea pigs for each material type. At intervals of 7, 14, 21, and 30 days, one of each group of four animals was sacrificed and a block of tissue containing the inoculum was removed from the tissues and organs, fixed, and examined histologically. The majority of materials induced only a mild and delayed inflammatory response followed by encapsulation at the end of 14 days and a relatively inert fibrous nodule produced by the 2lst or 30th day. Copper particles incited a marked inflammatory response with abscess formation which persisted until the 90th day, although showing signs of subsiding at this time. Cudmium lesions were characterized by a peculiar zone of necrosis about the particle aggregate which persisted until the 60th day. Duraluminum of one type incited a pseudoneoplastic fibrous response. Axle grease, in the early stages, induced one of the most intense acute inflummations, in contrast to that produced by motor oil and ordinary lubricating grease, but the process had subsided and was fibrosed by the end of 30 days. (auth)
Date: October 1, 1957
Creator: Chiffelle, T.L.; Sherping, F.; Goldizen, V.C. & White, C.S.
Partner: UNT Libraries Government Documents Department

BIOLOGICAL BLAST EFFECTS

Description: The scope and nature of several blast hazards are delineated. Tentative criteria are set forth for threshold damage to humans. These criteria are related 10 nuclear weapons in terms of ground ranges and areas involved for one MT and ten MT surface detonations. To allow appreciation of the relative importance of blast with other effects, appropriate values are noted for ionizing and thermal radiation. Four categories of blast hazards are defined, and the character of each is described. The occurrence of combined injuries from pressure, missiles, and displacement is discussed. Experiences in the Texas City disaster of 1947 are reviewed. Selected data relate environmental conditions to gross biologic damage from overpressures, missiles, and impact loading. 86 references. (C.H.)
Date: September 1, 1959
Creator: White, C.S.
Partner: UNT Libraries Government Documents Department

BIOLOGICAL EFFECTS OF PRESSURE PHENOMENA OCCURRING INSIDE PROTECTIVE SHELTERS FOLLOWING A NUCLEAR DETONATION

Description: In two series of experiments 277 experimental animals, including 66 dogs, 52 rabbits, 52 guinea pigs, 63 rats, and 44 mice, were exposed under selected conditions in six different general types of instrumented above- and belowground shelters to blast produced by nuclear explosions. The distance of the several structures from Ground Zero ranged from 1050 to 5500 ft. The most severe alterations in the pressure environment occurring inside the structures followed the detonation of a nuclear device with a yield approximately 50% greater than nominal. The highest overpressure to which animals were exposed was 85.8 psi, the rise time of which was 4 msec. The overpressure endured for about 570 msec. Overpressures ranged from this maximum downward in 15 other exposure situations to a minimum of 1.3 psi enduring for nearly 1346 msec but rising to a maximum in about 420 msec. The latter pressure occurred inside a reinforced concrete bathroom shelter, which was the only surviving part of a house otherwise totally destroyed, at 4700 ft where the outside incident pressure was about 5 psi. Following the nuclear explosions, all animals were recovered, examined, sacrificed, and subjected to gross and microscopic pathological study. All lesions were tabulated and described. The results of pressure-time data, documenting the variations on the pressure environment, are presented and analyzed, and an exploratory attempt is made to relate the alterations in the pressure environment to the associated pathology observed. A critical review of selected material from the blast and related literature is presented. All data are discussed, and the several problems related to the design and construction of protective shelters are noted and briefly, but analytically, assessed. The most outstanding contribution of the field experiments and the related study of the literature was the unequivocal demonstration that the provision of adequate protective structures can ...
Date: October 1, 1956
Creator: White, C.S.; Chiffelle, T.L.; Richmond, D.R.; Lockyear, W.H.; Bowen, I.G.; Goldizen, V.C. et al.
Partner: UNT Libraries Government Documents Department

BLAST BIOLOGY--A STUDY OF THE PRIMARY AND TERTIARY EFFECTS OF BLAST IN OPEN UNDERGROUND PROTECTIVE SHELTERS

Description: Dogs, pigs, rabbits, guinea pigs, and mice were exposed to nuclear detonatiors in two open underground pantitioned shelters. The shelters were of similar constructions and each was exposed to separate detonations. Each inner chamber filled through its own orifice; thus four separate pressure enviromments were obtained. An aerodynamic mound was placed over the escape hatch of each structure to determine its effect on the pressurecurve shape inside the chamber. In one test a sieve plate bolted across the top of the mound was evaluated. Wind protective baffles of solid plate and of heavy wire screen were installed in the shelters to compare primary and tertiary blast effects on dogs. The shelters also contained static and dynamic pressure gages, radiation detectors, telemetering devices, and, in one test, air-temperature measuring instruments, dustcollecting trays, and eight pigs for the biological assessment of thermal effects. One dog was severely injured from tertiary blast effects associated with a maximal dynamic pressure (Q) of 10.5 psi, and one was undamaged with a maximal Q of 2 psi. Primary blast effects resulting from peak overpressures of 30.3, 25.5, 9.5. and 4.1 psi were minimal. The mortality was 19 per cent of the mice exposed to a peak pressure of 30.3 psi and 5 and 3 per cent of the guinea pigs and mice exposed to a peak pressure of 25.5 psi. Many of the rabbits, guinea pigs, and mice sustained slight lung hemorrhages at maximum pressures of 25.5 and 30.3 psi. Eardrum perforation data for all species, except mice, were recorded. Following shot 2, thermal effects were noted. Animals of the groups saved for observation have died from ionizing-radiation effects. (auth)
Date: February 1, 1959
Creator: Ricmond, D.R.; Taborelli, R.V.; Bowen, I.G.; Chiffelle, T.L.; Hirsch, F.G.; Longwell, B.B. et al.
Partner: UNT Libraries Government Documents Department