Skin Exposure Reduction Paste

A. Skin Exposure Reduction Paste Against Chemical Warfare Agents.577... 

This new product was called Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA), SERPACWA consisted of fine particles of polytetrafluoroethylene (PTFE) solid dispersed in a fluorinated polyether. The excellent barrier properties of this polymer blend were related to the low solubility of most materials in it. SERPACWA is now a standard issue item to U.S. forces when there is a threat of CWA use. 

Table I shows that a 3x3.5 cm dorsal skin wound on a Wistar rat can ooze out 2.2 ml of serous fluid in about 3 days. This fluid volume is reduced to 1.2 ml, if the wound is exposed for 3 hr before treatment. Beyond the 3 hr exposure, there may be further reduction in oozing, but the chance of eschar formation will also increase. Various compositions of the AgN03 medicated dextran hydrogel paste have been evaluated. The one with a good spreadability and fluid absorption has been used in the present study. Measurements by a simple hygrometric method showed that the medicated paste on the wound reduced evaporative loss by almost 50% as compared to an open wound which had a rate of 93 mg H20/cm /hr (7.). On subsequent days, the relatively steady value of 12.5 mg H20/cm /hr was about 2x higher than the evaporative loss of the paste spread over a plastic sheet used as a control. The higher evaporative rate of the paste on the wound site might be due to the transmission of excess moisture from the wound surface. The oozing serous fluid had apparently been first absorbed into the paste, because no exudate accumulation was ever observed under the paste coating. The humectant in the paste which retained moisture obviously must have kept the wound surface sufficiently moist to prevent eschar formation.

The expected adverse effects of increased levels of uv-B radiation include increased incidence of skin cancer in fairskinned races, decreased crop yields and a variety of stresses on terrestrial and aquatic ecosystems. Such effects have been considered in the past in connection with possible reduction of the ozone shield by the operation of fleets of SST airplanes [65] and by the continued release of chlorofluoromethanes used as refrigerants and as propellants in aerosol spray cans [66]. The information available is insufficient to allow quantification of most of these effects. Epidemiological data were used in the NAS study [1] to estimate that a 50 % ozone shield reduction lasting 3 years would lead to an increase of skin carcinoma and melanoma of 3-30 % at midlatitudes, with a geometric mean of about 10 %, that will persist for 40 years. This may be compared with the estimate made in the same study that during the first generation a 10,000 Mt war would increase the spontaneous cancer death rate by about 2 % as a result of exposure to low levels of ionizing radiation from radioactive fallout. 

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