ee ee Oe sie pea C. SKIN EXPOSURES Background Information Radioactive fallout debris emits beta particles some of which emerge from fallout material with sufficient range in air to reach from the ground to the head of an erect man. However, in human tissue the range of these beta particles is limited principally to a very small fraction of an inch so that only the skin is irradiated when fallout debris is outside the body. Further, there has been no observed skin damage except from relatively heavy fallout where the radioactive fallout material has remained in direct contact with the bare skin. Even a single layer of cotton clothing apparently greatly reduces the radiation dose from beta particles. Approximately a 500 roentgen dose delivered by beta particles from fallout debris to the base of the outer layer of the skin tissue is required to produce erythema (reddening of the FIGURE 4a.— Highly radioactive fallout material remained in contact with the feet causing severe skin damage—28 days after initial contamination, . let