EFFECT OF FRACTIONATION OF BETA IRRADIATION ON RAT SKIN
Female rats were exposed to a BETA -ray Sr/sup 90/-Y/sup 90/ source at a skin dose rate of 14.6 rads/sec. Total doses of 5000 or 12.000 rads were given in fractions of 200 to 1000 rads at 24- or 48-hour intervals. Daily observation was made during the development of the lesion and subsequently on working days until healing was complete. At 200 rads every 45 hours epilation was the only observable response, even at a total dose of 12,000 rads. This total dose fractionated at 400 rads per 45 hours still failed to cause wet desquaination. Daily exposures of 400 rads to a 6000-rad total produced only dry desquamation. The threshold for wet desquamation lies below 500 rads daily to a 6000-rad total, a dose which produces 50% wet lesions. If the total dose was increased to 12,000 rads at 600 rads/day, all the rats had wet lesions. A dose rate of 1000 rads/day shortened the mean time before appearance of wet lesions at a 6000-rad total dose by 2 days, but 1000 rads per 45 hours reduced to 50% the number of rats having wet lesions. When the total dose at 1000-rad per fraction is increased to 12,000 rads, however, spacing no longer has an appreciable effect. Moreover. the injury induced appears to have reached a maximum, and the injury sustained is similar to that observed in the group receiving a total dose of 12,000 rads, 600 rads daily. (auth)
- Research Organization:
- U.S. Naval Radiological Defense Lab., San Francisco
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-12-016125
- OSTI ID:
- 4300988
- Journal Information:
- Radiation Research, Journal Name: Radiation Research Vol. Vol: 9
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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