title: Scab incidence on pig skin resulting from hot particle exposures under varying conditions.
abstract: External irradiations of pig skin using radioactive sources of less than 600 microm in the largest dimension (hot particles) were carried out. The objective of the study was to determine a threshold for scab induction. Hot particles used included fissioned 235U and activated 170Tm, 17SYb, and 46Sc with maximum beta-particle energies of approximately 1.8 (average), 0.97, 0.47, and 0.35 MeV, respectively. The photon emissions from the fissioned 235U were about 1 MeV per disintegration. The photon emissions from 46Sc were 0.89 and 1.12 MeV, with 100% abundance. Photon emissions from 170Tm and 175Yb were negligible. Responses followed cumulative normal probability distributions; thus, no true thresholds could be determined. Hence, 10% and 50% scab incidence rates (ED10 and ED50, respectively) were determined using probit analysis. For dose averaged over 1 cm2 at a depth of 70 microm, the ED10 (and 95% confidence limits) were 5.1 (2.7-7.2) Gy for 46Sc, 1.3 (0.89-1.8) Gy for 175Yb, 2.8 (1.9-3.5) Gy for 170Tm, 8.5 (5.7-9.8) Gy for on-skin fissioned UC2, and 4.5 (0.9-7.2) Gy for off-skin fissioned UC2. The ED50 values were 12 (8.8-17) Gy for 46Sc, 6.0 (4.3-9.7) Gy for 175Yb, 5.9 (5.1-6.7) Gy for 170Tm, 11 (9.9-19) Gy for on-skin fissioned 235UC2, and 11 (6.2-14) Gy for off-skin fissioned 235UC2.
authors: Department of Advanced Technology, Brookhaven National Laboratory, Upton, NY 11973-5000, USA. darryl.kaurin@mcmail.vanderbilt.edu
authors: D G
authors: DG
authors: Kaurin
authors: J W
authors: JW
authors: Baum
authors: A L
authors: AL
authors: Carsten
authors: C W
authors: CW
authors: Schaefer
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D015994:Incidence; D011832:Radiation Injuries / Q000473:pathology*; D012867:Skin / Q000473:pathology* / Q000528:radiation effects*; D013552:Swine