Current status of biological indicators to detect and quantify previous exposures to radiation. Biological Indicators Working Group.

Hematologic changes following whole-body exposure to gamma or x-ray radiation have been used to estimate dose. The usefulness of this biological indicator is limited because of the recovery of these cells with time, thus making it unsuitable for estimation of dose years after exposure. The same is true for spermatogenic indicators; recovery and restoration of sperm numbers and fertility makes this biological indicator impractical for assessing radiation dose decades after radiation exposure.

Effect of various biological factors on spontaneous marmoset and tamarin colitis. A retrospective histopathologic study.

Histological sections of colons from 69 tamarins (46 Saguinus oedipus and 23 Saguinus fuscicollis illigeri) and 27 marmosets (Callithrix jacchus) that died between 1979 and 1984 were examined for colitis. Evaluated biological factors were species, age at death, source of animals, manner of death, presence of colon cancer, and time after importation. Most normal colons were found in young animals (dead at less than 1 years of age).