Elimination of tritiated thymidine from birds.

The kinetics with which tritiated thymidine is eliminated from birds and the concentration of radioactivity remaining in the carcass after 350-430 h were measured. Birds injected with tritiated thymidine eliminated 98% of the radioactivity injected within 28 h. Ninety-eight percent was identified in the excreta, and less than 2% of the radioactivity injected remained in the birds 28 h after injection.

Detecting removable surface contamination.

Although surveying for radioactive contamination by wiping surfaces is the norm, this practice can be highly variable and may be inefficient for detecting low-energy beta emitters. Relying on wipe testing may likewise be an inefficient use of personnel and may seriously underrepresent the amount of contamination present. In general practice, it is better to clean and, where applicable, renew surfaces regularly as part of standard operating protocols and work practices.

Management of mixed wastes from biomedical research.

Mixed radioactive and chemical wastes generated by biomedical research were characterized, and various treatment methods for reducing their volume were evaluated. These wastes consist primarily of organic solvents used in the extraction and purification of radiolabeled biomolecules that are contaminated with low levels of the long-lived radionuclides, 3H and 14C. The Rockefeller University's mixed wastes fall into three broad chemical categories: phenol/chloroform, acetonitrile/water, and mixtures of miscellaneous solvents such as carbon tetrachloride, benzene, and other hazardous chemicals.