Radionuclide uptake

Millard, J.B. and F.W. Whicker. 1990. Radionuclide uptake and growth of bam swallows nesting by radioactive leaching ponds. Health Phys. 58 429-439. 

Medical personnel working with highly contaminated patients should consider performing a urine bioassay 24 to 72 hours after exposure to check for evidence of radionuclide uptake. About 20 mL of urine... 

Experimental studies. Sorption of radionuclides by colloids is affected by the same solution composition parameters discussed in the previous section on sorption processes. The important parameters include pH, redox conditions, the concentrations of competing cations such as Mg " " and K, and the concentrations of organic ligands and carbonate. The high surface area of colloids leads to relatively high uptake of radionuclides compared to the rock matrix. This means that a substantial fraction of mobile radionuclides could be associated with carrier colloids in some systems. The association of radionuclides with naturally occurring colloids and studies of radionuclide uptake by colloids in laboratory systems give some indication of the potential importance of colloid-facilitated radionuclide transport in the environment as discussed below. 

Evaluation of radionuclide uptake by hepato-cytes (parenchymal phase) assessment of liver function... 

After a radionuclide intake has occurred, any radionuclide remaining within the organ of intake will irradiate that organ or tissue. The rate at which the radionuclide leaves the site of intake by dissolution and absorption into the blood depends on the physical and chemical properties of the materials present. The term uptake is used to describe the quantity of the radionuclides that is absorbed into the blood after an intake has occurred. After absorption, portions of the radionuclide will be deposited in, and irradiate other organs and tissues as illustrated in Fig. 6.5. Fractions of the radionuclide uptake are excreted by various routes, such as in urine or faeces. A portion of radionuclide deposited in an organ may be recycled (i.e., returned to the blood) so that it is again available for deposition in an organ or excretion from the body. 

Ellis, K.M. and Smith, J.N., Dynamic model for radionuclide uptake in lichen. J. Environ. Radioactivity, 5 (1987) 185-208. 

The general principles of metal uptake by biota from soil systems are treated in chapters 7 to 10 of the book. The same rules govern radionuclide uptake by biological systems. Uptake and assimilation depend on the chemical and biological properties of the element. The rate-limiting step for the uptake of many radionuclides, those strongly immobilized by soil constituents, is the movement to the interface between the soil solution and the biological membrane. If absorption is more rapid than the movement of the solute to the interface, uptake becomes diffusion limited. The adsorption properties of the soil are therefore determinant. 

Shaw, G., Bell, J. N. B., Minski, M. J., and Nair, S. (1990). Experimental Studies of Radionuclide Uptake and Retention by Crops Under UK Field Conditions, final report of research contract undertaken by the Imperial College Reactor Centre (Silwood Park, Ascot) for Berkeley Nuclear Laboratories (CEGB, Berkeley, CA), Gloucestershire, England. 

MECHANISMS INVOLVED IN HEAVY METAL AND RADIONUCLIDE UPTAKE BY AM FUNGI AND MYCORRHIZAL PLANTS... 

The-long-term ffects-of-phosphate fertilization on radioactivity have been studied in the United States. TSP produced from Florida phosphate rock and applied at the rate of 30 kg/ha of P durir more than 50 years did not change the concentrations of U, Th, and Ra in corn leaves d grain, wheat grain and straw, or soybean leaves and bean in comparison with nonfertilized plots. The soil conditions facilitating radionuclides uptake by the crops have not been studied iii detail however, it is obvious that radionuclides present in the soil solutions are absorbed by the plants. 

Figure 68. Crayfish (Cambarus longulus longerostris) whole-body retention of after 7 days of radionuclide uptake from water. The points through day 4 are means of 5 animals 1 S.E. those from days 7-14 are the means of 2 animals 1 S.E. From Reed and Martinedes (1973).

Yousef, Y. A., T. J. Padden, and E. F. Gloyna. 1975. Diurnal changes in radionuclides uptake by phytoplankton in small scale ecosystems. Water Res. 9(2) 181-187. 

Environmental Problems—This section describes N Reactor operational activities that affected the environment. The affected environs are groundwater contamination (radionuclides, volatile organics, polychlorinated biphenyls (PCB), metals, and other Inorganics) soil contamination (surface and vadose zone contamination from radionuclides and organic compounds) biota contamination (flora [vegetation] and fauna [animals] from radionuclide uptake by plants or Ingestion by animals) and evaluated radiation at the Columbia River (unshielded sediments In the 1301-N Liquid Waste Disposal Facility). 

Thyroid iodine content measurement helps for the diagnosis of hyperthyroidism with undetectable radionuclide uptake... 

Radionuclide uptake in and efflux from isolated cells can detect enzyme activity, transport, and permeability of the apical and basolateral membranes. The weakness of this method is that it cannot differentiate a carrier from a channel (Sim and Gondos 1986), nor identify the exact permeability route (Todd, Inman et al. 2000). To circumvent this problem hydrophilic permeability probes such as [ Cr]-EDTA or [ " C] -maimitol can be used, which are markers that permeate mainly through the paracellular pathway (Bjamason, MacPherson et al. 1995 Nylander, Pihl et al. 2003). The transepithelial transport of [ " CJ-maimitol across the epithelial cell monolayer was assessed by the apparent permeability coefficient, Papp, according to the following equation ... 

Wieland, E., B. Lothenbach, M. Glaus, T. Thoenen and B. Schwyn (2014). Influence of superplasticizer on the long-term properties of cements and possible impacts on radionuclide uptake in cement based repository for radioactive waste . Applied Geochemistry 49 126-142. 

---