Ingestion of radionuclides

DE Baetolo D, Cantone MC, Giussani a, Gae-lASCHELLi L, Roth P and Weenee E (2000) Determination ofbiokinetic parameters for ingestion of radionuclides of zirconium in animals using stable tracers. Radiat Environ Biophys 39 53-58. 

Safety and operational aspects involve the hazards of ingestion of radionuclides and exposure to radiation [76[. 

Radionuclides MCLG (mgILf MCL or TT (mg/L) Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water... 

ICRP. 1993. Age-dependent doses to members of the public from intake of radionuclides Part 2, ingestion dose coefficients. The International Commission on Radiological Protection. ICRP publication 67. New York, NY Pergamon Press. 

The cow acts somewhat as a filter and discriminator in the transmission of radionuclides from feed to milk. Of the daily quantities of I and Cs ingested, about 1% is secreted in every kilogram of milk produced. For Ba and Sr the rate of transmission is less. Furthermore the cow discriminates against some of the radionuclides in favor of related elements. Thus the Sr/Ca ratio is reduced by a factor of about 10 in the passage from feed to milk. 

EPA. 1988. Limiting values of radionuclide intake and air concentration and dose conversion factors for inhalation, submersion, and ingestion. Federal Guidance Report No. 11. Washington, DC U.S. Environmental Protection Agency, Office of Radiation Programs. EPA-520/1-88-020. 

The RMBC assessed its regional public-health priorities and developed the following nine demonstration projects on the basis of the needs of the community possible correlation of exposure to arsenic in drinking water and type 2 diabetes, a spot blood metals-analysis feasibility study, health-clinic samples for chemical-terrorism baselines, of relationship between urine arsenic and metal concentrations and drinking-water exposure, assessment of exposure to VOCs from subsurface volatilization, cotinine concentrations associated with environmental tobacco smoke, assessment of exposure to mercury from ingestion of fish, analysis of radionuclides in urine, and biomonitoring of organophosphorus pesticides in urine (Utah Department of Health 2006). 

Radiation-induced cancer incidence also could be estimated using calculations of the probability of cancer incidence per unit activity intake of specific radionuclides by particular ingestion and inhalation pathways or the probability per unit activity concentration of specific radionuclides in the environment by particular pathways of external exposure (Eckerman etal., 1999) probabilities of fatal cancers for the different exposure pathways also have been calculated. These probability coefficients differ from those developed by ICRP (see Section 3.2.2.3.2) in that they are calculated with respect to activity of specific radionuclides rather than dose, and they thus bypass the need to estimate the effective dose. For external exposure, the methods used by Eckerman etal. (1999) and ICRP (1991) to estimate responses essentially are equivalent. However, there are significant differences in the methods used to estimate responses from intakes of radionuclides, and the results obtained by Eckerman et al. (1999) differ substantially in a few cases (e.g., intakes of 232Th)... 

ICRP (1996). International Commission on Radiological Protection. Age-Dependent Doses to Members of the Public from Intakes of Radionuclides. Part 5 Compilation of Ingestion and Inhalation Dose Coefficients, ICRP Publication 72, Annals of the ICRP 25 (3/4) (Elsevier Science, New York). 

Inhalation and ingestion of minor quantities of radionuclides. INTERNAL CONTAMINATION No immediate effects. Consult with specialist if possible. 

Inhalation and ingestion of large quantities of radionuclides. No immediate effects. Nasopharyngeal lavage. Early transfer to specialized center to increase excretion. 

The pathways of radionuclides in ecosystems are illustrated schematically in Fig. 21.2. Plants may take up radionuclides from the air by deposition on the leaves, or from the soil by the roots with water and minerals. In this step, the species of the radionuclides and their solubility are most important. Microorganisms incorporate radionuclides present in water or in the soil. Animals and man may be contaminated by radionuclides from the air (gases, aerosols, dust) by inhalation or deposition on the skin, or by uptake of water and via the food chain by digestion. Animals may also be contaminated by ingestion of contaminated soil particles. 

Radiotoxicity depends on the radiation emitted by the radionuclide considered, the mode of intake (e.g. by air, water or food), the size of the ingested or inhaled particles, their chemical properties (e.g. solubility), metabolic affinity, enrichment, effective half-life and ecological conditions. The radiotoxicity of some radionuclides is listed in Table 22.5. The limits of free handling of radionuclides and the acceptable limits of radionuclides in air, water and food are also laid down on the basis of their radiotoxicity. 

It is estimated that the inventory of nuclear reactor waste in the US will reach 1.3 X 10 Bq by 2020 (Ewing, 1999). Decay of the radionuclides from a reference inventory over lO yr is shown in Figure 2. In this figure, the change of ingestion toxicity of radionuclides important for... 

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