Internal exposure, radiation,

Miettinen JK, Mussalo H, Hakanen M, et al. 1980. Distribution of plutonium and americium in human and animal tissues after chronic exposures. In International Radiation Protection Society, ed. Radiation protection A systemic approach to safety Proceedings of the 5th congress of the International Radiation Protection Society, Jerusalem, March 1980. New York Pergamon Press, 1049-1052. 

Sikov MR. 1992. Hazards and risks from prenatal irradiation Emphasis on internal radionuclide exposures. Radiat Prot Dosim 41(2-4) 265-272. 

Exposure to natural sources of radiation is unavoidable. Externally, individuals receive cosmic rays, terrestrial X-rays, and gamma radiation. Internally, naturally occurring radionuclides of Pb, Po, Bi, Ra, Rn, K, C, H, U, and Th contribute to the natural radiation dose from inhalation and ingestion. Potassium-40 is the most abundant radionuclide in foods and in all tissues. The mean effective human dose equivalent from natural radiations is 2.4 milliSieverts (mSv). This value includes the lung dose from radon daughter products and is about 20% higher than a 1982 estimate that did not take lung dose into account (Table 32.4). 

If threatened by radiological contaminants after a terrorist attack, an individual can use a folded handkerchief, dust mask, gas mask, or any available material to limit the ingestion or inhalation of contaminants. Potentially contaminated puncture wounds can be washed to limit internal doses, although medical treatment by a trained professional is advised, as described in Chapter 7. A more detailed discussion on reducing exposure to internal radiation is presented in Chapter 4. 

Parker, H.M. (1956) Environmental radiation exposure. Proceedings International Conference on Peaceful Uses of Atomic Energy, vol. 13, pp. 305-10. 

Hakl, J., Hunyadi, I., Csige, I., Gecky, G., Lenart, K.L. Varhegyi, A. (1997) Radon transport phenomena studied in karst caves - international experiences on radon levels and exposures. Radiation Measurements 28, 675-684. 

Butler GC, Veld A. 1967. Evaluation of radiation exposure from internal deposition of three bone-seeking radionuclides. Health Phys 13(8) 916-918. 

Radioisotopes may enter the body by inhalation, drinking, eating, injection, or through broken skin (wound). If the radiation source is inside the body, the exposure is internal and more damaging. No attenuation is provided by skin or... 

Eisenhower s announcement failed to quiet the debate over radiation problems because new recommendations of the National Committee on Radiation Protection soon produced another controversy. The issue stemmed from a decision of the International Commission on Radiological Protection, made public in early 1959, to advise a maximum permissible level for whole-population exposure firom internal emitters of one-hundredth of the occupational limit for gonad-seeking radioisotopes and one-thirtieth of the occupational limit for radioisotopes that do not affect the reproductive cells. Most internal emitters, including strontium 90, cause somatic rather than genetic damage. The action of the ICRP... 

The cabinet system includes full radiation safety in the form of dual, forced breaking door interlocks so that there can be no risk of exposure outside the cabinet. Equally the system is equipped with emergency stops and red lights indicating when X-rays are on, in accordance with the international regulations. 

Radiation Dosimetry. Radioactive materials cause damage to tissue by the deposition of energy via their radioactive emissions. Thus, when they are internally deposited, all emissions are important. When external, only those emissions that are capable of penetrating the outer layer of skin pose an exposure threat. The biological effects of radiation exposure and dose are generally credited to the formation of free radicals in tissue as a result of the ionization produced (17). 

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