Radioactivity biological effects

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). 

Nuclear equation, 513 Nuclear masses, 521t Nuclear radiation. See Radioactivity Nuclear reactions biological effects, 527 equations, 513 fission, 523-526 fusion, 526-527,528 mass-energy relations, 520-523,... 

Radioactivity The ability possessed by some natural and synthetic isotopes to undergo nuclear transformation to other isotopes, 513 applications, 516-518 biological effects, 528-529 bombardment reactions, 514-516 diagnostic uses, 516t discovery of, 517 modes of decay, 513-514 nuclear stability and, 29-30 rate of decay, 518-520,531q Radium, 521-522 Radon, 528 Ramsay, William, 190 Random polymer 613-614 Randomness factor, 452-453 Raoult s law A relation between the vapor pressure (P) of a component of a solution and that of the pure component (P°) at the same temperature P — XP°, where X is the mole fraction, 268... 

The chemistry, and hence hazards, of hot, or radioactive, elements parallels that of their cold isotopes. However, the radiation poses additional toxicity hazards. A qualitative classification of selected isotopes in terms of their toxicity is given in Table 10.2. The biological effects of ionizing radiation stem mainly from damage to individual cells following ionization of the water content. Oxidizing species, e.g. hydrogen peroxide. 

P.S. Phut lavtte also Bernard Cob o d the University of Pittsburgh. He hm done great work biological effect of radioactivity. 

Leonard, A., M. Delpoux, J. Chameaud, G. Decat, and E.D. Leonard, Biological Effects Observed in Mammmals Maintained in an Area of Very High Natural Radioactivity, Canadian J. Genetic Cytology 23 321-326 (1981). 

Lebedeva, G. A. (1966). Some findings on the development of cirrhosis of the liver under the influence of radioactive cerium, page 463 in Distribution and Biological Effects of Radioactive Isotopes, Report No. AEC-tr-6944 (National Technical Information Service, Springfield, Virginia). 

Potassium iodine tablets can be used to reduce radioactive iodine exposure to the thyroid gland. According to the National Council of Radiation Protection and Measurement (NCRP), taking 130 milligrams of potassium iodine at or before exposure to radioactive iodine effectively blocks nearly 100% of radioactive iodine from reaching the thyroid (1977). See Table 3.3 for a summary of antidotes for various chemical and biological agents. 

Identification of thymine dimer is particularly easy if the irradiated DNA is obtained from an organism which has been grown on a medium containing radioactive thymine, and thus contains radioactive thymine dimer. The amount of thymine dimer isolated can then be estimated by simple counting of the eluted material. Estimation of the amount of thymine dimer can also be made by measuring the recovery of absorbance at 270 nm produced by irradiation of the aqueous eluate of the dimer spot. The amount of thymine dimer in irradiated DNA has sometimes been estimated without isolation by measuring the absorbance photorecovery of the DNA, and this quantity correlated with the biological effect this seems a potentially hazardous procedure. 

Larsen PR, Conard RA, Knudsen K. Thyroid hypofunction appearing as a delayed manifestation of accidental exposure to radioactive fallout in a Marshallese population. In Biological Effects of Ionizing Radiation 1. Vienna International Atomic Energy Agency, 1978 101. 

Harley (1985) [Available also in Radioactive Waste, see above] 10 Biological Effects of Non-ionizing Radiations Cellular Properties and Interactions by Herman P. Schwan (1987) [Available also in Nonionizing Electromagnetic Radiations and Ultrasound, see above]... 

In 1954, the book by Professor B.N. Tarusov "Principles of Biological Effects of Radioactive Emissions" was published [1] the book made a great impression on me. The author, an outstanding Soviet biophysicist. Head of the Biophysics Department at the Faculty of Biology of the Moscow State University, put forward a hypothesis that the development of radiation-induced disease is associated with the induction of ramified chain reaction of oxidation of fats of cellular shells (membranes), the oxidation products are very toxic for the cell. 

Distinguish the biological effects of radiation and the units used to measure levels of exposure. Illustrate medical and nonmedical uses for radioactivity. 

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