Chemical effects of alpha particles

L12. Lind, S. C. The Chemical Effects of Alpha Particles and Electrons, 2nd ed. 

Lind, 11 The Chemical Effect of Alpha Particles and ElectronsThe Chemical Catalog Co., New York, (1928). 

The literature suggests that the toxic effects of Thorotrast are due to the alpha radiation effects of thorium and not to the chemical effects of thorium or of the colloid (Faber 1973 BEIR IV 1988 Taylor et al. 1986 Wesch et al. 1983). Wesch et al. (1983) injected Thorotrast enriched with thorium-230 into rats and found a linear relationship between radiation level and tumor incidence. At a constant radioactive level, an increase in the injected colloidal volume had little influence on the number of liver tumors, but resulted in a decrease in tumor appearance time and, therefore, a decrease in lifespan. The larger colloidal volume may result in a more diffuse organ dose and a less "hot spot" distribution. Injection of the nonradioactive colloid resulted in no appreciable incidence of liver tumors. It is not known whether the colloidal particles induce the liver tumors when given in... 

The study of the chemical behavior of concentrated preparations of short-Hved isotopes is compHcated by the rapid production of hydrogen peroxide ia aqueous solutions and the destmction of crystal lattices ia soHd compounds. These effects are brought about by heavy recoils of high energy alpha particles released ia the decay process. 

In the case of radium, as well as any radionuclide, it is important to note that, in addition to the usual routes of exposure that must be considered (inhalation, oral, dermal, and occasionally parenteral) for toxic chemicals, there is also external and internal exposure to emissions of alpha and beta particles and gamma rays and it is these radioactive emissions which are considered to be responsible for most of the biologically deleterious effects observed in exposed persons. Further information about radionuclides is presented in Appendix B. 

Alpha particles from plutonium cannot penetrate the epidermis, so toxicity is limited to conditions where the substance is present within the body. The primary routes of entry are inhalation, ingestion, or through wounds, cuts, or abrasions. The potential for adverse health effects caused by plutonium isotopes depends on the route of entry and subsequent deposition, redistribution, and retention, which in turn is highly influenced by the physical (e.g., particle size) and chemical forms of the isotope. 

The preceding uncertainty equations presume that all pairs of input estimates are uncorrelated, which may or may not be true. One of the most common examples of correlated input estimates in radioanalytical chemistry occurs when the chemical yield Y is calculated from an equation involving the counting efficiency e. This happens in measurements by alpha-particle spectrometry with an isotopic tracer. In this case, the uncertainty equation can be simplified by treating the product e x T as a single variable. What happens in effect is that the efficiency cancels out of the activity equation and for this reason its uncertainty can be considered to be zero ... 

The interplay between the chemical and nuclear properties of radon makes it a health hazard. Because radon is a noble gas, it is extremely unreactive and is therefore free to escape from the ground without chemically reacting along the way. It is readily inhaled and exhaled with no direct chemical effects. Its half-life, however, is only 3.82 clan s. It decays, by losing an alpha particle, into a radioisotope of polonium ... 

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