Beta particles biologic effects

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. 

It is now usual to calculate the effective dose equivalent (Appendix 1.2). The dose equivalent measured in Sieverts (Sv), takes into account the relative biological efficiency of different radiations. For gamma and beta radiation, the conversion factor is unity, but for alpha radiation it is 20. The effective dose equivalent allows also for the relative importance of irradiation of various organs to the risk of cancer. To convert thyroid dose from beta particles, measured in Gy, to effective dose equivalent, a factor 0.03 is applied. Thus the maximum thyroid doses estimated by Loutit et al. correspond to effective dose equivalents of 4.8 mSv (child) and 1.2 mSv (adult). Adding the external whole body gamma radiation, for which the conversion factor is unity, gives 5.4 mSv (child) and 1.8 mSv (adult). 

Radiation is a phenomenon characterized more by its ability to canse biological effects than where it originates. Radiation was hrst discovered by German scientist Antoine Henri Becquerel, who received the Nobel Prize of Physics in 1903 for his work. Many of the terms associated with radioactivity come from those early pioneers in radiation physics Wilhelm Conrad Roentgen (1845-1923) and Pierre (1859-1906) and Marie Curie (1867-1934), who also received the Nobel Prize in Physics in 1903 for their work on radiation. Ernest Rutherford (1871-1937) is considered the father of nuclear physics. He developed the language that describes the theoretical concepts of the atom and the phenomenon of radioactivity. Particles named and characterized by him include the alpha particle, beta particle, and proton. Rutherford won the Nobel Prize for Chemistry in 1909 for his work. 

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