HEALTH PHYSICS FUNDAMENTALS

Health physics is the discipline that consists of all the activities related to the protection of individuals and the general public from potentially harmful effects of ionizing radiation. Ionizing radiation comes from two sources  

Natural or background radiation which is radiation emitted by radioisotopes that exist on or inside the earth, in the air we breathe, in the water we drink, in the food we eat, and in our bodies, as well as radiation incident upon the earth from outer space (cosmic rays). Humans have been exposed to this natural radiation for as long as they have existed on this planet. 

Man-made radiation which is radiation emitted by all the radioisotopes that have been produced through nuclear reactions (mainly fission), as well as radiation produced by machines used in medical installations (e.g.. X-ray machines) or in scientific laboratories (e.g., accelerators). 

Health physics is concerned with protection of people from radiation. Since the background radiation has been, is, and will always be on our planet at about the same level everywhere, there is not much a health physicist can do to protect individuals or populations from background radiation. Hence, health physics is concerned with protection of people from man-made radiation. 

A health physicist performs many tasks. He or she, most importantly, 

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Since improperly handled radiation may produce deleterious effects to humans, it is important that individuals who use radiation sources learn the fundamentals of dosimetry, definition of dose units, biological effects of radiation, standards for radiation protection, and operation of health physics instruments. This chapter briefly discusses all these items. If more detailed treatment of these topics is needed, consult the bibliography and references given at the end of the chapter. 

The Division of Chemistry and the Environment of the International Union of Pure and Applied Chemistry (IUPAC) has recently approved the creation of an IUPAC-sponsored book series entitled Biophysico-Chemical Processes in Environmental Systems to be published by John Wiley Sons, Hoboken, NJ. This series addresses the fundamentals of physical-chemical-biological interfacial interactions in the environment and the impacts on (1) the transformation, transport and fate of nutrients and pollutants, (2) food chain contamination and food quality and safety, and (3) ecosystem health, including human health. In contrast to classical books that focus largely on separate physical, chemical, and biological processes, this book series is unique in integrating the frontiers of knowledge on both fundamentals and impacts on interfacial interactions of these processes in the global environment. 

Preusch provided examples of investigator-initiated grant-based projects funded by NIH that address fundamental physical processes and reactions of elements that are important in both global energy cycles and human health. Note that NIH has not solicited proposals in this area, but has supported a considerable amount of research that reflects investigator-initiated ideas in the field. 

General References Crowl and Louvar, Chemical Process Safety Fundamentals with Applications, Prentice Hall, Englewood Cliffs, NJ, 1990, pp. 121-155. Hanna and Drivas, Guidelines for Use of Vapor Cloud Dispersion Models, AIChE, New York, 1987. Hanna and Strimaitis, Workbook of Test Cases for Vapor Cloud Source Dispersion Models, AIChE, New York, 1989. Lees, Loss Prevention in the Process Industries, Butterworths, London, 1986, pp. 428-463. Seinfeld, Atmospheric Chemistry and Physics of Air Pollution, Chaps. 12, 13, 14, Wiley, New York, 1986. Turner, Workbook of Atmospheric Dispersion Estimates, U.S. Department of Health, Education, and Welfare, Cincinnati, 1970. 

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