ABSTRACT
Radionuclides are the isotopes of elements that emanate alpha-and beta particles and gamma rays. An alpha particle is a positively charged helium nucleus (He2+) with an atomic mass of 4 and a positive charge of 2+. Beta particles are electrons with a single negative charge (1−) and negligible mass. Gamma rays are extremely short-wavelength electromagnetic radiation with no mass and no electric charge. Chronic exposure to these radioactive particles can cause cancer. Radon, a radioactive gas and a daughter element of radium is one of the leading causes of lung cancer in the United States. Many radionuclides are found in the environment in surface-, ground-, and wastewaters, soils and sediments, and in air in trace but detectable quantities that can pose health hazards to humans (Patnaik, 2007). Such radioisotopes are generated from natural sources as well from the human activities. All the elements form unstable radioisotopes. Several such isotopes, especially those of the lighter elements have found a multitude of applications in industry, mining, and medicine. e radionuclide of the heavy elements, such as uranium, plutonium, thorium, radium, radon, and polonium occur in nature. Some of them are used as nuclear fuel, producing many lighter radionuclides as ssion products. ey are generated in nuclear reactions in atomic power plants and in nuclear tests. e half-lives of radioisotopes may range in several orders of magnitude in time scale, from milliseconds to millions of years. e basic QA/QC requirements in such measurements have been described in detail (NCRPM, 1985).
