Gamma-Ray Spectrometry and the Investigation of Environmental and Food Samples

Gamma radiation consists of high‐energy photons and penetrates matter. This is an advantage for the detection of gamma rays, as gamma spectrometry does not need the elimination of the matrix. The disadvantage is the need of shielding to protect against this radiation. Gamma rays are everywhere: in the atmosphere; gamma nuclides are produced by radiation of the sun; in the Earth, the primordial radioactive nuclides thorium and uranium are sources for gamma and other radiation. The technical enrichment and use of radioisotopes led to the unscrupulously use of radioactive material and to the Cold War, with over 900 bomb tests from 1945 to 1990, combined with global fallout over the northern hemisphere. The friendly use of radiation in medicine and for the production of energy at nuclear power plants (NPPs) has caused further expositions with ionising radiation. This chapter describes in a practical manner the instrumentation for the detection of gamma radiation and some results of the use of these techniques in environmental and food investigations

Fate of Radiopharmaceuticals in the Environment

After World War II, the use of artificially produced radionuclides in medicine began and led to great success in the fight against cancer and other diseases. However, the highly radioactive compounds had to be handled with great care to protect patients and hospital personnel from radiation. The survey of these radionuclides in the environment followed some years later. In Switzerland, double-tracked monitoring programs were started. On the emission side, hospitals and industries handling radiopharmaceuticals had to report their consummation of radionuclides yearly. A monitoring program of their waste waters and solid wastes was also started. On the immission side, the remaining radioactive wastes, which were released to the environment, had to be surveyed. Overall, only a few violations of the limits for radiopharmaceuticals were observed over the last 30 years in Switzerland. Nevertheless, the monitoring of radioactivity in the environment remains an important task as long as radionuclides are used in medicine