Plastic Scintillators in Environmental Analysis

Environmental analysis is characterized for being a type of determination in which the amount of radioactivity in the sample is very low, usually more than one radionuclide is present and fast response is frequently constrained by the need for an accurate and precise determination. In the environmental field, plastic scintillators have been mainly used for the analysis of alpha and beta emitting radionuclides. This is because the determination of radionuclides is conditioned by the short path of such particles which makes that detector to be placed at a micrometric distance from the emitting radionuclide. This can be done with plastic scintillators prepared in form of microparticles, fibers or foils which are the shapes most suited for the detection of this type of particles. Moreover, as solids, plastic scintillators permit the flow of liquids among them without consuming them and the surface can be modified to retain selectively a certain radionuclide (PSresin). In the present chapter, the characteristics of the measurements of alpha and beta emitting radionuclides with plastic scintillators in the environmental field are described. Moreover, the preparation of plastic scintillators and resins in form of microspheres and foils is detailed. Finally, various applications of plastic scintillators (i.e., solid sample analysis, sensor and continuous monitoring, alpha/beta screening analysis, and selective analysis of specific alpha and beta emitting radionuclides) are reviewed.