A comparative study of alternative methods for 210Pb determination in environmental samples
E. Cuesta, A. Barba-Lobo, R.L. Lozano, E.G. San Miguel, F. Mosqueda, J.P. Bolı́var
Abstract
The accurate determination of the levels of 210Pb in environmental samples (e.g. atmospheric aerosols, waters, soils, biota, etc.) is essential due to its multiple applications in geochronology, radiation protection, groundwaters flows, air masses movement, etc. For this purpose, it has been developed a novel and thorough study of three alternative radiometric measuring methods of 210Pb activity concentrations in several types of samples. The three selected methods were low-level gamma spectrometry (210Pb), alpha-particle spectrometry (via 210Po), and Cherenkov counting (via 210Bi). This study has been performed in terms of precision, linearity and proportionality as well as spent time, type of matrix, and showing the most appropriate method of measure in each case. Several kinds of samples were analyzed such as atmospheric filters, soils, sediments and phosphogypsum (PG) matrices. These samples contain different 210Pb activity concentrations and were measured by the three techniques carrying out radiochemical procedures when necessary. There were not significant differences in the results obtained for the samples analyzed by the three methods. The major precision was obtained by using alpha-particle spectrometry, but this method is more expensive and time consuming.