Determination of Gross Alpha Radioactivity Content of the Atmosphere

Air particulate matter collected on a filter of high surface retention is counted with an alpha-sensitive detector to establish the gross concentration of alpha emitters present in the sampled ambient air. Since a given alpha emitter cannot be present in a greater concentration than the gross alpha concentration of a mixture of unidentified radionuclides, a gross analysis may eliminate the need for a more time-consuming and expensive analysis for specific radionuclides. While a gross alpha analysis does not yield specific information on the radionuclide composition of a sample, it is simple, rapid, and inexpensive. The method is therefore useful as a screening technique.