Determination of leachable uranium in airborne particulates

The uranium content of airborne particulates collected on cellulose filters was investigated. As a case study, filter samples from the large area of Thessaloniki, Greece, were used. For the uranium determination instrumental neutron activation analysis was used. To obtain equal counting conditions for all samples after irradiation, independent from the initial matrix, uranium was leached from the filter by using a 0.1M NH₄HCO₃ solution, forming a stable uranyl complex UO₂(CO₃)₃]. This complex was absorbed in a batch process on a small amount of chelating ion exchanger Srafion NMRR, which was directly irradiated in the reactor of the NCSR Demokritos. The study showed that over the investigated time period in 1997 the mean concentration was found to be 0.047 ng U/m³. In relation to the collected amount of airborne particulates having a mean concentration of 0.52 ng/gU. It can be assumed as a natural uranium level in the environment.