Determination of the contribution of long-lived dust to the committed dose equivalent received by uranium mine and mill workers in the Elliot Lake area

In 1945 K.R. May developed and described one of the first cascade impactors. It was used to collect airborne fine particles and classify them inertially into several aerodynamic size ranges. This allowed the determination of size distribution and any subsequent analysis to be carried out as a function of particle size. Today cascade impactors are used extensively for collecting airborne fine particles for gravimetric or chemical analysis, air quality monitoring and stack sampling. A cascade impactor should be calibrated under actual working conditions. In the absence of impactor calibration, the performance may be predicted through numerical calculation techniques developed by Ranz and Wong (1952). Stern et al (1962) or the best available theory developed by Marple et al (1974). The experimental data of Rao and Jaenicke and Blifford, agree well with Marple's theory provided that the conditions of the experiment correspond with those of the numerical model