Analysis of Particle Size and Radioactivity of Atmospheric Dust

Abstract

In Siena, over a period of 3 yr, atmospheric dust was collected by means of impaction and electrostatic precipitation. The radioactivity of the dust collected was analyzed and analysis was made of the particle size distribution. The relations of particle sizes and associated radioactivity are given and the effect of humidity is discussed.

Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA

“…Comparing this value to the known 7 Be concentration of 2-8 mBq m −3 (Yoshimori et al, 2003) we deduce a filter efficiency of 2.4±2.0% or, correspondingly, particle sizes of 0.4 µm. This roughly agrees with observations of radioactive particle sizes after the Chernobyl accident (Devell et al, 1986;Jost et al, 1986) and measured sizes of radioactive dust in the atmosphere (Bergamini et al, 1973). In an auxiliary measurement we exposed in addition to our standard filter a high efficiency particulate air filter (Hunter HEPAtech filter model 30930).…”

Seasonal variation of 210Pb activity concentration in outdoor air of Milan (Italy)

“…3.5 mm. Using this device, there are no losses of radioactive nuclei which are, as well known, mainly attached to sub-micronic particles (Bergamini et al, 1973;Porstendo¨rfer, 1994;Mohammed et al, 2000;Porstendo¨rfer and Gru¨ndel, 2004) and the clogging is reduced also in case of high particulate matter concentrations. It is noteworthy that the unattached fraction of Radon decay products is very small if the particle numbers in the atmosphere are greater than about 10 4 particles/cm 3 (Ga¨ggeler et al, 1995;Mohammed et al, 2000).…”