Environmental sampling of radioiodine

The distribution of 132I between the sampling components was different. Its radioactive half-life is short, and the activity on the sampler derived from its parent isotope 132Te (Fig. 3.1). The distribution of 132Te (Table 3.1) shows that it was almost entirely particulate. Hence the 30% of 132I found on the molecular sieve, and 5% on the charcoal pack must have derived from 132I which desorbed from the particles, either in the atmosphere or after capture on the filter. 

Elsewhere, two-component samplers were operated to separate the particulate and gaseous (Ig) fractions of iodine from Chernobyl, without attempting to distinguish inorganic and organic gaseous forms. The lpHg ratio was about 0.25 in Scandinavia (Devell etal., 1986), 0.2 at Harwell (Cambray et al., 1987), 0.5 in Japan (Aoyama et al., 1986) and 0.5 in New York (Leifer et al., 1986). The particulate fraction may have been derived partly from discrete particles of fuel disseminated in the accident, but it is noteworthy that the distribution between lp, I, and l0 observed at Munich is not dissimilar to the distribution of stable iodine as reviewed in the next section. 

Noguchi Murata modified the May Pack to include silver wire meshes to catch inorganic iodine downstream as well as upstream of the particulate filter. Activity on the second meshes was ascribed to desorption from particles. However, it is not certain that iodine desorbed from particles, or other surfaces, is necessarily inorganic. In the experiments 

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