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metrological quantities

Posted by fbochud on 02 Dec 2011 at 06:50 GMT

I am concerned by reporting a potential contamination as "less than 13 kcpm on Geiger-Müller (GM) survey meter". Such a statement is useless since this highly depends on the type of instrument, way of measurement, type of radiations, etc.
In order to be informative, the authors should have calibrated their instrument and provide an activity contamination per unit of surface (in Bq/cm2). Or they could have said that it was below a given detection limit expressed in term of contamination per unit of surface.

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RE: metrological quantities

Augustine replied to fbochud on 14 Dec 2011 at 09:27 GMT

First of all, radiation measurement under an initial emergency situation differs from the laboratory measurement. According to the web site of radiation emergency medicine network (REMNet), the purpose of body contamination screening is as follows;
It is to assess and determine the degree of suffering of a resident visiting the evacuation center, to classify depending on the level of suffering, and thus to provide them with optimal radiation emergency medical treatment. In concrete terms, the screening is to determine the presence or absence of radioactive material on the body surface or inside the body of the victim, and, if radiation is present in amounts exceeding the screening level, to estimate the amount.
It is not suitable for initial survey of an emergency to identify "an activity contamination per unit of surface", because the precise measurement of a large number of evacuees will need much time. Thus, the exact value of contamination level is not so important under the initial emergency situation. However, all the GM survey meters were calibrated by standard source, and the measurement technique was unified in each survey. When a contaminated person is found, we should estimate body contamination level as an activity contamination per unit of surface by further survey. In this case, several factors you pointed out have to be considered.

No competing interests declared.