Comparing different error-conditions in film dosemeter evaluation

In the evaluation of a film used as a personal dosemeter it may be necessary to mark the dosemeters when possible error-conditions are recognised, such as errors that have an influence on the ability to make a correct evaluation of the dose value. In this project a comparison has been carried out to examine how two individual monitoring services, IMS [National Institute of Radiation Hygiene, Denmark (NIRH) and National Research Centre for Environment and Health, Germany (GSF)], from two different EU countries mark their dosemeters. The IMS are different in size, type of customers and issuing period, but both use films as their primary dosemeters. The error-conditions examined are dosemeters exposed to moisture or light, contaminated dosemeters, films exposed outside the badge, missing filters in the badge, films inserted incorrectly in the badge and dosemeters not returned or returned too late to the IMS. The data are collected for the year 2003 where NIRH evaluated approximately 50,000 and GSF approximately 1.4 million film dosemeters. The percentage of film dosemeters is calculated for each error-condition as well as the distribution among eight different employee categories, i.e. medicine, nuclear medicine, nuclear industry, industry, radiography, laboratories, veterinary and others. It turned out, that incorrect insertion of the film in the badge was the most common error-condition observed at both IMS and that veterinarians, as the employee category, generally have the highest number of errors. NIRH has a significantly higher relative number of dosemeters in most error-conditions than GSF, which perhaps reflects that a comparison is difficult due to different systemic and methodical differences between the IMS and countries, e.g. regulations and monitoring programs etc. Also the non-existence of a common categorisation method for employee categories contributes to make a comparison like this difficult.