Lessons learned from interlaboratory comparisons of bioassay data interpretation

When a set of bioassay data is given to two different dosimetrists, it is likely that these data will be interpreted differently, that different methods and dosimetric models will be applied and therefore different numerical values will be obtained. Thus, it is important for laboratories dealing with internal dosimetry to undergo performance testing procedures such as interlaboratory comparisons of bioassay data interpretation. Several intercomparison exercises have already been organised at national and international levels. The largest one so far was the 3rd European Intercomparison Exercise on Internal Dose Assessment, which has been organised in the framework of the EULEP/EURADOS Action Group, 'Derivation of parameter values for application to the new model of the human respiratory tract for occupational exposure'. The most important lesson learned from these intercomparison exercises was the need to develop agreed guidelines for internal dose evaluation procedures to promote harmonisation of assessments between organisations and countries.     

Demonstration of sliding-filter-controlled soliton transmission at20 Gbit/s over 14 Mm

Soliton transmission of a 20 Gbit/s time/polarisation multiplexed signal over 14 Mm path in a recirculating loop with 46.3 km amplification span has been demonstrated using the sliding-filter soliton control technique. Demultiplexing was achieved by using a polarisation-insensitive electroabsorption modulator     

Robustness of 20 Gbit/s 63 km span 6 Mm sliding-filter controlledsoliton transmission

20 Gbit/s time/polarisation multiplexed solitons have been transmitted over 10 Mm in a recirculating loop with a 63 km amplification span using the sliding-frequency guiding filter soliton control technique. The soliton energy, sliding rate, filter bandwidth and wavelength margins for a BER of 10^-9 have been measured at 6 Mm     

Design and implementation of monitoring programmes for internal exposure (project OMINEX)

The costs of monitoring for internal exposure in the workplace are usually significantly greater than the equivalent costs for external exposure. Therefore, there is a need to ensure that resources are employed with maximum effectiveness. The EC-funded OMINEX (optimisation of monitoring for internal exposure) project is developing methods for optimising the design and implementation of internal exposure monitoring programmes. Current monitoring programmes are being critically reviewed, the major sources of uncertainty in assessed internal dose investigated, and guidance formulated on factors such as programme design, choice of method/techniques, monitoring intervals, and monitoring frequency. OMINEX will promote a common, harmonised approach to the design and implementation of internal dose monitoring programmes throughout the EU.     

IDEAS internal contamination database: a compilation of published internal contamination cases. A tool for the internal dosimetry community

In the scope of the IDEAS project to develop General Guidelines for the Assessment of Internal Dose from Monitoring data, two databases were compiled. The IDEAS Bibliography database contains references dealing with problems related to cases of internal contamination. The IDEAS Internal Contamination Database now contains more than 200 cases of internal contamination. In the near future, the IDEAS Internal Contamination database will be made available to the internal dosimetry community. The database has several potential applications, including: training, testing biokinetic models, testing software for calculating intakes and doses from bioassay data, comparison of data from a new accidental intake with that from previous exposures to similar materials. The database is by no means complete, and this presentation is also an appeal for internal contamination cases to extend and update it.     

Optimising monitoring regimens for inhaled uranium oxides

This paper provides guidance on the most appropriate monitoring procedures and intervals, the likely uncertainties in the assessment of intake and recommendations on appropriate investigation levels for repeated exposures to uranium trioxide, octoxide and dioxide of natural composition.     

Anomalies between radiological and chemical limits for uranium after inhalation by workers and the public

Exposure limits for workers and the public are based on both chemical toxicity and radiation dose. As a consequence of the different procedures used in their calculation they are incompatible, and adherence to one limit may result in a serious breach of the other. This paper explores the background to these limits, the problems posed by their application and proposes how best to achieve compliance with both limits.     

Guidance on internal dose assessments from monitoring data (project IDEAS)

Several international inter-comparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly, mainly due to the broad variety of methods and assumptions applied in the assessment procedure. Based on these experiences, the need of harmonisation of the procedures has been formulated as an EU research project under the 5th Framework Programme, with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project, eight institutions from seven European countries are participating, also using inputs from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. To ensure that the guidelines are applicable to a wide range of practical situations, the first step will be to compile a database on well documented cases of internal contamination. In parallel, an improved version of existing software will be developed and distributed to the partners for further use. Many cases from the database will be evaluated independently by more partners using the same software and the results will be discussed and the draft guidelines prepared. The guidelines will then be revised and refined on the basis of the experiences and discussions of two workshops, and an intercomparison exercise organised in the frame of the project which will be open to all internal dosimetry professionals.     

20 Gbit/s soliton transmission over 19 Mm using sliding-frequencyguiding filters

20 Gbit/s time-polarisation multiplexed solitons have been transmitted over 19 Mm in a recirculating loop with a 35 km amplification span using the sliding-frequency guiding filter soliton control technique. Soliton energy and sliding rate margin measurements are reported for 10 Mm     

General guidelines for the assessment of internal dose from monitoring data: progress of the IDEAS project

In recent major international intercomparison exercises on intake and internal dose assessments from monitoring data, the results calculated by different participants varied significantly. Based on this experience the need for harmonisation of the procedures has been formulated within an EU 5th Framework Programme research project. The aim of the project, IDEAS, is to develop general guidelines for standardising assessments of intakes and internal doses. The IDEAS project started in October 2001 and ended in June 2005. The project is closely related to some goals of the work of Committee 2 of the ICRP and since 2003 there has been close cooperation between the two groups. To ensure that the guidelines are applicable to a wide range of practical situations, the first step was to compile a database of well-documented cases of internal contamination. In parallel, an improved version of an existing software package was developed and distributed to the partners for further use. A large number of cases from the database was evaluated independently by the partners and the results reviewed. Based on these evaluations, guidelines were drafted and discussed with dosimetry professionals from around the world by means of a virtual workshop on the Internet early in 2004. The guidelines have been revised and refined on the basis of the experiences and discussions in this virtual workshop. The general philosophy of the Guidelines is presented here, focusing on the principles of harmonisation, optimisation and proportionality. Finally, the proposed Levels of Task to structure the approach of internal dose evaluation are reported.