In the last twenty years, the experience gained under different EC Contracts in the monitoring of the external environmental radiation has permitted to establish common procedures and get a good degree of harmonisation within the participating organisations. As result, two excellent facilities were established (the environmental calibration facilities at Risø National Laboratory and the low-level UDO facility at the PTB) and many scientists participated in comparing different approaches and procedures.

In 1999, an EURADOS Working Group chaired by I.M.G. Thompson published a document "Technical Recommendations on the measurement of external environmental gamma radiation doses" (CEC Radiation Protection Report 106, 1999). In the same year, the WG organised an intercomparison exercise focused on the instruments that are being employed by different countries in large national networks of radiation detectors in order to give early warning of accidents having transboundary implications. A detailed description and preliminary results can be found in Radiat. Prot. Dosim. 92, 89-100 (2000). The conclusions provide the basis for this working group on "environmental radiation monitoring" in the actual EURADOS network.

The first goal for the WG 3 will be to publish the Final Report of the 1999 exercise, emphasising the conclusions and the lessons learned. Due to logistic limitations in the UDO facility at that time, the number of participants was restricted to seven European countries (Austria, Czech Republic, Denmark, Germany, The Netherlands, Portugal and Spain).

The WG 3 goal for the year 2002 is to perform a further run of the exercise inviting countries which did not participate in 1999, including those which are relevant by their activities in the nuclear field (France, United Kingdom). During the last EURADOS General Assembly, institutions from other countries (Sweden, Switzerland, Greece, and Poland) already showed their interest to participate. In addition, laboratories from candidate Member States of the EU will be invited and some contacts with IAEA are also planned.

As other motivation for WG 3, the establishment of reference environmental field stations in Europe will be encouraged. Furthermore, the WG 3 likes to link its activities with other groups with relevant activity in Environmental Monitoring, especially experts on ‘in situ’ gamma spectrometry or the development of new environmental detectors. To this aim, new members are welcomed to join the Working Group. Networking with CEC funded projects related to environmental radiation will also performed.