IAEA's ALMERA network: Supporting the quality of environmental radioactivity measurements.

The International Atomic Energy Agency coordinates and provides methodological and analytical quality support to the network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA), comprising 150 laboratories in 84 countries. Annual proficiency tests (PTs) are organized for the network laboratories using sets of different samples typically encountered in environmental and food monitoring laboratories. The PT system is designed to respond to the needs of the network for rapid response and reliable measurement results, and to metrological principles and international standards and guides. Comparison of performance of ALMERA and non-ALMERA laboratories in PTs indicates that the "PT - method development - training - PT" strategy adopted for capability building is beneficial to the network.