The goal of the EMN is a harmonized, sustainable, coordinated and intelligently specialized infrastructure to support the needs expressed in the European Radiation Protection Ordinance. Such an EMN under the umbrella of EURAMET is in the founding phase and is being prepared in parallel by the EMPIR project 19NET03 supportBSS with five technical work packages. EURAMET is the Regional Metrology Organisation (RMO) of Europe. The EMN was established by signature on 16 September 2021.

Underground laboratories (ULs) are of great interest and must be adequately tested, a.o. for their natural radioactivity (NR). It is essential from the point of view of safety and radiological protection of people and the success of underground experiments. The article contains a summary of six ULs operating in the Baltic Sea region regarding their NR. The study was performed using specialized measurement methods. The lowest level of NR characterizes salt deposit in Conceptual Lab (Cuprum).

Tritium concentration analyses were performed on groundwater samples collected in wells in the south part of Treviso city, to correlated the presence of tritium with the young age of the water recharge. The results show strong differences in recharge by recent rainwater which reflect the variation in permeability of the sediments. The aquifer analyzed was vulnerable to prolonged drought periods which could produce a worsening of water quality, consequently limiting water availability.

Radon gas is the largest source of public exposure to naturally occurring radioactivity. Radon can also be used, as a tracer to improve indirectly the estimates of greenhouse gases important for supporting successful GHG mitigation strategies. Both climate and radiation protection research communities need improved traceable low-level atmospheric radon measurements. The EMPIR project 19ENV01 traceRadon started to provide the necessary measurement infrastructure and transfer standards.

Sardinia Region promoted a plan to protect the population from exposure to radon gas. Communication activities are ancillary to develop the whole monitoring and risk identification, a work in collaboration among professionals, a dialogue with policy-makers and the community in general, to develop awareness and prevention. Strengths, weaknesses and lessons learned are shown.

There is a growing need in health and climate research for high-quality radon observations. A variety of radon monitors, with different uncertainties, operate across global networks. Better compatibility between the measurements is required. Here we describe a novel, portable two-filter radon monitor with a calibration traceable to the International System of Units, and demonstrate the transfer of a traceable calibration from this instrument to a separate monitor under field conditions.

Indoor/outdoor air exchange on indoor radon concentration was investigated. We evaluated the effect of air exchange on radon concentration in a scale model room. Air introduction was more effective than air extraction to reduce indoor radon, especially at higher flow rates. The presence of plasterboard shields on the inner walls of the room improved the results. This suggests that the combined use of inner coatings and outdoor air introduction are a good strategy for radon mitigation.

Airborne Gamma-Ray spectrometry (AGRS) is a rapid method to identify and quantify natural as well as man-made radionuclides in large areas. The quantitative response of a standard AGRS detection system was simulated with the Monte Carlo radiation transport code FLUKA. Based on validation measurements with radiation sources, the simulation results show superior accuracy compared to previous models. The validated model can be used for an improved calibration of AGRS systems.

A radon long-range atmospheric transport modelling is set up from soil (exhalation) to soil (deposition of its progeny) and the consequent ambient gamma dose rate is evaluated. The whole is statistically assessed in regards to more than 15 000 gamma dose rate peaks. The model has proven to be of the correct magnitude, with room for substantial improvements. It may be used to validate an atmospheric transport modelling and to test any exhalation maps of radon at continental scale.