Radon (Rn) is a gaseous trace element, chemically inert and ubiquitous in soil and groundwater. It occurs naturally as an intermediate step in normal radioactive decay, through which thorium and uranium slowly decay into lead. Radon gas is colourless, tasteless and odourless, even at high concentrations. It is generally unreactive and eliminated from the body. Given that it is radioactive and easily inhaled, however, it represents a concrete health hazard. According to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), radon is the most important source of ionizing radiation related to indoor air quality. Indeed, it is often the single largest contributor to an individual's background radiation dose; though radon-gas hazard level is dependent on local geological differences. Despite its short half-life (3.8 days), radon gas from natural sources can accumulate in buildings and especially, due to its high density, in low areas such as basements and crawl spaces. Epidemiological studies have shown a clear link between breathing high concentrations of radon and incidence of lung cancer, childhood leukaemia, pancreatic cancer and other forms of cancer. Radon is hence a contaminant that affects indoor air quality worldwide and a remediation system is necessary to guarantee good air quality within buildings.

The LIFE RESPIRE project aims to develop a system for the real-time monitoring of indoor radon, to help direct appropriate remediation actions. This will contribute to the implementation of the European directive regarding human exposure to natural radiation (2013/59/EURATOM) which deals primarily with indoor radon, and encourages national action plans to identify areas where a significant number of buildings have average radon levels exceeding national reference levels (i.e. Radon Prone Areas, RPAs) and to propose remediation. The project will also help in the direct measurements of soil gas radon, which coupled with geological data, are widely used to define the geogenic radon potential (GRP) of an area (i.e. an estimate of Rn originating from geological sources). The GRP can then be used to guide indoor surveys, as indoor radon values are often highly variable.

The main specific objectives of the RESPIRE project are to:

• Demonstrate in four representative areas in Italy and Belgium, with different GRPs, a cost-effective and eco-friendly solution for the real-time measurement and remediation of radon, to keep indoor radon levels below 100 Bq/m3;
• Construct a real-time geodatabase of continuously collected radon measurements, coupled with other geological, geochemical and building characteristics data; and
• Provide local authorities with radon hazard guidelines and real-time WebGis radon maps for land use planning and health risk assessment, thus facilitating the preparation of national action plans.

  Expected results: The main expected result of the LIFE RESPIRE project, linked to radon measurement, will be the WebGis real-time updated European map of radon concentrations indoors, including geological-geochemical characteristics, soil gas radon activity, radon flux from soil, dissolved radon in groundwater and public waters, GRP and Radon Prone Areas (RPA), and building characteristics (e.g. year of construction, building materials, type of foundations, floor and ventilation).

  The main expected results regarding radon remediation:

• An integrated system for the remediation of natural radon hazard indoors, able to reduce indoor concentrations at demonstration sites to below 100 Bq/m3 (compared to a current value of 500 Bq/m3);
• Questionnaire of risk perception, with over 80% of people living at demonstration sites and exposed to natural hazards informed about the project and radon risks;
• Manuals and guides for dealing with radon risks, and their distribution around Europe;
• Information and dissemination material, integrating field data and modelling results, distributed to inform local authorities about radon and radon-prevention measures during remediation activities and new construction; and
• RESPIRE WebGis radon map produced as an instrument for both researchers and policy-makers, for evaluation of radon risks and to aid the implementation of effective counter measures.