The Citizen Observatory of Radon Gas is a participatory science initiative for monitoring indoor radon concentrations and enhancing public perception of risks associated with this gas. Source International carried out the project between 2023 and 2024 in the municipality of Abbadia San Salvatore, near Monte Amiata (Tuscany). This six-month initiative was supported by the RadoNorm consortium of the Euratom program of the European Union, which contributed 25,000 euros.
Radon is a naturally occurring radioactive gas, which is formed in the soil during the radioactive decay of the uranium present in rocks. Radon is the second cause of lung cancer after tobacco smoking in the world (source: WHO). According to the Italian Health Institute, approximately 10% of the 31,000 cases of lung cancer recorded each year in Italy are attributable to radon. The European Directive 2013/59/Euratom sets 300 Bq/m³ as the annual average reference level for radon in workplaces and homes built before 2024. For buildings constructed after 2024, the reference level has been set at 200 Bq/m³.
In September 2023, Source International delivered 231 radon passive samplers to citizens in Abbadia San Salvatore. Passive samplers are devices that allow one to measure average concentrations of a certain gas over the deployment period – in this case, we measured radon for 3 months inside public and private buildings. In total, we monitored 37 classes in 4 schools, 47 offices and workplaces, and 147 private homes. The dosimeters were collected in December 2023 and sent to Harmat srls, an accredited laboratory based in Albano Laziale. The results highlighted that 21% of the sites had radon concentrations above the reference limit of 300 Bq/m³. The average concentration among the 231 sites was 234 Bq/m³, with a minimum value of 48 Bq/m³ and a maximum of 1965 Bq/m³. All classrooms in Abbadia’s middle school had radon levels above 300 Bq/m³, sometimes even doubling the permitted limit. This observation triggered the headmaster and administrators to adopti urgent mitigation measures and plan structural actions to protect the health of students, teachers, and school personnel.
This project represents the first radon-focused citizen science initiative in Tuscany, and the only example of a “bottom-up” (i.e., not led by academic or governmental institutions) radon monitoring project in Italy – an innovative experience that brings citizens at the core of research efforts and public health protection.
The project triggered the Regional Agency for Environmental Protection of Tuscany (ARPAT) to extend the monitoring efforts beyond the three months of the project, which allowed to obtain average yearly values in compliance with Italian legislation. This follow-up involved only 93 households – a fraction of those participating in the 3-month monitoring campaign but still significantly more than the last official ARPAT sampling (2019), which included only 19 measurements.
Following the public presentation of the project’s results (February 2024), the school headmaster and his collaborators adopted several temporary radon gas mitigation measures, adapting them to the radon levels found in each classroom, as recommended by Source International.
The project also prompted local stakeholders – the municipality, the school, ARPAT, and the local health authority – to initiate several roundtables to manage the various phases of health risk mitigation. The mayor of Abbadia San Salvatore reiterated the urgency of moving the secondary school to a new building by 2026.
The project was also a catalyst for regional initiatives on radon. Following our presentation in February 2024, the Region organized several meetings with the mayors of the Amiata area announcing the imminent start of a new radon survey and promoting the establishment of a training course on radon risk for health authorities and local institutions.
Furthermore, with resolution 1579 of 23 December 2024, Tuscany approved the delimitation of the radon risk area, which includes Abbadia San Salvatore and other 10 municipalities. Identifying priority areas is the first step towards the launch of information campaigns that encourage owners in risk areas to measure radon and adopt corrective measures, further initiating radon monitoring programs in social housing. Indeed, 40% (62 of 156) of citizens interviewed at the beginning of the project declared they had never heard of radon before. This figure highlights the urgency of planning and implementing an information and awareness campaign aimed at both citizens and authorities, both of whom have limited knowledge of the topic.
Thanks to the project, citizens have increased their awareness of the risks of radon and mitigation measures, also changing their perception regarding the risks and costs of mitigation interventions.
Last, this project represented a good opportunity for students and teachers to gain more information on the topic with implications in both the public (school projects) and private (risk prevention) contexts.
