During this winter, the concentration of radon gas has been constantly measured for three months in ten facilities of the Masnou City Council (Maresme), located in different areas of the municipality. 122 detectors have been placed in different rooms and spaces of these buildings. Of the total number of sensors, only two have given results higher than the annual average reference level (300 Bq/m³), set by the Regulation on health protection against risks derived from exposure to ionizing radiation (RD 1029/2022). .
The first room in which a higher concentration of radon has been detected (512 Bq/m³) is the workers’ locker room of the Municipal Sports Complex, located in the basement of the facility’s oldest pavilion. The other room where this circumstance has been recorded is an office at the Can Mandri Senior Citizens’ Center (414 Bq/m³).
The City Council has already implemented preventive measures in these spaces. The basement of the affected Sports Complex will no longer be used until the intervention recommended by the same study is carried out, which dictates that no one should spend more than 50 hours a year in this room. The proposed corrective measure is to excavate a manhole beneath the basement floor, in contact with the subsoil and permeable to gases. Thus, this cavity will capture the radon gas emitted by the ground and evacuate it through a duct that will act as a chimney. This should stop gas from accumulating in the basement.
The solution proposed in the Casal de la Gent Gran office is much simpler: the space must be ventilated often, taking advantage of the fact that it has windows, or an air renewal system must be installed that guarantees overpressure in the room. It should be said that the study recommends the same measure, ventilating often, in two other spaces that do not exceed the reference limit but are close to it. One is another room of the same Casal (239 Bq/m³). The other, the citizen service office of the Local Police station (287 Bq/m³).
During the next fall and winter, the concentration of radon gas will be measured again in these equipment, especially in the rooms where the highest concentration has been detected. It will therefore be checked whether the corrective measures work. The study carried out this winter was requested by the El Masnou City Council at the Technical Office of Environmental Assessment and Management of the Barcelona Provincial Council, which commissioned it from the specialized company Tüv Nord Acpro. Masnou has been the first municipality in the province to request that the Barcelona Provincial Council carry out a radon gas concentration study.
The El Masnou City Council has launched these actions in compliance with the motion approved by the Municipal Plenary on December 22, 2022 and in accordance with the map of radon potential in Spain prepared by the Nuclear Safety Council (CSN, 2017 ) as one of the tools of the National Action Plan against Radon. Almost the entire Maresme region is one of the areas that the CSN has declared priority action. These are the territories of the Spanish State in which, due to their geological characteristics, they have a greater risk of radon concentration and it is more likely to find buildings with high levels of this gas.
What is radon gas?