Three-year assessment of indoor air quality and preservation strategies at the Museo del Violino in Cremona (Italy)

Air quality inside the rooms and showcases of Museo del Violino was monitored during three campaigns between 2022 and 2024 to assess the effectiveness of display cases in protecting violins from airborne pollutants and maintaining suitable microclimatic conditions. Nitrogen dioxide, ammonia, and VOCs were collected using diffusive samplers and analysed according to NIOSH methods (spectroscopic detection for inorganic gases, and gas chromatography with flame ionisation detector for VOCs). Principal Component Analysis was applied to investigate relationships between pollutant concentrations inside the showcases and in the surrounding exhibition rooms. Temperature and relative humidity remained within recommended conservation ranges throughout the study. However, the first two campaigns revealed elevated concentrations of ammonia and limonene (up to 44.4 and 4.2 µg/m³, respectively), together with non-negligible concentrations of benzene (3.2–13.2 µg/m³) and particulate matter (PM10 > 20 µg/m³). Following the implementation of mitigation measures, including modified cleaning practices and activated carbon adsorbers, pollutant concentrations decreased by up to 90% during the third campaign. The study demonstrates that while appropriate temperature and humidity control are essential for preventive conservation, monitoring and managing indoor air pollutants are equally important. Targeted mitigation measures significantly improved air quality highlighting the value of continuous microenvironmental monitoring in museum settings.