Comparison process of air quality measurement systems applied to the context of cultural heritage

Air pollution is a problem that affects both human health and the state of historical artifacts. The interaction between pollutants and historical artifacts leads to a material degradation and therefore to the ruin of the artistic heritage. To define the impact of air quality on historic artifacts, it is necessary to measure these levels through an air quality measurement system. In this study the levels of particulate matter, PM10, PM2.5 and PM1, measured in the historic sanctuary of the Beata Vergine dei Miracoli in Saronno (Varese) were analysed using two measuring devices. Two air quality sensors, operating 24/24h and 7/7 days, were installed inside the sanctuary near the “Last Supper” wooden sculptural group realized during Renaissance period by Andrea da Corbetta and decorated by Alberto da Lodi. Similar concentration values and trends were observed with the two devices. Particulate matter levels were often above the recommended values for conservation and this may pose a threat to the artifacts present in the sanctuary. The two sensors return similar values in both trends and measured concentrations. From the analysis of the particulate matter levels it can be seen that they are high and sensitive to the activities, such as religious services, that take place in the sanctuary.