Study of indoor air quality and microclimatic conditions in the Sanctuary of the Beata Vergine dei Miracoli in Saronno

The Sanctuary of the Beata Vergine dei Miracoli was built between the XV and XVII centuries and is located in Saronno, a small town in the Lombardy region of Northern Italy. Once the architecture of the sanctuary was completed at the start of the XVI century, some of the most renowned and influential artists of the time were summoned to work on the interior decorations [1]. Thanks to the work of these artists, the sanctuary is still today the home of several masterpieces, including frescoes, wooden sculptures and carvings. Poor indoor air quality and microclimatic conditions are two factors which contribute significantly to the degradation of works of art such as the ones previously mentioned. For this reason, museums have imposed concentration limits on the major air pollutants, along with temperature and relative humidity ranges that need to be respected [2]. However, the same regulations do not apply directly to sanctuaries and other indoor sites which attract large numbers of people acting as vehicles for the penetration of pollutants from outdoor. Hence, a proper and thorough air quality characterization is of the upmost importance for the safeguard of the works of art in such places.