Environmental monitoring of sacred artworks – A case study for the search for an index of correlation between particle concentration and mass of fine dust

•Experimental investigation of the parameters of the internal microclimate and particle concentrations (TPS).•Produced pollution by Unburnt Candles or incense.•The survey for monitoring of temperature and humidity and microclimate indoor.•Monitoring and identify the most critical situations for the protection and conservation in situ of the sacred art works normally exposed.•Comparison of the values with the reference limits parameters, to suggested UNI 10829/99. The present work concerns the study of the concentration of Total Suspended Powders (TSP) mainly from uncombusted residues of smoke candles or incense. The aim is identifying the most critical situations for the preservation and conservation in situ of works of sacred art, normally exposed to the veneration of the faithful. These peculiar types of works of art cannot be placed out of context. This because the artifact is an object of worship for many years, it is often object to physical contati by the faithful, subjected to frequent expositions and microclimate changes. Also it suffers an intensive smoking derived from incense and votive candles. The experimental analysis carried out by the authors concerned the monitoring of TSP in the niche of the SS. Crucifix in the Church of St. Papino in Milazzo (ME). The niche, as well as the wooden statue of the Crucified contained, includes a great variety of objects of different nature: bone relics, scrolls, tapestries, precious votive offerings. At present all this precious material is been pouring in clear degradation. The monitoring of TSP was performed using a particle counter and a extractor plug with a collection filter for the gravimetric test. Tools have provided quantitative data of the number of particles per unit volume and the value of particles mass per unit volume, respectively. Then it was possible to determine a correlation marker between the two different instrumental control methods. Scanning electronic microscope analysis, applied to the samples collected, also provided detailed indication on the nature of various inorganic components stored on filters. The research results will lead to the definition of new screening equipment useful for particulate matter filtering or suppression, specifically in churches. These devices can be validated by subsequent and more detailed monitoring surveys.