Application of EDXRF and Thin Window EPMA for the Investigation of the Influence of Hot Air Heating on the Generation and Deposition of Particulate Matter

Abstract.

This paper presents a systematic micro-analytical study for the assessment of the influence of a typical hot-air “blow-in” heating system on the generation, transport and deposition of suspended particulate matter (SPM) in the church of Rocca Pietore (Italian Alps). This kind of heating system is very popular in cold regions due to its fast response and economic properties. The size, chemical composition and abundance of individual particles responsible for the negative impact on the displayed artworks are determined by ultra-thin window EPMA. EDXRF is used to determine the bulk chemical composition of SPM. Some gaseous pollutants (SO₂, NO₂ and O₃) are sampled with the application of passive diffusion tubes and quantified with ion-chromatography and spectrophotometry. It is pointed out that several deterioration processes, such as the abrasion of the plastered walls, the re-suspension of the particulate pollution and the generation of NO₂ gas, arise mainly from using the heating system. Each of these observations is a concern for the preservation of the displayed works of art.