Monuments as sampling surfaces of recent traffic pollution

The surfaces of the monument were scraped in areas both exposed to atmosphere and sheltered by the architectural elements of the building. The powders were dissolved by microwave-assisted mineralisation with a solution of HCl and HNO(3). The solution was filtered, irradiated and analysed by adsorptive cathodic stripping voltammetry. The powders were also analysed by infrared spectroscopy and X-ray diffraction in order to determine the chemical and mineralogical composition.

A new approach towards monuments, considering them as a passive sampler of pollution, is presented. Cultural Heritage objects suffer daily the damages of environmental pollution, especially in those areas interested by heavy traffic. Since monuments undergo only periodic conservation or maintenance works, surfaces are able to accumulate atmospheric deposit and to record changes in its composition. An optimised analytical protocol was developed in order to quantify platinum and rhodium at trace level on surfaces. The two elements have become tracers of automobile emissions in recent years, since the introduction of catalytic converters, and could have catalytic effects on the decay reactions of natural and artificial stone materials. As a first case study, the cement mortar surfaces of a twentieth century monument, the Camerlata Fountain, in Como (Italy) were investigated.