Analysis of PAHs (polycyclic aromatic hydrocarbons) and other main components in black crusts collected from the Monumental Cemetery of Milan (Italy)

Abstract

The present work focuses on the chemical characterization of some chemical components present in black crusts collected from the Monumental Cemetery of Milan located in the homonymous city (Northern Italy). Samples of black crusts, recovered over two sampling campaigns, were analysed by using X-ray Diffraction and Fourier Transform-Infrared spectroscopy. Moreover, Ionic chromatography analyses were performed on water extracts of the black crust samples, while High Performance Liquid Chromatography measurements were carried out on dichloromethane/pentane extracts. This approach was used with the aim to identify the presence of polycyclic aromatic hydrocarbons (PAHs) in these black crusts and the pollution sources responsible for their formation. The knowledge of the pollution sources responsible for the degradation phenomena occurring on cultural heritages, such as black crust formation, is fundamental for the identification of proper preservation strategies, as well as for the development of emission reduction policies on a local scale.

The Impact of Air Pollution on Stone Materials

“…They are composed of multiple fused aromatic rings and have a characteristic planar structure. PAHs are persistent environmental pollutants and can be found in black crusts and stone [67,68]; these molecules can be extracted from the matrix and then analyzed by high-performance liquid chromatography (HPLC) [69]. The amount of PAHs found in black crust can be up to 20 ppm [70].…”

“…Combustion-type sources are characterized by a wide range of PAHs, while petroleum and organic sources produce lighter PAH molecules. All studies have suggested that the combustion source is the predominant one [69][70][71][72][73].…”

Monitoring of the concentration of particulate matter, volatile organic compounds and nitrogen dioxide in the Vesuvius National Park

“…In particular, stone materials are strongly damaged by air pollution in urban areas characterized by high anthropogenic emissions [24]. In the limestone's case, for example, black crusts are a common alteration of this material, due to the interaction of sulphur dioxide, PM10, and acidic rain [25,26]. It is well known that NOx concurr in the acidification of rain, thus these Major degradation results in cultural heritagescompounds are important in the degradation of limestone, [27].…”

Development of an analytical methodology based on stable isotope ratios for air quality assessment in cultural heritage

“…Different air pollutants, comprising carbon dioxide (CO2), nitrogen dioxide (NO2), hydrogen sulfide (H2S), sulfur dioxide (SO2), particulate matter, and some persistent organic pollutants, have negative effects on cultural heritage [7][8][9][10][11][12][13][14][15], and at high concentrations can pose risks to human health [16][17][18][19].…”