wAbstract
@A noble approach of studying dust, black crust and host limestones
by using various techniques is presented in this paper. Samples
were collected from limestone monuments located in rural, urban
and industrial areas in Germany and Hungary. The paper focuses
on differences in the mineralogical composition, major and trace
element distribution of materials and their total polyaromatic
hydrocarbons (PAH) concentration having different exposure to
air pollutants. High concentration of gypsum was found in laminar
and dendritic black crusts and even in the dust of both urban
and rural areas, despite the low concentration of SO2
in rural atmospheric environments. The black crusts show a typical
microfabric with distinct layers of various gypsum-calcite mineral
associations, silt-sized mineral fragments and black particle
content. In dust, newly formed gypsum crystals were found along
with mineral fragments, and siliceous and, less frequently, carbonaceous
fly ash particles. High concentration of lead was found both in
samples of urban and rural areas of Germany and Hungary. Lead
mostly accumulates in dust and also in the black crust. Highest
lead concentrations were found not on the surface of the black
crust, but close to the crust/limestone boundary according to
LA-ICPM analyses. It indicates that despite the ban of leaded
petrol, lead is still present in the dust and the in the soiled
zones of the built environment. Similarly to lead, no significant
difference in the total PAH content of dust and crust samples
were found in the two countries. Dusts are equally enriched in
PAH in both countries, whereas black crusts contain fewer amounts.
Most of the aqueous extracts of the samples were saturated with
respect to sulphate, which also indicate the presence of gypsum,
whilst in some German samples unsaturated conditions were detected.
In summary, by using a combination of these analytical techniques,
it was possible to distinguish rural and urban samples and to
outline the role of dust in bringing pollutants to the stone surface.
It is suggested that the analysed dust and stone samples indicate
not only present, but also the past, pollution fluxes and as a
consequence stones similar to sediments or surface waters can
be used as environment indicators.
Keywords: Stone decay; Atmospheric pollution; Dust; Gypsum; Lead;
PAHx
Introduction
Materials and methods
@Sites
@Air quality
@Sample description
@Analytical methods
Results
Discussion
Conclusions
Acknowledgments
References