Aerosol composition and properties variation at the ground and over the column under different air masses advection in South Italy.

Aerosol composition and properties variation under the advection of different air masses were investigated, as case studies, by contemporary measurements over the atmospheric column and at the ground in a semi-rural site in South Italy. The absence of local strong sources in this area allowed to characterize background aerosol and to compare particle mixing effects under various atmospheric circulation conditions. Aerosol optical depth (AOD) and Ǻngström parameters from radiometric measurements allowed the detection and identification of polluted, dust, and volcanic atmospheric conditions. AODs were the input for a suitable model to evaluate the columnar aerosol composition, according to six main atmospheric components (water-soluble, soot, sea salt accumulation, sea salt coarse, mineral dus,t and biological). Scanning electron microscope (SEM) analysis of particulate sampled with a 13-stage impactor at the ground showed not only fingerprints typical of the different air masses but also the effects of transport and aging on atmospheric particles, suggesting processes that changed their chemical and optical properties. Background columnar aerosol was characterized by 72% of water-soluble and soot, in agreement with ground-based findings that highlighted 60% of contribution from anthropogenic carbonate particles and soot. In general, a good agreement between ground-based and columnar results was observed. Under the advection of trans-boundary air masses, water-soluble and soot were always present in columnar aerosol, whereas, in variable percentages, sea salt and mineral particles characterized both dust and volcanic conditions. At the ground, sulfates characterized the amorphous matrix produced in finer stages by the evaporation of solutions of organic and inorganic aerosols. Sulfates were also one of the key players involved in heterogeneous chemical reactions, producing complex secondary aerosol, as such clay-sulfate internally mixed particle externally mixed with soot chains.

[Exposure to asbestos in buildings in areas of Basilicata characterized by the presence of rocks containing tremolite]. / Esposizione ad amianto in edilizia in aree della Basilicata caratterizzate dalla presenza di rocce contaminate da tremolite.

Lucania, in southern Italy, is characterized by areas with natural outcrops of rocks containing tremolite. The study aims to assess the risk of exposure to asbestos in the building workers in these areas through environmental sampling near sites for implementation of safety of roads built on serpentinite rocks and personal sampling in a group of persons who work in the building industry and a group of residents engaged in activities without contact with the ground. Near road sites was found the presence of airborne tremolite in 66% of environmental samples with peaks up to 31 ff/l. The analysis of personal samples showed the presence of tremolite in doses higher than the natural background in 100% of the building workers, while there were no fibers in the samples of residents employed in activities without soil disturbance. The study shows that the building in areas with naturally occurring asbestos determines a condition of significant occupational exposure to asbestos. Adequate safety measures for workers exposed are needed.