Wanda Wilczyńska-Michalik

Fine and ultrafine TiO2 particles in aerosol in Kraków (Poland)

Abstract During single particle analysis of aerosol in Kraków (Poland) we noticed a new component, that is, aggregates of TiO2 particles. These aggregates are from 0.5 to 4 μm and are composed of individual particles whose size typically varies from between 100 and 350 nm. Smaller particles (below 100 nm) also occur. TiO2 particles are relatively abundant in the summer. The size distribution of the particles corresponds to “pigmentary” TiO2, which indicates that they could be derived from paints and building materials. TiO2 particles were not previously identified in aerosol samples in Kraków, and therefore this phenomenon is likely to be related to the common usage of new building materials and paints. A review of the literature suggests that TiO2 particles, especially within the nanosize range, could result in health and environmental impacts; however, evaluation of the actual threat is difficult.

WEATHERING OF CARBONATE ROCKS IN A POLLUTED URBAN ATMOSPHERE: THE MECHANISM OF PROCESSES

For a long time, salt weathering was a dominant process of rock decay in polluted atmosphere in Kraków. Weathering zones developed on the Middle Triassic dolomite surfaces exposed to direct rain-washing and sheltered from rain were studied in order to discuss the influence of exposure conditions on the mechanism of weathering. Optical microscopy, scanning electron microscope with energy dispersive spectrometer, and Xray diffraction were used. On the walls exposed to rain, fragments exposed to intensive washing by rainwater are bright and devoid of secondary minerals. Less intensively washed surfaces are covered by a black brittle gypsum-rich crust. On the surface of the sheltered walls a dark grey crust has developed. It is composed of loosely packed agglomerations of platy gypsum crystals with abundant dust particles. Crystallisation of gypsum from rainwater and reactions of sulphur-containing components from the rainwater with Ca ion from the rock are important in the formation of black gypsum crust. The deposition of dust particles and adsorption of sulphur-containing components are the most important factors in the grey crust formation.

AIR POLLUTION IN KRAKOW – A GLANCE INTO THE FUTURE FROM A HISTORICAL PERSPECTIVE

High concentrations of air pollution probably occurred in Krakow in the nineteenth and early twentieth centuries. Since the late 1960s due to the development of monitoring networks level of air pollution is well documented. In the past few decades, a considerable drop in SO2 concentration has been observed in conjunction with a major increase in the particulate matter and nitrogen oxides concentrations. The complex composition of aerosol particle samples (quartz, feldspars, clay minerals, carbonates, sulphates, chlorides, aluminosilicate and iron or iron oxide spherules of industrial origin and soot) suggests the multiplicity of their sources. In the near future, increased concentration of very fine particles and precursors of photochemical smog should be expected because of increasing emission from vehicle engines.

Characterisation of solid particles emitted from diesel and petrol engines as a contribution to the determination of the origin of carbonaceous particles in urban aerosol

Solid particles emitted from diesel and petrol engines were studied using a scanning electron microscope fitted with an energy dispersive spectrometer. The soot emitted from different engines under different operating conditions differed in particle size, and the form and size of aggregates. Identification of the soot particles emitted from diesel or petrol engines in urban aerosol based on their size and morphology was found to be impossible.

CELESTITE IN THE WEATHERING CRUST ON LIMESTONE EXPOSED TO AN URBAN ATMOSPHERE IN CRACOW (POLAND)

Celestite in the Weathering Crust on Limestone Exposed to an Urban Atmosphere in Cracow (Poland) Celestite containing very low amounts of barium occurs in weathering reaction zones developed on the Pińczów limestone exposed to the polluted atmosphere of Cracow. The mineral occurs both in limestone pore spaces filled with gypsum and in black gypsum crust. The Pińczów limestone contains ca 500 ppm strontium which was released during the reaction with atmospheric pollutants. The nucleation and growth of celestite, requiring significant concentration of components in evaporating solutions, is associated with gypsum crystallization.