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

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.