Granulometrie composition of dust coming from main technological nodes - i.e. from the sinter plant, blast furnace and lead refinery - of the zinc smelter in Poland was investigated. Samples of dust trapped in bag filters were collected. The sieve analysis, sediment analysis and a laser analyzer of granulomeric composition were used in investigations. Mass and particle number contributions of the dust to nine granulometrie fractions having aerodynamic diameters in intervals: 0-2.5, 2.5-5, 5-10, 10-20, 20-32, 32-40, 40-63, 63-100, I 00-250 μm were determined. To determine mathematical functions describing (mass and particle number) changes in the fractional composition of each dust the results were statistically analyzed by applying the nonlinear estimation. Using of the polynomial regression provided a very good correlation between the sought functions and results of measurements. The results of measurements are presented in tables and charts. High degree of granulometrie diversity of the investigated dust samples, depending on the dust formation mechanisms, i.e. on the technology used and composition of raw materials, was noted. High share of the fine particles in the dust may be a serious hazard to human health, especially in the case of breakdown in functioning of dust collectors.

Results of testing air quality in the vicinity of Gliwice transport routes arc presented in the paper. Assessment of air contamination with nitrogen dioxide from motor transport, for typical conditions dominating in big cities of high transit movement without any ring roads was the studies objective. Presented results will be used in the future to determine the impact of opening the ring road on air quality in the city. In the studies, the passive method of sampling, with further application of spectrophotometric technique to determine nitrogen dioxide concentration, was used. Average annual nitrogen dioxide concentrations were based on average daily concentrations measured from July 2004 to June 2005 at 16 measuring points. As they meet conditions for random distribution of measuring days and cover the measuring time, they were treated as average concentrations of nitrogen dioxide in a calendar year and were compared with a permissible concentration to make an assessment of air quality..