COMPARISON OF PAH MASS CONCENTRATIONS IN ZAGREB AIR MEASURED AT TWO DIFFERENT LOCATIONS

The purpose of this investigation was to evaluate if there were differences in air concentrations of PM10 particle fraction, particle-bound PAH mass concentrations and PAH content measured in PM10 particle fraction collected at two different locations in Zagreb. Measurements were carried out simultaneously at both sampling sites in the winter (January) and summer (July). Samples were taken by two different samplers. At sampling site A the samples were taken from about 50 m3 of air using a low-volume sampler. At site B PM10 fraction was collected from about 700 m3 of air using a high-volume sampler. Concentrations of PM10 fraction were determined gravimetrically. The analysis of PAHs was performed using a Varian Pro Star high-performance liquid chromatograph (HPLC) and fluorescence detector. In the winter PM10 fraction concentrations at site B ranged from 31.2 m g/m3 to 175.0 m g/m3 and were significantly higher than those measured at site A, which ranged from 12.6 m g/m3 to 154.6 m g/m3. Concentrations of all measured PAHs were from 19.1% to 44.5% higher at site B than at site A, but the differences were not statistically significant. Summer average concentrations of PM10 particle fraction were very similar at both sampling sites. At site B the average concentration was 29.2 m g/m3 and at site A 27.5 m g/m3. Mass concentrations of all measured PAHs were similar at both sampling sites, except for BbF and BghiP which were slightly higher at site B.