Boundary layer ozone in Osijek, eastern Croatia

Results of the first ozone monitoring in ambient air in eastern Slavonia are reported for the growth season in 2002 (April through September). The monitoring site at the northern boundary of the city was chosen to distinguish two types of air masses: one from the rural and marshy region to the north and the other urban and suburban from the south. The measured hourly average ozone volume fractions varied between 0 and 80 ppb, the average being 35 ppb. The low value indicated that the air is well mixed. No significant differences were found between air masses from the north and from the south. Thus, no significant photochemical pollution problems are expected for the city Osijek.