Emissions and ambient levels of sulphur dioxide in the Rijeka Bay area

During the eighties the city of Rijeka was one of the most polluted cities in Croatia with sulphur dioxide due to high emission of this pollutant from industrial plants. In mid-eighties, annual means of SO2 exceeded 100 micrograms/m3 in the city centre, in the Bakar Bay area varied between 70-80 micrograms/m3, while in the suburban residential area they were up to 40 micrograms/m3. In 1995 annual means were below the guideline value of 50 micrograms/m3 in the whole Rijeka Bay area. Emission inventory based on 1989 data estimated total SO2 emission to approximately 36,000 t a year, 95% of which from industrial sources. The update from 1995 data gave a new estimate of approximately 11,000 t a year, which is a 70.5% reduction of SO2 emission. However, the contribution of emissions from industrial sources remained practically unchanged (95%). The emission reduction resulted in the decrease of ambient levels of SO2. The paper presents trends in SO2 annual mean concentrations in the period 1986-1995 for two urban sites, two sites situated in the industrial area east of the city, and a suburban residential site.