KAZALCI OKOLJA

The main sources of sulphur dioxide (SO2) emissions are large thermal power plants and heat production plants and in urban areas also small and medium-sized coal-burning boiler facilities. SO2 is also produced in certain processes in industry (e.g. cellulose production plants).

The indicator shows the frequency in exceedances of 1-hour limit concentration value (350 μg/m3) and the frequency in exceedances of 24-hour limit concentration value (125 μg/m3) for SO2 in the major Slovenian urban areas by individual year.


Charts

Figure ZR05-1: Number of hours with SO2 concentrations exceeding average 1-hour limit value (350 μg/m3) in Slovenian urban areas
Show data
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
Ljubljana number of hours 80 51 13 16 32 39 14 14 0 0
Maribor number of hours 41 7 0 0 0 0 0 0 0 0
Celje number of hours 94 104 22 11 0 4 4 0 1 1
Trbovlje number of hours 249 162 61 46 17 52 14 18 12 20
Zagorje number of hours 219 137 71 22 31 48 38 49 15 25
Hrastnik number of hours 110 82 24 14 23 58 24 40 11 14
Nova Gorica number of hours np np np np np np np np np np
Murska Sobota - Rakičan number of hours np np np np np np np np np np
Velenje number of hours 38 27 16 0 2 3 6 13 6 0
Šoštanj number of hours 324 318 218 131 175 127 289 249 324 334
Topolšica number of hours 209 194 83 9 26 38 62 33 47 2
2002 2003 2004 2005 2006 2007 2008
Ljubljana number of hours 0 0 0 0 0 0 0
Maribor number of hours 0 0 0 0 0 0 0
Celje number of hours 0 1 1 0 0 0 0
Trbovlje number of hours 10 28 np 17 1 0 0
Zagorje number of hours 15 33 72 17 0 0 2
Hrastnik number of hours 43 8 49 12 0 0 0
Nova Gorica number of hours 0 0 0 0 0 0 0
Murska Sobota - Rakičan number of hours 0 0 0 0 0 0 0
Velenje number of hours 1 1 0 0 0 0 0
Šoštanj number of hours 228 108 47 22 12 11 1
Topolšica number of hours 13 5 0 0 0 0 0
Figure ZR05-2: Number of days with SO2 concentrations exceeding average 24-hour limit value (125 μg/m3) in Slovenian urban areas
Sources:
Show data
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
Ljubljana number of days 38 28 2 3 1 1 1 0 0 0
Maribor number of days 22 7 1 0 0 0 0 0 0 0
Celje number of days 50 36 18 8 0 4 0 0 2 0
Trbovlje number of days 59 53 25 21 7 8 4 3 1 2
Zagorje number of days 61 48 28 14 6 0 5 4 3 3
Hrastnik number of days 50 28 4 4 3 4 0 2 1 1
Nova Gorica number of days np np np np np np np np np np
Murska Sobota - Rakičan number of days np np np np np np np np np np
Velenje number of days 4 1 1 0 0 2 0 1 0 0
Šoštanj number of days 41 37 25 14 22 17 34 30 44 52
Topolšica number of days 29 30 12 1 1 2 5 6 4 0
2002 2003 2004 2005 2006 2007 2008
Ljubljana number of days 0 0 0 0 0 0 0
Maribor number of days 0 0 0 0 0 0 0
Celje number of days 0 0 0 0 0 0 0
Trbovlje number of days 1 0 0 1 0 0 0
Zagorje number of days 1 1 8 1 0 0 0
Hrastnik number of days 5 0 4 0 0 0 0
Nova Gorica number of days 0 0 0 0 0 0 0
Murska Sobota - Rakičan number of days 0 0 0 0 0 0 0
Velenje number of days 0 0 0 0 0 0 0
Šoštanj number of days 29 9 1 0 1 0 0
Topolšica number of days 1 0 0 0 0 0 0

Goals

The main aim of air quality management is reduction of air pollution in Slovenia caused by SO2, as stated in the Decree on Sulphur Dioxide, Nitrogen Oxides, Particulate Matter and Lead in Ambient Air (OJ RS No 52/02) and the EU Directive (1999/30/EC). Legislation provides that average 24-hour concentration of SO2 may exceed the value 125 μg/m3 not more than three times per calendar year, and average 1-hour concentration of SO2 may exceed the permissible 1-hour value not more than 24 times per calendar year. Since, according to the Decree, the permissible 1-hour value will reach the target limit value 350 μg/m3 in 2005, the indicator also shows the exceedances of this target limit value for the purposes of comparison with the preceding years. The target is to ensure that the requirements of this Decree are fulfilled. Reduction of air pollution due to SO2 is also a target of the National Environmental Action Programme.


The figures clearly demonstrate that Slovenia has in some urban areas achieved the required standards. A number of individual and smaller combustion plants fuelled with coal was transferred to central power plant heating and cleaner fuels. The situation is improving in Europe as well. Exception in Slovenia is Šoštanj, where the monitoring site is influenced by emissions from the thermal power plant. The established hourly and daily limit values are exceeded too frequently, but the problem is being resolved with desulphurisation units having been installed. There are also occasional exceedances of limit values in the Zasavje urban areas, which have an unfavourable geographical position, especially in winter period when thermal inversions occur and are, in addition to local emission sources, also affected by the influence of emissions from the Trbovlje Thermal Power Plant. Particularly unfavourable conditioned occured in December 2004, when there was a long period of very strong thermal inversions.


Methodology

The data for Slovenia are taken from the National authomatic measurement air quality network database (ANAS) maintained by the Monitoring Office (Environmental Agency of the Republic of Slovenia) and Šoštanj Thermal Power Plant measurement database provided by the Electroinstitute Milan Vidmar, Ljubljana. The database is updated monthly; the data are available in their entirety upon the completion of final annual review.

Information on the ANAS automatic network monitoring sites:
Ljubljana had two monitoring sites until 2001 – Figovec and Bežigrad. By the end of that same year, it was put out of operation, since the Bežigrad monitoring site was considered representative enough for determining the impact on health of the majority of Ljubljana’s population. The monitoring site in Maribor is located directly at the carriageway in the city centre, near an intersection; therefore the air samples show a higher level of traffic-related pollution. Since traffic is not the source of SO2, the monitoring site is also representative for a wider urban area. In Celje, measurements are taken in the hospital complex located just outside the city centre. The monitoring site is representative for a wider urban area. Monitoring site in Nova Gorica is placed on the edge of the city. The Trbovlje and Zagorje monitoring sites are set up at roadside locations in the city centres. The Hrastnik monitoring site, however, is not directly affected by the influence of traffic-related emissions. All three monitoring sites are representative of the above mentioned urban areas. The Rakičan by Murska Sobota monitoring site is representative for rural area in the vicinity of a town.

Information on the Šoštanj Thermal Power Plant automatic network monitoring sites:
The Šoštanj monitoring site is located east of the city and in the event of south-western winds is exposed to the influence of emissions from lower stacks of the Šoštanj Thermal Power Plant. The measured SO2, concentrations are not representative for the Šoštanj urban area. The monitoring sites at Velenje and Topolšica are representative for the Velenje urban area and Topolšica with close surroundings.


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