3. Pollutant Emissions of SO₂ and Particulates

	Economic recession in the SILAQ countries has brought with itself a downward trend in the levels of emissions. Although the SILAQ countries vary in size and differ as emitters, the observed trends are similar - general decreases in both particulate matter (PM) and SO2 emissions, which even with economic recovery, appear to be continuing to decline. The reasons for this are the restructuring and modernization of production systems and the impact of new environmental legislation and regulations. The following sections examine the nature and reasons for the declines in levels of emissions, as well as the main responsible sources.
3.1 Sulfur Dioxide
Decreasing Emissions	The data on SO2 emissions obtained through the questionnaire survey and shown in Figure 1 clearly indicates a predominant downward trend in emission levels, as well as a number of fluctuations. For example, after an initial drop in SO2 emissions for all countries during the 1990-1993 period, continuing decreases in Slovakia, Slovenia and Romania (until 1994), were offset by a slight upward trend in Bulgaria after 1993, with a later stabilizing of values. At the same time, the decreases in emission levels vary substantially from country to country. The drop is most explicit, for example, in Slovakia (some 41.62 percent in 1996 if 1990 values are set at 100 percent) and in the Czech Republic (50.43 percent in 1996 if 1990 values are set at 100 percent). Absolute values of SO2 emissions are given in Table 3.
Figure 1. Trends in SO2 emissions [kt]

TABLE 3: Total Annual Emissions of SO2 [kt]
Country	1990	1991	1992	1993	1994	1995	1996
Bulgaria	2,020	1,678	1,128	1,426	1,480	1,497	1,420
Czech Republic	1,876	1,776	1,538	1,419	1,278	1,091	946
Hungary	1,010	913	827	757	741	-	660
Poland	3,210	2,995	2,820	2,725	2,605	2,337
Romania	1,311	1,041	952	928	912	932	-
Slovakia	543	446	380	325	239	239	226
Slovenia	195	181	190	183	177	119	110

Main Sources	Based on questionnaire data, the main sources of SO2 pollution have been identified as power generation and district heating plants, contributing in 1996 in Slovenia to as much as 87.2 percent of the total emissions. During the surveyed period, emissions from power, co-generation and district heating sources have actually increased as a percentage of the total SO2 emission. In Slovakia, for example, 44.8 percent of SO2 emissions in 1990 originated from such sources while by 1996 this share had grown to 68.6 percent. Generally, however, this source is most significant in Slovenia and Bulgaria where it tends to be responsible for more than 70-80 percent of the SO2 emissions. In 1980, SO2 emissions in Hungary were about 1,600 kt, having decreased to 660 kt by 1996. Of this figure, approximately 65 percent were emitted by public power plants.
Residential Sources	Figures 2 and 3 illustrate the emission sources and their respective share for two separate years (1990 and 1995) during the surveyed period. The share of commercial, institutional and residential combustion sources tends to remain relatively constant throughout the surveyed period for all countries. It can be noted that the share of emissions from these sources are much greater in Romania and Slovakia than in Bulgaria and Slovenia. In general, residential combustion tends to be the most serious small-scale source responsible for urban pollution.
Figure 2. SO2 emissions by sector, 1990 [%]
Figure 3. SO2 emissions by sector, 1995 [%]
	Although incomplete, the above data also indicates the significant decrease in emissions from industrial combustion plants and processes, and this is particularly evident for Bulgaria. The tendency is typical of all countries in transition and can be explained by the reduction in industrial output and the more stringent environmental regulations adopted since 1990. According to the data collected in the questionnaire survey, the non-combustion and other SO2 sources have negligible shares in the total levels of emissions. The absolute figures and the precise share of these sources are doubtful, however, since the surveyed countries work with different categories and data is not easily comparable. Better specifications and a clear definition of each category is required in order to extract more reliable data. While the data presented on the previous page shows the absolute levels of SO2 emissions per country, with Bulgaria emerging the greatest producer, closely followed by Poland and the Czech Republic, more useful information on the levels of SO2 emissions per capita and per area is given above. Figures 4 and 5 compare Bulgaria, the Czech Republic, Hungary, Romania, Slovakia and Slovenia during the period 1990-1995. Polish and Hungarian per capita emissions data is noticeably similar.
Figure 4. SO2 emissions per capita [kg/capita]
Figure 5. Emissions per unit of area [tons/km2]
Emissions per Capita and Area	The results show that in respect to both per capita and per unit of area, emissions remain highest in Bulgaria and the Czech Republic. The values in terms of both these criteria were highest at the beginning of the surveyed period but are steadily decreasing. A steady decrease can also be observed in Slovakia, while in Bulgaria, an increase in emissions occurred after 1992. The remaining countries maintain relatively constant values with a sharp decrease having occurred in Slovenia between 1994 and 1995. Data also indicates that the SILAQ countries are identically ranked by both criteria. The decline in levels of emissions is apparent for all SILAQ countries (with the exception of Bulgaria) and is the most explicit in the Czech Republic and Slovakia.
OECD Average	If the SO2 emissions for 1993 in the SILAQ countries are compared with the OECD average of 52.6 kg SO2/capita, one can see that Slovakia and Romania are well below this value while the Czech Republic and Bulgaria substantially exceed it.
Emissions per GDP	Comparisons might also be made based on emissions per unit of GDP. For Western countries SO2 emission levels (per GDP) are less than 10 kg SO2/USD 1,000 while for several CEE countries it is almost 10 times higher (see Figure 6). One reason could be the large dependency of the SILAQ countries on fossil fuels, particularly the low-heat and high sulfur and ash-laden local lignites. In addition, these countries are characterized by industrialized economies where energy efficiency lags far behind that of OECD countries, due in many cases to the use of obsolete technologies. Due to the financial constraints, emission control devices available on the market have not been widely implemented.
Figure 6. SO2 emissions per GDP [kg/USD 1,000*]
Shift in Polluting Sectors	At the same time, owing to the overall economic recession, the so-called market transition, the modification and restructuring of aged industrial production systems, and the ceasing of the production of goods requiring high energy intensity, etc., GDP has significantly decreased over the last few years. However, restructuring and modernization of obsolete production systems has resulted in a shift in the share of different sectors contributing to GDP. The energy intensive industrial sector for example has reduced its share and hence the structure of energy consumption has shifted resulting in significant improvement not only in terms of energy consumption but in environmental impact. All these factors lead to the indicated decrease in GDP, while the overall decrease in SO2 emissions, both as an absolute value and as a ratio to the population levels, area and GDP are also due to the measures already taken to address air pollution and to the changes in energy supply structure. According to the Hungary Country Status Report, the sharp decrease in SO2 emissions during the period 1985-1990 can be attributed to the installation of new nuclear reactor blocs in the Paks nuclear power plant. The changes in the subsequent period (1990-1996) resulted from the overall economic recession, restructured economic and production patterns, and a decline in fossil fuel consumption (through the implementation of natural gas programs with sharp decreases in household and industry coal consumption and decreases in the use of residential oil due to increased prices).