Environmental Issues of the Ljubljana Urban Region

Dela 21 • 2004 • 567-579 ENVIRONMENTAL ISSUES OF THE LJUBLJANA URBAN REGION Metka Špes Oddelek za geografijo, Filozofska fakulteta Univerze v Ljubljani Aškerčeva 2, 1000 Ljubljana, Slovenia. e-mail: [email protected] Abstract The main environmental problems of Ljubljana urban region which are obstacle of sustainable development are presented in the paper, especially the main sources of air pollution and water manegment. Actual quality of life in urban environment is seen also in noise pollution, quality and accessibility of green areas and in traffic. On the end the article discusses the attitudes of Ljubljana residents to environmental problems and quality of life in urban region. Key words: Ljubljana, air quality, drinking water, noise pollution, trffic, green areas, attitude of residents to environmental problems INTRODUCTION Looked at from the point of view of sustainable development, the present quality of the geographical environment of Ljubljana represents a developmental obstacle. However, generally speaking we have not yet reached the point of irreversible degradation of the environment or its components. Critical concentration values for Nox, and O3 are still exceeded from time to time, the level of emissions from motor vehicle traffic has been increasing, soil pollution from certain heavy metals (especially lead) is high, and the Ljub- ljanica River in the section just before it joins the Sava has been classified in the 3rd to 4th category of water quality. However, the data on water quality during the second half of the nineties indicate that the water pumped at Ljubljansko polje was of suitable quality as a supply of drinking water, mainly due to its high self-cleaning capacity. AIR QUALITY IN THE URBAN ENVIRONMENT Until the mid-seventies, Ljubljana was classified among Slovene cities with the highest air pollution, with maximum values reached during the colder half of the year. Such excessive 567 Metka Špes / Dela 21 • 2004 • 567-579 pollution was due to numerous individual chimneys as well as to a thermal power plant which used coal with the high sulphur content. Natural geographic factors contributing to the pollution problem include the location of the city in a basin and frequent climatic inver- sions, which gave rise to an average of 140 foggy days per year. According to the data, Ljubljana is the foggiest European capital city, with the thickness of the inversion often between 200 and 300 meters. The average wind velocity is only 1.3 m/s in January and 2.0 m/s in May, with no wind at all occurring about 6 to 10 percent of the time (Jernej, 2000). Local winds are generated by the closed basin position and they are indirectly affected also by the city and its morphology, building types, and in particular by the heat island. During the last two decades efforts to improve the air quality were directed primarily towards decreasing SO2 emissions and particulate matter. Average annual concentrations, which at the beginning of the eighties exceeded 200 µg/m3, or three times the maximum permissible value, decreased up until the end of the nineties to 27 µg/m3. Concentrations of SO2 differ significantly depending on the microlocation of individual monitoring sites in Ljubljana, but as a rule do not exceed 50 to 70% of the maximum permissible value. Concentrations are exceeded only during periods of extremely unfavourable weather conditions and when the thermal power plant in Ljubljana relies heavily on domestic coal. The largest share of SO2 emissions continues to be contributed by this plant; however, the resulting pollution is still much lower than it would be if the city’s buildings each had its own source of heat. A decrease in SO2 emissions from the plant was achieved by using a larger proportion of good quality, low sulphur Indonesian coal, and correspondingly less domestic coal (Vpliv …, 1999). SO2 emissions from general and industrial use also decreased, due mainly to the phas- ing out of solid and liquid fuels, which were replaced by reliance on long-distance heating networks and gas, with virtually negligible SO2 emissions. The use of coal as a heating fuel in Ljubljana has decreased from 15% to only 2% of the total over the last fifteen years, while the use of natural gas has increased significantly, from 7.4% to 29%. This change of the structure of emissions causing air pollution in Ljubljana has less- ened the seasonal nature of the problem, as SO2 and smoke as characteristic winter pollutants are replaced by pollutants (NOx and CO2) which are distributed fairly equally through- out the year, or by pollution in the summer season (ozone). The share of traffic emissions is increasing: traffic contributes 50% of NOx and almost 30% of CO2 emissions. Traffic is becoming a permanent source of NOx emissions, a finding which has also been supported by measuring the concentrations at monitoring sites in the center of Ljubljana, with average annual concentrations of 75 µg/m3. Excessive concentrations of ozone are becoming a problem of critical importance for ensuring air quality in Ljubljana. The maximum permissible limit of O3 pollution in the city was most frequently exceeded during the period from April throough August. However, pollution caused by this secondary pollutant is even greater at the city's outskirts, indicating negative effects spread from the city itself to its wider environs. Air pollution in the city from SO2 and smoke (concentrations of the latter are even lower) is lower now than it was a few years ago, and it is also quite evenly distributed, so there are no urban areas with particularly heavy pollution, except during the exceptional 568 Environmental issues of the Ljubljana urban region circumstances already mentioned. The city center on the one hand, and areas in the imme- diate vicinity (up to 100 meters) of heavily frequented urban main roads on the other, are hot spots for air pollution resulting from traffic-related emissions (NOx, CO2 and ozone) (Onesnaženost...,2000). Figure 1: Estimation of air pollution Carbon dioxide emissions, which are the main target of the Kyoto Protocol, display annual fluctuations in Slovenia, depending on the variable level of traffic-related emissions. Over- all, this curve is still increasing, and has exceeded 8 tons per capita. Since 1986, when Slo- venia first undertook to implement the provisions of the Kyoto Protocol), SO2 emissions in Ljubljana have increased by 22%. This means that the "Kyoto value" has been exceeded by nearly 33%. However, the structure of the sources of the emissions has fundamentally changed. The share of emissions from industrial sources has decreased by about 15% as a 569 Metka Špes / Dela 21 • 2004 • 567-579 result of technological and consequently ecological restructuring of industrial plants, whereby solid and liquid fuels have been replaced by natural gas, and by a drop in produc- tion from economically unprofitable industrial plants. Also, CO2 emissions originating from general consumption have decreased by almost 16%, since long-distance heating and use of natural gas has become more and more frequent in the city during this period. CO2 emissions originating from a major source in Ljubljana—the thermal power plant–are also slowly decreasing, but these reductions have been more than offset by a 72.8% increase (Gasperič, 2000) in the quantities of emissions produced by traffic over the past fifteen years, due to the rapidly increasing dependence on automobile transportation, especially over the past decade. Graph 1:Proportions of emissions of CO2 , SO2, NOx and solid particles by major sources of pollution 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% CO2 SO2 NOx Solid particles Industry Transport Energy transformers Other Table 1: Proportions of emissions of CO2, SO2, NOx and solid particulate matter from major sources of pollution in 1998. Sector CO2 SO2 NOx Solid particles Industry 5.8 2.2 3.1 1.2 Transport 28.3 0.9 50.1 38.1 Energy transformers 48.9 86.6 38.2 56.4 Other 17.0 10.4 8.6 4.3 Source: Inštitut za energetiko..., 1999. On the basis of the results of both foreign investigations and a comparative analysis of the data during times of increased air pollution in Ljubljana, as well as drawing on public 570 Environmental issues of the Ljubljana urban region health data, we can conclude that an increased number of emergency room visits from patients with aggravated chronic pulmonary disease and from people seeking treatment for acute respiratory diseases coincides with the days when the maximum permissible 24-hour concentration of SO2 is exceeded. Furthermore, concentrations, which exceeded the one- hour maximum permissible, results in an increased incidence of asthmatic attacks and ag- gravates the condition of asthmatic patients. Judging from the results of foreign investigations, it can be anticipated that the number of respiratory diseases in children and physically active adults will continue to increase in Ljubljana during days of increased ozone concentration (presumably by 20–30%). Swiss studies show a 30% increase in respiratory system diseases of children exposed to environments which exceeded the maximum permissible concentration over a period of eight hours. Ozone measurements in Ljubljana show that there are about 40 days during the summer months when concentrations exceeded the maximum permissible level over eight hours (Otorepec, Letnar-Žbogar, 1997). WATER MANAGEMENT More than 27 million m3 of water are consumed in Ljubljana per year, of which more than 10 million m3 are consumed by industry (water for cooling not included) and about 16 million m3 by households. The use of water increased rapidly in the past decades (from 4 million m3 in 1940). The greatest consumption was registered in 1987 with 33.9 million m3, but after this year a slight decrease was observed due to a lower consumption by industry (Brečko, 1996).

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