STAznanost

Air pollution in Slovenia among the worst in EU

Ljubljana, 24 January - The quality of air in Slovenia is improving but some areas are still experiencing significant air pollution. PM10 and PM2.5 particles cause trouble in winter, while in summer the concentrations of ground-level ozone are concerning, shows data by the Environment Agency (ARSO).

In 2023 air pollution with PM10 particles was at similar levels as in previous years.

Measurements for 2024 are yet to be released, but those for the first eleven months of the year show that the daily limits were most often exceeded in Črnomelj (25 times) in the southeast of the country, followed by Murska Sobota (24) in the northeast and the capital Ljubljana (23). All were still below the permissible annual number of 35 exceedances.

Preliminary data by ARSO shows that in the northern town of Črna na Koroškem the daily limits were surpassed 52 times, though this information may not be completely reliable as the location of the measuring station does not fully meet the legal requirements. The authorities are looking for an alternative location.

The measurements there were also affected by the damage the August 2023 floods caused to the soil and by the ongoing reconstruction works.

More dangerous for health than the PM10 are PM2.5 particles that can be found in dust, car tire particles, smoke and soot.

The average annual level of those particles was at 14 mg/m3 and did not exceed the annual limit of 20 mg/m3 at any of the measuring stations. Pollution was the highest in Murska Sobota with the average annual level at 19 mg/m3.

Slovenia is among the EU countries with the highest pollution with both PM10 and PM2.5 particles because of its diverse landscape and location in the Alpine foothills.

The country remains among EU countries with relatively low pollution levels when it comes to nitrogen oxides, pollutants associated with emissions from road traffic, head of the air quality sector at ARSO Tanja Koleša said, adding that in the last few years the levels have not exceeded the limits but they remain a problem in big cities.

Ground-level ozone, which is not a pollutant on its own but forms from other pollutants, is more concerning, especially in the summer months. "In the Primorska region the conditions are ideal because a lot of ozone precursors come from the polluted Northern Italy and then react in combination with the heat," Koleša said.

Air pollution higher in winter

The levels of polluting particles in the air increase in winter, when air is not only polluted by traffic and industry but also emissions from heating.

In the colder months of the year harmful emissions also stay in the air for longer, especially in the case of temperature inversions. The situation is the worst in valleys with high population densities.

Even though harmful emissions are not as high in Slovenia as in some other countries, air pollution is still high because the polluted air accumulates in the valleys, Koleša said.

There are some 20 official measuring stations, mostly in large cities. ARSO chooses an additional location each year to perform the measurements, last year it was Črnomelj, SE. "The results there surprised us because the quality of air was extremely bad," Koleša said, adding that the town is in a basin where cold, polluted air lingers.

Air pollution claims lives

According to a study by the European Environment Agency the mortality rate that can be attributed to long-term exposure to PM2.5 particles in Slovenia decreased by 45% from 2005 to 2022.

A shorter term comparison shows that the number of deaths related to the exposure to PM2.5 has increased to 1,280 in 2022, up by 90 compared to the year before. "This is a large figure that compares that of all the factors, air, even more than water, affects our health," dean of the Nova Gorica School of Environmental Science Griša Močnik told the STA.

Long-term nitrogen oxide exposure is estimated to have contributed to 140 deaths in 2022, down by 20 from the year before, while exposure to ozone contributed to 340 deaths, up from 140 the year before.

New air quality standards coming in 2030

Slovenia has two years to transpose an EU directive on air quality, which came into force in December 2024, setting stricter limits for pollution levels and increasing the number of measuring stations.

Last year the government adopted a programme to monitor air pollution, which includes measures for the energy sector, industry, transport, agriculture and heating.

Households can access subsidies to replace old heating appliances with EUR 117 million made available for 2023-2026 from the Climate Fund. New biomass furnaces are still more polluting than other heating sources, the Environment Ministry said, recommending they be used as a last resort.