Air pollution in Ljubljana above guideline value

Freepik/@ freestockcenter

Original article (in Slovenian) was published on 26/07/2022

The Slovenian Medical Chamber published on 11 July an open letter in which it expresses opposition to the construction of a waste-to-energy plant in Ljubljana, a project that was presented to the public by Ljubljana Mayor Zoran Janković on 6 July.

The Medical Chamber stressed that the average concentration of hazardous PM2.5 airborne particulate matter is already at least three times above the guideline value recommended by the World Health Organisation (WHO).

PM2.5 is hazardous airborne particulate matter that causes coronary and respiratory diseases and cancer. In 2021 the WHO recommended that the average daily concentration of PM2.5 should not exceed 15 micrograms per cubic meter (µg/m3).

Between January and May this year Ljubljana recorded eight days on which the average concentration was three times above the guideline value, according to data by the National Environment Agency (ARSO). The highest recorded value was in the Bežigrad borough in January, when it stood at 59 µg/m3. In total, the average daily concentration exceeded the WHO guideline value 68 times until the end of May, according to ARSO data.

In addition to the maximum daily concentration, the WHO also has a recommendation on the maximum annual concentration of PM2.5, which should not exceed 5 µg/m3. In Ljubljana it was 15 µg/m3 according to ARSO data.

The Medical Chamber told Razkrinkavanje.si that their claim about average daily PM2.5 concentration in Ljubljana being three times above the WHO guideline value was based on data by the U.S. non-profit Berkeley Earth, which collects scientific data on the environment. According to this data, the average annual concentration of PM2.5 last year was 14 µg/m3. The organization states that the WHO guideline value is 10 µg/m3, but this was true from 2005 until last year when the WHO reduced the guideline value to 5 µg/m3.

The claim by the Medical Chamber that the average concentration of hazardous and carcinogenic PM2.5 particulate matter is already at least three times above the WHO guideline value is correct.

Air quality is among the worst in Europe

The Medical Chamber also warned that air pollution in Ljubljana is among the worst in Europe. The European Environment Agency ranked Ljubljana 279th among 344 European cities in countries that are members of the Agency. The Agency ranked cities based on PM2.5 concentrations in the two years preceding June 2021, from which it calculated average two-year concentrations. The average two-year concentration in Ljubljana was 15.7 µg/m3.

The European Environment Agency ranked cities in five categories by air quality, from good to very poor. Ljubljana ranked among the cities with poor air quality, the second to last category. The worst performers with the poorest air quality are cities where the average two-year concentration exceeds 25 µg/m3. This is also the annual limit in the EU.

According to the members of the Medical Chamber, construction of the waste-to-energy plant would worsen air quality in the city since hazardous substances from the smokestack would linger in the basin and accumulate in the center of the city in cold months with little wind. The Chamber also warned that the incineration of waste emits not just particulate matter but also heavy metals, carcinogenic dioxins, furans, and polycyclic hydrocarbons, which is why people in cities with waste-to-energy installations are more likely to get lymphatic, lung, and colon cancer.

The Chamber’s claim that the air in Ljubljana is among the most polluted in Europe is not true.