To evaluate the impact of meteorological conditions on air quality in the vicinity of the Prudinec/Jakuševec landfill in Zagreb, daily concentrations of particulate matter (PM10), hydrogen sulphide (H2S), and ammonia (NH3), monitored over a five-year period (2020–2024), were analysed. Under meteorological conditions in which the mixing layer height (MLH) falls below 1,000 m, an inversion layer forms above the city, suppressing vertical air mixing and leading to atmospheric stability and pollutant accumulation. The results showed that nearly 80 % of stable conditions occurred during the cold season (autumn and winter) of the study period. During these stable episodes, 88 % of all daily PM10 limit exceedances and 70 % of H2S exceedances were recorded. Comparable PM10 concentrations were measured at several monitoring stations across Zagreb, suggesting that the landfill is not a dominant source of PM10 pollution. The seasonal pattern of H2S concentrations at the landfill showed higher levels during winter, opposite to the pattern observed at the nearby Central Wastewater Treatment Plant of the City of Zagreb (CUPOVZ). This behaviour indicates the landfill is most likely a specific local source of H2S. NH3 concentrations were higher during the warm season both near the landfill and at CUPOVZ, suggesting different dominant emission sources. The differing seasonal patterns of PM10, H2S, and NH3 indicate that these pollutants originate from distinct dominant emission sources. In the south-eastern part of Zagreb, agriculture and livestock farming are likely among the main contributors to NH3 emissions.
Bešlić et al. (Mon,) studied this question.