The xEco Top PM application ("eXtreme ECOlogy" - Extreme Ecology) shows the ranking list of municipalities in the Republic of Serbia with at least one suspended particle analyzer using the composite European Air Quality Index for air ranking based on two pollutants: Suspended particles with a diameter of up to 10 and 2.5 microns (PM10 and PM2.5). With each of the air categories, the percentage of the population potentially exposed to the negative effects of polluted air is shown (based on data from the Republic Institute of Statistics).

Measurements of PM10 and PM2.5 suspended particles are shown, spatially aggregated as mean values ​​at the municipal level and temporally aggregated at the hourly and twenty-four-hour levels from state networks for automatic air quality monitoring using reference methods taken from the open data portal of the Government of the Republic of Serbia (Open Data Portal) as and indicative measurements of concentrations of PM10 and PM2.5 suspended particles from publicly available real-time air quality databases belonging to the "Sensor community" (luftdaten.info), i.e. from the "Citizens' Air" project (klimerko.org).

Evaluation and ranking of air quality is done according to the calculation methodology for the European Air Quality Index applied on the "European Air Quality Index" and "Up-to-date Air Quality Data" portals managed by the European Environment Agency (EEA). by introducing a range of air quality indices in 6 categories:

Good,
Acceptable (Fair),
Medium (Moderate),
Bad (Poor),
Very poor i
Extremely poor.

In addition, xEco Top PM, by applying the current legislation in the field of air quality protection, provides a quality assessment according to the defined limit values ​​for twenty-four-hour concentrations of PM10 (GV) GV given in the Decree on conditions for monitoring and air quality requirements of the Government of the Republic of Serbia ("Official Gazette of the RS", No. 11 of March 5, 2010, 75 of October 20, 2010, 63 of July 19, 2013) as well as in relation to the limit values ​​recommended by the World Health Organization - WHO (WHO - World Health Organization).

European Air Quality Index, that is, the European air quality index, which does not have a numerical value, for the purposes of the xEco Top PM application, is formally presented through a numerical amount based on the formula used to calculate the United States Air Quality Index (US AQI), using the limits of certain categories from the European index and according to the methodology given in the document (page 13) AQI Technical Assistance Document of the American Environmental Protection Agency (US EPA - United States Environmental Protection Agency)

The index is calculated on the basis of average hourly or average 24-hour values ​​collected from the existing state automatic air quality monitoring network. It also applies to the results of indicative monitoring (PM10 and PM2.5) carried out by citizens on their own meters (sensors). The data has not been formally verified.

The index indicates the short-term, current and daily air quality situation. It does not reflect the long-term (annual) air quality situation, which can vary significantly. The index is not a means of checking compliance with air quality standards and cannot be used for that purpose.