The application xEco Air ("eXtreme ECOlogy" - Extreme Ecology) presents the European Air Quality Index in the Republic of Serbia using data on concentrations of five pollutants: Suspended particles up to 10 and 2.5 microns in diameter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2) and ground-level ozone (O3).

Measurements aggregated at the hourly and 24-hour level from automatic air quality monitoring networks (source: The national open data portal) are shown, as well as indicative measurements of PM10 and PM2.5 - suspended particulate matter concentrations from publicly available real-time air quality databases belonging to "Sensor community" (luftdaten.info) and from the project "Air to the citizens" (klimerko.org).

Evaluation and ranking of air quality is performed according to the methodology applied on the portals "European Air Quality Index" and "Up-to-date Air Quality Data" managed by the European Environment Agency (EEA), by introducing an Index level classifing air quality situation in one of 6 categories:

Good,
Fair,
Moderate,
Poor,
Very poor, and
Extremely poor.