The air quality index indicates the short-term state of air quality.
The index is not a tool (means) for checking compliance with the limit values given in the official regulations (Regulation on monitoring conditions and air quality requirements) and cannot be used for these purposes and does not reflect the long-term air quality situation, which can vary significantly. It reflects the current potential impact of air quality on human health and is used primarily to inform the public.
The air quality index is based on unverified data of measured hourly values of concentrations of pollutants sulfur dioxide SO2, nitrogen dioxide NO2, suspended particles PM10 and PM2.5 and ground ozone O3.
Concentration values are classified into six categories: good, acceptable, moderate, polluted, highly polluted and extremely polluted, and each category is represented by a corresponding color. The current value of the air quality index for a certain measuring station is determined by the worst category that one of the five pollutants has in the given term.
In order to determine the air quality index for traffic stations, it is necessary to have the results of measuring NO2 and at least one of the two types of suspended particles PM10 or PM2.5. For industrial, urban, suburban and rural stations it is necessary to have measured concentrations of NO2, O3 and either PM10 or PM2.5. For the stations in Bor, it is necessary to have SO2 measurement results. The concentration of carbon monoxide (CO) is not taken into account when determining the index.
The color shade with which the index is represented can be darker or lighter. The darker one is used in the case when all the required pollutants are present to determine the index, the lighter one when some pollutant is missing. In the event that there is no data for a single pollutant at the station in the given period, the color is gray.
