Last update:
05-Dec-2022

OBJECTIVE To analyze the Air Quality Index (AQI), the most widespread tool for recording air quality, for the region of Thessaloniki.

METHOD Calculation of the AQI was made from the concentrations of PM₁₀, PM_2.5, NO₂, CO and O₃, i.e., the gaseous pollutants the concentrations of which are systematically recorded by the national air pollution recording network. To evaluate the AQI in the area of Thessaloniki, the data for the years 2011–2019 from seven air pollution recording stations, with different urban characteristics, in the region of Central Macedonia were used.

RESULTS The data processing indicated that PM10 and O3 are the main pollutants determining AQI. Based on the data form the Aghia Sophia monitoring station in the center of Thessaloniki, the AQI shows a statistically significant difference between the cold (October–March) and the warm (April–September) periods of the year in all stations (p<0.01), which is attributed to the seasonal differentiation of anthropogenic sources (e.g., heating systems), high concentrations of O3 during the summer months (secondary pollutant favored by sunshine) and meteorological factors. Another interesting finding is the statistically significant difference in AQI between weekdays and weekends (p<0.05) at the downtown stations, which reflects the effect of human habits on the concentrations of pollutants that make up the index.

CONCLUSIONS AQI is an easy-to-use tool with the ability to calculate the hazard of gaseous pollution levels and produce information that could be beneficial to public health.

Key words: Air pollution, Air Quality Index, Particulate matter, Public health.