Spatiotemporal trend of ambient air particulate matter with aerodynamic diameter less than 2.5 and 10 μm and ozone in Tabriz city, Iran, during 2006–2017

This study was conducted to investigate the long-term temporal trends and spatial variations of ambient PM10, PM2.5, O3, concentrations in Tabriz city during the years 2006-2017.

Real-time hourly concentrations of PM10, PM2.5, O3 measured at nine air quality monitoring stations (AQMSs) were obtained from the Tabriz Department of Environment (TDoE) during 2006-2017 and analyzed. Spatial and temporal variations of pollutants using the Mann-Kendall's test and Moran’s I index were analyzed.

The results of this study showed that the annual trend of PM10, PM2.5 was decreasing but remained almost constant for O3 during the study period. During some of the studied days, PM10, PM2.5 levels were exceeded greater than the WHO AQG and National standard levels. Moreover, the highest monthly mean concentrations of PM10 in October (80.3 µg/m³), PM2.5 in January (42.9 µg/m³) and O3 in June (77.8 µg/m³) were observed. Comparison between the stations indicated that the Raste Kuche station was more polluted than other stations.

Effective control planning and implementation policies are essential to improve the air quality of the Tabriz environment. Hence, information provided in this research can be used as a key step for city managers, policymakers, and health officials to reduce the health impacts of air pollution.