GIS-Based Assessment of Air Pollutants in Erbil, Kurdistan-Iraq through Seasonal and Monthly Variations in Air Quality

Air pollution in Erbil, Kurdistan Region of Iraq, has increased significantly in recent years, due to rapid urbanization, increased vehicular emissions, industrial activities, and the use of low-quality fuels. This study assessed the monthly variation of key air pollutants in Erbil, Iraq, over a 12-month period, focusing on carbon monoxide (CO), formaldehyde (HCHO), methane (CH₄), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), and ultraviolet (UV) radiation. The data analysis revealed that CO concentrations ranged from 5.90 ppm in October to 7.42 ppm in June, with a mean of 6.66 ppm. Formaldehyde levels varied between 0.0124 ppm and 0.0382 ppm, peaked in summer months, while methane showed minimal variation around 4.67 ppm. Nitrogen dioxide ranged from 0.0512 ppm to 0.1004 ppm, with higher levels observed in warmer months. Ozone concentrations fluctuated between 0.2997 ppm and 0.3684 ppm, exceeding WHO guidelines throughout the year. Sulfur dioxide showed significant seasonal variability, rose to 0.0232 ppm in December. The UV index varied markedly, with a maximum of 16.76 in January and a minimum of 6.35 in June. Regression analysis revealed significant negative trends for CO and UV, while HCHO, CH₄, and SO₂ revealed increasing trends over time. Air Quality Index (AQI) values indicated consistently high levels of O3 and NO2 reached hazardous levels. Correlation and principal component analyses identified CO and NO₂ as the primary contributors to air pollution. The findings demonstrated notable seasonal and spatial variability, with pollutant concentrations frequently exceeding WHO limits, highlighting the urgent need for effective air quality management in Erbil.