Introduction and purpose: Nowadays, the effects of air pollution, especially its detrimental effects om health, have made air quality control a matter of national concern. The present study aimed to compare air quality in Urmia based on the Air Quality Index in a five-year period of 2012-2017.
Methods: The samples in the present study included hourly data of five air quality criteria, including PM10, PM2.5, SO2, NO2, and CO collected and validated by the
Environmental Protection Agencyof Iran during a five-year period. Afterwards, the highest daily index value for the pollutants was determined using a standard method. The highest value among the calculated indices was considered as the final index, and pollutant that represents the highest index was introduced as the main pollutant of the day.
Results: The results showed that air quality in Urmia was more than the expected standard of the Environmental Protection Agency of Iran during 297, 265, 245, 267, 290, and 292 days in 2012-2017, respectively. On the basis of the results, the major pollutant in 2011 was SO2. Regarding other investigated years, PM2.5 played a significant role as a pollutant.
Conclusion: The evaluation of the air quality of Urmia during 5 years revealed that the current condition is far from the ideal.