A comparative study of air quality in Hamadan province before, during, and after the COVID-19 pandemic
Journal of Behdasht dar Arseh (i.e., Health in the Field),
Vol. 12 No. 3 (1403),
1 March 2025,
Page 4-12
https://doi.org/10.22037/jhf.v12i3.46580
Background and Aims: Hamadan Province, located in western Iran, covers 20,000 square kilometers and has a population of 1.7 million. The onset of COVID-19 and the cessation of public gatherings significantly affected air quality. This study aimed to examine the air quality in Hamadan Province over two years prior to the COVID-19 outbreak, during the pandemic, and after its resolution.
Materials and Methods: This research adhered to ethical standards. Daily air quality data were obtained from five monitoring stations. After validation, the data were analyzed during the three aforementioned periods. Descriptive results were presented as means and standard deviation, and parameters were evaluated using SPSS software with the Post Hoc Bonferroni tests.
Results: During the COVID-19 period, the average concentrations of CO2, O3, and PM10 decreased compared to pre-COVID-19 levels, while PM2.5, SO2, and CO concentrations increased. After COVID-19, the average concentrations of NO2, O3, and SO2 decreased compared to the COVID-19 period, conversely, PM10 and CO concentrations increased, with PM2.5 maintaining a stable average concentration. The highest average concentrations of NO2 and O3 occurred in summer, CO in autumn, and SO2 in winter.
Conclusion: The mandatory lockdown during the COVID-19 period significantly impacted the air quality of the province. The subsequent ban on Mazut fuel in power plants and industrial units also had a notable effect on air quality. Therefore, traffic control and the simultaneous prohibition of Mazut fuel are recommended to improve air quality in this province.