Investigating air pollutant trends based on temporal air quality indexes in Karaj, Iran, during 2012 - 2018

Abstract

Aim: Due to the importance of the relationship between air pollutants and the incidence of many diseases in polluted cities, in this study, we collected the data related to yearly, seasonally, monthly, daily, and hourly concentrations of particulate matter (PM)2.5, PM10, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) recorded at four monitoring stations across Karaj city, Iran, to investigate the air pollutant trends based on air quality indexes (AQIs) in the city during 2012-2018. Materials and Methods: The correlations between PMs and gaseous pollutants were analyzed using the Pearson correlation coefficient. The concentrations of air pollutants indexes including O3, NO2, SO2, CO, PM10, and PM2.5 were recorded in four air pollution monitoring stations in Karaj obtained from the monitoring system of the environment department. Then, the data were analyzed using SPSS and Graph pad softwares. Results: The findings showed that in 20-40 and 1-5 of days during 2012-2018, higher concentrations of PM2.5 and PM10 were experienced than the national standard (NS) concentration, respectively. Furthermore, during this time, 0.3-0.9 of days indicated the higher concentrations of CO and SO2 than the NS, respectively. Although the daily concentration of NO2 was lower than NS, 0.5-5 of days were exposed to the higher concentration of O3 than NS. SO2 concentration showed a negative and positive correlation with PM10 (r = -0.69, P = 0.013) and O3 (r = 0.58, P = 0.03), respectively. Conclusion: These results indicated that Karaj AQI was moderate and the most problem with air quality in Karaj city was attributed to the PM2.5 concentrations. To reduce health disorders related to this pollutant, it is necessary to control PM2.5 sources and sensitive groups should reduce outdoor activities. © 2023 Advanced Biomedical Research.