The effect of climatic parameters on air pollution in Sanandaj, Iran

Air pollution is one of the emerging environmental issues of the western cities of Iran. Daily data (2009-2012) on air pollutants in Sanandaj, Iran, were collected from the Department of Environmental Protection, Kurdistan Province, Iran. Climatic parameters were collected from the Kurdistan Meteorological Bureau. The quality of air was assessed based on the air quality index (AQI). The relationship between climatic parameters was analyzed using the Pearson correlation coefficient and multiple regression analysis. AQI indicated that the air quality in Sanandaj is under normal conditions. However, Particulate Matter (PM10) was at medium and critical level, requiring precautionary measures for the health of the elderly and children. The concentration of PM10 has increased in recent years during the months of April to June (reached an unhealthy level in the warm days of the year). The highest pollutant concentration (CO and SO2) was observed during cold days of the year (December to February). The highest concentration of NO2, NO, O3, and PM10 were observed in summer and spring, whereas the lowest concentrations were observed in cold seasons. The Pearson correlation analysis revealed a significant correlation between air pollutants and climatic parameters. The multiple regression analysis and R2 analysis showed the influence of climatic factors on pollutant concentration. ANOVA indicated Factors which cause the most significant variability in pollutant concentration are air temperature, relative humidity, and wind speed.