Determination of Air Quality Index and Its Relationship With Meteorological Parameters in City of Mashhad

The aim of this study was to determine the air quality index (AQI) and to investigate its relationship with meteorological parameters in Mashhad for ۲۰۱۴. In this study, moment concentrations of air pollutants in Mashhad for ۲۰۱۴ were prepared and the amount of AQI was calculated and air quality was determined. Then, data analysis was performed using Kruskal-Wallis and Mann-Whitney tests at a significant level of ۵% in SPSSV.۲۳ software. Finally, data related to meteorological parameters were prepared during ۲۰۱۴ and ARIMA time series model and R software (۳.۳.۰) were used to investigate its relationship with air index pollutants in non-delayed and one day late modes. The results showed that air quality of Mashhad was in a very bad condition in terms of maintaining the health of community members, especially sensitive groups, as the concentration of pollutants in this city was higher than Iranian standard (۱۰۰) in ۲۴۵ days of the study period. The PM۲.۵ was the most important pollutant during the study. It was also found that among the climatic parameters, temperature and pressure have the greatest direct effect on the concentration of air pollutants. Moreover, results showed the immediate effect of temperature on the concentration of air pollutants, although other atmospheric elements are able to significantly affect the outcome over time and with a time delay (one day in this study). The results indicated that quality of model computation depends on changes in atmospheric parameters, so that a quantitative measurement for each pollutant can be achieved based on meteorological data.