عنوان مقاله [English]
Background and Purpose: Air pollution problem in metropolitan’s city is made by different sources of pollutants. The proportion of air pollutants’ emissions have been increased in many cities of Iran such as Mashhad. This study aimed to investigate the relationships between the trend of particular matter concentration changes and metrological parameters in the atmosphere of Mashhad.
Materials and Methods: In this descriptive cross - sectional study, data including temperature, sunny hours, precipitation, evaporation, moisture, speed and direction of wind were collected from 11 monitoring stations of air pollutants and Metrologic synoptic stations in Mashhad during 2010-2016. Daily average concentrations of PM10 of PM2.5) were calculated, and then relationships between pollutants and metrological data analyzed by Spss18 software.
Findings: The results showed that the maximum concentrations of particle matter occurred in October and autumn season. Numbers of unhealthy days were increased during the years of 2011-2013, decreased in 2014 - 2015 and increased again in 2016. The variations of PM10 and PM2.5 are significant with season, month and year (P <0.001). PM10 was directly related to temperature and evaporation (r=0.095). Also, there was a reverse relation among humidity and rainfall. A reverse relationship was observed between PM2.5 concentration and minimum temperature, sunny days, rainfall and wind speed; however, it was directly related to wind direction.
Conclusion: According to the obtained results in the autumn and October, the highest concentration of particulate matter was observed. Also, GIS maps showed that eastern and relatively center of Mashhad is more polluted than other areas.
Keywords: Air pollution, Mashhad, PM2.5, PM10, Meteorology data