Elham Asrari; Maryam Paydar
Abstract
Abstract
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 ...
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Abstract
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
Mohammad Reza Atabaki; Mohammad Sakhaei; Hassan hoveidi; Mohammad Pooteh rigi; Ehsan Karimimanesh
Abstract
Introduction: suspended particles has numerous negative effects on human health and plants.it plays an extremely important role in global climate change as well. Objective:In this survey, variations and influence of meteorological parameters on the concentration of PM10 concentrations were studied. Methods: ...
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Introduction: suspended particles has numerous negative effects on human health and plants.it plays an extremely important role in global climate change as well. Objective:In this survey, variations and influence of meteorological parameters on the concentration of PM10 concentrations were studied. Methods: In this study, first, daily, monthly and seasonal concentrations variation of PM10 were investigated. Then, the degree of correlation between PM10 and meteorological parameters were analyzed by Pearson correlation. Also regression model was used to predict PM10 concentration. Findings: Daily average PM10 concentration during the study period indicates that the highest concentration was in the 22nd August (1077 µg/m3) and the lowest in the 8th march (42 µg/m3). It also shows the monthly average concentration was in August (301/06 µg/m3), While the lowest concentration is accounted November (152/16 µg/m3). Seasonal concentration showed that the highest concentrations are in the summer (272/76 µg/m3). Pearson correlation coefficient analysis shows that particulate matter has a direct correlation with temperature and wind speed, while reverse correlation with precipitation and atmospheric pressure. conclusion: Based on the results of Pearson correlation, it was found that rainfall and relative humidity have adverse effects but the temperature and wind speed have a direct impact on the concentrations of PM10. So that the increased rainfall will reduce the concentration of PM10. While the temperature and the wind speed increases the concentration of suspended particles. Also, the coefficient of determination in the regression model Suggests that 13, 25 and 6 percent of PM10 changes in spring, summer and fall are explained by meteorological parameters used in the model. Based on these results we can say that adverse meteorological conditions may lead to increased concentrations of PM10.