Fatah GHangi Zadeh; Abdolreza Karbassi; Naser Mehrdadi
Abstract
Background and Purpose: Benzene is one of the primary volatile organic compounds in urban air pollution. Beside its environmental implications, benzene poses various health risks to urban inhabitants. This study aimed to measure benzene levels at fuel stations (petrol pumps) in a specific area of Tehran ...
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Background and Purpose: Benzene is one of the primary volatile organic compounds in urban air pollution. Beside its environmental implications, benzene poses various health risks to urban inhabitants. This study aimed to measure benzene levels at fuel stations (petrol pumps) in a specific area of Tehran and model its dispersion to determine safe distances from the release point. Materials and Methods: The study, assessed benzene pollutant concentrations at 11 selected gas stations in Tehran’s 4th district over one-year using gas chromatography with a GC-FID flame ionization detector. Additionally, pollution dispersion modeling was conducted using the AEROMOD model, while the WISER software determined safe distances to aid emergency responses to chemical releases exceeding standard limits. Results: Benzene measurements at the selected stations indicated average emissions of 3.07 µg/ in spring, 3.50 µg/ in summer, 2.95 µg/ in autumn, and 2.35 µg/ in winter. Notably, levels surpassed standards at three locations, posing environmental and health risks to residents’ station 53 and the Takhti sampling area exhibited the highest and lowest benzene emissions, respectively, at 4.24 µg/ and 1.62 µg/ . The dispersion model revealed a maximum annual benzene concentration of approximately 7.89 µg/ , exceeding the standard limit. Safe distances determined by the WISER model ranged from 0.5 to 0.7 µg/ , extending between 50 and 300 meters from the sampling area. Conclusion: The study concludes that benzene emissions are higher in summer and lower in winter at the sampled locations. Distance from emission sources correlates with reduced benzene concentrations, thus minimizing population exposure. Safe areas were identified based on these findings. Given the health risks posed benzene emissions from gas stations, particularly in locations exceeding standard levels, targeted monitoring and control programs are imperative municipal areas and fuel stations.
Mahdi Ale Ahmad; Abdolreza Karbasi; Amir Hossein Davami; Reza Jalilzadeh Yengejeh
Abstract
Background and purpose: An accurate estimation of air quality and meteorological conditions is required to make the sound air pollution management decisions. Thus, the data analysis from monitoring stations is unavoidable in air pollution research. The present study uses the statistical tests to ...
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Background and purpose: An accurate estimation of air quality and meteorological conditions is required to make the sound air pollution management decisions. Thus, the data analysis from monitoring stations is unavoidable in air pollution research. The present study uses the statistical tests to survey the homogeneity of meteorological factors and air quality station data in Mahshahr.Materials and methods: At first, a decade's worth of meteorological station data and the data from air quality stations in Mahshahr were collected over 2016-2019. The minimum and maximum values, standard deviation, variance, skewness, and kurtosis of parameters were then calculated, and heterogeneities and improbable fluctuations in the data were examined.Results: The results indicated that an average of 12% of data from the meteorological station in the special region were invalid, and that the data from this station had a non-normal distribution. Moreover, 98% of meteorological data collected at Mahshahr airport were valid which had a normal distribution. Statistical analysis of pollutant concentration data from air quality stations revealed that among 21 pollutants monitored across four air quality stations in the study region, only PM2.5 in Mahshahr station, NO2 in the mobile station, and CO, O3 in the special region fix station yielded normal distributed data.Conclusion: Consequently, when compared to other regional stations, the data from special zone's fixed air quality station, and Mahshahr meteorological station were the most reliable, with an average invalid data percentage of 16.4 and 0.48, respectively. Finally, it is recommended that the data should be adjusted to a more normal distribution over the desired period before using the data from other stations.