Showing 15 results for Particulate Matter
A. Alizadehdakhel, A. Ghavidel, M. Panahandeh,
Volume 3, Issue 1 (4-2010)
Abstract
Backgrounds and Objectives: The dispersion of particulate matter has been known as the most serious environmental pollution of cement plants. In the present work, dispersion of the particulate matter from stack of Kerman Cement Plant was investigated using Computational Fluid Dynamics (CFD) modeling.
Materials and Methods: In order to study the dispersion of particulate matter from the stack, a calculation domain with dimensions of 8000m × 800m × 400m was considered. The domain was divided to 936781 tetrahedral control volumes. The mixture two-phase model was employed to model the interaction of the particulate matter (dispersed phase) and air (continuous phase). The Large Eddy Simulation (LES) method was used for turbulence modeling.
Results: The concentration of particulate matter in the whole calculation domain was computed. The predicted concentrations were compared to the measured values from the literature and a good agreement was observed. The predicted concentration profiles at different cross sections were analyzed.
Conclusion:The results of the present work showed that CFD is a useful tool for understanding the dispersion of particulate matter in air. Although the obtained results were promising, more investigations on the properties of the dispersed phase, turbulent parameters and the boundary layer effect is needed to obtain more accurate results.
Soheila Rezaei, Kazem Naddafi, Hossain Jabbari, Masoud Yonesian, Arsalan Jamshidi, Abdolmohamad Sadat, Alireza Raygan Shirazinejad,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: In recent years exposure to fine airborne particles has been identified as an important factor affecting human health. Epidemiological studies have showed that the aerosol laden air can be an agent for microorganisms’ dispersion. Ignoring internal sources, ambient air quality significantly affects indoor air quality. Since people spend most of their times in the indoor spaces and little data are available on the general understanding of the indoor air quality, therefore, the aim of this study is to determine the particulate matter concentrations in indoor and ambient air of Tehran Children Medical Center Hospital.
Materials and Method: PM10/PM2.5 samples were collected in the indoor environment of the Tehran Children Medical Center Hospital and its adjacent outdoor environment by a portable GRIMM dust monitor model 1.108 from November 26 to March 10, 2007. The places of sampling for indoor and ambient air were in the patient room and the roof of the hospital respectively.
Results: The results showed that indoor PM10 level was higher than WHO standards in 80% cases in patient room, whereas, for indoor PM2.5 level, this value was 42 and 64% more than the EPA standards and WHO standards respectively. The relationship between outdoor and indoor particulate matters was examined by linear regression analysis. The indoor particulate matter levels were correlated with the corresponding ambient air ones.
Conclusion: Our analysis revealed that infiltration of ambient air could substantially increased indoor pollutants and thereby influences the indoor air quality.
Mohammad Sadegh Sekhavatjou, Roya Zekavati, Mohsen Peymani Froshani,
Volume 6, Issue 3 (12-2013)
Abstract
Objectives: Many of non-respiratory and respiratory disorders are associated with bioaerosols in indoor and outdoor air. The best conditions for bioaerosols life are high humidity and moderate temperatures, which exist usually in indoor spaces such as the prisons, where density of individual is high. Pathogen spreading centers cause the prisoners health at risk of disease outbreaks through airborne and breathing, sneezing, and coughing. Therefore, the aim of this research work was to measure concentration of particulate matters and also to identify and determine bacteria existing in the prisoners breathing air at high-density areas in one of the prisons and their relationship with each other.
Materials & Method: we conducted this research during summer and winter of 2012. We used TSI apparatus for collecting particles (PM2.5 and PM10). Blood agar and EMB agar media were applied to measure bacteria in indoor air (bedchambers and clinical admission wards) of the prison. According to NIOSH 0800 method, High volume pump with 28.3 L/min flow and a Single-stage Anderson Impactor were used for sampling. The time of measuring for each plate was 2.5 min. Finally, the data achieved were analyzed using SPSS after counting and detecting bacterial colonies grown and determining its density (CFU/m³) for two consecutive seasons of summer and winter. The tests analyzed by SPSS were ANOVA, Post hoc, correlation, and Pearson correlation tests.
Results: Amounts of particulate matter in bedchambers were exceeded than 24-hour EPA limits, while it was less than the limits in clinical admission wards. Gram-positive and gram-negative bacteria were found in three bedchambers (50% of the bedchambers) however, gram-positive bacteria were cultivated only in three bedchambers. The maximum bacterial contamination was measured at the main Lobby of the prison and bedchamber II and the minimum value was observed in admitted patient and TB patient wards. Results showed that there is no significant relationship between the particulate matters and the bacterial density during neither summer nor winter, but there is a strong and direct relationship between the prisoners population density, ventilation systems, and bacterial density n indoor air of the studied prison.
Conclusion: Based on the results, the maximum contamination load and exceeded concentration was observed in public sections and bedchambers. This findings were attributed to the daily entry of new prisoners, high population density in prison, presence of ill prisoners, prisoners with hidden respiratory disease showing no symptoms yet, old building, climatic conditions of the region, low efficiency of ventilation systems, and influx of particulates. To filter and purify prison indoor air, it is crucial to take serious action plans such as reducing criminal population density, sanitary and engineering measures
A Gholampour, R Nabizadeh, M. S. Hassanvand, H Taghipour, S Faridi, A.h. Mahvi,
Volume 7, Issue 4 (1-2015)
Abstract
Background & Objectives: Determining the impacts of air pollution in cities is facing two major challenges first, the limited data on the health effects of pollutants, and secondly, the lack of information on exposure to air pollutants and their concentration. This is an applied-observational carried out to determine the concentration, seasonal changes, and to estimate the health impacts attributed to the particulate matters in Tabriz during September 2012 to July 2013. Materials and Methods: The particulate matters were sampled using high volume sampler and were analyzed using portable HAZ-DUST EPAM-5000. The health impacts of particulate matterswere estimated using AirQ software developed by W.H.O. Results: The annual mean concentration of TSP, PM10, PM2.5, and PM1 in the urban sampling site were 139, 83, 38, and 27 µg/m3 respectively. In addition, these concentrations were 178, 110, 40, and 27µg/m3 in industrial area. The average of PM10/TSP, PM2.5/PM10, PM1/PM10, and PM1/PM2.5 ratio level was 0.6, 0.48, 0.33, and 0.7 in the urban areas and 0.61, 0.37, 0.28, and 0.77 in the industrial areas respectively. The total mortalities associated with the TSP, PM10, and PM2.5 concentrations were estimated as 327, 363, and 360 respectively. Nevertheless, the calculated cardiovascular mortality for TSP and PM10 were estimated to be 202 and 227 respectively. Conclusion: This research found that the concentrations of PM10 and PM2.5 were 73 and 69% more than National Standard and 8 and 5% more than USEPA Standards respectively. In Tabriz, especially industrial area, the soils of surrounding ground and re-suspension of particles fromcontaminated soils have a significant contribution to particulate emissions.
A Sepahvand, H Godini, Y Omidi, M.j Tarrahi, R Rashidi, H Basiri,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: The presence of fungal bioaerosols in hospitals indoor environments have affected the health of patients with the defect in immunity system. Therefore, determination of the rate and species of these agents is essential. This study aimed to investigate association between fungi contamination and particulate matter (PM10, PM2.5 and PM1) concentrations in the main indoor wards and outdoor environment and to determine I/O ratio in two educational-medical hospitals of Khorramabad City.
Materials and Methods: In this description-analytical study, the concentration of fungal bioaerosols and particulate matter was measured in 10 indoor parts and 2 outdoor stations over 6 mounts. The sampling was conducted using Quick Take-30 at an airflow rate of 28.3 L/min and sampling period of 2.5 min onto Sabouraud dextrose agar medium containing chloramphenicol. The particulate matters were measured using Monitor Dust-Trak 8520. Moreover, the relative humidity and temperature were recorded using digital TES-1360.
Results: Analysis of 288 fungi samples and 864 particulate matter samples showed that the average of fungi accumulation was 59.75 CFU/m3 and the mean concentrations of PM10, PM2.5 and PM1 in the indoor environment was 27.3, 23, and 20.2 µg/m3 respectively. In addition, in ambient air the mean concentration was 135.3 CFU/m3 for fungal bioaerosols and 40.2, 35.7, and 29.8 µg/m3 for PM10, PM2.5 and PM1 respectively. At the total of fungi samples, 12.5% were negative and 87.5% were positive. Having 101.7%, Infection ward was the most contaminated ward. The operation ward in both hospitals showed the minimum fungal contamination.
Conclusions: The results of the present study showed that at all of the samplings the ratio of I/O was lower than one. It was noticed the dominancy of fungal bioaerosols and particulate matter of outdoor source on the indoor environment. In addition, a significant correlation (P < 0.001( was found between fungal bioaerosols frequency and particulate matter and as well as fungal bioaerosols frequency, relative humidity and temperature.
A Gholampour, Ms Hassanvand, R Nabizadeh, Z Alizadeh, Ah Mahvi,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: The present study was carried out to determine the amount and ionic characterization of TSP and PM10 aimed at identifying the potential emission sources of particulates in the ambient air of Tabriz.
Materials and Methods: TSP and PM10 samples were collected by two high volume samplers during September 2013 to August 2014. Water-soluble ions in particulate matter were extracted using ultrasonic method and were identified by ion chromatography. Using Stata12 software, linear regression analysis was performed between the ions to determination of the major ionic component of the particulates. In addition, in order to identify the potential emission sources of PM10, the rotation varimax model was used.
Results: Total measured water-soluble ions in TSP and PM10 of the urban sampling site were 20.33±20.77 and 16.04±14.08 µg/m3, respectively. Among all detected ions, sulfate (8.69±5.79 µg/m3) and nitrate (8.47±7.9 µg/m3) were the dominant constituents followed by calcium and sodium.
Conclusion: The modeling results revealed that the soils of surrounding ground together with secondary PM and also resuspension of PM from polluted soil account for 80 percent of PM10 mass.
K Naddafi, M Yunesian, S Faridi, A Rafiee, S Parmy, Gh Safari, R Nabizadeh Nodehi , K Yaghmaeian, N Rastkari, R Ahmadkhaniha, S Niazi, M Hoseini,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants that are mostly generated during the incomplete combustion. The main objective of this study was to characterize potential sources of PAHs in Tehran.
Materials and Methods:, Samples of PM10 were collected at 10 monitoring stations belonging to Tehran Air Quality Control Company (AQCC) and transferred to laboratory for analysis. Besides, a SKC Flite 2 Air Sampling Pump (SKC, USA) equipped with a sampling head and PM10 size-selective inlet was used at four stations to compare the results obtained by collecting AQCC monitors (AQCCMs) tapes with the standard sampling procedures for assessing the interchangeability of two field sampling methods. The principal component analysis (PCA) and diagnostic ratios were applied to identify emission sources and source contribution.
Results: The average diagnostic ratios of phenanthrene (Phe)/ (Phe+anthracene (Ant)), benzo(a)anthracene (BaA)/ (BaA+chrysene (Chry)), fluorantene(Flu)/ (Flu+pyrene (Py)), and indeno(1,2,3cd) pyrene (IcP)/(IcP+benzo(ghi)perylene (BghiP)) in samples were 0.79, 0.52, 0.43 and 0.38, respectively. These ratios showed that the combustion, especially fossil fuels and motor vehicles, was the main sources of PAHs emission in Tehran. The results of PCA analysis also indicated that 49, 29 and 22% of PAHs sources in Tehran atmosphere were attributed to gasoline-driven vehicles, diesel vehicles and other sources, respectively.
Conclusion: According to the results, the combustion, especially fossil fuel and motor vehicle, was the main sources of PAHs emission in Tehran.
A Tavakoli,
Volume 11, Issue 1 (6-2018)
Abstract
Background and Objective: Air pollutants and noise level are areas of concern for public health, especially in metropolitan areas. In tunnels, underground stations and indoors with insufficient ventilation rate and noise reflection, accumulation of pollutants and noise pollution are serious problems.
Materials and Methods: The present study was conducted to evaluate the level of PM and noise level in the Majlesi terminal, located close to Imam Ali Square in Isfahan. Sampling was done in two phases, spring and summer. Samples were taken during six working days, twice a day, morning and afternoon and at traffic peaks. The effect of launching a BRT system was also evaluated. The SKC sampling pump and sound level meter of KIMO were used for the evaluation of particulate matter and noise.
Results: The results showed that the launch of a BRT system led to a change in PM concentration from 85.17 μg/m3 to 53.58 (37% reduction), however, the average value of summer noise level (78.34 dB) was higher than the average value of spring (76.23 dB). Both PM and noise levels were higher than the values of international standards of EPA and WHO guidelines. The level of PM and noise level was a function of traffic and varied during weekdays. On Thursdays and after medieval holidays, the highest level was observed. The pollution and noise levels were higher during afternoon than the morning peak hours due to the traffic and accumulation of contaminants.
Conclusion: The research revealed that indoor and underground environments are not suitable options as a parking lot or bus terminals, due to a need for mechanical ventilation, lack of adequate air circulation and sound reflection.
M Hatami-Manesh, S Mortazavi, E Solgi, A Mohtadi,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Today, the presence and increase of particulate matter is one of the serious factors that threaten human health. In the meantime, trees can accumulate airborne particles by their foliage. In this study, the accumulating ability of various PM by the leaf of some tree and shrub species was evaluated in Isfahan.
Materials and Methods: 12 species of trees and shrubs were selected at 8 locations in Isfahan and the total PM, PM10, PM2.5 and PM0.2 were measured using water and chloroform washing methods by paper filters 91, 42 μm, and Polytetra Fluorethylene filters and digital balance.
Results: The results showed that the highest and lowest mean total accumulation of total particulate matter was related to Morus nigra and Salix alba, that were 190.23 ± 23.5 and 11.9 ± 4.42 μg/cm2. In addition, the trend of accumulation of total PM on the leaf surface from the highest to the lowest was: Morus nigra> Platanus orientalis> Ulmus umbraculifera> Morus alba> Acer negundo> Ailanthus altissima> Fraxinus excelsior > Nerium oleander >Robinia pseudoacacia> Cercis siliquastrum> Nerium oleander > Euonymus japonicas> Salix alba and in epicuticular Waxes, Morus nigra> Ulmus umbraculifera > Platanus orientalis > Morus alba> Ailanthus altissima> Acer negundo > Robinia pseudoacacia>Cercis siliquastrum> Fraxinus excelsior > Nerium oleander > Euonymus japonicas> Salix alba.
Conclusion: The results indicated that the ability of different tree species to absorb PM depended on the morphological, physiological and ecological characteristics of the leaf. Finally, among the different species the Morus nigra had the highest ability to capture various PM.
R Bayat, Kh Ashrafi, M Shafiepour Motlagh, Ms Hassanvand, R Daroudi,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Despite the significant improve in air quality in Tehran in 2018 and reducing the average concentration of most pollutants, compared to previous years, air quality is still far from the WHO air quality guideline level and national air quality standards. The purpose of this study was to estimate the effects of air pollution on health in Tehran by considering the spatial distribution of particulate matter 2.5 micrometers or less in diameter (PM2.5) and population in determining exposure levels.
Materials and Methods: In this study, while introducing the GEMM concentration–response function and BenMAP-CE software, the mortality attributed to PM2.5 in Tehran and its distribution for 2017 and 2018 was calculated. Hourly PM2.5 from monitoring stations used to estimate the mean PM2.5 for 349 Tehran neighborhoods.
Results: The results showed that the average population weighted PM2.5 concentrations in Tehran in 2017 and 2018 was estimated to be 31.8 and 26.2 µg/m3 respectively. Using the GEMM function, about 7,377 (95% CI: 6,126-8,581) total mortality attributed to PM2.5 was estimated in adults in 2017 (> 25 years) and the figure for 2018 was estimated as 6,418 (95% CI: 5,918-6,753).
Conclusion: The spatial distribution of deaths attributable to PM2.5 showed that the total mortality rate per 100000 in the districts 16 and 18 of the Tehran municipality were higher than other districts and the lowest rate observed in the district 1.
Saeed Sotoudeheian, Behnaz Shirazi Rumenan,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: During the last few years, air pollution and increasing levels of particulate matters (PMs) have become major public health issues in the megacity of Tehran. The high cost of constructing and maintaining air pollution monitoring stations has made it difficult to achieve adequate spatial-temporal coverage of PM data over various regions. In this regard, the use of remote sensing data such as aerosol optical depth (AOD) can be a simple and cost-effective way to overcome the problem.
Materials and Methods: Due to the weakness of univariate linear relationship of PM10-AOD under normal conditions, this relationship has been studied for the time periods of dust storm occurrence during 2007-2010 in Tehran. Satellite product with spatial resolution of 3 and 10 km obtained from MODIS sensor were used to fit the models.
Results: Results showed that the best performance of univariate model was achieved for 5 km radius of AOD extraction and daily mean of PM10 concentrations (r = 0.55). Moreover, the use of meteorological auxiliary variables and the development of multivariate linear regression model have improved the performance of the model (r = 0.64). The final model also exhibited accurate capability for prediction of high PM10 concentrations during dusty days.
Conclusion: Overall, the obtained univariate linear relationships of PM10-AOD was stronger during dusty episodes than those of normal conditions, suggest a higher correlation between AOD and PM10 from dust activities as compared with PM10 originating from other sources. Furthermore, the final developed model could be used to predict daily level of PM10 concentrations during dusty episodes.
Hossein Kamani, Mohammad Sadegh Hassanvand, Abdolali Khammari, Sadegh Haghighat,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Air pollution is one of the most important environmental risk factors that exposure to it can cause many acute and chronic effects on human health. Some regions of Iran, especially the western, southern and southeastern provinces of the country, have been affected with dust storm for years. Studies on the frequencies of dusty days in the country show that central pits of Iran and the cities of Zabol and Zahedan have the highest incidence of dusty days. The purpose of this study was to determine the concentration of suspended particles with aerodynamic diameter of 2.5 μm or less (PM2.5) in various seasons and months during 2019 in Zahedan.
Materials and Methods: In this descriptive-analytical and cross-sectional study samples were typically collected once every 6 days during a 24-hour period as well as on dusty days using an air sampler (PQ200 / BGI) from July 2018 to July 2019.
Results: The results show that the mean concentration of PM2.5 in Zahedan during this study was 36.86 µg/m3. The maximum and minimum PM2.5 daily concentrations in the sampling days were also measured as 130.8 and 4.75 µg/m3, respectively.
Conclusion: In conclusion, 88% of samples contained PM2.5 concentration above the WHO 24-hr air quality guideline level (25 µg/m3), which could be due to the high incidence of summer dust storms. This indicates that particulate matters are a serious health threat to people living in those areas and calls for the implementing measures to tackle the problem.
Vahideh Barzeghar, Akbar Gholampour, Mohammad Sadegh Hassanvand,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: This study was conducted to investigate the long-term temporal trends and spatial variations of ambient PM10, PM2.5, O3, concentrations in Tabriz city during the years 2006-2017.
Materials and Methods: Real-time hourly concentrations of PM10, PM2.5, O3 measured at nine air quality monitoring stations (AQMSs) were obtained from the Tabriz Department of Environment (TDoE) during 2006-2017 and analyzed. Spatial and temporal variations of pollutants using the Mann-Kendall's test and Moran’s I index were analyzed.
Results: The results of this study showed that the annual trend of PM10, PM2.5 was decreasing but remained almost constant for O3 during the study period. During some of the studied days, PM10, PM2.5 levels were exceeded greater than the WHO AQG and National standard levels. Moreover, the highest monthly mean concentrations of PM10 in October (80.3 µg/m³), PM2.5 in January (42.9 µg/m³) and O3 in June (77.8 µg/m³) were observed. Comparison between the stations indicated that the Raste Kuche station was more polluted than other stations.
Conclusion: Effective control planning and implementation policies are essential to improve the air quality of the Tabriz environment. Hence, information provided in this research can be used as a key step for city managers, policymakers, and health officials to reduce the health impacts of air pollution.
Seyyed Reza Karimi, Nabiollah Mansouri, Lobat Taghavi, Mazaher Moeinaddini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The city of Tehran is always exposed to adverse consequences due to the establishment of various sources of heavy metals. Therefore, the purpose of this study is to identify the types of heavy metals in airborne particles and the origin of heavy metals in the 21st district of Tehran.
Materials and Methods: According to the EPA standard, 5 stations from District 21 of Tehran were selected for sampling. Using the ASTM D4096 method and using a high volume sampling pump, 50 samples of total airborne particles were collected. The samples were transferred to the laboratory and the concentration of heavy metals was measured by ICP-OES. The UNMIX source model was used to identify heavy metal sources.
Results: The average concentration of heavy metals in 1400 is a decreasing trend including Li according to the concentration of heavy metals in the air in the SPECIATE database, the role of light vehicle sources was 47 percent 34 percent on the street and 18 percent at the airport.
Conclusion: The source of light vehicles exhibited the highest share of emissions and the element aluminum showed the highest concentration among heavy metals in Region 21. Therefore, the UNMIX source model can correctly identify index elements and priority sources for contaminant control.
Zohreh Nourouzi, Atefeh Chamani, Mozhgan Ahmadi Nadoushan,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: Particulate matter is an important air pollutant in urban areas with unknown effects on the fetus. The present study investigated the effect of PM2.5 concentration on the level of liver enzymes in the neonate born in Isfahan city, one of the most polluted cities in Iran was investigated.
Materials and Methods: This case study was conducted between March 2019 to September 2020 in Isfahan. Blood samples were collected from the umbilical cord of 200 newborns to measure the level of liver enzymes from their blood serum using quantitative diagnostic kits and the spectrophotometry method. Seasonal distribution of PM2.5 concentrations was estimated using the data of monitoring stations; thus, modeled and used to measure their correlations with liver enzyme levels at trimester in buffers of 500, 1000, and 2000 meters.
Results: The mean levels of liver enzymes were 38.42 (AST), 10.09 (ALT), 407 (ALP), and 152 (GGT) IU/L. Spring and fall with PM2.5 concentrations of 24.35 and 35.35 and μg/m3 had the lowest and highest levels, respectively. Enzyme levels within the third trimester and the whole period of pregnancy in the 2000-m buffers had the highest correlation coefficient, which indicates the effect of high PM2.5 concentrations on neonatal liver function, especially in late pregnancy.
Conclusion: Proximity to particulate matter sources in cities will increase the likelihood of elevated neonatal liver enzymes during the fetal period which is higher and more effective in late pregnancy.
