Article

Study of geographical factors in Tehran air pollution

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... It is known that between 65 to 70 percent of total emissions are related to urban transport operations (Alijani and Safavi, 2007). The problem is compounded by topographical (mountains to the north and the east) and climatological factors (sunshine, frequent temperature inversions), which favour photochemical transformation of volatile organic compounds (VOCs) and nitrogen oxides (NOx) to produce smog and tropospheric ozone (Fig. 10). ...
... 9. Landuses: Industrial land uses in the west of Tehran are caused lots of problems. Settling industry in unsuitable place and not considering hygiene rules are caused Tehran air pollution and West and South western prevailing winds lead factories surplus materials to the city (Alijani and Safavi, 2007). 10. ...
Article
Full-text available
In an urban area, one of the great problems is urban heat island effect, which is due to many factors such as urbanization and climatic factors, resulting from the production and accumulation of heat in the urban mass. The main characteristics of UHI effect are the raised temperatures in the city centre, leading to excessive energy use for cooling and putting urban population at great morbidity and mortality risks. Therefore, it becomes increasingly important to study that how could various factors form UHI over the city in order to reduce environmental challenges. This paper, therefore, is focused on urbanization and climatic factors to understand the influence way of these factors on formation of UHI. The percentage of UHI formation is high when great interaction exists. This paper explores literally the conceptual framework of interaction between urbanization and climatic factors on formation of UHI with the case study of city of Tehran. The urbanization factors that affect Tehran are discussed in relation to location of the city, the size of the city and population, density of built-up area, urban geometry, thermal property of fabric, surface waterproofing, anthropogenic heat, air pollution, land use and wind speed.
... This is a major environmental problem that will become much more serious if adequate precautions are not taken. It is known that between 65 to 70 percent of total emissions are related to urban transport operations [33]. The problem is compounded by topographical (mountains to the north and the east) and climatological factors (sunshine, frequent temperature inversions), which favor photochemical transformation of volatile organic compounds (VOCs) and nitrogen oxides (NOx) to produce smog and tropospheric ozone (Fig. 22). ...
... Industrial land uses in the west of Tehran are caused lots of problems. Settling industry in unsuitable place and not considering hygiene rules are caused Tehran air pollution and west and south western prevailing winds lead factories surplus materials to the city [33]. ...
Article
Full-text available
Increasing the number of population, pollutions, urban expansion and many other kinds of urbanization factors in metropolitan areas are affected climatic factors and vice versa. In fact, there is a correlation between these two factors in general. This paper put forward the conceptual model and two hypotheses. In order to test the model, UHI mapping has been carried out in Tehran as a case study. The investigation has been done at macro-level to get surface temperature. The methodology employed is to use satellite image with a thermal band (obtained on 18 July 2000). To map out the UHI, mapping of LST and NDVI were necessary and then overlaid them and extracted maximum temperature value for both urban and rural areas. The results show that the maximum urban and rural temperature values are 39°C and 27°C respectively. Therefore, daytime Tehran surface UHI shows 12ºC of difference between urban and rural areas which is quite strong. Analyzing the data specified that the urbanization factors have direct impact on increasing the UHI intensity in Tehran metropolitan area.
... The traffic and exhaust gas emissions are considered as major causes of air pollution in megacities [1].Traffic emissions are considered as damaging substances for the ozone reaction. The worst pollutants which badly affect the urban areas include Sulphur Dioxide, suspended particulate matter, Carbon Monoxide, Nitrogen Dioxide, Lead, and Ozone [2]. Identifying air pollution variables is important in the policymaking process. ...
Article
Full-text available
Industrialization and urbanization have brought along repercussions such as air pollution in urban areas. Air pollution has turned to a major concern for societies as it brings about a wide variety of problems. This reality illustrates the need for defining and formulating the air pollution problem properly. In this regard, variables have to be identified and analyzed systematically. Therefore, in this practical study, data gathering was conducted, and interviews were carried out for identifying the effective factors. Then, the interrelations among these variables were modeled, and the trend was analyzed using the VENSIM software. The investigation was carried out in the megacity of Tehran. This metropolitan has been greatly affected by air pollution due to its special geographical situation. Finally, dynamic relationship between variables and their contribution to the whole system was simulated. The result of the simulation shows that the "public transport" as the leverage variable has the most influence on air pollution among other effective variables.
... Also, Table 2 Furthermore, the spatial source and distribution of pollutants appeared to be important. In the city, most factories and industries are located in the west and the southwest [42] . Consequently higher concentration of PM 10 was observed in the southwest of study area although it had lower education rate. ...
Article
Full-text available
Introduction: Inequalities in urban environment are of significant concern, where socioeconomic status
... In another study, Safavi et. al. [2] analyzed the geographical factors in Tehran's air pollution and influential pressure patterns on it based on the maps of polluted days according to clustering algorithms. In that research, the pollutants exist in higher amounts during fall. ...
Article
Full-text available
Abstract: The study of synoptic systems helps in recognizing the mechanism through which weather phenomena occur and can be predicted. The present research studies the relationship between synoptic patterns and the number of days of severe air pollution in Tehran that led to a two-day closing of the capital city. For this purpose, the original data on air quality in Tehran from 2nd to 6th of December 2012 at 12 stations measuring air pollution in Tehran were obtained from The Air Quality Control Company and then using the re-analysis data from NCEP / NCAR, Omega and pressure level maps (500 to 1000 hp) were drawn in Grads and synoptic patterns were analyzed during the mentioned days. The results showed that the spatial distribution of emissions, the highest and lowest pollutant in North West, South West and South East stations were PM10 and CO respectively. In the central and north east parts, the highest and lowest shares belong to Nox and CO. Study the relationship between concentration of pollutants and synoptic patterns demonstrated the reasons of atmospheric stability conditions that led to severe increase in pollutants were descending dynamical high-pressure conditions of Siberia from North-East of Iran, negative omega, the location of occluded-low blocking system and anti-cyclone conditions over the area under study. Keywords— Air pollution, Synoptic patterns, Spatial distribution, Tehran.
... But the western and southern parts of Tehran are not that much high, therefore, mountain dams in north and east prevent wasted materials, brought forth by the western winds into the city climate, to go out and this causes that the urban air be polluted especially in the central and eastern areas. Since the prevailing winds in Tehran have western direction and that most of the industries are stationed in the western part so it can be expected that the urban air be frequently polluted [14]. The data utilized in the present study include all data recorded by pollution measurement stations that are placed in different areas in Tehran and are collected and registered by the Tehran air quality control organization and Tehran air pollution monitoring center in Dey 1390. Figure 1 shows the geographical locations of pollution measurement stations in Tehran. ...
Article
Full-text available
Nowadays, air pollution in cities with regard to its harmful outcomes has been turned into one of the serious challenges in urban management. Pollutants as Carbon monoxide, sulfur dioxide, and the aerosols that are known to be among the most important factors related to heart, vascular, and lung disease, have underlined public welfare and health, and the organizations concerned with community health undertake remarkable expenses for disease coming out of these pollutants per year. Awareness of the air situation and its quality over periods and the process of air pollutants’ changes in locations, and especially detection of high risk places can play an important and efficient role in urban health management and land use policymaking. In this paper, for the prediction of the possibility of occurring a pollutant in different locations, based on location information, one modern method of analysis entitled indicator kriging method is introduced. Since, nowadays, CO and PM10 are the two major pollutants in Tehran city, using the mentioned method, the probability of occurrence of each of them in Dey 1390 along with their accuracy is being measured and then a map is provided for the possible occurrence of these pollutants over the whole city of Tehran.
... It should be mentioned that in the first hours of the day in the cold seasons, calm winds are frequent and concentration of the pollutants is resulted from the limitation of boundary layer which caused the accumulation and intensification of air pollution in Tehran during the cold seasons. In addition, in Tehran, geographical factors (Safavi and Alijani 2006) coupled with atmospheric stability conditions are provided for the increase of air pollution and urban ventilation is not appropriate, so the only solution is the reduction of emitting pollutants. ...
Article
Full-text available
The air pollution is a process which partially depends on the atmospheric conditions. The subject of the present research is analyzing the distribution of the pollutant “CO” in Tehran considering the effects of different wind patterns in cold seasons of year. The main objective of this research is to identify Tehran’s thermo-dynamical synoptic systems resulting in intensification of atmospheric stable condition, and to analyze the pollutant movements by wind. 14 samples of severe and widespread polluted days in the cold period (October to April) of 2002–2012 are selected and statistical, synoptic, and simulation methods are applied to investigate the air pollution in Tehran. According to the results, generally, concentrations of CO pollutant have reduced during the under studied decade. In addition, the results showed that the air pollution of Tehran follows a high-pressure system pattern which is located in the mid-levels of the atmosphere. In severe air pollution conditions, Tehran is located in the axis of a ridge which leads to the air subsidence due to the convergence of upper air currents. According to the analysis of upper air conditions, there was a column of steady air (about 1.5 km above the sea level) in which the density of pollutants increased and all indices confirmed stability conditions during the polluted days. The TAPM model is applied to simulate the wind pattern of Tehran. Four domains with horizontal resolutions of 5, 3, 2, and 1 km are chosen. The results of simulation show that winds in Tehran have different patterns during 24 h and local parameters such as slope directions can affect the air pollution concentration in stable synoptic conditions. In addition, Anabatic and Katabatic winds are frequent in Tehran due to its location in a valley in Alborz southern slopes and winds are considerably affected by the topography of the city. According to the results in the first hours of the day, calm winds are frequent and concentration of the pollutants is resulted from the limitation of boundary layer which caused the accumulation and intensification of air pollution in Tehran during the cold seasons.
... In another study, Safavi et. al. [2] analyzed the geographical factors in Tehran's air pollution and influential pressure patterns on it based on the maps of polluted days according to clustering algorithms. In that research, the pollutants exist in higher amounts during fall. ...
Article
Full-text available
The study of synoptic systems helps in recognizing the mechanism through which weather phenomena occur and can be predicted. The present research studies the relationship between synoptic patterns and the number of days of severe air pollution in Tehran that led to a two-day closing of the capital city. For this purpose, the original data on air quality in Tehran from 2 nd to 6 th of December 2012 at 12 stations measuring air pollution in Tehran were obtained from The Air Quality Control Company and then using the re-analysis data from NCEP / NCAR, Omega and pressure level maps (500 to 1000 hp) were drawn in Grads and synoptic patterns were analyzed during the mentioned days. The results showed that the spatial distribution of emissions, the highest and lowest pollutant in North West, South West and South East stations were PM10 and CO respectively. In the central and north east parts, the highest and lowest shares belong to Nox and CO. Study the relationship between concentration of pollutants and synoptic patterns demonstrated the reasons of atmospheric stability conditions that led to severe increase in pollutants were descending dynamical high-pressure conditions of Siberia from NorthEast of Iran, negative omega, the location of occluded-low blocking system and anticyclone conditions over the area under study. .
... The most of Iranian industries include the manufacturing of automobiles, electrical equipment, military weaponry, textiles, sugar, cement, and chemical products, are headquartered in Tehran. There are more than 7000 industrial units in Tehran which have been established 30 percent in West, 54 percent in South and 16 percent in East [8]. Therefore, since Tehran has been surrounded with these industrial units, all the energy consumed by these industries is converted into heat, contributing to the urban heat island. ...
Article
Full-text available
This paper is focused on understanding the most important factors of UHI formation and their effects on urban population health with an emphasis on the considerable growth of both population and rapid urbanization of Tehran, Iran. To achieve this aim, this paper explores literally a conceptual framework about the relationship between UHI and human health. Then, it suggests three important strategies to minimise the impact of UHI on human health: achieving appropriate transportation for mitigating air pollution, providing appropriate landscape, increasing the albedo of building materials. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of UniversitiTeknologi MARA Perak and Institution of Surveyor Malaysia
... Topography has an absolute effect on the air pollution of Tehran. The heights on the east, north and south of the city and also the west-east direction of the wind cause the pollution remain in the environment of the city (Safavi, Alijani, 2003). Also the temperature of the central city is higher than the suburbs and it makes the wind blow inside the city and take the polluted air of the west to the city (Afshar, 2000). ...
Thesis
Full-text available
In order to find the possible uses of the traditional urbanism in solving the modern urban problems, some of the contemporary urban problems that were likely to be partly or completely solved were targeted in chapter 1. The two research questions that were going to be answered were 1) which characteristics of the traditional Iranian urbanism can we use to solve some of the modern urban problems of the country? and 2) How can the effective traditional city characteristics be applied to ease some of the modern problems? Before studying the Iranian cities, the similar experiences in other countries and cultures were considered. The neo-traditional trends, practices, and built communities were discussed so that the nature of the research is determined. For example it was explained how the compact and traditional urban form was used to control urban sprawl in North America. Apart from the practical background, the theoretical aspects were reviewed. These theoretical bases were the interactions of built environment with urban transportation and environment. Before starting the main body of the research, the previous researches on the traditional urbanism including urban form, the main elements of the Iranian city, and the historical views of the urban growth were discussed. Also some of the neighbourhood infrastructures were described to make the foreign reader familiar with the Middle Eastern urban architecture. The main research methods that were used were direct observation, literature review, and Space Syntax theory. The theoretical bases and applications of SS were explained in chapter 6. Two case study cities were selected to be studied; Yazd and Kashan that both are located in the center of Iran. The studied cities contain a population of 400000 and 270000 so the results are generalized for the cities with the same range of population in similar climates and geographical conditions. Such cities are mostly mid-sized cities or small large cities in the south, east, and center of the country and also some parts of the western provinces. The historical urban growth, population growth, the typology of the constructions in the historical core and the new developments, mobility flows in the new and old textures, neighborhood organization, Neighborhood unit centers, and the hierarchy of the street networks of the two cities were studied. The first research question was answered by defining the main characteristics of the traditional Iranian city. To answer the second question, solutions in form of general strategies were discussed. Each of the suggested strategies can be implemented via some practical ideas. The study was started by the following hypothesis: “There are tips in the traditional Iranian city that have the capability to be used in contemporary Iranian cities to improve the related conditions of urban transportation, environment, energy use, and land consumption”. At the final stage of the work, it became apparent that the hypothesis is true because the possibilities and circumstances of using the traditional specifications and values became clear.
Article
One of the main challenges in highly populated cities such as Tehran is air pollution, which originates mainly from rapid and irregular urbanization and industrialization. This study was carried out to investigate trace elements contamination in airborne dust of Tehran, the capital of Iran. Dust samples were collected from 44 different sites on a monthly basis from March 2016 to March 2017. Results of trace elements pollution using three factors of enrichment factor, contamination factor and pollution load index, revealed that the pollution has spread in all seasons and its highest amount was observed in the cold seasons, the results of these indices also showed Pb, Zn, Cd and As play an important role in air pollution in Tehran. Three main groups were identified in the sources analysis study: (1) Co and Fe, (2) As, (3) Ni, Cr, Cd, Pb and Zn. The first group does not seem to be much influenced by human activities and originates mostly from geogenic sources; but the second and third groups are mostly from anthropogenic sources. Traffic, fossil fuel combustion and industrial activities are among the most important human factors that have a significant impact on the amount of Trace elements in the dust.
Conference Paper
بی تی ای ایکس (بنزن،تولوئن،اتیل بنزن و زایلن) از ترکیبات مهم خانواده آلاینده های آلی فرار هستند که استفاده گسترده ای در فرایندهای صنعتی دارند و از منابع مختلفی تولید و منتشر می شوند. اولین گام در راستای کنترل آلاینده ها اندازه گیری و تجزیه و تحلیل آن هاست. این مواد اثر مخرب بر سلامتی انسان و محیط زیست دارند. در مطالعه حاضر نمونه برداری و آنالیز آلاینده های هوا در شهر تهران انجام شده است. نتایج نشان می دهد میانگین غلظت بی تی ای ایکس در منطقه 19 شهرداری تهران برای بنزن 00389/0، تولوئن 00753/0، اتیل بنزن 00134/0، زایلن 00227/0 بخش در میلیون (پی پی اِم) می باشد. در این تحقیق نمونه برداری با استفاده از لوله های جاذب کربن فعال و آنالیز هوا توسط دستگاه گاز کروماتوگرافی با دیتکتور انجام شده است. نتایج نشان می دهد میانگین غلظت تمام ترکیبات مورد نظر در مناطق اندازه گیری شده پایین تر از حد مجاز استانداردهای هوای تنفسی ارائه شده توسط سازمان بهداشت حرفه ای می باشد
Article
Full-text available
This paper presents a methodology of determining the air pollution potential based on pollutant source identification and meteorological parameters, using as a case study the Isfahan Province in Iran. First, taking the county as the evaluation unit, the regional air pollution information system database of Isfahan Province was established, supported by Geographic Information Systems. Then, the air pollution potential of the study area was assessed based on the analysis of regional air pollution, review of available literature, seeking advice from experts, and using determining factors such as population density, traffic, industries, wind speed, precipitation, temperature and humidity. A layer for each factor was prepared in GIS. After data acquisition, criteria were set and weighted by experts. Finally, all criteria were integrated using the Weighted Linear Combination method to obtain the spatial distribution of air pollution potential. The results showed that 55 % of the total land area in Isfahan Province maintains a high to moderate level of air pollution potential resulting from unsuitable meteorological conditions along with high density of emissions from human activities. However, winds counteract the serious air pollution in some parts. The results suggest that very strict air quality management is needed in days of low wind speed, especially at places of increased air pollution resulting from human activities.
Article
In this study, a new array of meteorological elements and a synoptic climatologic classification to produce a baseline climate and to derive meteorological factors that are effective on air pollution in Tehran, which is located in a semi-enclosed basin was developed. The data set includes daily sea-level pressure and 500mb geopotential height fields from NCEP-NCAR and Tehran upper air sounding data at 00:00UTC for six months (July-December) of every year in the period 2001-2006. The classification is done through the principal component analysis (PCA) of data from the upper-air station. The results show that three meteorological factors are effective on variations of the Carbon Monoxide (CO) concentrations in the complicated terrain of Tehran basin. Thickness variations of different pressure layers (especially 850mb-700mb), Total totals index (TT) and surface wind speed are the most important dependent variables of these factors. Examination of the Carbon Monoxide (CO) pollution levels in Tehran, where emission sources are high shows that the synoptic classification identifies the patterns that are conducive to high pollution and those that are conducive to low pollutants build up in the basin. The synoptic climatology of events associated with five categories of CO concentrations show the role of synoptic forcings on decreasing CO concentrations. On the other hand, the role of high and thermal low pressure patterns in producing sever polluted episodes in the basin is also shown. These events occurred exclusively under special synoptic situations with high pressure developing on the airflow entrance of the basin and a thermal low pressure on the leeward side of the mountainous region. The coupled pressure system inducing horizontal pressure gradient produces a low level southerly cross wind toward the mountain barrier.
Article
Full-text available
Changes in temperature and precipitation, sea level, fisheries, agriculture, natural ecosystems, and air quality will all directly or indirectly affect human morbidity (illness) or mortality. One of the great challenges facing our current generation of scientists and engineers is how to protect urban population from health stressors associated with summertime heat. As heat-waves are likely to increase in frequency because of global climate change, the most effective interventions, measures and policies to protect the health need to be developed and evaluated. Therefore, this paper is focused on understanding the most important factors of urban heat island (UHI) formation and their effects on urban population health with an emphasis on the considerable growth of both population and rapid urbanization of Tehran, Iran. To achieve this aim, this paper explores literally a conceptual framework about the relationship between UHI and human health. Then, it suggests three important strategies to minimize the impact of UHI on human health: achieving appropriate transportation for mitigating air pollution, providing appropriate landscape, increasing the albedo of building materials.
Article
Full-text available
BACKGROUND AND OBJECTIVE: The BTEX chemicals (Benzene, Toluene, Ethyl benzene, and Xylene) are volatile monoaromatic hydrocarbons. Motor vehicles and fuels are examples for major sources of these environmental pollutants emission. They have harmful health effects. To reduce their health influences, monitoring their concentrations and controlling these pollutants in ambient air is indispensable. The aim of this study was to survey 24 hour variations of BTEX concentration in the ambient air of Tehran, Iran. METHODS: In this cross sectional study, round-the clock concentration variations of these compounds in the atmosphere of Tehran metropolitan city were surveyed. Two air quality monitoring stations, Aghdasieh and Ray, in two different locations in the city were applied. Twenty four hour sampling was carried out by an online sampler on a monthly basis. FINDINGS: The mean concentration of benzene (63.24±11.19 ppb), ethyl benzene (38.23±9.08) and xylene (14.13±3.29), in Ray was higher than Aghdasieh (16.57±5.86, 5.08±1.67 and 5.96±1.89, respectively) and the mean concentration of toluene in Aghdasieh (9.11±1.16) was higher than Ray (7.6±1.78). The results showed correlations among the concentrations of pollutants in each station in most cases and between two stations (p< 0.05). CONCLUSION: According to the results, despite of the different concentrations of pollutants for two studied stations; a similar trend of daily concentration changes was seen in the stations. This similar trend can be useful in 24 h concentrations prediction of BTEX in ambient air for different places.
ResearchGate has not been able to resolve any references for this publication.