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Showing 7 results for Air Quality
Analysis of Tehran Air Pollution Data in Recent Decade (2000-2009)
Mehdi Ahmadi Moghadam, Parviz Mahmoudi,
Volume 6, Issue 1 (5-2013)
Abstract

Background and Objectives: Exceeding the standard level in most cases, Tehran air pollution has become a national environmental challenge. Therefore, it is crucial to analyze Tehran air-pollution data set during 2000-2009 for trend analysis.
Materials and Methods: In this study, we collected the hourly data of Tehran air pollution during 2000-2009 recorded by monitoring station of Tehran Air Pollution Control Company and statistical methods was used to determine the trend of the five pollutants, including: CO, PM10, SO2, NO2 and O3.
Results: The results indicate that average annual concentration of PM10, CO, NO2, SO2 and O3 has changed from 91, 11.18, 102.6, 46.8, and 22.1 at monitoring station in 2000 to 88 µg/m3, 3.64 ppm, 66.1 ppb, 21.4 ppb, and 83 ppb in 2009 respectively.
Conclusion: Our findings revealed that although the air quality in Tehran has improved in term of particulate matter, SO2 and NO2 during this decade as a result of government's recent program in air pollution control, ozone concentration has increased.


Designing and Development of a Software System for Calculating the Air Quality Health Index (AQHI) and Its Verification Based on Actual Stations Data
M Asghari, R Nabizadeh, H Norzad, H Mortezaee,
Volume 9, Issue 3 (12-2016)
Abstract

Background and Objective: Increasing air pollution and consequently adversely effects on the quality of life for many people has resulted in the use of the air quality indice for determination of the actual amount of pollutants and air quality, as one of the most important and effective measures for air quality control, to be considered further. The air quality health index (AQHI) is a new index related to air pollution developed in collaboration with Environment Canada and Health Canada, in 2001. The purpose of this study was to design and develop a software system for calculating AQHI for the first time in the country that calculates the health effects caused by the presence of several pollutants (NO2, O3,PM10, and PM2.5) at the same time with a new approach.

Materials and Methods: To achieve those aims, the software was designed and coded in Visual Basic. Net. After preparation of the software, it was tested using the real-time database of  six air pollution monitoring stations in Tehran including Aghdasyeh, Setad Bohran, Shahrdari 4, Golbarg, Park-e- Roz, and Shahrdari 11.

Results: This program is a software package installed on the computer with the possibility of exporting Excel file. The performance of software testing was verified using real data.

Conclusion: The results of the verification tests show that the index calculated by the software introduced and presented in this study can be used as a useful tool to assess air quality.


Site selection of air quality monitoring stations over city of Mashhad by multiple-criteria decision-making techniques
H Adab, A Atabati, R Esmaili, Gh Zolfaghari, M Ebrahimi,
Volume 10, Issue 1 (6-2017)
Abstract

Background and Objective: Optimum number of air quality monitoring stations in Mashhad is an essential task for management of the urban environment. However, real monitoring and accurate information on the status of air quality require proper spatial distribution of air quality monitoring stations in the city of Mashhad. The aim of the present study was to determine optimum site locations for air quality monitoring, including Downtown Pedestrain Exposure Station, Downtown Background Exposure Station, and Residential Population Exposure Station by three Multiple-Criteria Decision-Making (MCDM) techniques.

Materials and Methods: In the precent study, sites for new air quality monitoring stations t in Mashhad were determined based on a proposed protocol in the United States. Accordingly, the criteria effective for site selection such as population density, distance from existing stations, vicinity to vegitation, vehicle density and other factors were used by applying Analytic Hierarchy Process (AHP), Fuzzy set, and Probability Density Function (PDF).

Results: Location similarity of the sites proposed by decision making methods was evaluated to know its reliability. The compactness of distribution of the proposed sites were compared by applying spatial statistic methods auch as Average Nearest Neighbor (ANN) and Standard. The results from ANN indicated that fuzzy set mapped the suggested sites was fully scattered within the entire city of Mashhad and was statistically significant at 99% confidence level. The PDF method also offered the same spatial pattern as fuzzy set. Overall results of this study indicated spatial optimization of suggested sites location for fuzzy set and PDF.

Conclusion: The overall results of the decision-making methods used in this study indicated that it is necessary to increase number of air quality monitoring stations at Northwest of Mashhad due to the urban growth in the city. The results also showd the possibility of using Probability Density Function (PDF) as a method of decision-making in GIS for locating and ranking of new air quality monitoring stations.


Review of studies on air quality status and its health effects in Iran
K Naddafi, Ms Hassanvand, S Faridi,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Air pollution is a leading environmental risk factor on health and it is the major cause of death and disease at global level. Air pollution has been shown to have a significant share in the non-communicable diseases (NCDs) burden. After smoking, it is the second cause of deaths due to NCDs, associated with an increased risk of developing acute and chronic diseases and mortality.
Materials and Methods:  In this study, a review was initially conducted on the basis of indices conducted in the world, the status of ambient air pollution and its effects on health in Iran and other countries, and then the status of ambient air quality and its effects on health in Tehran metropolitan between 2006 and 2017 were shown, based on the results of the studies conducted by the Environmental Research Institute of Tehran University of Medical Sciences.
Results: The results showed that the annual mean of ambient air population-weighted PM2.5 exposure concentration in Iran was about 48 μg/m3, which is relatively lower than its global mean concentration (51 μg/m3). Based on the most recent study (in 2018) about 8.9 (7.5-10.3) million deaths in those aged above 25 years were attributed to exposure to outdoor air PM2.5 in the world. Although there are substantial differences between the results of studies have been done regarding the number of air pollution attributed deaths, numerous studies showed that air pollution is a major cause of death. Results regarding temporal variations of air quality in Tehran that is performed by the Institute for Environmental Research (IER) of Tehran University of Medical Sciences (TUMS), indicated that PM concentration had an increasing trend from 2006 to 2011. The maximum mean concentration of PM2.5 over the past 12 years has occurred in 2011, which was 38 μg/m3. The PM concentration had a decreasing trend from 2012 to 2015, reaching about 30 μg/m3. However, in the years 2016 and 2017, the annual mean PM2.5 concentration in Tehran was increased compared to its corresponding value in 2015. Furthermore, results of this study demonstrated that, in Tehran, not even one day was classified as "good” (AQI=0-50) from 2011 to 2017 based on the air quality index (AQI), but the number of days in which AQI was “moderate” (AQI=51-100) was increased from 2011 to 2015, and the number of days with the AQI of “moderate” reached 80 in 2015, while the rest of the days having an unhealthy air quality. In 2017, AQI was “moderate” in 20 days, “unhealthy for sensitive groups” in 237 days, “unhealthy” in 107 days, and "very unhealthy” in 1 day. The obtained results indicated that about 4878 (3238, 6359( of deaths due to all (natural) causes were attributable to long-term exposure to PM2.5 in Tehran in 2017.
Conclusion: Studies showed that air pollution has a considerable share in the number of attributed deaths. Moreover, there were substantial differences between the results of national and international studies in the burden of disease attributed to air pollution. Therefore, there is a crucial need for accessing to reliable data on air pollution as well as baseline mortality and morbidity in order to study the status of air quality and its effects on health over the country. 

Allocating and prioritizing Karaj air quality monitoring stations by two stage approach
Mazaher Moeinaddini, Seyed Hassan Mousavi, Zohreh Isakhanbeygi, Somayeh Heidari,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: One of the most important goals for urban environmental management system is the monitoring of air quality. Allocating optimum air quality monitoring stations (AQMS), is a key factor in establishing effective and accurate air quality monitoring program. The objective of this study was to determine optimal allocation for AQMS in Karaj.
Materials and Methods: Based on two stages approach, at first, the suitability map was obtained by WLC method. For AQMS implementation, municipal districts were ranked. The extracted alternatives were graded using TOPSIS. In the next stage, the position of preferred sites were investigated by site visiting and detailed criteria. Finally, the AQMS locations were introduced.
Results: Ten suitable stations were suggested based on population and number of municipal districts. During the first stage important criteria such as distance from roads and street cross-section were weighted and standardized. The distance from roads and green space were the lowest and highest important criteria, respectively. The lowest and highest ranks for AQMS implementation were Nos. 9 and 3 districts, respectively. During the first phase 30 alternatives were obtained. At the second stage, 10 best alternatives were selected following field observation and considering implementation criteria (eg. distance from trees, cross section and pollutants emission sources).
Conclusion: In this study, at the first stage the preferred alternatives were determined. In the next stage the best alternatives for AQMS implementation were selected considering reasonable time and effort. The suggested approach could be used to implement AQMS for other areas.

Evaluation of ambient air quality in Arak with emphasis on aggregate and health risk-based indices
Adel Sheykhan, Gholamreza Moussavi, Mohsen Heidari,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The air quality index (AQI) does not account the interaction of multiple pollutants, meaning the high concentration and health risk of one pollutant may amplify the effects of others. The main aim of this study was to characterize the ambient air quality of Arak by assessing the combined effects and health risks associated with criteria air pollutants.
Materials and Methods: This study evaluated the ambient air quality of Arak for the year 1401 on the Persian Calendar, using the concentrations of criteria air pollutants averaged over appropriate timeframes. Additionally, the AQI, aggregate air quality index (AAQI), and health risk-based air quality index (HAQI) were calculated.
Results: Findings showed that the 1-hour concentrations of NO2, SO2, PM10, and PM2.5 exceeded national standards in 0.05%, 0.2%, 12.1%, and 35.5% of hours, respectively. The AQI, AAQI and HAQI values were above 100 in 54.4%, 77.3%, and 56.2% of hours, respectively. PM2.5 was the major pollutant in over 99% of cases.
Conclusion: The results indicated that AAQI and HAQI, in comparison to AQI, characterized the air quality as more polluted. This stricter assessment by AAQI and HAQI may encourage more precautionary measures by authorities and the public. Thus, it is recommended that the decision-makers in Iran’s air quality monitoring in consider adopting these indices.
 

Advanced evaluation of indoor air purification by plants: modeling the impact of Chlorophytum comosum and Aglaonema silver in benzene
Farzaneh Borzabadi Farahani, Mahmood Alimohammadi, Jamshid Rahimi, Sanaz Khoramipour, Emad Dehghanifard,
Volume 18, Issue 2 (9-2025)
Abstract
Background and Objective: People spend over 90% of their time indoors, where air pollutant concentrations—including volatile organic compounds (VOCs)—are significantly higher than outdoors. Among these VOCs, benzene is particularly critical due to its carcinogenic properties. Phytoremediation offers a sustainable solution for removing such pollutants from indoor environments. This study evaluates the benzene-reduction efficiency of two ornamental plant species, Aglaonema ‘Silver’ and Chlorophytum comosum, under controlled temperature and humidity conditions.
Materials and Methods: The plants were exposed to two temperature levels (18°C and 24°C) and two relative humidity conditions (35% and 50%). Benzene was introduced into sealed chambers at concentrations of 1, 0.5, 0.25, and 0.125 µL/mL. After 12 hours of exposure, benzene reduction was quantified using gas chromatography.
Results: At 20°C and 35% RH, Aglaonema 'Silver' removed 96% of benzene, outperforming Chlorophytum comosum (38%). Removal efficiency depended on species, environmental conditions, and initial concentration. Predictive models (Eq. 2–3) correlated strongly with experimental data (R² > 0.9).
Conclusion: Aglaonema 'Silver' demonstrated superior benzene removal compared to Chlorophytum comosum under lower temperature and humidity conditions. Our findings highlight that selecting plant species adapted to specific environmental parameters can significantly improve phytoremediation effectiveness. Furthermore, the proposed model indicates that elevated temperature and humidity levels may enhance benzene removal efficiency by indoor plants.
 

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