N Rastkari, F Izadpanah, M Yunesian,
Volume 8, Issue 2 (8-2015)
Abstract
Background and objective: Benzene is one of the main pollutants in air and one of the most extensive chemical compound used in both natural and industrial processes. Benzene exposure leads to the most dangerous adverse health effects, particularly blood cancer. The aim of this study was to evaluate the gas station workers’ exposure to benzene by measuring benzene in breathing air and urinary trans, trans-muconic acid. Materials and Methods: This cross-sectional study conducted in summer 2014 investigated 40 gas station workers and 40 occupationally non-exposed persons. Spot urine samples were obtained prior to and at the end of the work shift from each subject. The urinary levels of trans, trans-muconic acid was determined by liquid chromatography (HPLC) with diode array detector. At the end of the work shift, the benzene collected on sorbing cartridges was desorbed using carbon disulfide and was analyzed using gas chromatography and mass spectrometry detection. Results: The mean value for exposure to benzene in breathing zone of gas station workers was 5.90 ±1.93 ppm, which was significantly greater than the occupationally non exposed group (1.15±0.744 ppm). The mean urinary concentrations of trans, trans-muconic acid differed significantly between samples of gas station workers (64.75±19.47 µg/L) and occupationally non-exposed persons (47.10±13.67 µg/L). Conclusion: A good correlation (r = 0.581) between the mean values of benzene in breathing zone and the urinary concentration trans, trans-muconic acid was observed. Gas station workers were found to be probably the most exposed groups in this study. Inhalation is presumably the main route of exposure in gas station workers.
G.a Fallah Ghalhari, F Mayvaneh, F Shakeri,
Volume 8, Issue 3 (12-2015)
Abstract
Background and Objectives: Assessing human bioclimatic is foundation for many programs and plans, especially in the field of healthcare. In this study, human thermal comfort and its relationship with the incidence of diseases were investigated in Kurdistan province.
Materials and Method: The daily data of temperature, wind speed, relative humidity, and cloudiness between the years 1995-2014 were used. In the First step, Tmrt parameter was calculated in the Ray Man software environment. Then, UTCI index values were calculated using Bioklima software. In the final step, the climatic comfort zones were drawn in the ArcMap software.
Results: It was found that the UTCI values change from 20 to -23. Bijar and Zarrineh stations have the highest cold stress conditions. The calculated values showed that severe cold stress conditions prevail in most parts of the province almost throughout the year. The correlation coefficient values showed that the highest correlation with the height was observed in the cold months of the year (December- February). The results of UTCI zoning also showed that the central parts of the province consistent with the higher altitude areas had severe stress conditions.
Conclusion: The research showed that the province is faced with moderate to severe stresses in terms of human stress conditions. In the cold periods of the year, it will be more severe and more cold conditions are experienced in high places.
M Zare Jeddi, M Yunesian, R Ahmadkhaniha, H Kashani, N Rastkari,
Volume 8, Issue 3 (12-2015)
Abstract
Background and Objective: One of the air pollutants is volatile organic compounds (VOCs). Benzene, as a part of petrol, is a VOC, known to be carcinogenic to human beings (Group 1) and it has widespread application in various industries and professions. Hence, the aim of the present study was semi-quantitative and quantitative health risk assessment of petrol bank workers exposure to benzene via inhalation in the Tehran, Iran.
Material and method: For these purpose, this descriptive cross-sectional study was conducted in three stages. First stage consisted of measurement of benzene in two groups of participants: (1) petrol bank workers and (2) non-exposed people as control group. The second stage included the evaluation of worker's exposure to benzene and semi-quantitative risk assessment, and the third stage was estimating the lifetime cancer risk caused by exposure to benzene.
Results: Benzene mean concentration was near the threshold limit value (1600 µg/m3) and the mean benzene personal air level was 1527±246.4 µg/m3 in the petrol bank areas. With regard to semi-quantitative risk assessment method, benzene introduced as the most hazardous chemical with risk ratio of 4.5 has 5th rank in risk levels (Extremely dangerous). Lifetime cancer risk estimation showed that in petrol bank workers the excess lifetime cancer risk was 27.5 times higher than unexposed group and the chance of cancer was one in a 1000 petrol bank workers.
Conclusion: This study indicates that petrol bank workers in Tehran have a potentially high cancer risk through inhalation exposure. Thus, preventative actions regarding to this hazardous and carcinogenic chemical must be started as soon as possible.
Kh Ashrafi, M Shafie Pour Motlagh, M.s Mousavi, M.h Niksokhan, H.r Vosoughifar,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objectives: In this study, contribution of exhaust emission and CO distribution was estimated in enclosed residential complex parking.
Materials and Methods: This was a descriptive - analytical study consisted of two stages. In the first stage, the emission contribution of vehicles was determined. In order to determine the contribution of exhaust gas emissions, through gas species, only four species CO, O2, CO2, and N2 were measured. Concentration of CO, O2, and CO2 was estimated using data obtained from the vehicle emissions monitoring system. The amount of N2 was estimated from sum ratio of all species, which equals to 1. Then, using computational methods, the amount of the emission contribution from vehicles. In the second phase, to measure the distribution of CO pollutant, gas sampling and collecting was performed using sampling bags made of inert materials with a volume of 10 l at six points. Sampling was conducted in accordance with the requirements of OSHA ID 210. The Obtained data were analyzed using SPSS Ver.16 software and Pearson statistical test (P > 0.05 means there was no significant difference).
Results: Maximum contribution was estimated for Pride with amount of 44.4 g/s and minimum contribution was estimated for Tiba with amount of 0.3 g/s. The minimum and maximum distribution value of CO concentration was achieved 3.6 and 69.48 ppm respectively. It was found that no significant relationship was observed between the values of exhaust emissions and CO distribution. However, the distribution of concentration was associated with locations and the number of openings, the number and type of vehicle, time of operation of the vehicle, the vehicle performance, and environmental factors.
Conclusion: Measuring vehicles CO emission indicated that the concentration was beyond the permissible level recommended by the World Health Organization at some. Moreover, it was indicated that natural air conditioning is an effective alternative for improving the air quality in built environments and suitable quality in built environments is achievable through reasonable architectural design, without need to spend too much expense.
F Rezaei, G Moussavi, A.r Riyahi Bakhtiari, Y Yamini,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objectives: Adsorption is one of the most common methods for VOCs elimination from waste air stream. The study on the application of a selective and cheap adsorbent with high efficiency in VOCs removal is important from economic aspects. In this study, the potential of MnO/GAC and MgO/GAC composites was investigated for toluene adsorption from air stream at lab scale.
Material and methods: The MnO/GAC and MgO/GAC adsorbents were prepared through Sol-gel method and then were characterized using BET, XRF, and SEM analysis. The effect of operational parameters including; retention time (0.5, 1, 1.5, 2, and 4 S), inlet toluene concentration (100, 200, 300, and 400 ppmv) and the temperature of the air stream (25, 50, 75, and 100 ˚C) were examined on the efficiency of both adsorbents. The efficiency of MnO/GAC and MgO/GAC were determined from the breakthrough time and adsorption capacity and the results were compared statistically.
Results: The breakthrough time of MnO/GAC and MgO/GAC adsorbents increased 90% by increasing retention time from 0.5 to 4 S. Adsorption capacity of MgO/GAC and MnO/GAC was increased 39and 61.1% by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of MgO/GAC and MnO/GAC decreased 65 and 59% by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. The efficiency of MgO/GAC and MnO/GAC adsorbents had a direct relationship with the increase of air temperature from 25 to 100 ˚C. Accordingly, the efficiency of MgO/GAC and MnO/GAC was increased 78 and 32% by increasing air temperature, respectively.
Conclusion: The results of the study showed that MgO/GAC and MnO/GAC adsorbents had high efficiency in toluene removal from air stream. The difference between the efficiency of MgO/GAC and MnO/GAC adsorbents was significant and MgO/GAC adsorbent showed higher efficiency than MnO/GAC for toluene adsorption from waste air.
S Farhang Dehghan, B Maddah, F Golbabaei,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objectives: The goal of the present study was to develop nanofibrous media filters containing MgO nanoparticles for future application in removing particles from gas stream.
Materials and Methods: Electrospun nanofibers were fabricated using experimental design prepared by Response Surface Methodology. Optimization of electrospinning parameters was conducted for achieving the desired filter properties including fiber diameter, porosity, and bead number. After taking SEM images, the determination of fiber diameter and number of beads were performed through Image Analysis and the calculation of porosity percent was performed by MATLAB. A filter media was produced based on the optimized conditions of electrospinning and it was certified by the HEPA filter performance test.
Results: In terms of morphological quality of fibers including fiber uniformity, absence of branching and lower numbers of beads, experiment standard No. 2 (STD 2: concentration 16 wt%, voltage 10 kV, and distance 15 cm) had the best combination. Maximum fiber diameter was also observed in STD 2. Among the electrospinning, the highest correlation coefficient was observed between solution concentration and response variables and the relationship between concentration and both fiber diameter and porosity percent was statistically significant (p <0.05 and p <0.01, respectively). A weak positive correlation was found between fiber diameter and porosity percent (r=0.29, p>0.05) and a weak negative relationship was seen between fiber diameter and bead number (r=-0.2, p>0.05).
Conclusion: Solution concentration was found as the most affecting factor on the filter properties, so that the higher concentration leaded to the lower bead number and greater fiber diameter. Increase in fiber diameter resulted in larger pore size and higher porosity. Quadratic models were known for understudy variables. Efficiency of the optimized filter was comparable with the HEPA filter and it had the lower pressure drop.
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.
N Rastkari, F Izadpanah ,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: Formaldehyde is a toxic volatile organic compound, which its removal from polluted air is essential. One of the techniques available for removing such compounds is photocatalytic degradation. The aim of this study was to investigate the photocatalytic degradation of gaseous formaldehyde on TiO2 nanoparticles coated on reduced graphene oxide
Materials and Methods: The synthesized reduced graphene oxide- TiO2 nanocomposite was characterized using SEM, EDS, and FTIR spectra. The photocatalytic activity of prepared reduced graphene oxide- TiO2 nanocomposite was investigated for degradation of gaseous toluene under different operational conditions such as different initial concentration, flow rate, and time.
Results: The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite was much higher than P25 TiO2. The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite decreased by increasing the flow rate so the flow rate is a key factor for the use of RGO-TiO2 nanocomposite as a photocatalyst. The results showed that the photocatalytic degradation rates decreased from 89 to 30% with increasing formaldehyde initial concentration from 0.1 to 1 ppm.
Conclusion: This research indicated that RGO-TiO2 nanocomposite can be effectively used as suitable photocatalyst to remove gaseous pollutants. One of the advantages of the as-prepared composite was using visible light instead of UV to activate the oxidation process.
Z Javidaneh, Ar Zarsevandi, F Rast Manesh ,
Volume 9, Issue 2 (9-2016)
Abstract
Background and Objectives: Street dust reflects one of the most important indicators of pollution in the urban environment. Most studies carried out in the world on heavy metal pollution are related to cities and metropolitans, while less attention has been paid to towns. Masjed-e- Soleiman, the most oil-rich town is located in the north eastern part of Khuzestan Province in Iran. This town contains geogenic pollutants such as gas and oil sources, oil and gas activities, oil and gas combustion, industries, and heavy traffic, which make it important from the viewpoint of environmental impact assessment.
Materials and Methods: For monitoring and management of pollution, 11 samples of street dust were collected and prepared from different stations within the town during the dry season (June 2013). Each sample was analyzed using ICP-OES instrument.
Results: Possible sources of the heavy metals were identified by multivariate analyses such as Principal Component Analysis (PCA) and Cluster Analysis (CA). In addition, factors such as the Index of Geo-accumulation (Igeo), Pollution Index (PI), Integration Pollution Index (IPI), and Enrichment Factor (EF) were assessed to determine the degree of heavy metals pollution in street dust of the Masjed-e- Soleiman Town. The results of PCA and CA indicated that the region is mostly affected by oil pollution (both natural and combustion of fossil fuels), traffic, and industrial activities (PI revealed high levels of Pb, Cd, Cu, and Zn pollution in samples and the average level of Ni, As, and V pollution in other samples). Igeo indicated the moderate to severe pollution of some samples to Pb, Cd, Cu, and Zn while no to moderate pollution against Ni, As, and V in other samples. EF for Pb, Cd, Cu, and Zn showed a significant pollution in some samples and other samples represented the least pollution against Ni, As, and V.
Conclusion: Results showed that the concentrations of heavy metals in dust samples were higher than control samples in Masjed-e- Soleiman. Thus, the classification of pollution in street dust in Masjed-e- Soleiman is as follows: IPI> EF> Igeo ≈ PI.
Gh Fallah Ghalhari, R Esmaili, F Shakeri,
Volume 9, Issue 2 (9-2016)
Abstract
Background and Objectives: Nowadays, indicators related to human physiology have special roles in human bioclimatic and environmental studies. One of these indices is Physiological Equivalent Temperature (PET). In the present study, trends of physiological equivalent temperature index over the past half century, which is the foundation of plans, especially in the field of health and environment, were evaluated in four climatic regions of Iran (Mashhad, Rasht, Esfahan, Tabriz and Bandar Abbas).
Material and methods: In this study, the data required to calculate the heat stress in the daily scale for 50 years during 1961-2010 were obtained from Iranian Meteorological Organization. Then, PET index at the daily scale was calculated and values greater than 35°C were identified for warm periods of the year. In the next step, the seasonal trends were analyzed by Mann-Kendall test.
Results: Changes in the frequency of days with heat stress in stations of Mashhad, Isfahan, and Tabriz have been rising during spring and summer. In other words, the greatest amount of positive change has occurred over the long-term average in these cities. The highest frequency of hot days was observed in Rasht and Bandar Abbas stations. The main reason for this subject has to do with how adjacent they were to the sea and the high rate of evaporation in such areas.
Conclusion: The 1980s-1990s have been allocated as the most days of hot stress. Upward trend of thermal stress occurring in the studied stations has increased the attention to the problem of heat stress and disease (thermal attack, fainting, muscle cramps) from the field of planning and management of the crisis.
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.
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.
Sh Hosseini, A Salehi, E Shokry,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: Increasing population growth and construction of high-rise buildings have doubled the amount of environmental pollution in the cities. Moreover, people use the open urban spaces more than before in order to meet their ecological needs. Accordingly, some parameters such as various vegetation and continuous winds streams can be considerably influential in transmittance of the particle pollution. Therefore, the aim of this research was to study the impacts of different green roofs on the dispersion of pollutants in the standpoint of height and density for urban airflow condition of Shiraz City, Iran.
Materials and Methods: In this study, a literature review in the field computer simulation with the help of computational fluid dynamics (CFD) model in Envi-met software environment was used.
Results: Regarding the importance of using vegetation in the urban spaces, vertical dispersion of the particles in presence of vegetation was explored. By comparing the basic model (without vegetation) results with models including vegetation with short, medium and high crowns, it was revealed that vegetation with medium crowns is the closest model to the basic model with a difference of 7.65 m2/s in terms of vertical dispersion of particles; in fact, it was the most optimized condition for maximizing the dispersion of environmental pollutants.
Conclusion: The results showed that the green roofs in the buildings increase the horizontal dispersion of the particulate pollution and decrease this term in the vertical dispersion. Finally, by an expansion of green roof usage in the buildings the sustainability in architecture and urbanism can be achieved.
. P Broomandi, A Bakhtiar Pour,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: The aim of this study was to investigate the physico-chemical properties, size distribution and shape of the falling mineral dusts over Masjed Soleyman and to identify their origins. Also, seasonal and annual variations of climatic parameters and their relation with dust storm occurrence were investigated.
Materials and Methods: The collected samples were as result of dry deposition process during warm season in 2013. Particle size distribution was determined by laser size diffraction. Chemical and mineralogical compositions were measured with atomic absorption spectrophotometer (AAS) and X-ray diffraction (XRD). Crustal and non-crustal origins for elements in the dust samples were determined using enrichment factor (EF). In addition, dust storm sources were identified using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT.4).
Results: The study of the annual and seasonal changes in meteorological parameters associated with the occurrence of dust storms indicated an agreement between the occurrence of dusty days, temperature and rainfall in summer. The chemical and mineralogical analysis of dust particles demonstrated that the likely origin of these particles is of neighboring countries in the South West of Iran. Also, some of the detected trace elements had non-crustal sources.
Conclusion: Using HYSPLIT.4 results, it was concluded that the main origin of dust storms are North West of Iraq and East of Syria in Masjed Soleyman.
F Khodamoradi, A Fotouhi, M Yunesian, Mh Emamian, H Amini, M Shamsipour,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: The aim of present study was to assess environmental inequality in long-term exposure to outdoor air pollution in 22 districts of Tehran in 2012.
Materials and Methods: The present study is an ecological study and concentration index was used for assessment of inequality. In this study the amounts of pollutant concentrations (PM10, NO2, SO2) obtained were based on land use regression (LUR) for exposure assessment. Variables that their effects have been studied on the distribution of exposure to pollutants included: education level, employment status and car ownership, which were obtained from census demographic and Tehran Municipality's dataset.
Results: The concentration index for PM10 in the case of illiteracy, people with higher education and private car owners was 0.059 (0.004-0.113), -0.056 (-0.001- -0.110) and -0.079 (-0.031- -0.127), respectively. These relationships were statistically significant. Concentration index for PM10 was 0.016 for the workers population, which was not statistically significant. For NO2 and SO2, no inequality was found in illiterate people, people with higher education, employees and car owners.
Conclusion: This study showed that there was significant inequality in terms of exposure to PM10 between different regions of Tehran in the illiterate, people with higher education and car owners. Considering these subgroups of population can be helpful in policy-making process.
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.
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.
Y Hajizade, Sh Nazmara, H Teiri, I Parseh,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: During the past few decades, air pollution has been the focus of international attention due to an increase in deaths from air pollution. In this study, Volatile Organic Hydrocarbons (VOCs) and Total Hydrocarbons (THCs) in ambient air of a Petrochemical Complex, Iran, was measured. Also, the relationship between these pollutants and some of their urinary metabolites was evaluated in the petrochemical complex workers.
Materials and Methods: These pollutants were measured in two stages, in spring (40 samples) and summer (40 samples), in ambient air of the different units of the complex. Urinary metabolites were measured in accordance with the NIOSH standard method using a GC-FID and TD/GC-MS.
Results: Total average of THCs in the spring and summer was 14.06 and 15.85 ppm, respectively; this amount was 14.09 and 16 ppm for VOCs. In summer, the highest values of VOCs (48.19 ppm) and THCs (47.63 ppm) were measured in Recovery unit. Total average of the urinary metabolites including Phenol, Phenylglyoxylic acid (PGA) and Mandelic Acid (MA) was 16.67, 34.8, and 67.24 mg/g creatinine respectively; in spring, it was 15.34, 57.34, 30.5 mg/g creatinine respectively
Conclusion: Background variables such as age, weight, and smoking habit had different impacts on the level of metabolites. The values of measured pollutants were lower than the guideline values proposed by the American Association of Industrial Hygienists (ACGIH). In addition, the values of measured metabolites in urine were less than the biological exposure index (BEI) provided by ACGIH.
A Tavakoli, A Parizanganeh, Y Khosravi, P Hemmati,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Radon is highly regarded because of its impacts on public health. Northern regions of Iran have a high potential for radon emissions. This research aimed to measure residential radon concentrations in Tarom country- Zanjan and to compare the results with international standards and acceptable values.
Materials and Methods: Passive diffusive samplers, Solid State Nuclear Track Detector (SSNTD), with the ability to determine background and longtime concentration, were selected for this study. A total of 30 detectors were located based on a pre-identified network in the residential buildings of Chavarzaq, Ab Bar and Gilvan for a period of three months. Then, detectors were sent to a laboratory for counting the traces.
Results: Based on the results, average radon concentrations in Chavarzaq, Ab Bar and Gilvan were 220.51, 95.25 and 119.84 Bq/m3, respectively. The average radon concentration in Tarom was about 130.57 Bq/m3. There was no meaningful relationship between radon concentration with the age of buildings or number of occupants. In comparison of the results with USEPA standards it was observed that among total samples just one of them was in the range of target level, and 15 detectors were in the range of target to action levels and the remaining samples showed high level of radon requiring corrective measures. In addition, 12 detectors showed values less than the reference level of WHO and the remaining detectors had higher values than WHO level.
Conclusion: Based on results of this research, soil analysis before construction, application of building materials resistant to leakage and regular monitoring of radon levels in region were suggested.
Sh Khaledan, L Taghavi, P Paykanpour Fard,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Population explosion and human ever-increasing demands has been resulted in industrialization which its mismanagement led to land pollution and consequently irreversible harm to nature and living organisms. Thus, it is an important measure to investigate the role of industrial centers in soil pollution.
Materials and Methods: We studied Mobarakeh Steel Industrial Complex and surface soil samples were taken in a regular grid with a dimension of 2 km of a 10 km buffer zone. 49 samples were taken from different sites. Soil parameters such as texture, pH and salinity were analyzed and concentrations of heavy metals including lead and cadmium were measured using flame atomic absorption spectrometry.
Results: Data analysis in the GIS environment using geostatistical techniques showed that a spherical model is a good model to investigate the spatial variability of lead and cadmium. The lowest and highest lead concentrations were 88.50 and 71.26 mg/kg and that of Cd was 6 and 26.1 mg/kg, respectively. No significant relationship between the heavy metals and soil properties (p>0.05). However, the correlation between two elements was significant (p<0.001). Among the various parameters, it was realized that wind direction played a great role in the distribution of lead and cadmium in the area.
Conclusion: The results showed the role of the industrial complex in the environmental pollution. The hot spot for lead was eastern and southwestern parts of the steel complex and for Cd it was in eastern and western parts. Proper management and more accurate monitoring are necessary to protect the environment in the complex industry.
