Iranian Journal of

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Backgrounds and Objectives:Today, One of the most important environmental issues is solid waste Produced in Dentistry That because of the presence of hazardous, toxic and pathogen agents has special importance. In this survey, solid waste produced in Hamadan Dentistry laboratories and practical dentist offices is studied.
Materials and Methods: In this descriptive study, from 24 Dentistry laboratories in Hamedan 5 offices and from 27 practical dentist offices 5 offices were selected in simple random way. From each offices 3 sample at the end of successive working day (Sunday, Monday and Tuesday) were analyzed. Samples were manually sorted into different 41 components and by means of laboratory scale were measured. Then, measured components were classified based on characteristic and hazardous potential.
Results: Total annual waste produced in Dentistry laboratories and practical dentist offices in Hamaden is 15921.79 and 8677.56 Kg respectively. Production percentages of domestic type, chemical and pharmaceutical waste, potentially infectious and toxic wastes in practical dentist offices were 91.14, 6.7, 2.14 and 0.02 respectively. Dentistry laboratories solid waste comprises of 94.47 percent domestic type and 5.53 percent chemical and pharmaceutical waste. Main components of produced analyzed wastes were 2 components that consist of more than 80 percents of total dental solid waste. So, waste reduction, separation and recycling plans in the offices must be concentrated on these main components.
Conclusion: In order to waste suitable management, it is suggested that in addition to educate waste producer for waste reduction, separation and recycling in the offices, each section of dental waste (toxic, chemical and pharmaceutical, potentially infectious and domestic type wastes) separately and according to related criteria are managed.

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Background and Objectives: Over the last three decades environmental pollutions became a more noticeable problem in all around of the world. In many countries, noise pollution as a basic problem has a great importance.Development of the city, increasing of industrial centers, increasing vehicles, other annoying noise resources and also little information about the noise pollution of Tabriz city, has led to the doing of this research.
Materials and Methods: Sampling and measuring of noise pressure levels was done 180 times According to the EPA standards, measuring was done simultaneously in two stations(commercial-residential areas), three times a day (morning 7:30 -9:30 am, midday 12:30-14:30 pm and night 19:00-21:00 pm) and 30 days in month. 
Results: Sound pressure level in both stations was higher than the standards and the highest average level with 71.4 db was recorded in Raste-koche station at midday. Also lowest calculated average value with 68.5 db was measured in Golbad station at the morning time that is 8.5 db higher than the standards.
Conclusion: Average measured sound pressure level in two stations was higher than the standards. The results show that Tabriz has a noise pollution in commercial and residential - commercial areas. It is suggested that other noise pollution resources identified and the proper management actions for its reduction be done.

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Background and Objectives: Nowadays, most countries of the world have shortage of water due to many reasons such as population growth, rising of living standards, indiscriminate water use, and so on. Besides, in absence of adequate water resources, desalination of brackish and saline waters have been used to supply potable water. Freezing process is one of the methods which can be used to desalinate saline waters.The aim of this study was to survey freezing process to produce potable water from saline water of Persian Gulf shores.
Materials and Methods: This study was conducted in lab-scale by using indirect contact freezing. Three samples of 50 liter were provided from Bushehr shores. The implemented process steps were freezing (crystallization), separation of crystals, surface washing, and thawing. Freezing of the samples (each in 0.5 liter containers) were performed by a refrigerator at -20°C and 0.1KW/h energy consumption.
Results: The removal efficiencies of TDS in the first, second, and third samples by first freezing process were 56, 56, and 51 percent, respectively. Moreover, the removal efficiencies by EC were 42, 44, and 40 percent, respectively. Meanwhile, the removal efficiencies of TDS in first, second, and third samples by second freezing process observed 69, 69, and 68 percent, respectively. Moreover, the removal efficiencies by EC were 61, 60, and 63 percent, respectively. Also, the removal efficiencies of TDS in first, second, and third samples by third freezing process were 72, 73, and 72 percent, respectively. Moreover, the removal efficiencies by EC were 77, 78, and 77 percent, respectively. The production of the potable water by this method was 15-20 percent of the entry water.
Conclusions: According to the obtained results, potable water was obtained after third freezing of the saline water. Meanwhile, TDS of the produced water was less than maximum allowed concentration of Iranian standards.

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MicrosoftInternetExplorer4 Background and Objectives: Nosocomial infection is the cause of deaths, morbidity, higher costs and increased length of stay in hospitals. Correct and appropriate use of antiseptic and disinfectants play an important role in reducing infections. In this study the efficacy of antiseptics on bacteria causing hospital infections has been studied.
Materials and Methods: This study was conducted in the laboratory of Imam Khomeini Hospital of Uremia. In this study the Antimicrobial activity of Descocid, Korsolex basic, Mikrobac forte and persidin 1% was studied against bacteria causing hospital infections such as Enterobacter aeruginosa 1221 (NCTC 10006), Staphylococcus epidermidis (PTCC: 1435 (Cip81.55) and Pseudomonas aeruginosa Strain PAO1. Sensitivities of bacteria were determined by Minimum inhibitory Concentration (MIC) and Minimum bactericidal Concentration (MBC) antiseptics. In the second stage, the concentration of antiseptics was prepared according to the manufacturer's suggested protocol and the effect of antimicrobial agents were studied at the certain concentration and contact time.
Result: All disinfectants (Descocid, Korsolex basic, Mikrobac forte) concentration and contact time, Accordance with the manufacturer's brochure, had inhibitory effect on all bacteria. That this is consistent with the manufacturer's brochure. Persidin one percent in concentration of from 2 and 4 V/V % and exposure time 5 minutes could not inhibit the growth of bacterial. But at concentrations of 10 and 20% respectively 15 and 30 minutes exposure time, all three types of bacteria can be inhibited, which is consistent with the manufacturer's claims.
Conclusion: In this study, the efficacy of antiseptics was determined with the Micro-dilution method recommended by the NCCLS. Korsolex basic, weakest antiseptics (the highest MIC) for the inhibition of three bacteria was determined. But Between all four antiseptics (according to manufacturer concentration), Only one percent Percidine 2 and 4 V/V %  in consumer dilution and 5 minutes exposure time failed to inhibit the growth of Pseudomonas aeruginosa, Staphylococcus epidermidis and Enterobacter aeruginosa.

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MicrosoftInternetExplorer4 Background and Objectives: Environmental pollution and health risks of dyestuffs extensively are caused by many industries. Nonbiodegradability of dyes is important so that different methods are studied for removing them. The use of white rot fungi is promising technique in this regard. Therefore, objective of this work is to investigate Rimazol Brilliant Blue Royal decolorization by immobilized Ganoderma sp. in sodium alginate from aqueous solution.
Material and Methods: This is an experimental study. First, the nutritional, environmental, and operational conditions of decolorization process were optimized. Then, efficiency of immobilized fungal cells was investigated. Experimental designs were provided using fractional factorial methods and quadratic model was fitted on decolorization data by MiniTab software.
Results: Our findings showed that type and concentration of carbon source, temperature, and pH were the most important factors affecting decolorization and statistically significant. Optimal conditions to 95.3 percent color removal were: glycerol as carbon source at 19.14 g/L temperature, 27 oC and initial pH, 6.26. Moreover, decolorization efficiency increased from 75 percent up to 95 percent by improving process and fungal immobilization.
Conclusion: Ganoderma fungus has suitable potential to decolorization. Besides, optimization and cell immobilization can improve its capability. Application of experimental design to research methodology is important because of decreasing in experiments and saving resources. It is suggested to use these potentials in environmental pollution control.

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Background and objectives: Nowadays, landfilling is most common method in many countries owing to lower cost and adaptation to wide range of solid waste. Site selection of landfill requires evaluating several parameters such as municipal government requirements, environmental regulations and a large number of quantitative and qualitative criteria. The aim of current study was to compare AHP and TOPSIS in landfill site selection. For this purpose, two mentioned methods were applied to select suitable site in Karaj. Materials and methods: In present study, 4 candidate sites in south of Karaj were selected for landfill by overlaying data layers (digital maps) and query functions in Arc GIS 9.2. Prioritizations between alternatives were conducted by AHP and TOPSIS technique according to the criteria mentioned. Eventually, we compared and evaluated the AHP results and TOPSIS results with each other. Result: According to AHP, site prioritization was 3,2,4,1 respectively whereas, in the case of TOPSIS, it was ranked 4,3,2,1, respectively. These results showed that both methods are suitable to determine site priority. Conclusion: As in AHP, alternatives are compared with respect to goal and criteria, consequently it has better precision and higher accuracy and confidence compared with TOPSIS.

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Background & Objectives: Remaining crude oil in storage tanks lead to accumulation of oily sludge at the bottom of the tank, which should be treated and disposed of in a suitable manner. The aim of the present study was to investigate the efficiency of chemical oxidation using H₂O₂ and Fenton’s reagent in removal of Total Petroleum Hydrocarbons (TPH) from bottom sludge of crude oil storage tanks. Materials & methods: In this experimental study, hydrogen peroxide and Fenton’s reagent were added to the sludge in six concentrations including 2, 5, 10, 15, 20, and 30% (w w^-1) and TPH was measured for a period of 24 and 48 h of reaction time. The oxidants were added in a single and stepwise addition way, both to the pristine and saturated sludge. The elemental analysis of sludge and TPH measurement were carried out using ICP and TNRCC methods respectively. Results: The mean TPH removal of 2, 5, 10, 15, 20, and 30% oxidant concentrations were 1.55, 9.03, 23.85, 33.97, 41.23, and 53.03%, respectively. The highest removal efficiency was achieved in stepwise addition to the saturated sludge. Increasing oxidation time from 24 to 48 h had a little effect on increase in TPH removal. Moreover, the removal efficiency of H₂O₂ and Fenton was nearly similar. Conclusions: Mere application of chemical oxidation is not capable of complete treatment of the sludge but it is an effective process as a pre-treatment step for decreasing toxicity and increasing its biodegradability.

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Background and objectives: In recent decades, progress of telecommunication industry resulted in public availability to cost-effective cellular mobile hence, boom of base stations of cellular mobile in response to vast public demands. Base stations of cellular mobile are specific source of microwave production in a certain frequency in environment. Antennas are installed on high towers to create proper coverage. General public exposure because of possible health effects resulting from radiofrequency fields has become challenging problem. The purpose of this study was to investigate microwave radiation status in actual exposure in inside buildings vicinity of macro cellular base stations in Zanjan. Materials and methods: considering location of base station antenna in city, power density of microwave around 64 base stations in indoor sites such as health care places and residential areas at different distances and different heights was measured. Measurements were performed based on IEEE Std C95.1 standard method using a portable SPECTRAN, HF– 4060 Rev. 3. Analyzing of data was conducted using SPSS Ver. 18 software and statistical tests like Kolmogorov-Smirnov, univariant variance, and multi variant linear regression. Results: It was found that the maximum level of power density was measured at a distance of 20 m from base station about 0.03787mW/m². With increasing distance from base station, the density of wave power decreased. Minimum measured at a distance of 300 m from tower was 0.00108mW/m². The positive variation of power density with height increase was shown. Conclusions: The maximum level of power density among total of 252 measurements, in indoor sites was7.320mW/m². This is about 0.166 % of the Permissible Exposure Limits of the standards for public exposure. We did not consider factors such as building location and interior furniture. Therefore, we suggest such factors be included in the future studies.

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Background and Objectives: Bottles for packaging drinking water represent one of the most popular uses of plastic and polymer additives. Recently, public concerns related to possibility of exposure to chemicals through the consumption of polyethylene terephthalate bottled water has caused great concern to consumers. Phthalate esters, as a class of these compounds, are often classified as endocrine disruptors and one of them is a possible carcinogen for human. The aim of this study was to determine the concentrations of phthalates in bottled water and to calculate the health risk of phthalates intake via consumption of bottled waters. Materials and Method: After purchasing, samples were immediately stored according to the recommended conditions (25 ºC, dark place) given on the bottle label. Migration of phthalates was investigated in PET-bottled water at different time intervals using gas chromatography–mass spectroscopy. Therefore, a phthalate exposure assessment was performed to characterize their risk to the consumer’s health via a calculated hazard quotient (HQ). Results: It seems that the duration of storage affects phthalate migration. Total increases of DEHP (811.8%), DBP (2545.2%), and BBP (832%) were observed at 12 months over the initial level before storage (bottled water immediately after production) but the level of phthalates in bottled water was always very low (<EPA:6 μg/L). Non-carcinogenic risk assessment from exposure to phthalate via consumption of bottled water was negligible in all of the subject groups (HQ<1). Furthermore, a little excess cancer risk of 9.9×10^-7 for bis (2-ethylhexyl) phthalate (DEHP) was observed.Conclusion: The research showed that the concentration of phthalates in PET-bottled water was extremely low. Consequently, based on the risk assessment results, bottled waters regarding existence of safe for consumers and they phthalates are not considered as public health issue for consumers as phthalates does not have any risk exposure for the consumers.

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Background and Objective: Nitrate is one of the dissolved anions having great health importance in water. Human activities and natural sources are considered as the main roots of nitrate intrusion in to water bodies. The main objective of this paper was to study nitrate removal by packed bed column filled with (PAN)-oxime-nano Fe₂O₃. Materials and Methods: PAN-oxime-nano Fe₂O₃ were synthesized and used as an adsorbent in glass column for the removal of nitrate from aqueous solution. Nitrate solution tank was set above the prepared column. The effect of factors, such as flow rate (2, 5, and 7 mL/min) and bed depth (5, 10, and 15 cm) were studied. Results: It was found that the data fit well with Thomas model and breakthrough curve was designed accordingly. The column performed well at lowest flow rate. As the flow rates and time increased, earlier breakthrough was observed. The column breakthrough time (C_e/C₀ = 0.05) was reduced from 9 to 4 h, as the flow rates increased from2 to 7 mL/min. Conclusion: fixed-bed using PAN-oxime-nano Fe₂O₃ exhibited good removal of nitrate. The adsorption studies showed that at longer bed depth, better removal of nitrate would be achieved. Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data also were in good agreement with logistic regression.

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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.

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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 5^th 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.

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Background and Objectives: Chemical hair color are one of the most widely used cosmetics. The presence of heavy metals in these products can affect the health of consumers. Unlike other cosmetics, no study has been conducted on the heavy metal levels in the synthetic chemical hair colors. This study determined the concentration of heavy metals in these products and the risk assessment of non-carcinogenic effects by these elements were calculated.

Material and Method: 32 samples of chemical hair color from eight brands (3 local and 5 imported ones) and four most used colors were collected from the markets in Tehran. The concentration of cadmium, lead, and barium was determined using ICP-MS. The information required to assess exposure risk was gathered through  a questionnaire distributed among citizens of Tehran. The assessment of exposure was conducted using Mont Carlo method and  non-carcinogenic risk was determined using the index of Hazard Quotient. .

Results: Barium concentration measured was 0.86 mg/kg and concentrations of Cadmium and Lead were 0.45 and 185.34 µg/kg respectively. Among the elements, Pb with Hazard Quotient equals to 7.46×10^-4 had the most risk and cadmium with Hazard Quotient equals to 3.57×10^-5 had the lowest risk. Moreover, the Iranian brand and blond had the highest risk among the samples.

Conclusion: Based on the index of Hazard Quotient, heavy metals in the studied samples had no risk for consumers of these products.

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Background and objectives: Swimming is one of the most popular sport fields and entertainments that has considerable benefits for human health, but on the other hand microbial water contamination in swimming pools through transmission and spread of infectious diseases is a significant threat against public health. In this study, microbial water quality of all public swimming pools in Tehran were assessed and effective factors on microbial water quality were analyzed.

Materials and Methods: This cross-sectional study with the analytical approach was performed in 2013. The whole public swimming pools in Tehran were inspected and water samples were taken for measurement of microbial indicators including thermotolerant coliforms, heterotrophic plate count (HPC), and physicochemical parameters affecting the microbial water quality including turbidity, free residual chlorine and pH and an integrated swimming pool microbial water quality index were used to describe the overall situation. Operational parameters with probable effects on microbial water quality were checked through inspection using a checklist.

Results: The assessment of the swimming pool microbial water quality indicated that the compliance rates of thermotolerant coliforms and HPC were 91.4 and 84.5%, respectively. Compliance rates of free residual chlorine, turbidity, Ph, and temperature were also obtained to be 82.7, 45.5, 85.6, and 65.4% respectively. Based on the integrated swimming pool microbial water quality index, the proportions of swimming pools with excellent and good microbial water quality were 39.6 and 50.4% respectively and the others had not proper microbial water quality. The parameters of water free residual chlorine and turbidity, swimmer density, water recirculation period, dilution amount, cleaning, usage rates of shower and disinfection basin and operation of water treatment systems had significant effects on the microbial indicators (P<0.05).

Conclusion: The study showed that the overall microbial water quality status of public swimming pools in Tehran was acceptable and analysis of the results determined the most efficient interventions for improvement of the microbial water quality of the pools.

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Background and Objective: The performance of in-vessel composting process, as one of the most effective methods of oily sludge treatment, depends on factors such as nutrients and temperature. Therefore, it is crucial to investigate the trend of changes of these factors. The aim of the present study was to investigate the trend of changes of organic carbon, nitrogen, phosphorus, and temperature during the composting of bottom sludge of crude oil storage tanks.

Materials and Methods: The sludge was mixed with the immature compost at the various ratios of sludge to compost including 1:2, 1:4, 1:6, 1:8, and 1:10 with the initial C/N/P of 100/5/1 and then was composted for a period of 10 weeks. The process of mixing and moisture adjustment of the mixtures was done 3 times a day during the composting period. Sampling and analysis were performed every week for organic carbon, nitrogen, and phosphorus and every day for temperature.

Results: The research indicated that the concentrations of organic carbon, nitrogen, and phosphorus were decreased sharply during the first weeks of the process and then they were decreased gently. At the final stage of the composting, the ratios of C/N and C/P increased from 20:1 and 100:1 to 26:1 and 166:1, respectively. In addition, the temperature of the reactors was kept in the mesophilic range during the process period.

Conclusion: The similar trend of decrease of organic carbon, nitrogen, and phosphorus in the composting reactors is an indication of decreasing the activity of the microorganisms involved in petroleum hydrocarbons degradation.  

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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.

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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.

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