Iranian Journal of

Background and Objective: In the present study, EC and TDS quality parameters of Karun River were modeled using data-mining algorithms including LSSVM, ANFIS, and ANN, at Mollasani, Ahvaz and Farsiat hydrometric stations.
Material and Methods: Eight different inputs including the combination of Cl^-1, Ca⁺², Na⁺¹, Mg⁺², K⁺¹, CO₃^2-, HCO₃, and SO₄^2- with discharge flow (Q) were selected as non-random and random calibration inputs for these algorithms. Then, in order to guarantee the accuracy of the results, the simulation was performed by random calibration and the results of the two methods were compared. In the next step, the EC and TDS parameters were modeled based on the four parameters of Na⁺¹, Cl^-1, Ca⁺², and Q and a lag time of zero to three months.
Results: Modeling results indicated that Na⁺¹, Cl^-1, and Ca⁺² have the highest influence on modeling of EC and TDS parameters. The LSSVM algorithm was the most accurate in modeling EC and TDS parameters. Among the studied stations, the highest precision for EC and TDS modeling belongs to Ahvaz and Mollasani station, which has 16% and 36% higher coefficient of determination. LSSVM has highest accuracy in modeling the oscillation and peak EC and TDS parameters in during times.
Conclusion: The methods and models applied in the present study especially the LSSVM algorithm, can be a useful decision-making tool for predicting and qualitative management of rivers, including rivers in the Karun catchment area. The results of modeling the quality parameters of the rivers were reliable and usable by using both non-random and random calibration methods. However, the accuracy of the random calibration method was slightly higher.

Background and Objective: Increased use of pesticides and chemical fertilizers in agriculture in order to increase the productivity of fertile lands has led to pollution of water resources with a variety of pollutants, including herbicides. In this study, a new polymer magnetic nanoadsorbent named PV/S-g-3D-GO/N was synthesized and used to remove 2,4-D and MCPA herbicides from aquatic environment.
Materials and Methods: To investigate the synthesized nanoadsorbent structure FTIR, FESEM, TEM, XRD, VSM and TGA techniques were used and the effect of parameters affecting the optimal removal of herbicides by the adsorbent, including pH, temperature, contact time, adsorption dose and initial herbicide concentration was investigated. The kinetic, isotherm and thermodynamic studies of adsorption were also investigated.
Results: The results showed that in the optimal adsorption conditions including pH 3 for both herbicides, contact time of 180 min for 2.4-D herbicide and 300 min for MCPA herbicide, absorption dose 5 g/L and temperature 50°C for both herbicides, the maximum absorption capacity (q_max) was 5.62 mg/g for 2.4-D and 4.94 mg/g for MCPA. The synthesized nanoparticles that were used to remove 2,4-D and MCPA herbicides from real samples were totally successful (100% removal efficiency). For both herbicides studied, the isothermal data followed the Longmuir model (2,4-D: R² = 0.995; MCPA: R² = 0.998), and the kinetics of the adsorption process was a pseudo-second-order model (2,4-D: R² = 0.991; MCPA: R² = 0.999).
Conclusion: The results of the present study indicate that the synthesized nano-adsorbent can be used to remove phenoxic herbicides from agricultural runoff as well as water sources contaminated with the studied herbicides.

Background and Objective: In this study, we aimed to assess Iran’s position and trends for environmental health status among the countries of “Iran’s perspective document in 1404” according to the indicators used in Environmental Performance Index (EPI) report in 2018.
Materials and Methods: The score of indicators in environmental health area; air quality (including household solid fuels, exposure to PM_2.5, and PM_2.5 exceedance), water and sanitation (including drinking water and sanitation) and heavy metals (including lead) were extracted for all studied countries as well as for the last and baseline (generally ten years prior to last report) years from EPI 2018 database. According to EPI scores, the performance of the studied countries in each indicator was ranked. The percent change in the score of each indicator from baseline to current year was calculated and compared with the mean percent change for all studied countries.
Results: Iran ranked 7^th regarding air quality in 2016. Also, it ranked 6^th, 8^th, and 9^th in terms of household solid fuels, exposure to PM_2.5, and PM_2.5 exceedance, respectively. The EPI score for Iran regarding water and sanitation was 54.4 in 2005 and 58.74 in 2016 (percent change=7.98%). Iran ranked 21^st in 2005 regarding lead exposure index. Although this index showed a growth of 100% in 2016, which is very desirable compared to the average growth of all countries (34.47%), but only leads to one step up in the ranking of Iran and was ranked 20^th in comparison with other countries.
Conclusion: Totally, according to EPI 2018, Iran ranked 6^th in the field of environmental health issues among 23 countries of “Iran’s perspective document in 1404”. However, there is uncertainty in the accuracy of the EPI raw data used for calculating index scores. Hence, caution should be exercised in their interpretation.

Background and Objective: Noise pollution is one of the serious environmental issue. Sound control technologies based on sound absorption and sound insulation are considered as the two widely used methods. Therefore, the aim of this study was to modify silica aerogel nanocomposites to improve its acoustic properties.
Materials and Methods:  This applied experimental research involved in examining eight various types of nanocomposites to evaluate their performance of acoustic properties. In this study, nanocomposites were synthesized by sol-gel method. For this purpose, TEOS and ethanol were added to SiO₂ which subsequently stirred and diluted with ethanol as a precursor of silica sol. A solution of 5.5 M ammonium hydroxide is added drop-wise to the silica sol and then was stirred. The activated silica sol was quickly poured into the mold in which the samples were placed and finally placed in an oven at 150 °C for 3 hours. The acoustic properties of the samples were measured by the impedance tube and the reduction sound pressure level using a sound level meter. Each sample morphology was characterized by scanning electron microscopy.
Results: The sound absorption properties of as prepared nanocomposite relatively increased at high frequencies. The results indicated > 0.6 sound absorption coefficient by the modified nanocopmosites at higher frequencies. The sound absorption coefficient and transmission loss of D1 nanocomposite were higher at medium and low frequencies as compared to other nanocomposites. 4.6 and 9.73 dB average reduction of sound pressure level were achieved by either with or without nanocomposite enclosure, respectively, at a distance of 1 meter.   
Conclusion: The results of the current study showed that the simultaneous addition of organic and mineral materials to silica aerogels (especially with the highest amounts of nanoclay) improves its acoustic properties, especially at medium and low frequencies. Among the samples, D1 nanocomposite shows better acoustic properties at medium and low frequencies. The sound absorption coefficient of D1 nanocomposite at frequencies of 315, 400, 500, 1000, 1250, 2000 Hz were obtained as 0.27, 0.38, 0.51, 0.78, 0.83 and 0.84, respectively. The findings also indicated 9.37 dB reduction of sound pressure level using D1 nanocomposite.

Background and Objective: Vegetables are an essential part of our diet and a major dietary exposure route to heavy metals. Therefore, this study aimed to investigate the concentration and potential health hazards of heavy metals in the vegetables sold in Kashan markets.
Materials and Methods: 4 types of widelyraw-consumed vegetables, including parsley, coriander, basil, and fresh chives, were investigated in this study. Questionnaires were randomly given to individuals to determine vegetable consumption rate. Heavy metal were quantified using inductively coupled plasma- optical emission spectroscopy. Monte-Carlo Simulation was utilized to identify the associated health risks.
Results: Among tested heavy metals, Pb showed the highest concentration in parsley (4.8 ± 0.98 µg/g), coriander (3.8 ± 1.3 µg/g) and basil (3 ± 0.94 µg/g). Cr levels in fresh chives (2.8 ± 1.6 µg/g) was higher than other heavy metals. Also, the highest total hazard quotient values among examined heavy metals (Taking into account 95% confidence interval) were found for Pb (0.7), Cr (0.39), and Pb (1.034) in coriander, basil, and fresh chives, respectively.
Conclusion: Cr and Pb concentrations were generally beyond WHO/FAO guidelines in the samples. The THQ value for Pb in parsley was greater than 1, suggesting elevated adverse health effects due to parsley consumption.

Background and Objective: Pesticides are the major components of production in modern agriculture, however, as their widely usage, the hazards associated with their wastes have become of increasing concern. The aim of this study is to investigate orchard farmers’ attitudes toward proper disposal of pesticide wastes.
Materials and Methods: The statistical population of the study includes all orchard farmers in Meshkinshahr County (N=32,300). A total sample size of 300 farmers was selected and the data were collected. The research instrument was a questionnaire which was validated by a panel of university staff. A pilot study was conducted with 30 farmers outside the sample villages and Cronbach's alpha showed high reliability of the instrument.
Results: Due to the pesticides use, significant amounts of wastes are produced annually. Farmers do not properly dispose pesticide wastes. They leave the wastes on the farm, dump it in canals or river flow, or burn it. Farmers were not well informed about triple rinsing of containers before disposal. Most farmers used masks, hats, and gloves, 53% used boots and 7.7% used goggles, though none of them used coverall during pesticides’ handling. Respondents took negative to moderate attitudes towards proper wastes disposal. Age, education, and participation in extension programs were the most important determinants of the attitudes.
Conclusion: Considering the relatively negative attitude and improper waste disposal, it is necessary to establish centers for waste collection, to inform and encourage farmers to dispose of waste properly. Relevant organizations, such as health and the environment should plan for pesticide waste management.

Background and Objective: Air pollution is one of the most important environmental risk factors that exposure to it can cause many acute and chronic effects on human health. Some regions of Iran, especially the western, southern and southeastern provinces of the country, have been affected with dust storm for years. Studies on the frequencies of dusty days in the country show that central pits of Iran and the cities of Zabol and Zahedan have the highest incidence of dusty days. The purpose of this study was to determine the concentration of suspended particles with aerodynamic diameter of 2.5 μm or less (PM_2.5) in various seasons and months during 2019 in Zahedan.
Materials and Methods: In this descriptive-analytical and cross-sectional study samples were typically collected once every 6 days during a 24-hour period as well as on dusty days using an air sampler (PQ200 / BGI) from July 2018 to July 2019.
Results: The results show that the mean concentration of PM_2.5 in Zahedan during this study was 36.86 µg/m³. The maximum and minimum PM_2.5 daily concentrations in the sampling days were also measured as 130.8 and 4.75 µg/m³, respectively.
Conclusion: In conclusion, 88% of samples contained PM_2.5 concentration above the WHO 24-hr air quality guideline level (25 µg/m³), which could be due to the high incidence of summer dust storms. This indicates that particulate matters are a serious health threat to people living in those areas and calls for the implementing measures to tackle the problem.

Background and Objective: The bibliometric analysis is the most effective way to study the scientific output and trend of research. The purpose of this study is to analyze the scientific output of the Institute of Environmental Research (IER) at Tehran University of Medical Sciences using bibliometric technique.
Materials and Methods: All related IER articles that have been indexed in Scopus and WoK were retrieved from the beginning of 2009 till November 23, 2019. The bibliometric data were extracted and analyzed using R software.
Results: The document production follows an increasing exponential trend with a rate of 10% per year. 807 documents were retrieved with an average citations of 19.26 per each document. The documents per author and authors per document were obtained 0.196 and 5.1, respectively. The highest citations to documents was in 2017 (35.5 citations). The most frequent keywords were found “Adsorption”, “Drinking water”, “Air pollution”, “Particulate matter”, “Risk assessment” and “Response surface methodology”. Thus, engineering-based studies are more prominent in the published studies. Health-based studies, including risk assessment studies, accounted for the most area of research. The largest numbers of international research collaboration were recorded with the United States, Switzerland, Canada and India. While, in the national scale, Shahid Beheshti University of Medical Sciences’ collaboration was prominent.
Conclusion: It is still necessary to promote the level of the IER’s international collaborations to raise its regional status. In addition, more attention should be paid to health-based topics like risk assessment studies. These studies need to be given higher priority in the action plan of the IER’s centers and research groups.

Background and Objective: Monitoring of traffic emissions is a good way to build a safe ecosystem for living organisms. Therefore, the present study was conducted to assess the feasibility of using Achillea wilhelmsii and Cardaria draba located along the suburban roads of Hamadan for Zn, Pb and Ni removal by their aerial and underground organs in 2020.
Materials and Methods: In this descriptive study, after selecting 3 sampling stations, a total of 126 plant samples and 63 soil samples were collected. In the laboratory, the samples were prepared, and were then digested with acid. Subsequentely, the concentration of each heavy metal was measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Moreover, bioconcentration factor (BCF), bioaccumulation factor (BAF), transfer factor (TF) and metal accumulation index (MAI) were also calculated. Statistical analyses of the results were performed using SPSS statistical software.
Results: The mean values of BCF and BAF in both A. wilhelmsii and C. draba for all tested elements were greater than 1. On the other hand, A. wilhelmsii showed TF greater than 1 for zinc while C. draba showed TF greater than 1 for zinc and lead. The highest mean values of MAI in unwashed and washed shoots and roots of A. wilhelmsii were 98.48, 64.87 and 72.38, respectively.
Conclusion: Based on the calculated average values of BCF, BAF and TF of each elements, it can be argued that A. wilhelmsii and C. draba species have the potential of phytoextraction and Phytostabilization of the measured heavy metals and can be used for biomonitoring and bioremediation from soil and air in the heavy metals polluted areas.

Background and Objective: The aim of this study was to investigate dust origin particulate (PM_2.5) in Mashhad city in a long period of time (2014-2019) based on unhealthy days. Furthermore, changes in meteorological parameters and their relationship with dust storms have also been investigated.
Materials and Methods: In order to locate dust pollution hotspots in mashhad air, first, information about unhealthy days of Mashhad city in a 5-year period was obtained from the site of Mashhad Pollutants Monitoring Center and then HYSPLIT model was used to locate air pollution hotspots caused by particulate matter. To verify the results, the outputs obtained from this model were also compared with the DREAM8b model.
Results: By examining the meteorological parameters and its relationship with the outputs obtained from THEHYSPLIT and DREAM8b models, the maximum wind speed and relative humidity were obtained in autumn. There was no rainfall in the studied days (19 days) and the highest temperature was related to summer, indicating the relationship between the occurrences of polluted days due to particulate matter less than μ 2.5, wind speed and relative humidity in autumn. The results of the two models showed that the southern and northeastern regions of Mashhad city had the highest source of dust particles during the studied days.
Conclusion:  Although in previous articles, the origin of dust in Mashhad city was announced outside the geographical boundaries of the province, long-term investigation at low altitude (below 10m) showed that local origin of dust have an essential role in air pollution in Mashhad city under unstable atmospheric conditions. Inappropriate use of agricultural lands and severe changes in land use often in the northern region and implementation of construction projects such as the southern belt of Mashhad city play essential roles in increasing PM_2.5 particles in the air of Mashhad. This finding shows the importance of decision making for the implementation of soil stabilization projects etc... at the local level.

Background and Objective: N-methylpyrrolidine is a highly potent solvent with toxic and adverse ecological properties that has historically been widely used in the chemical and petrochemical industries. Due to the health and safety، toxicity and environmental effects of effluents containing NMP، these effluents should be pre-treated before biological treatment methods. The aim of this study was to remove N-methylpyrrolidone by photo- Fenton process.
Materials and Methods: For testing, solutions such as sulfuric acid, iron sulfate 7, oxygenated water, sodium hydroxide and distilled water were added to N-methypyrrolidine compounds in the reactor. Then, the removal process was investigated in two stages: complete mixing and adding solutions.
Results: The results revealed that the Fenton process cannot be used successfully to treat the hypothetical refinery effluent containing NMP. However، the photo-phanton process mineralized and degraded the NMP composition. Increase in 30% H₂O₂ concentration to the optimal dose of 1 mL led to the highest degradation (94%) and decrease in COD level of solution (42.1%).
Conclusion: It can be concluded that advanced oxidation by photo-phanton reaction can be a promising advanced oxidation technology for decomposition and pre-treatment of NMP-containing wastewaters for further biological treatment.

Background and Objective: Understanding the factors contributing to the mortality of COVID-19 patients can provide comprehensive information for preventive decisions and public health, and will help in better management of the epidemic. In this regard, the present study was conducted with the aim of identifying and introducing risk factors affecting the mortality of COVID-19 patients by modifiable and non-modifiable factors.
Materials and Methods: In this review study, according to the objectives of the study, related papers on risk factors affecting the mortality of COVID-19 patients were searched and collected in the international databases of Web of Science, Scopus, Embase, PubMed, and Google scholar. Then the results were extracted and reported by modifiable and non-modifiable factors.
Results: The results showed that almost all studies conducted in this field address non-modifiable risk factors such as age, sex, and underlying diseases including cardiovascular disease, diabetes, hypertension, respiratory diseases, cancer, self-diseases, autoimmune, and neurological diseases. Although few studies have been conducted on modifiable risk factors, lack of early admission or long waiting for hospital admission, occupancy of hospital beds and ICUs, as well as lack of equipment in hospitals were associated with increased mortality in these studies.
Conclusion: Regarding the situation of different countries in this epidemic, improving the control of the COVID-19 epidemic and reduce the mortality rate is possible by considering modifiable factors and taking appropriate measures. According to the results of studies, allocating sufficient financial, personnel and equipment resources can be effective in reducing COVID-19 mortality. However, controlling the COVID-19 epidemic to reduce morbidity and mortality as well as its economic and social consequences is possible by integrated management in the country. Also, using the experiences and guidance of the World Health Organization and successful countries, and stability in measures with a comprehensive approach should be considered.

Background and Objective: Microbial fuel cell (MFC) is a new green technology that uses the catabolic ability of microorganisms to produce bioenergy while simultaneously removing organic matter and other wastewater contaminants. Electrode material is one of the factors affecting the performance of microbial fuel cells. The aim of this study was to investigate the performance of microbial fuel cells in COD removal and bioenergy production from synthetic and real beverage wastewater.
Materials and Methods: In this research, a two-chamber microbial fuel cell with Nafion membrane and aerated  cathode was set up using two electrodes made of carbon felt and flat graphite after being contacted by synthetic wastewater with a concentration of COD 5000  mg/L and real beverage wastewater. Organic matter removal efficiency and voltage, power density and maximum current were determine.
Results: Experimental results showed that maximum COD removal efficiency of 92 % was achieved in synthetic wastewater and with a carbon felts electrode. In this condition, maximum voltage, power density and output current density of 469 mV, 175.28 mW/m², and 855 mA/m², were obtained, respectively. However, by using real industrial wastewater (beverage), maximum removal efficiency of COD, voltage, power density and output current density, related to carbon felt electrodes ‎were obtaines as 84 %, ‎460 mV, 91/65 mW/m², and 635 mA/m², respectively.
Conclusion: The findings showed that synthetic wastewater outperforms microbial fuel cells in terms of bioelectric production and organic matter removal as compared to real wastewater (beverage). The reason for the decrease in the cell performance might be the presence of solids and other confounding pollutants in real wastewater.

Background and Objective: By accurately identifying environmental issues, individuals can acquire skills to better solve environmental problems. To this end, the most appropriate method is to assess the educational needs of individuals to pave the way for the promotion of environmental knowledge. The present study aims to assess the need for training courses to empower professionals to increase their knowledge of environmental issues and educate others to take an important step in improving environmental health in society.
Materials and Methods: The present study was a descriptive needs assessment study using Delphi technique. In the first stage, the designed questionnaire was given to 150 people (faculty members, experts and students) to express their opinions in the proposed areas. In the second stage, a supplementary questionnaire entitled General needs for faculty members, specialized needs for experts and general and specialized needs for students were provided to individuals and the importance of the issues from their point of view was examined. Finally, the most important issues were prioritized by experts. Data analysis was performed using SPSS-26 software.
Results: The total number of educational needs extracted from the first stage of Delphi was 120 items, of which 31 items related to general needs (11 teaching and evaluation areas, 10 research areas and 10 communication and personal development items) and 89 items related to specialized needs. (27 cases of air pollution, 23 cases of waste management, 17 cases of wastewater treatment and reuse of wastewater, 10 cases of water treatment and pollution and 12 cases of soil pollution and its removal methods). In the second and third rounds, the importance of these items was determined by the target groups by scoring, and at the end, the first five priorities of each item were identified.
Conclusion: The results of this study, considering the comprehensive review of three target groups and determining and prioritizing the needs for each group, can increase the level of environmental awareness and empowerment of experts, which ultimately enhance the efficiency of the system and is an important step for environmental educational planning.

Background and Objective: Soils and sediments contamination with trace and toxic elements lead to potential ecological risk and adverse effects on human health and so have been the cause of increasing concern worldwide. Therefore, this study was carried out to potential ecological risk assessment of As, Cd, Ni and V in surface sediments of Khazar Abad, southern parts of Caspian Sea in 2019.
Materials and Methods: In this descriptive cross-sectional study, a total of 36 surface sediment samples were collected from 12 sampling sites. After samples preparation, the elemental contents were determined using ICP-OES. Also, potential ecological risk factor (Eⁱ_r) and cumulative potential ecological risk index (RI) were calculated. All statistical analyses were performed by SPSS software.
Results: Based on the results obtained, the mean contents of As, Cd, Ni and V in analyzed samples were found to be 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The computed values of Eⁱ_r  showed that factor values were decreased in the order Cd > As > Ni > V. Additionally, the mean values of RI with 53.7 indicated that all the examined elements have the "low potential ecological risk".
Conclusion: Accordingly, although the examined elements have shown a low potential ecological risk, cadmium with 46.4% and arsenic with 45.4% mean values of RI can cause for concern. Therefore, source identification and management of organic and inorganic pollutants and also periodic monitoring of water and sediments as the sink of environmental pollution are recommended.

Background and Objective: barbershops are one of the most important public places for beauty activities, which requires attention to health issues (personal and environmental), and non-compliance with health standards and procedures can be a threat to public health. The level of awareness and performance of employees can affect the management of waste production. This study aimed to investigate the level of knowledge of personnel about waste production and performance in southern Tehran in 2021.
Materials and Methods: This descriptive cross-sectional study was conducted in southern Tehran with a statistical sample of 330 places. In this study, a questionnaire was used which comprised of three sections; demographic information, the level of awareness and performance of personnel, and the information was completed after interviews with hairdressers. Data were analyzed by Kolmogorov-Smirnov, Chi-square, Pearson correlation coefficient, one-sample t-test, and Mann-Whitney using SPSS software (IBM-v.26).
Results: The average scores of awareness and performance of individuals in waste management were 43.18 and 48.27, respectively, and based on the results of qualitative analysis, the scores of awareness and optimal performance of individuals in waste management were 53.6% and 72%, respectively. Also, 46.6% and 28% of the participants obtained unfavorable scores on knowledge and practice in waste management, respectively. People's knowledge about the management of waste produced in hairdressers had a significant relationship with gender, history of health education, history of health crimes, education and performance of people about the management of waste produced in hairdressers with gender and history of health education. There was no significant relationship between knowledge and practice with other variables.
Conclusion: Barbershop is a place where paying attention to environmental health is effective in promoting community health and disease control. Ignoring this issue can lead to the spread of various diseases. In general, the results of this study showed that the level of awareness is effective in the performance of barbers regarding the management of waste production. Additionally, health education was known effective in the level of awareness and performance of hairdressers in this field, so the improtant roles of these variables should taken into consideration. 
 

Background and Objective: With increasing water pollution, serious water shortages and increased pressure to save water, recycling and reuse of water has attracted more attention in various industries. Removal of silica from cooling water is essential for recycling and reuse of water. The aim of this study was to remove silica from water using magnesium oxide nanoparticles (MgO) synthesized by chemical deposition method.
Materials and Methods: Synthetic nanoparticles were successfully determined using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). To determine the optimal adsorption conditions the batch system, the effect of important parameters such as pH (2-8), contact time (0-150 min), initial concentration of silica solution (50-1000 mg/L), adsorbent amount (0.01-0.14 g) and temperature (25-60 ˚C) were studied.
Results: Under optimal conditions, an almost removal of 200 mg/L silica solution was achieved in 60 min reaction time. Equilibrium data were analyzed using the Langmuir and Freundlich isotherms. The adsorption process can be well described by the Langmuir model, and the maximum adsorption capacity was calculated as 75.76 mg/g. Synthetic data were analyzed using pseudo-first-order and pseudo-second-order equations. The pseudo-second-order model showed good agreement with the obtained data (R² = 0.9949).
Conclusion: Due to the high potential of magnesium oxide nanoparticles in silica removal, it can be a good candidate for the removal of silica and industrial wastewater treatment.
 

Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants produced by anthropogenic activities that contaminate all environmental matrices, including soils, and can enter the food chains. Therefore, this study was conducted for the analysis of PAHs compounds content in agricultural soils of Hamedan city, west of Iran, in 2021.
Materials and Methods: a total of 36 surface soil specimens were collected from 12 sampling sites in agricultural soils and after extraction of analytes based on the soxhlet method, the gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, soil samples were further analuzed for the amounts of pH, electrical conductivity (EC), and total organic carbon (TOC). Statistical analysis was performed using SPSS software.
Results: Results showed that 16 PAHs (∑16PAHs) total concentrations ranged from 435 to 3292 µg/kg with an average value of 1806 µg/kg. PAHs with higher molecular weight (≥ 4 rings) were dominant in PAHs profiles accounting for 78%. Based on the results, the mean concentrations of all 16 PAHs were lower than MPC established by MHWaS. Furthermore, the mean concentrations of Pyr, B(a)A, Chy, B(b)F, B(k)F­, B(a)P, and B(ghi)P were higher than the MPC established by the Iranian Department of Environment.
Conclusion: Based on the results obtained, as the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
 

Background and Objective: The city of Tehran is always exposed to adverse consequences due to the establishment of various sources of heavy metals. Therefore, the purpose of this study is to identify the types of heavy metals in airborne particles and the origin of heavy metals in the 21st district of Tehran.
Materials and Methods: According to the EPA standard, 5 stations from District 21 of Tehran were selected for sampling. Using the ASTM D4096 method and using a high volume sampling pump, 50 samples of total airborne particles were collected. The samples were transferred to the laboratory and the concentration of heavy metals was measured by ICP-OES. The UNMIX source model was used to identify heavy metal sources.
Results: The average concentration of heavy metals in 1400 is a decreasing trend including Li according to the concentration of heavy metals in the air in the SPECIATE database, the role of light vehicle sources was 47 percent 34 percent on the street and 18 percent at the airport.
Conclusion: The source of light vehicles exhibited the highest share of emissions and the element aluminum showed the highest concentration among heavy metals in Region 21. Therefore, the UNMIX source model can correctly identify index elements and priority sources for contaminant control.
 

Background and Objective: Nowadays, the demand for seawater desalination plants (SDPs) has risen worldwide. However, there is a lack of knowledge on the effects of discharging the SDPs brines into the Persian Gulf marine environment and its aquatics health. Therefore, this research was performed to examine the effects of SDPs brines discharged from this facility in the ecosystem of the Persian Gulf on survival and electrolytes in the Blue swimmer crab, Portunus segnis (Forskal,1775) under laboratory conditions.
Materials and Methods: Brines of two types of active SDPs in Hormozgan were collected; then,75 crabs of (P.segnis), with mean (±SD) carapace width of 9.71±2.18 cm and total weight of 61.22±1.04 g, were collected and transported to the laboratory from the Bandar Abbas coast. As a completely randomized design, the samples were tested in 5 treatments (with three repetitions). Mortality was recorded, and at the end of the experimental period (60 days),the level of some electrolytes of the hemolymph (sodium, calcium, magnesium, and potassium) was measured.
Results: Crabs' survival percentage in treatments containing SDPs effluent decreased compared to control (86%), which was more evident in RO 100% and MED 100% treatments with 46.7% and 40%, respectively (p <0.01). The examined electrolyte levels in treatments containing SDPs brine increased compared to control, which were more significant for RO 100% and MED 100% treatments (p <0.01).
Conclusion: This study showed that the SDPs brines would have physiological consequences on aquatic organisms. In nature, the synergy of SDPs effluents with other sources of ecological stress will have severe impacts. Therefore, the necessary regulations and actions should be taken to minimize the environmental effects of SDPs.