Showing 14 results for Yari
Roohollah Noori, Gholamali Hoshyaripour, Khosro Ashrafi, Omran Rasti,
Volume 6, Issue 1 (5-2013)
Abstract
Backgrounds and Objectives: Precise air pollutants prediction, as the first step in facing air pollution problem, could provide helpful information for authorities in order to have appropriate actions toward this challenge. Regarding the importance of carbon monoxide (CO) in Tehran atmosphere, this study aims to introduce a suitable model for predicting this pollutant.
Materials and Method: We used the air pollutants and meteorological data of Gholhak station located in the north of Tehran these data provided 12 variables as inputs for predicting the average CO concentration of the next day. First, support vector machine (SVM) model was used for forecasting CO daily average concentration. Then, we reduced the SVM inputs to seven variables using forward selection (FS) method. Finally, the hybrid model, FS-SVM, was developed for CO daily average concentration forecasting.
Result: In the research, we used correlation coefficient to evaluate the accuracy of both SVM and FS-SVM models. Findings indicated that correlation coefficient for both models in testing step was equal (R~0.88). It means that both models have proper accuracy for predicting CO concentration. However, it is noteworthy that FS-SVM model charged fewer amounts of computational and economical costs due to fewer inputs than SVM model.
Conclusion: Results showed that although both models have relatively equal accuracy in predicting CO concentration, FS-SVM model is the superior model due to its less number of inputs and therefore, less computational burden.
M Hatami Manesh, M Mirzaei, M Gholamali Fard, A.r Riyahi Bakhtiyari, M Sadeghi,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objectives: one of the most important environmental concerns is heavy metals emissions from human activities to natural ecosystems, particularly transfer to soil. The aims of this study were measured the concentrations of Cu, Zn and Cr in landfill soil and hospital waste ash of Shahrekord municipal solid waste landfill. Materials and Methods: Soil samples were collected from three sites: out of the landfill, municipal landfill and hospital landfill. In each site 2, 1, and 1 stations ware selected respectively and each sample was replicated in three times. Results: We found that there was a significant difference between concentrations of Cu, Zn and Cr in the landfills soil (95% confidence, P <0.05). Furthermore, the highest levels of Zn and Cu were detected in the hospital landfill and also for Cr in the municipal landfills. However, the concentration levels of heavy metals in all of the sites were in order as follows: Zn>Cu>Cr. Conclusion: High concentrations of metals determined in the present study represents the high application of these metals in the structure of municipal and hospital solid wastes and also their inaccurate separation. Thus, awareness about physical and chemical characteristics of municipal and hospital wastes and also the landfill soil is necessary for evaluating their effects on the soil quality and surrounding environments.
H Irvani, H Shojaee - Farah Abady, M Shahryari, M Nakhaei Pour,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Styrene monomer is a volatile organic compound that is used in the various industries. Due to the hazardous effects of this chemical substance on the environment and humans, control and elimination of this vapour is necessary. Therefore, the aim of this study was to remove the styrene vapors from air flow using photocatalytic activity of zinc oxide immobilized on ZSM-5 zeolite.
Materials and Methods: In this experimental study, the fabricated catalysts were characterized using analysis of BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dynamic Concentrator System were used to generate styrene vapors at a certain concentration and flow, and then removal efficiency of the styrene vapors was investigated using UV/ZnO and UV/ZSM-5/ZnO.
Results: The results of XRD analysis and SEM images showed that produced zinc oxide had nano dimensions. In addition, these nanoparticles was successfully stabilized on ZSM-5 zeolite. The results of the photocatalytic removal showed that ZnO and ZSM-5/ZnO catalysts at the concentrations of 50 ppm eliminated the styrene vapor 14% and 37%, respectively.
Conclusion: Findings of this study showed that stabilization of zinc oxide nanoparticles on ZSM-5 zeolite had an ssynergistic effect on the photocatalytic degradation of styrene. According to this finding, the use of adsorption-photocatalyst hybrid systems can be an appropriate technique to remove styrene vapors and other similar pollutants.
S Bita, M Mesbah, A Shahryari, M Ghorbanpoor Najafabadi,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Nanoparticles are already widely used in technology, medicine and consumer products, but there are limited data on their effects on the aquatic environments. The aim of this study was to evaluate the response of antioxidant defense system in common carp gills exposed to silver nanoparticles, which are produced by bioreduction method.
Materials and Methods: Common carp fish were exposed to the silver nanoparticles at concentrations of 0.11, 1.13 and 5.67 mg/L for 14 days. A treatment without silver was considered as a control. After sampling, 1 g of gill was weighed and homogenized in 5 mL phosphate buffer. The homogenized samples were analyzed for measuring the activity of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (TAC) and malondialdehyde (MDA).
Results: CAT activity in gill at the concentrations of 1.13 and 5.67 mg/L AgNPs was significantly reduced compared to that of the control (p<0.05). When the activities of GSH and TAC of different treatments and the control were compared, no significant difference (p>0.05) was observed. Activity of SOD and MDA of all treatments sampled at different days was fluctuated, that is, it was either increased or decreased. However, superoxide dismutase activity was significantly higher in exposure to concentrations of 5.67 mg/L and 1.13 mg/L.
Conclusion: According to the results, fish gills are one of the most susceptible organs of oxidative damage in exposure to silver nanoparticles. This can affect the health of common carp and thus increase the risk of disease in the fish.
E Hoshyari, N Hassanzadeh, A Charkhestani,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Nowadays linear alkyl benzene sulfanate (LAS) is widely used in the production of various detergents. The purpose of this study was to assess the health and ecological hazards of this pollutant on target organisms such as fish and daphnia in the Doroodzan Dam water.
Materials and Methods: According to the research objective and given existing restrictions, 21 water samples were collected in September 2018 from 7 selected stations based on the source of contamination in Doroodzan dam. Water quality parameters including pH, Dissolved Oxygen (DO), potential Redox (ORP), Total dissolve solid (TDS) and Electrical conductivity (EC) was measured at the site. The amount of linear alkyl benzenesulfonate (LAS) was measured using an optimized methylene blue method after transferring samples to the lab. Then ecological and health risk assessment was performed by calculating the RQ index (risk index).
Results: The results showed that the mean of pH, EC, TDS, salinity and DO were 8.88, 732.19 µs/cm, 482.49, 366.16 and 6.87 mg/L, respectively. The highest and lowest concentrations of LAS were 0.039 and 0.055 mg/L, respectively. The results also showed that there is a significant relationship between LAS concentration and pH. The results of the risk assessment showed that the health risk index in all stations is less than 0.1, while the ecological risk index except at station 7, are in low risk level.
Conclusion: In general, the results show that the RQ index in the Droodzan Dam water is in appropriate range and in the low risk level. Therefore, it is necessary to conduct long-term studies in this field to ensure the persistence of optimal water conditions in the dam ecologically and health-wise.
Kh Faraji Mahyari, Sh Rafiee, Ar Keyhani, Z Faraji Mahyari,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Knowledge about the quantity of municipal solid waste (MSW) generation plays a key role in formulating policies of waste management. So far, different methods have been applied to estimate the quantity of waste generation. In this study, eight specific forms of mathematical functions were evaluated to predict waste generation by the regression analysis method based on population.
Materials and Methods: The significance test of each model and the existence necessity of predictor parameters were performed using the F- and t-statistic, respectively. The statistical indicators of determination coefficient ( ), adjusted determination coefficient ( ), root mean square error (RMSE), mean bias error (MBE) and mean percentage error (MPE) were used for model’s goodness of fit. The predicted determination coefficient ( ) was calculated to assess the predictive ability of models by method of Leave-one-out cross validation.
Results: The results showed that polynomial models of second order and more are not significant (at 0.01 level) despite good accuracy and are not suitable for long-term prediction. Linear, power and exponential models are best with equal to 0.942, 0.932 and 0.936 and equal to 0.904, 0.893 and 0.898 respectively. However, the uncertainty was greater in the exponential model.
Conclusion: The status of waste generation was investigated in four scenarios based on growth rate of population (increasing, fixing and decreasing births) at Tehran metropolis in 2021-2051. In all scenarios, annual generation and per capita of waste are increased to 2051. The daily waste generation will increase to 12317 ton in 2051.
O Nasri, M Yunesian, M Alimohammadi, N Shalyari, S Masoomi, M Shamsipour,
Volume 12, Issue 4 (2-2020)
Abstract
Background and Objective: Regular use of household cleaning products and cosmetics can result in adverse consequences for human health. Therefore, the knowledge of consumption pattern of these products can help to evaluate the effects and finally control the consequences of their inappropriate application. As there is not an appropriate tool for evaluating public use-pattern for these products in Iran, we studied the reliability and validity of a questionnaire designed for the use-patterns of these products.
Materials and Methods: In the present study, a questionnaire, which was previously applied in similar studies for this purpose, was first translated to Persian. Then, some changes were made in the questionnaire according to the studied population. In the next step, the assessment of both content validity and face validity of the instrument was performed. Finally, the questionnaire reliability was studied in two test-retest steps at a 14-day interval with 40 subjects older than 14 years old being resident in Tehran city.
Results: Total Content Validity Index (CVI) of this questionnaire ranged 0.66-1 for all question items. Cronbach's alpha coefficient was 0.814. The correlation assessment of each question item based on the total correlation score showed that all questionnaire items had a direct and strong correlation with the total instrument score.
Conclusion: Given the acceptable validity and reliability obtained for the questionnaire in Persian in this study, it can be used in those investigations that evaluate use patterns or asses the exposure risks to chemical pollutants from cosmetic products or detergents.
Naseh Shalyari, Ramin Nabizadeh, Mohsen Vijeh, Omid Nasri, Farnaz Saeidi, Masud Yunesian,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: In assessing the risk of community related poisonings due to insecticide use a practical and effective tool is needed to evaluate insecticides Therefore, the present study aimed to investigate the reliability and validity of exposure patterns to insecticides.
Materials and Methods: In this study, after performing validity, translation of the final version of the questionnaire was prepared based on the agreement of experts in accordance with the study population. In the next step, the reliability validity of the study was investigated. Finally, the questionnaire reliability was evaluated by test-retest method at a 14-day interval with the participation of 40 resident of Tehran city.
Results: The results of R-CVI and C-CVI were evaluated as good for all of items (between 0.91 and 0.97). The total CVI index for the whole questionnaire ranged from 0.75 to 1 in terms of proportion and transparency. On the other hand, the total coefficient of kappa for reliability of the questionnaire was obtained between 0.89 and 1.
Conclusion: Considering the acceptable validity and reliability level of the Persian version, this questionnaire is a valid tool and can be applied to assess the risk of insecticide use and its associated injuries in the Iranian population.
Mehrnaz Asghari Mahforujaki, Ailar Jamalli, Saeed Golfiroozi, Ali Shahryari,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: In hospitals, the emergency department is a complex healthcare environment, and it is necessary to attention to nosocomial infections. This study aimed to evaluate the implementation of nosocomial infection program in the emergency department.
Materials and Methods: This descriptive study was conducted in hospitals of Gorgan, Iran, in 2022, using the WHO checklist with 96 questions in 9 section staff; patients, environment, equipment, drug, prevention of infections wound, urinary, respiratory, and blood. Data were collected via observation and interviews. A checklist containing 45 questions was used to determine the impact of staff awareness on the infection control program, in 4 sections oftheoretical knowledge, performing procedures, immunization, and environmental hygiene.
Results: The results show that 82.46% of the infection control program was satisfactory. The percentage of scores for different sections of nosocomial infection program including staff, patients, environment, equipment, drug, infection prevention of wound, urinary, respiratory and blood was 79.31, 77.78, 81.25, 83.34, 100, 44.34, 75.00, 87.88 and 100, respectively. Moreover, the percentage awareness score for emergency medicine specialists, general practitioners, medical interns, and nurses was 100, 95.83, 87.5, and 79.92, respectively.
Conclusion: The implementation quality of the infection control program was acceptable and satisfactory. However, some factors were lower than the desired level, which could be dangerous for medical staff, patients, and visitors. The medical staff believed that the support of the senior managers of the University was essential for the implementation of an infection control program, and also holding training courses, and accelerating data sharing.
Mohsen Pourkhosravani, Fatemeh Jamshidi Gohari, Nasrin Sayari,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: This research tries to analyze the spatial distribution and trend of arsenic level changes in the underground water resources of the Sirjan basin, and also to evaluate and analyze the factors affecting the concentration of this element in these water resources.
Materials and Methods: Sampling of underground water sources in the study area was done by systematic-random method and arsenic concentration was done by ICP-MS method in the laboratory. Also, to evaluate the factors affecting the concentration of arsenic in the underground water resources of Sirjan bathe sin, the method of land systems analysis was used.
Results: The results of the research show that the amount of arsenic in all samples is higher than the Guidelines provided by the World Health Organization so the amount of this element in the underground water sources of the study area varies between 30 and 390 µg/L. Samples No. 9, 13, and 16, which are located in the deepest parts of the basin, have the highest amount of arsenic. For this reason, the durability of water in this part of the basin increases. This reduces the intensity of the current. As a result, according to the cumulative effect law, this process can lead to an increase in arsenic concentration.
Conclusion: The evaluation of changes in the concentration of arsenic in the underground water resources of the study area indicates that the concentration of this element had a high increasing trend. According to the results, the location of the studied area in the center of hydrothermal and geothermal processes (copper mineralization belt in Iran), the cumulative effect, and the effect of pH on the absorption and desorption of arsenic are among the most important factors affecting the increase of arsenic in the underground water resources of Sirjan Basin.
Fatemeh Momeniha, Mohammad Kouhkan, Hoda Safamanesh, Parviz Yarahmadzahi, Mohammad Osman Khodayari, Ali Mohammadi, Amir Hossein Mahvi,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Due to the importance of managing medical sharps waste and the potential harm caused by these types of waste, the use of safe technologies that simultaneously encapsulate and reduce their volume is considered one of the essential needs for managing medical waste in hospitals and other healthcare facilities. The main objective of this study was to investigate the efficiency of disinfecting and encapsulating device for medical sharps waste.
Materials and Methods: This device provides the process of containment and encapsulation of medical sharps waste by creating a stable protective foam without oxidation through inductive heat in a closed environment, preventing the dispersion and release of these wastes. Gas samples from the device's output were collected using the NIOSH 1501 method and analyzed using GC-MS. The performance efficiency of the device was evaluated based on the biological monitoring of the indicator bacterium Bacillus stearothermophilus.
Results: The results showed that the average concentration of BTEX gases (benzene, toluene, ethylbenzene, and xylenes) and other volatile organic compounds in the device's output was within the permissible limit. The concentrations of Benzene, Toluene, Ethylbenzene and Xylene gases were 0.04, 0.033, 0.029, and 0.029 ppm, respectively. The results of biological monitoring showed that the reduction of the microbial load was 9999.99 (Log 6) and the decontamination process was acceptable.
Additionally, this device has the advantage of reducing the volume of sharp and plastic objects during the encapsulation process, which can be further used in plastic pyrolysis/recycling industries.
Conclusion: It is hoped that by using this innovative and domestic device in the decontamination units of hospitals across the country, we can take an effective step towards improving medical waste management, reducing waste production, reducing hospital costs, and preserving and enhancing the country's health.
Arezoo Yari, Ali Ardalan, Abbas Ostadtaghizadeh,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: Demographic characteristics are among the factors that can contribute to flood-related deaths. Investigating the relationship between these factors and flood-related deaths, as well as measuring their impact on the prevention, reduction, and elimination of such deaths, is essential.
Materials and Methods: This study was conducted as a case-control study in all flood-affected areas of Iran that experienced flood-related deaths from 2002-2018. The sample size of the study was 369 (123 cases and 246 controls) from 12 provinces and 30 counties. The study measured the impact of demographic characteristics on flood-related deaths using a valid and reliable tool.
Results: The findings of this study revealed that individuals under the age of 15 face a 31.974 times higher risk of flood-related death compared to individuals over 65. The young population, specifically those aged 15 to 29 in Iran, have a 1.475 times higher risk. Drivers face a 13.874 times higher risk, while individuals involved in agriculture, shepherding, and livestock farming have a 0.947 times higher risk compared to homeowners.
Conclusion: Among the demographic characteristics, children, young adults, and engaging in certain high-risk occupations such as driving or agriculture increase the risk of flood-related deaths. Therefore, it is recommended to prioritize protection, education, and vulnerability reduction measures for these individuals, especially in flood-prone areas.
Alireza Bakhtiyari, Behrouz Akbari-Adergani, Parisa Shavli-Gilani, Liela Karami, Najmeh Yazdanfar, Parisa Sadighara,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: Given the crucial role of milk and its products in human diets, it is imperative to implement effective measures to ensure the safety of milk by minimizing the presence of hazardous pollutants. This study aims to assess the concentration and potential risks associated with lead in raw milk produced in Tehran province.
Materials and Methods: This cross-sectional descriptive study involved the collection of raw milk samples from 24 diverse livestock farms in Tehran province during the winter season of 1401. The samples were analyzed for lead contamination using flame atomic absorption spectrometry. Statistical tests were applied to compare the results with international standards, and subsequent risk assessment was conducted based on the average amounts.
Results: The study revealed that none of the samples exceeded the permissible limit for lead. The mean and standard deviation of lead concentration in the samples was 7 ± 5.8 (ppb), well below the international standard. There was no significant variation in lead levels among the tested livestock farms. The Hazard Quotient (HQ) values for both children and adults were calculated to be less than 1.
Conclusion: The concentration of lead in all samples remained below the permissible limits set by Codex and the Iran Standards Organization, indicating no non-carcinogenic risks associated with milk consumption in terms of lead contamination, as suggested by the calculated HQ values.
Gholamreza Shaghaghi, Amir Hossein Javid, Sara Allahyaribeik, Ali Mashinchian Moradi,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The discharge of seawater concentrate from desalination plants into the sea causes irreparable effects on the environment. The purpose of this study is to identify the effects of this discharge, model methods for optimizing it, and design an effective outlet that minimizes environmental impacts and costs.
Materials and Methods: This study discusses impacts of seawater concentrate discharged into the sea, numerical modeling of diffusion, and outlet design based on discharge standards.A review of articles and sources from databases such as Google Scholar, Academia, Scopus, Civilica and Irandak was conducted using keywords such as “brine discharge”, “numerical modeling”, and “outlet design.” Out of 132 reviewed articles, 45 articles were consistent with the objectives of the study.
Results: The effects of seawater discharge can be observed in the discharge area and at greater distances. Numerical modeling is employed to predict pollutant concentrations at various distances and to determine the optimal discharge point while considering established standards. The design of the diffuser and the use of multiple nozzles at an angle of 60 degrees result in the greatest dilution at the discharge point.
Conclusion: The use of desalination systems necessitates addressing the effects of climate change. Appropriate modeling and design of the outlet are essential for complying with environmental standards and optimizing costs. Further research in this field is needed.
