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Abstract Metals are significant contributors to water pollution, posing serious threats to human health. This study aims to assess the carcinogenic and non-carcinogenic health risks associated with metals in Isfahan drinking water. Eighty water samples were randomly collected from the city's distribution network between January and March 2020–2021. Inductively coupled plasma Optical Emission Spectrometry was used to measure toxic metals, namely Pb, Cr, Cd, Ni, and As concentrations. Results revealed that the mean concentration of Ni (70.03 µg/L) exceeded the WHO reference value (70 µg/L), while the other metals were below the standard values. The average chronic daily intake order of toxic metals was Ni > Cr > Pb > As > Cd. Non-carcinogenic risk assessment through hazard quotient (HQ) and hazard index (HI) demonstrated that both THI for adults (HQingestion + HQdermal = 4.02E−03) and THI for children (HIingestion + HIdermal = 3.83E−03) were below the acceptable limit (less than 1). This indicated no non-carcinogenic risk to residents through water ingestion or dermal exposure. However, findings indicated that the ingestion route was the primary exposure pathway, with HQ values for ingestion exceeding HQ values for dermal adsorption. Carcinogenic risk assessment showed that the risk associated with As metal exceeded the acceptable limit (1 × 10−6). Therefore, implementing treatment improvement programs and appropriate control measures is essential to safeguard the health of Isfahan City residents.

Abstract Regarding the long-term toxic effects of Pb (II) ions on human health and its bioaccumulation property, taking measures for its reduction in the environment is necessary. The MMT-K10 (montmorillonite-k10) nanoclay was characterized by XRD, XRF, BET, FESEM, and FTIR. The effects of pH, initial concentrations, reaction time, and adsorbent dosage were studied. The experimental design study was carried out with RSM-BBD method. Results prediction and optimization were investigated with RSM and artificial neural network (ANN)-genetic algorithm (GA) respectively. The RSM results showed that the experimental data followed the quadratic model with the highest regression coefficient value (R2 = 0.9903) and insignificant lack of fit (0.2426) showing the validity of the Quadratic model. The optimal adsorption conditions were obtained at pH 5.44, adsorbent = 0.98 g/l, concentration of Pb (II) ions = 25 mg/L, and reaction time = 68 min. Similar optimization results were observed by RSM and artificial neural network-genetic algorithm methods. The experimental data revealed that the process followed the Langmuir isotherm and the maximum adsorption capacity was 40.86 mg/g. Besides, the kinetic data indicated that the results fitted with the pseudo-second-order model. Hence, the MMT-K10 nanoclay can be a suitable adsorbent due to having a natural source, simple and inexpensive preparation, and high adsorption capacity.

Abstract 4-Chlorophenol pollution is a significant environmental concern. In this study, powdered activated carbon modified with amine groups is synthesized and investigated its efficiency in removing 4-chlorophenols from aqueous environments. Response surface methodology (RSM) and central composite design (CCD) were used to investigate the effect of different parameters, including pH, contact time, adsorbent dosage, and initial 4-chlorophenol concentration, on 4-chlorophenol removal efficiency. The RSM-CCD approach was implemented in R software to design and analyze the experiments. The statistical analysis of variance (ANOVA) was used to describe the roles of effecting parameters on response. Isotherm and kinetic studies were done with three Langmuir, Freundlich, and Temkin isotherm models and four pseudo-first-order, pseudo-second-order, Elovich, and intraparticle kinetic models in both linear and non-linear forms. The synthesized adsorbent was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. The results showed that the synthesized modified activated carbon had a maximum adsorption capacity of 316.1 mg/g and exhibited high efficiency in removing 4-chlorophenols. The optimal conditions for the highest removal efficiency were an adsorbent dosage of 0.55 g/L, contact time of 35 min, initial concentration of 4-chlorophenol of 110 mg/L, and pH of 3. The thermodynamic study indicated that the adsorption process was exothermic and spontaneous. The synthesized adsorbent also showed excellent reusability even after five successive cycles. These findings demonstrate the potential of modified activated carbon as an effective method for removing 4-chlorophenols from aqueous environments and contributing to developing sustainable and efficient water treatment technologies.

Abstract Wastewaters discharged from different industries and hospitals may contain pharmaceuticals, especially dexamethasone (DEX). Thus, we applied the UV/H2O2 photocatalytic method in the presence of the MgO nanoparticles to remove dexamethasone from synthetic wastewater. Moreover, the effects of parameters such as pH (3–11), hydrogen peroxide concentration (1–8 mM), initial DEX concentration (5–30 mg/L), and catalyst dosage (0.01–0.2 g/L) during the reaction times (0–30 min) were investigated. Furthermore, the efficiency of UV/H2O2 in the presence and absence of catalysts was investigated. The photocatalyst is characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and Fourier-transform infrared spectroscopy (FTIR) techniques. It was found that the removal rate was enhanced by decreasing pH and the initial dexamethasone concentration. The removal rate was enhanced somewhat with concentrations of hydrogen peroxide and MgO. In the case of UV/H2O2/MgO, 87% removal efficiency was achieved, under the optimal conditions: pH 3, contact time of 30 min, dexamethasone concentration of 20 mg/L, H2O2 of 0.5 mM, and UV radiation of 55 watts. The kinetic data indicated that the reaction followed the second-order kinetic model. The results showed that the UV/H2O2 photochemical process can efficiently remove dexamethasone from aqueous in the presence of a MgO catalyst, and the mineralization efficiency was reached at about 98%.

Abstract An amino-functionalized MIL-68(Al) metal–organic framework (amino-MIL-68(Al) MOF) was synthesized by solvothermal method and then characterized by FESEM, XRD, FTIR, EDX-mapping, and BET-BJH techniques. In order to predict arsenate (As(V)) removal, a robust quadratic model (R2 > 0.99, F-value = 2389.17 and p value 1000 m2/g) and high reusability for As(V)-contaminated water.

Abstract The need for fresh water is more than before by population growth, and industrial development have affected the quality of water supplies, one of the important reason for water contamination is synthetic dyes and their extensive use in industries. Adsorption has been considered as a common methods for dye removal from waters. In this study, Acid Red18 removal in batch mode by using Granular Ferric Hydroxide (GFH) was investigated. The GFH characterized by XRD, FESEM and FTIR analysis. Experiments were designed using RSM-CCD method. The maximum removal efficiency was obtained 78.59% at pH = 5, GFH dosage = 2 g/l, AR18 concentration = 77.5 mg/l and 85 min of contact time. Optimization with RSM and Genetic Algorithm carried out and is similar together. The non-linear adsorption Isotherm and kinetic fitted with Freundlich (R2 = 0.978) and pseudo-second-order (R2 = 0.989) models, respectively. Thermodynamic studies showed that the AR18 adsorption is endothermic process and GFH nature was found spontaneous.

Abstract In the present study, reactive red 198 (RR198) dye removal from aqueous solutions by adsorption using municipal solid waste (MSW) compost ash was investigated in batch mode. SEM, XRF, XRD, and BET/BJH analyses were used to characterize MSW compost ash. CNHS and organic matter content analyses showed a low percentage of carbon and organic matter to be incorporated in MSW compost ash. The design of adsorption experiments was performed by Box–Behnken design (BBD), and process variables were modeled and optimized using Box–Behnken design-response surface methodology (BBD-RSM) and genetic algorithm-artificial neural network (GA-ANN). BBD-RSM approach disclosed that a quadratic polynomial model fitted well to the experimental data (F-value = 94.596 and R2 = 0.9436), and ANN suggested a three-layer model with test-R2 = 0.9832, the structure of 4-8-1, and learning algorithm type of Levenberg–Marquardt backpropagation. The same optimization results were suggested by BBD-RSM and GA-ANN approaches so that the optimum conditions for RR198 absorption was observed at pH = 3, operating time = 80 min, RR198 = 20 mg L−1 and MSW compost ash dosage = 2 g L−1. The adsorption behavior was appropriately described by Freundlich isotherm, pseudo-second-order kinetic model. Further, the data were found to be better described with the nonlinear when compared to the linear form of these equations. Also, the thermodynamic study revealed the spontaneous and exothermic nature of the adsorption process. In relation to the reuse, a 12.1% reduction in the adsorption efficiency was seen after five successive cycles. The present study showed that MSW compost ash as an economical, reusable, and efficient adsorbent would be desirable for application in the adsorption process to dye wastewater treatment, and both BBD-RSM and GA-ANN approaches are highly potential methods in adsorption modeling and optimization study of the adsorption process. The present work also provides preliminary information, which is helpful for developing the adsorption process on an industrial scale.

Abstract In the present study, the adsorptive removal of organophosphate diazinon pesticide using porous pumice adsorbent was experimentally investigated in a batch system, modelled and optimized upon response surface methodology (RSM) and artificial neural network-genetic algorithm (ANN-GA), fitted to isotherm, kinetic and thermodynamic models. The quantification of adsorbent elements was determined using EDX. XRD analysis was utilized to study the crystalline properties of adsorbent. The FT-IR spectra were taken from adsorbent before and after adsorption to study the presence and changes in functional groups. The constituted composition of the adsorbent was determined by XRF. Also, the ionic strength and adsorbent reusability were explored. The influences of operational parameters like pH, initial pesticide concentration, adsorbent dosage and contact time were investigated systematically. ANN-GA and RSM techniques were used to identify the optimal process variables that result in the highest removal. Based on the RSM approach, the optimization conditions for maximum removal efficiency is obtained at pH = 3, adsorbent dosage = 4 g/L, contact time = 30 min, and initial pesticide concentration = 6.2 mg/L. To accurately identify the parameters of nonlinear isotherm and kinetic models, a hybrid evolutionary differential evolution optimization (DEO) is applied. Results indicated that the equilibrium adsorption data were best fitted with Langmuir and Temkin isotherms and kinetic data were well described by pseudo-first and second-order kinetic models. The thermodynamic parameters such as entropy, enthalpy and Gibbs energy were evaluated to study the effect of temperature on pesticide adsorption.

Introduction: Legionella Pneumophila bacteria is known as one of the most important nosocomial infections and the most common cause of death in patients. This study was aimed to identify Legionella Pneumophila bacteria in hospital water supply systems. Material and Methods: This descriptive cross-sectional study was performed to identify Legionella pneumophila in hot and cold-water systems of important and sensitive wards of Imam Khomeini Hospital in Divandareh city (neonatal, dialysis, obstetric, gynecological and menchr('39')s surgery). A total of 60 samples were collected from these sections. Results: According to the results of this study, a total of 17 (28%) of all samples were infected by Legionella pneumophila bacteria in water supply systems including hot showers and cold water in neonatal, dialysis, delivery, surgery. gynecology and menchr('39')s surgery wards were identified. Conclusion: Lack of proper water treatment system, low residual chlorine content, and presence of biofilm in water supply system and proper temperature range of growth with this bacterium could be the major causes of Legionella contamination in the studied hospital.

Background and aim: Water supply systems and various parts of dentistry unit have the ability to aggregate biofilms and thus the transmission of dangerous diseases to staff and patients. The aim of this study was to determine the bacterial contamination of surfaces and water lines of dental units of health center (Qods 2) in Divandareh city. Material and methods: This cross-sectional descriptive study was conducted on dental units of the health center (Qods 2) in Divandareh city in 2019. 125 samples were collected from different parts of the units including unit lamp handle, lamp ON/OFF power button, open/close bolt of unit water, setting switch button (before and after disinfecting), and the inlet and outlet water of units. The samples were tested for Staphylococcus aureus, Pseudomonas aeruginosa, Coliforms and Escherichia coli. Results: The results of this study showed that all samples collected from the studied parts of the units including unit lamp handle, lamp ON/OFF power button, open/close bolt of unit water, and setting switch button were positive as presence of Staphylococcus aureus, Pseudomonas aeruginosa, and coliforms before and after disinfection. Also, the unit lamp handle and setting switch button were positive as Escherichia coli. The inlet and outlet water were also positive for all the studied bacteria. The number of Staphylococcus aureus bacteria in the handle of the unit lamp before disinfection (210±80.5 CFU/ml) and in the ON/OFF button of the lamp after disinfection (300±82.6 CFU/ml) were higher than the permissible amount (200 CFU/ml). Also, the number of Pseudomonas aeruginosa bacteria detected in setting switch button, before disinfection, was higher (200±75.2) than the allowable value. Conclusion: According to the obtained results, the contamination level of water and surface of the studied dental units was high. Also, identifying of the considerable number of bacteria at the different surfaces of the units, indicating the improper use of the disinfectants and the possibility of biofilms presence in the unit waterlines.

The use of mobile phones by healthcare personnel, doctors, patients, and patients’ companions are unavoidable in health centers, especially in hospitals. Besides being rarely clean, the mobile phone is a potential reservoir of disease and pathogens and hospital infections on bedside of hospitalized patients. In this study, the microbial contamination of mobile phones and potential of transmitting infections and their antibiotic resistance pattern were investigated. In this descriptive cross-sectional study, a questionnaire was prepared to assess the importance of maternity, neonatal, and intensive care unit (ICU) staff attention to how to use and clean the cell phones in terms of valid sources. Samples were taken from 116 cell phones using a sterile swab. The standard plate count was used to detect the existing bacteria, and the antimicrobial resistance patterns of isolated bacteria were determined by standard methods. The microbial culture experiments indicated that 107 cell phones had microbial contamination, accounting for 92.24% of mobile phones. From 132 isolated strains, 115 strains (87.12%) were gram-positive while 17 were Gram-negative (12.88%). Furthermore, 67 (57.76%), 9 (7.7%), 4 (3.45%), 10 (8.62%), 12 (10.35%), 22 (19%), and 8 (6.9%) strains were coagulase-negative staphylococci, Pseudomonas aeruginosa, Staphylococcus aureus, Corynebacterium, Bacillus, Streptococcus, and Escherichia coli, respectively. The results of this study indicated that cell phones were contaminated with different types of bacteria, and that all species isolated partially played an important role in the development of hospital-acquired and opportunistic infections. Therefore, continuous disinfection of mobile phones and non-use or limited use of them in the hospitals are recommended.

Background and objectives: Construction is one of the most dangerous industries in the world and one of the authorities’ concerns of officials in this area is to improve their safety. This study was carried out so as to investigate the causes of unsafe behaviors in a combined cycle power plant. Materials and Methods: In this cross-sectional study, a questionnaire for 300 workers of the combined cycle power plan were used. The obtained information was divided into criteria and sub-criteria affecting the causes of unsafe behaviors. Criteria and sub-criteria were distributed as a pairwise comparison questionnaire among 19 people who worked on the safety and they were supposed to answer based on their experiences as well as the distance scale. Criteria and sub-criteria were ordered by Analytic Hierarchy Process (AHP) and using Expert Choice‌ software. Results: the results showed that the criterion of individual characteristics (34 %) is the most effective factor for unsafe behaviors and followed by employer (22%), teaching 915%), education (12%), specialization and experience (7.8%), age (7.6%), job characteristics (3%), and weather condition (2%) respectively. Conclusion: the most important sub-criterion of individual characteristics is a onechr('39')s susceptibility to accident. Hence, it is necessary to prevent unsafe behaviors by employing vulnerable people in less dangerous occupations.

Background: The discharge of a large volume of colored wastewater into receiving water sources has caused widespread concern around the world. The aim of this study was to investigate the efficiency of pumice as an adsorbent in removing methylene blue (MB) from aqueous solution. The adsorption process was also modeled and optimized by the methods as follows: central composite design-central composite design (RSM-CCD) and artificial neural network-genetic algorithm (ANN-GA). Methods and Materials: The independent variables in the study were included pH (3-11), contact time (10-50 minutes), adsorbent dose (0.1-2 g/L), and MB concentration (20-100 mg/l). The effect of these parameters on the efficiency of pumice in MB uptake was modeled and optimized by RSM-CCD and ANN-GA methods. A spectrophotometer at 620 nm was used to measure the residual MB concentration in solution. Results: The results showed that the RSM-CCD method has the ability to develop a quadratic polynomial model with high validity (R2 = 0.9997) for the adsorption process. Similarly, the ANN-GA method fitted well with experimental data to develop a model with high validity (R2 = 0.9978). The results of optimization process by RSM-CCD and ANN-GA methods obtained the highest adsorption efficiency at pH = 11, contact time = 50 minutes, adsorbent dose = 1 g/L, and concentration MB = 20 mg/L. Adsorption efficiency shows a direct relationship with pH, contact time and adsorbent dose and inversely with contaminant concentration. The linear effect of pollutant concentration and adsorbent dose variables had the greatest effect on adsorption efficiency. Conclusion: In this study, it was observed that pumice as a cheap and available adsorbent can be considered as a suitable choice for absorbing dye pollutants from aqueous media. RSM-CCD and ANN-GA methods can also be used to model and optimize adsorption processes.

Nitrate is one of the most important contaminants that can release into the environment predominantly as a result of anthropogenic processes. Excessive intake of nitrates may increase the risk of certain types of cancer. The aim of this study was to investigate the concentration of nitrate in drinking water and its health to people in Iran. This cross-sectional study has performed in 2019. Nitrate concentrations in drinking water supplies were obtained from peer-reviewed publications. Monte Carlo stimulations and mathematical models were used to determine the excess cancer risk. Risk level for assessing the carcinogen risk was 10−5 (1 per 100,000 persons). Nitrate concentrations and cancer risk related to nitrate were classified by GIS software. According to the obtained results, the drinking water supplies of Tehran, Mashhad (Khorasan Razavi), Zahedan (Sistan and Baluchestan), Shiraz (Fars), Qom, Ardabil and Ahwaz (Khuzestan) have higher nitrate concentrations than the limit recommended by WHO and Institute of Standards and industrial Research of Iran (ISIRI). The estimated cancer risks for the provinces of Tehran, Mashhad (Khorasan Razavi), Zahedan (Sistan and Baluchestan), Shiraz (Fars), Qom, Ardabil and Ahwaz (Khuzestan) were in the no negligible range set by the Health Canada and WHO. The majority of Iran provinces that have impermissible level of nitrate in drinking water supplies had a significant association between cancer prevalence and nitrate exposure. • The findings demonstrated that carcinogen risk values of nitrate exposure through drinking water was 0.001%. • Results showed that Tehran, Mashhad (Khorasan Razavi), Zahedan (Sistan and Baluchestan), Shiraz (Fars), Qom, Ardabil and Ahwaz (Khuzestan) are more exposed to additional cancer risk related to nitrosamine. • The results of this study is considered as the comprehensive report that indicate the association between gastrointestinal cancer and nitrate exposure through drinking water. Method name: This research is an comprehensive study which was performed in order to evaluate carcinogenic risks related to nitrate exposure in drinking water in Iran, Keywords: Cancer risk, Nitrate, Drinking water, Iran provinces

Background and purpose: Styrene, one of the most important compounds of VOCs, causes some health concern. In current study, the ability of ZSM5, TiO2/ZSM5, UV/ ZSM5, and UV/TiO2/ZSM5 methods was investigated in removing styrene from air synthetic current. Materials and methods: In order to synthesize the zeolite and TiO2-coated zeolite, the sol-gel and saturation methods were employed, respectively. In this study, the effect of the type of removal process, saturation time and initial pollutant concentration were investigated on the removal of styrene in a photoreactor. Phocheck device with direct reading system was applied to determine the output concentration. Also, SEM, XRD, EDX, and BET analyses were used to characterize the chemical and physical properties of ZSM5, and TiO2/ZSM5. Results: SEM analysis showed that zeolite has a crystal form, and TiO2 successfully covered the surface of this compound. In addition, the EDX analysis demonstrated that a great part of zeolite structural includes Al and Si constituents. The XRD pattern showed the presence of attached TiO2 in the zeolite structure. BET analysis revealed that the surface area of zeolite decreased when TiO2 was coated on its surface. The order of increase in removal efficiency was as follows: UV/TiO2/ZSM5 > ZSM5> TiO2/ZSM5. The saturation time of ZSM5 and TiO2/ZSM5 in the 300 ppm concentration was 370 and 280 min, respectively, while the outlet concentration in the UV/TiO2/ZSM5 method was fixed at 74% removal efficiency after elapsing 310 min. The increment of time exposure and initial styrene concentration also led to decrease in removal efficiency. Conclusion: In this study application of UV/TiO2/ZSM5 process provided a higher efficiency of the styrene removal than that of TiO2/ZSM or ZSM5 in the same time.

Background and Objectives: Synthetic dyes are an important group of additivesused in food products, and because of health concerns about consuming population, the application of these compounds is needed to be enough controlled. The aim of this study was to investigate the types and frequencies of the dyes used in making pastries in the confectionery of Tuyserkan city. Materials and Methods: In this cross-sectional study investigated the types of consumed dyes in confectionery’s pastries of Tuyserkan city. A total of 80 samples including wet and dry pastries are randomly sampled from 17 confectioneries. The steps of the experiment consisted of degreasing the sample, purification, and determining the type of dye were down by using Tin Layer Chromatography (TLC) method. All charts used in the study were drowned by Excel Software (2013). Results: The results indicate, among the total 80 samples, 17 samples contained no dye, 15 samples with natural dye, 44 samples with permitted synthetic dyes, and 4 samples have non-permitted synthetic dyes. Moreover, of all the synthetic dyes, 8 samples contained Quioline yellow dye, 10 samples with Sanset yellow dye, 8 samples with Azorubine dye, 5 samples with Brilliant blue dye, 5 samples with ponceau 4R, and 4 (5%) samples have Allura Red. Conclusions: This study showed a remarkable part of used dyes in the confectionery of Tuyserkan city is non-permitted. Therefore, it is proposed to reduce the amount of synthetic dyes by restriction in distribution, more controlling by health departments, and increasing the awareness in consumers and manufactures.

Introduction and Aims: Pharmaceutical pollutants in aqueous can cause a number of health problems for people and other creatures. In this study, a survey of Dexamethasone removal from synthetic aqueous solutions was investigated by using UV/S2O8 and UV/H2O2 methods. Materials and Methods: This experimental study carried out at lab scale at a reactor with the batch flow. In this study, the parameters of time (5- 60 min), pH (3, 7 and 11), dose of S2O8 (0.1-7.5 mM), dose of H2O2 (0.1- 7.5 mM), and Dexamethasone concentration (5- 20 mg/L) were studied to specify their effects on Dexamethasone removal. Furthermore, the remaining concentration of dexamethasone was determined by spectrophotometer DR (model 5000) in the 241 nm wavelength. Results: Results showed that with the increasing amount of parameters of pH, retention time, and a dose of H2O2 and S2O8 and with decreasing parameter of dexamethasone concentration, removal efficiency raised. Removal efficiencies of dexamethasone in the optimum condition of time=40, pH=3 and dexamethasone concentration = 5 mM was obtained 47, 59, 82, 91, and 98 percent for UV/S2O8 concentrations of 0.1, 0.5, 1.5, 5, and 7.5 mM, and 19, 49, 61, 65, and 72 percent for UV/H2O2, respectively. Conclusion: According to higher removal efficiencies of UV/S2O8 method than UV/H2O2, easier storage and moderate stability of S2O8 and also more oxidation ability of SO4- than OH°, it is better to apply UV/S2O8 method to degradation of dexamethasone.

Background: Due to their polycyclic and toxic structure, dyes have a high ability in causing adverse acute and chronic effects on human exposed to them. In present study, the decolorization of acid green3 from aqueous solution by UV/ H2O2 method was investigated Methods: This is an applied-experimental study. Parameters of pH in the amount of 3,7 and 11, contact time in 5,15, 30, 45 and 60 min, dose of H2O2 in 10, 30 and 50 mg/l and initial concentration of acid green3 in 50, 100 and 150 mg/l were examined to reveal the optimum amounts of these parameters. In order to emit the UV radiation, photo reactor with a 2-lit volume was applied, also to measure remaining concentration of dye, spectrophotometer device, model DR 5000 was employed. Chemical oxygen demand (COD) test based on 5220C method (standard method book) was used for determining amount of oxidation. Results: Results showed that contact time = 60 min, pH=7, acid green concentration=50 mg/l and dose of H2O2 =30 mg/l are optimum condition at which the removal amounts of dye and COD were obtained about 97 and 85%, respectively. Conclusion: In the study, it is observed that parameters of contact time, pH, initial concentration of dye, and dose of H2O2 have a significant influence on the removal of the dye by UV/H2O2 process. Due to acceptable results of UV/H2O2 in the oxidation of the dye and the reduction of COD, this method can be introduced as reliable process to remove of acid green 3 from industrial wastewaters.

Background: Expanding urbanization and increasing the number of vehicles have led to adverse effects on both the environment and human health. The propose of this study is to evaluate the concentration of CO2, CO, HC, O2, NOX in the exhaust outlet of vehicles tested in technical examination center, and to determine the relationships between their variation and lambda coefficient, type of fuel injection system as well as vehicle type. Methods: This cross-sectional study was conducted on 1000 vehicles tested in technical examination centers in Hamadan city. To do this, the concentrations of CO2, CO, HC, O2, NOX gases emission were obtained, and then the relations between variation of these gases and lambda coefficient, type of fuel injection system and vehicle type were investigated. The statistical analysis that used in this study include one-way ANOVA and independent t-test (SPSS 16). Results: The results of this study showed a significant relationship between the concentration of emitted gases and the lambda coefficient, the vehicle type and the type of fuel injection system (p

Background and purpose: Today, due to improvement and progress of human knowledge in food industry, plastic coatings such as PET (polyethylene terephthalate) that has unique characteristics are widely used for food and beverage packaging such as water and doogh. Phthalate esters are used in order to improve flexibility, efficiency and sustainability of materials. Chronic exposure with such materials play a role in incidence of many diseases and cancer in human. The aim of this study was to investigate the presence and concentration of phthalates in different brands of doogh. Materials and methods: In this study, we synthesized multi-walled magnetic carbon nanotubes using iron oxide. Then, the synthesized magnetic nanotubes were used for absorption and extraction of phthalate esters from doogh matrix. After sample preparation, the concentration of each phthalate esters was measured by GC-MS. Results: Concentration of phthalate esters in all samples were found to be lower than the standard levels but DEHP had the highest concentration. Statistical analysis showed no significant differences between the concentration of phthalate esters in different brands and storage time of doogh. Conclusion: According to these findings and low concentration of each phthalate ester compared with standard levels in different types of doogh, it has no health effect on consumers.

Aims: Nitrate can enter water bodies through using chemical fertilizers and discharging the effluents from municipal and industrial sewage treatment plants. As a superiority to the conventional statistical models, Grey models (GMs) require only a limited amount of representative data to estimate the behavior of unknown systems. In the current study, the nitrate concentration of the year 2023 in Babol groundwater resources was forecasted by using GM, namely GM (1, 1). Materials and Methods: This descriptive-cross-sectional study was performed in the city of Babol. The data of 63 wells in urban and rural areas during the warm and cold seasons between 2007 and 2017 were supplied from the Health Center and Babol Rural Water and Sewage Company. In data set, the observed values between 2007 and 2015 were used to fit models, and the observed values between 2016 and 2017 were used to evaluate the accuracy of the model's predictions. To assess the efficiency of the model fitted and precision of the predicted values, we used indexes of forecast absolute error, small error probability, and the proportion of variance statistical metrics. Results: Simulated results showed that the accuracy of the model GM (1, 1) to predict and forecast both data sets is entirely appropriate and reliable. The forecasting values of nitrate concentration of the year 2023 and 8 years later, for urban and rural areas in warm and cold seasons, are 21.30 and 7.30 and 15.63 and 5.34 mg/L, respectively. Conclusion: Although the predicted concentration of nitrate in the studied area is lower than that the standard concentration suggested by the World Health Organization, all water resources should be protected effectively.

Background: 2،4 dichlorophenol (DCP), one of the most chlorophenol compounds family with highly toxic effect, exists in agricultural areas, chlorinated waters, discharging wastewater of pulp industries and paper factories. Chlorophenols can cause damages to the kidneys, liver, pancreas and weaken the central nervous system (CNS). In the current study we would evaluate the adsorption of DCP by chitosan in aqueous environments. Materials and Methods: In this study we evaluated the effect of operational parameters such as time (15-90min), pH values (3-9), initial concentration of DCP(15-100mg/l)and the dose of chitosan (0.1-0.9g) in a batch reactor. A spectrophotometer at wavelength of 280nm was used to measure the concentration of DCP. Freundlich and Langmuir isotherm models and Pseudo-first order kinetic models and Pseudo-second-order kinetic was drawn by using of the results obtained in the absorption process. Results: Equilibrium time in the adsorbtion process was estimated to be 75 minutes (DCP Concentration- 15mg/l, Chitosan Concentration – 0.5g and pH- 6.5) with 76% removal efficiency. PH=3 was calculated as the optimal PH in absorption process (DCP Concentration- 15mg/l, Chitosan Concentration- 0.5g and Time Equilibrium-75 min) with efficiency 79% and the value of efficiency decreased by increasing PH. In 15 mg/l concentration of DCP maximum adsorption with an efficiency of 79% was observed. (Chitosan Concentration – 0.5g, Time Equilibrium -75 min and pH-3) and the maximum 87% adsorption efficiency of DCP was observed at the 0.08mg/l absorbent dose of chitosan. (DCP Concentration - 15mg/l, time equilibrium-75 min and pH=3). Adsorption process follows of Freundlich isotherm with correlation coefficient of 0.9599 and the pseudo second order kinetic model with correlation coefficient of 0.9649. Conclusion: According to results of the study, chitosan can be used to remove of DCP from industrial wastewater due to of its perfect characteristics such as biodegradability, resurgent ability, low cost and adsorption acceptable efficiency.

Aims: Organophosphates are well-known as an important group of poisons. The aim of the current study is to investigate acetylcholinesterase enzyme (ACHE) level in workers' blood of a poison-producing industry and its relationship with annual poison production and the use of personal protective equipment (PPE). Materials and Methods: This cross-sectional study was conducted during 2012–2015 on 84 workers from different units of a poisons-producing industry and a 20-person control group. The PPE used during the years of study includes Asphalt gloves, rubber gloves, and mask felt. The AChE level was detected based on the modified Ellman method. Results: The maximum AChE level was observed in the control group. In addition, the minimum was found in the workers in 2015. The mean AChE level in the control group was significantly higher than that in the worker (P < 0.05). The mean AChE level in the workers based on the study years was significantly different, but this was not significant between the blood samples taken in the years of 2014 and 2015. Furthermore, it was found that both poisons-producing amount and PPE distribution were enhanced more during the past year of the study, while the poison amount entering to the body decreased. Conclusion: It was deduced that the AChE level in workers' blood was lowered with increasing at the exposure years due to irreversible effects. It is also observed that growth at the PPE application acted as an important parameter to decline exposure to poisons and subsequently various health complications.

BACKGROUND: Helicobacter pylori (H. pylori) infection is thought to play an etiologic role in several gastroduodenal diseases including gastric ulcer, duodenal ulcer, gastric MALT lymphoma, and distal gastric cancer. Several studies have suggested that H. pylori which express cytotoxin-associated gene A (CagA) may be more virulent than those that do not, but limited populations have been studied to date. The aims of the present study were to evaluate the seroprevalence of anti-H. pylori IgG, IgA and anti-CagA antibodies in peptic ulcer (PU) patients and healthy individuals in the city of Rafsanjan. METHODS: A total of 60 PU patients (30 males and 30 females, aged 17 to 60 years) and 138 age-matched healthy individuals (65 males, 73 females) were enrolled in this study. Diagnosis of PU disease was established on the basis of findings by gastrointestinal endoscopy. The control group was recruited from among healthy blood donors referred to Blood Transfusion Center of Rafsanjan. A blood sample was collected from each participant and the sera were tested for the presence of anti- H. pylori IgG and IgA antibodies and antibody to bacterial virulence factor (CagA) by use of enzyme-linked immunosorbent assay. The serum concentrations of anti-H. pylori IgA and anti-CagA antibody were expressed as mean ± SD in each group. RESULTS: In PU patients the overall seroprevalence of anti-H. pylori IgG (95.8%), IgA (96.6%) and anti-CagA (91.6%) were higher than those observed in the control group (73.2%, P

Objective: To study the stinging flying Hymenoptera (Apidae and Vespidae) fauna in four Iranian Islands, Qeshm, Greater Tunb, Lesser Tunb and Abu-Musa on the Persian Gulf. Methods: The flies were captured by used of Malaise trap, fly trap, bottle trap and insect net-hashing from March 2011 to July 2012. Results: In this study, 11 species of stinging Hymenoptera were reported for the first time in Persian Gulf region. Conclusions: Some of this species such as Vespa orientalis and Polistes olivaceus are more common in the Persian Gulf islands and can cause clinical problem to islands resident and travelers.