Iranian Journal of

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Background and Objectives: Bottled water is a main beverage at many developed and developing countries. It can be polluted with chemical agents. One of these agents is nitrate which affects the safety of bottled and mineral water and cause healthy effects on consumer health. Today&aposs consumption of bottled water get a grate develop, thus infer of the quality of this matter is compulsive for each consumer.
Materials and Methods: A descriptive-analytical and cross- sectional study was done with the aim of determination of nitrate in bottled water available in market of Tehran City in 2007. In this study, 18 samples of six various manufacturers of product were examined.
Results: Results showed that the mean of nitrate is 9.02 mg/L and all samples have nitrate bellow 50 mg/L and they are at the standard level. Also, the results of the examinations have good correspondence with the concentration of nitrate on bottled water labels and according to statistic meaningful relation, was considered.
Conclusion: The nitrate content of these bottled water available in market of Tehran city is located at the level of national and global standards and it can not be a serious problem for health of consumer.

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Background and Objectives:Nowadays vermicompost production of food wastes is posed as one of appropriate methods to food wastes. disposal, its production used in agriculture and gardening. Moreover this process has some by products beside useful fertilizer that one of them is the worms. we can use them in variety of products specially in production of poultry and fish food. So determination of optimal condition for operating vermicompost production process of food wastes and worms. growth in these wastes is important. The aim of this study was determination of optimal temperature and moisture range for process progression in vermicompost production of food wastes.
Materials and Methods: In this study we used Eisenia foetida species. Process performed in pots with 15 cm (h) and 12 cm (d) and in a mouth period of time. Three ranges of temperature including 5-15, 15-25, 25-35 oC and three ranges of moisture including 55-65%, 65-75%, 75-85% were applied in this study.
Results: Multivariate analysis was used for analyze of results and it showed that influence of temperature and moisture on C:N ratio is significant in vermicomposting process (p <0.05).
Conclusion: The results showed that the range of temperature 15-25 oC is more appropriate for operating of process. Due to these study.s results with increasing or reduction of ambient temperature, like summer and winter, conservation of moisture around the range of 65-75 %, is effective in better performance of the process. According to this study.s results, it seems that the temperature of 15- 25 oC and moisture of 65-75% are better conditions for worm.s growth.

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

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Backgrounds and Objectives: Due to having features such as toxicity, corrosiveness, ignitability, reactivity or other similar characteristics, hazardous wastes refer to the wastes that jeopardize man's health and environment. A study was required to identify the hazardous wastes in Tehran University of Medical Sciences (TUMS), since it plays an important role in the development of the country's education. The objective of this research was to provide a review of hazardous wastes production and its management at Tehran University of Medical Sciences.
Materials and Methods: In this study, four schools that were in the central campus of Tehran University of Medical Sciences, Iran, were selected and the necessary data were gathered using a sampling, questionnaire, interviewing those in charge of the units, and referring to the available documents. The information includes the type and amount of waste, method of temporary storage, frequency of waste discharge, and method of final disposal of wastes.
Results: The obtained results indicate that approximately 2072 Kg of hazardous wastes are produced each year, excluding the uncontrolled wastewater. Moreover, schools of dental, pharmacy, medicine, and public health produced approximately 993, 606, 256, 217 Kg/year, respectively, of hazardous wastes in the central campus. Also, the results show that, of total amount of annual hazardous waste that was 2.72 tons, 954, 848, 475, 427, 245, 49 Kg were wastes that the features infectious, toxicity, ignitability, carcinogenesis, corrosiveness, and reactivity, respectively.
Conclusion: It  is to be mentioned that hazardous solid wastes were manage with household solid waste and hazardous liquid waste were discharged into sink without any kind of control. Improper practice is evident from the point of waste production to final disposal.

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Backgound and Objectives: The aim of this study is to investigate water consumption, domestic wastewater generation and organic matter concentration, based on both, economical income and meteorological temperature.
Materials and Methods: The method of this study is descriptive and analytical. A checklist was used to collect data on economical income. Water consumption was obtained based on water bills. Wastewater generation and organic matter such as biochemical oxygen demand (BOD) per capita/ day were measured every four hours, during a day in three regions of Kermanshah city: Kasra, Ellaheiah and Taavon.
Results: Comparing water consumption in winter and summer showed significant difference in three regions, mentioned above. The water consumption was (398 ± 75, 291 ± 48 and 188 ± 50) for warm climate and (200 ± 25, 188 ± 35 and 140 ± 41) for three regions respectively in cold weather. In spite of an apparent difference in BOD in three regions, it was not significant statistically. Water consumption has strongly considerable relationship with economical income (r =0.988, P_value <0.001), while the generated wastewater in these regions were not different, statistically for warmclimate (220 ± 60, 204 ± 15 and 170 ±34), and in cold weather (170 ± 21, 158 ± 31 and 112 ±29), also the generated wastewater did not have considerable difference in cold climate. This study confirms that, the effects of these two parameters, i.e.monthly economical income and environmental temperature on water consumption, generated wastewater and biodegradable organic loading per capita/day is considerable. It was concluded that water consumption and wastewater generations were much more in warm climate than in cold weather.
Conclusion: Finally through this study the estimation of water consumption, wastewater generation and BOD concentration becomes possible, which is beneficial for establishment of water consumption.

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Background and Objectives: Nowadays nitrate concentrations in surface water and especially in groundwater have increased in many locations in the world. Since nitrates cause many health and environmental concerns, increased nitrate concentrations in groundwater have led to rendered aquifers unusable as water sources. So, as the water demand is still increasing the throughout the world, decreasing the nitrate concentration in drinking water is imperative. Magnesium powder has been determined to be potentially useful for the removal of nitrate in the water environment. This research is aimed at subjecting the kinetics of nitrate chemical reduction by Mgo to an analysis of some factors affecting the chemical denitrification.
Materials and Methods: Nitrate concentrations determined in 220 nm using a spectrophotometer.To determine the performance of nitrate removal by Mg0 powder, double distilled water was used for preparation of reagents and simulation of contaminated water with nitrate.All experiments were triplicate and the averaged results were reported.
Results: Kinetics analysis from batch studies revealed that the denitrification reaction with Mgo powder appeared to be a first-order with respect to substrate and the observed reaction rate constant (kobs). The effects of mixing intensity on the denitrification rate suggest that the denitrification appears to be coupled with oxidative dissolution of magnesium through a largely mass transportlimited surface reaction. Also in the denitrification by Mgo determined that Mgo dose related with kobs ( R2>0/99 )S
Conclusion: In this research was determined that denitrification effectively by Mg0 powder can achieved in a wide range of concentrations under atmospheric conditions and without pH controlling within short reaction time. Denitrification rate was related to some parameters such as contact time, Mgo dosage, mixing rate and initial nitrate concentration.

 

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Backgrounds and Objectives:since large cities of Iran due to specific population, topographic, cultural and economical conditions have a numerous population per surface unit, , results in everincreasing population and it.s accumulation and have prepared favorable conditions for increasing various mice and rats species in these cities. Efforts, designing, construction and evaluation of electronic traps for mouse and rat controlling is one of the controlling methods which may be studied beside the other methods.
Materials and Methods:At first the types and species of mice and rats in Tehran city were studied (including length, weight, behavior characteristics etc.). Next, using a system producing attractive fragrance attracts mouse and rat to the trap. Then, using electronic sensors, mouse presence with commandswhich is sent to electrical bobbins evaluates.Later, themiddle section becomes electrically activated. Contacting the trap, the animal will die within 3 to 5 seconds contacting. Mouse corpse will transfer to the beneath section of trap. This section includes a drawer to be emptied daily or weekly. Preventing electric shocks, the power of all the sections will go with drawing out the drawer. Testing efficiency of the device, it was tried first with lab mice thus in each level of experiences the problems were solved.
Results:According to the design, each section of the device including attraction, killing and removing sections were evaluated separately. For instance, in killing section, the amount of voltage and its type also the method of electricity transfer to the animal was evaluated. In addition in attraction section the variety of fragrances were compared and it was found that walnut fragrance gave the best result for all the animal samples attraction. Also, the results showed 300 volts current voltage with 15 Amperes current intensity, has the best killing efficiency in less than a second than other voltages.
Conclusion:According to the different evaluations, it was clear there were no good results of killing in 2.5 to 15Amperes direct current intensity. Thus using direct currentmethods in these trap devices were not practical. In addition, using sexual fragrances for attraction males, in several species were tested and results showed that the proteins in these fragrances became decomposed very fast in environmental conditions and the attraction nature of these substances decreased. For this reason it seams according to its easy availability, food fragrances as attraction substances are more practical and useful.

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Backgrounds and Objectives: Geological situation and/or anthropogenic contamination contain an increased concentration of ions such as hexavalent chromium as well as some other dissolved components such as sulfate in the upper of the establishedMCLs (50µg/L). In this paper, simultaneous removal of Cr (VI) and sulfate from water was investigated using nanofiltration as a promising method for reaching drinking water standards.
Materials and Methods: For varying pressure, pH , anion and cation solution effect, Sulfate and Cr (VI) concentration which have chosen were levels found in drinking water sources (Cr=0.1- 0.5mg/L) and (SO4-2= 100-800mg/L).Experiments were performed using NaCl, Na2SO4,K2 Cr2O7and anhydrous CrCl3. 6H2O which prepared with de mineralized water on procedure detailed in standard methods. All salts were purchased from Merck Corporation with purity over 99'.
Results: The results for hexavalent chromium experiments showed that when the concentration decreases, the chromate anions were given a better retention to 4 bars (96'). But when the concentration increases, concentration polarization led to increased removal of Cr (VI) (98'). For Cr (III) the influences of the ionic strength as well as the concentrations were strongly dependant on rejection but operating pressure were found weak. In addition, with increasing total dissolved solids, perfect rejection of chromium was seen. The effect of pH showed that better retention was obtained at natural and basic pH.
Conclusion: This study indicates that the nature of anions and cations, driven pressure and pH have significant effect on nano filtration operation. Research findings show that it seems nano filtration is a very good promising method of simultaneous removal of Cr (VI) and sulfate from water.

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Backgrounds and Objectives: High level of nitrate ion in the water resources cause some health and environmental problems. The aim of this research is to study nitrate removal by Zero-Valent Magnesium (ZVM) and MgCl2-modified pumice from aqueous solutions.
Materials and Methods: The pumice granules were modified by MgCl2 . The removal of nitrate was studied in a batch system. The pH, initial nitrate concentration and sorbent mass parameters and the Langmuir and Freundlich models were studied in the sorption of nitrate onto the pumice. The ZVM was also used in a bach system and the previous parameters were studied.
Results: The removal efficiencies of nitrate by ZVM at the the initial pH of 3, 5 and 7 with controlling the pH were 70%, 40% and 30% ,respectively. These values are much higher than the values of the condition during which the pH was not controled. The nitrate removal efficiency increased by increasing of initial nitrate concentration in a constant molar ratio of Mgo/NO3. The removal efficiencies of nitrate by the modified pumice at the the initial pH of 3, 6.5 and 10 (when pH kept under control) were 49%, 29% and 16%, respectively. By increasing of the initial nitrate concentration the removal efficiency increased. The values of R2 for the Langmuir and Freundlich models were 0.944 and 0.810, respectively. The sorption process Fitted well the Langmuir model with a monolayer sorption capacity of 0.68 mg/g.
Conclusion: The modified pumice had lower efficiency than ZVM in the removal of nitrate ion and its usage is not considerably affected bye the pH in comparison with ZVM. The pH of the solution should be cansiderd as a main controling parameter to get an optimum efficiency in the nitrate-ZVM process.

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Background and Objectives: Particular importance of hazardous wastes is due to having characteristics such as toxicity, flammability, corrosively and reactivity. Some of the chemical wastes due to having hazardous materials must be collected and managed in a proper manner, since they are potentially harmful to the environment. Owing to the fact that educational centers have important roles in developing countries, so the main objective of the present study was to investigate, hazardous waste management in chemistry laboratories of Ministry of Science universities, in Tehran, Iran.   
Materials and Methods: Study area of this research includes all chemistry laboratories in Tehran universities which were covered by Ministry of Science. To obtain the number of samples, based on Scientific Principles and identification formula, 64 samples were calculated. In addition, sampling was done by Stratified sampling. Validated checklists were used for data gathering. Data analysis were done by Descriptive statistics (mean, frequency and etc.) and inferential statistics (kruskal- wallis test).
Results: results obtained in this study indicate that Sharif University by obtaining the mean score of 60.5 and Tehran University by obtaining the mean score of 4.5-6 are placed in best and worst rank, respectively. Beheshty, Alzahra and Tarbiat Moallem univesities by acquiring the mean score of 20-28.5 have a same position in ranking table. 
Conclusion: Results show that most of the studied laboratories do not have any collection program and only 26.5 percent of them have acceptable programs.The separation and storing program observed in about 12.5 percent . Hazardous wastes' management in chemistry laboratory of Tehran Universities was not in good status. And from the standpoint of management, only 12.5 percent of studied cases are in good status, while 75 percent was in undesirable status.

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Background and Objectives: New studies indicate that nitrate concentration in groundwater is increasing in most cities. High concentrations of nitrate in water increase the potential health risk in the community and the environment. In infants, No₃ _ is reduced to No₂ _, which combines with hemoglobin in the blood to form met hemoglobin leading to blue-tinged blood for babies under six months old in particular ,Namely, so-called ‘‘blue baby syndrome&apos&apos and  it  also produce carcinogenic compounds . Therefore high nitrate concentration is important. The aim of the present study is removing nitrate from water using zero_valent iron.
Materials and Methods: Analyses were conducted on synthetic samples. These samples were analyzed considering reaction times, pH, initial nitrate and sulfate concentration.
Results: Results showed that at Nitrate with an initial concentration of 200mg L1^-  after 60 min of reaction at pH(s) 7, 6 and 5 about 67.8%, 72.5 % and 88% was reduced, respectively in concentration of 100 and 300 mgL^- (pH=6) the removal efficiency is 60 and 83 percent, respectively. In sodium sulfate and nitrate with concentration of 300, the removal efficiency reached from 72 to 70 percent.
Conclusion: Results show that the initial pH is important to achieve maximum efficiency of nitrate removal. So the lower pH levels increases removal efficiency of nitrate. All of the experiments indicated that removal is the highest in the first 5 min. Generally with an increasing initial nitrate concentration the removal efficiency of nitrate increases.

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Background and Objectives Autoclaving is one of  the methods which sterilizes infectious solid wastes. Since variety of parameters such as temperature, time, and pressure influence autoclave performance, this study was carried out to evaluate the parameters and set optimum condition for the autoclave apparatus  applied in Shahid Beheshti Hospital in Kashan.
Materials and Methods: In this descriptive-analytical study, the performance of subjected autoclave was surveyed based on biological index and through setting 144 tests. Variables were packaging type in two groups (open and wrapped), loading type in three groups (light, medium and heavy), and four temperature-time features in fixed pressure equal to 101 kpa. Biological index was ATCC 7953 which contained Stearotermophilus Geobacillus spores. Finally obtained results were analyzed by Chi-Square test.
Results: The results of statistical test showed that there isn't any meaningful relation between packaging type of waste, system loading, and efficiency of sterilization(P>0.05),while meaningful relation was found between system performance and variety states of temperature-time feature(P<0.05), illustrating temperature and time effects in fixed pressure on sterilization of solid waste.
Conclusion: Based on the results, the best autoclave operational condition for sterilizing infectious solid wastes are: temperature-time equal to 10 min-140°C and 15 min-134°C in fixed pressure of 101 kpa, respectively. It was also revealed that temperature-time condition suggested by manufactory, i.e. 20min-121°C, is not sufficient for complete sterilization of solid waste.

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Background and Objectives: city bus drivers, during driving, are always exposed to the whole body vibration. This can lead to central- neural, musculoskeletal, and blood circulation disorders and develop occupational diseases due to vibration. The objective of this descriptive- analytic study is to investigate Tehran bus drivers&apos exposure to the whole body vibration.
Materials and Methods: We measured parameters related to the whole body vibration, such as acceleration of the frequency weighted root sum of squares, the overall equivalent acceleration, vibration dose value, and crest factor were measured separately at three directions (X, Y, Z) in 80 buses in 5 different types, which were selected randomly. The results obtained were compared with ISO 2631: 1997 Standard, and finally permitted driving time was calculated for different buses.
Results: Acceleration of the frequency weighted root mean of squares at X, Y axes in all of the buses was below the district of health warning and at Z axis, it was in the district of health warning, while the overall equivalent acceleration in Icarus buses was above the district of health warning and in other buses it was in the district of health warning according to standard ISO 2631: 1997. Vibration dose value (VDV) was less than 8.5 and crest factor was less than 9 and in all of the buses, it was less than the suggested permitted limits of ISO 2631: 1997 standard. Moreover, permitted driving time was estimated less than 8 hours per day and Icarus buses had the most and Man buses had the least vibration acceleration, crest factor, and vibration dose value respectively.
Conclusion: According to the results obtained, there is the possibility of developing potential health risks in bus drivers therefore, it is recommended that the health and safe managers consider decrease of working hours and increase of rest time while purchasing new buses.

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MicrosoftInternetExplorer4 Background and Objectives: Nitrate is one of the most groundwater pollutants in world. Reduction of nitrate to nitrite by microorganisms cause serious health hazards. Nitrate can be eliminated using either adsorbtion or reduction. In this study, we investigated the adsorption of nitate on zeolite and the feasibility of removal improvement using supported  zero valent nano iron on zeolite via the reduction process.
Materials and Methods: The study was done in two phases investigation the zeolite and modified zeolite with zero valent nano iron in nitrate removal from water. First, we determined the optimum pH and time then the effect of adsorbent and nitrate concentration was investigated in one factor at the time. The adsorption isotherm was calculated according to the optimum condition. The physical characteristics of adsorbents were determined using SEM and TEM.
Results: The morphology investigation of adsorbent showed that the particle size of supported zero valent nano iron on zeolite was approximately 30-50 nm in diameter. The best conditions were pH 5, contact time of 120 min and 15 g/L for zeolite, while pH 3, contact time of 50 min and 7.5 g/L for supported  zero valent nano iron on zeolite. The isotherm equations revealed that nitrate adsorption follows Langmiur in both cases.
Conclusion: The supported  zero valent nano iron on zeolite could be considered as a high potential adsorbent for nitrate because it has several adsorbent sites, and Fe⁰ as a function for nitrate reduction.

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Background and Objectives: Pollution of water resources to nitrate is an environmental problem in many parts of the world. This problem possibly causes diseases such as methemoglobinemia, lymphatic system cancer and Leukemia. Hence, nitrate control and removal from water resources is necessary. Considering that application of nanomaterials in treatment of environmental pollutants has become an interesting method, in this research use of Ag-doped TiO₂ nanoparticles synthesized through photodeposition produced under UV irradiation was studied for removal of nitrate from aqueous solutions.
Materials and Methods: Three nitrate concentrations of 20, 50, and 100 mg/L were considered. In order to determine the effect of Ag-doped TiO₂ nanoparticles on  nitrate removal, dosages of  0.1, 0.4, 0.8 and 1.2 g/L nanoparticles were used pH range of 5-9 was also considered. The effect of Ag-doped TiO₂ nanoparticles both in darkness and under UV irradiation was studied. Moreover, the presence of chloride and sulfate anions on the system removal efficiency was investigated.
Results: The optimum performance of nitrate removal (95.5%) was obtained using nitrate concentration of 100 mg/L, in acidic pH and 0.8 g/L Ag-TiO₂. Increase of nanoparticle dosage up to 0.8 g/L, increased the removal efficiency, but for 1.2 g/L dosage of nanoparticles, the removal efficiency decreased. Maximum reduction performance without nanoparticles, under UV irradiation and under darkness conditions were 32% and 23.3% , respectively. In addition, we found that presence of sulfate and chloride anions in aqueous solution reduced efficiency of nitrate removal.
Conclusion: Results of this study showed that Ag-doped TiO₂ nanoparticles may be efficiently used for nitrate removal from aqueous solutions.

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Background and Objectives: The contamination of nitrate (NO3−) in groundwater resources causes two adverse health effects: induction of “blue-baby syndrome” (methemoglobinemia), especially in infants, and the potential formation of carcinogenic nitrosamines. The aim of this research is to investigate nitrate removal from groundwater using alumina nanoparticles and to determine the adsorption isotherms. Materials and Methods: This analytical-descriptive study was carried out at lab-scale, under batch conditions, and at room-temperature. The structure of alumina nanoparticles was determined using XRD, SEM, and TEM techniques. The concentration of nitrate in the solutions was determined by spectrophotometer at wavelengths of 220 and 275 nm. In addition, we investigated the impact of the important operational parameters including initial dose of Al2O3 (0.06-0.25 g/l), initial concentration of the solution (50- 300 mg/l), contact time (5-60 min), and pH (3-9). Moreover, we used Freundlich and Langmuir isotherm models to calculate equilibrium constant. Results: It was found that nitrate removal efficiency increased as we increased contact time, initial concentration and pH in batch system. A maximum of 60% nitrate removal was achieved under following conditions: 60 min contact time, pH 5, and initial nitrate concentration of 300 mg/l as N. The obtained results showed that the adsorption of nitrate by Nano-Gamma-Alumina follows Langmuir isotherm equation with a correlation coefficient equal to 0.982. Conclusion: Overall, our findings showed that the alumina nanoparticles can be used as an effective adsorbent to remove NO3 from aqueous solutions.

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Backgrounds and Objectives: Medical waste management is one of the important issues in solid waste managment in each community. This research was carried out to study the quantity, quality and the management practices of solid wastes of hospitals in Zanjan City in 2011. Materials and Methods: In the present study, the hospital wastes were categoried and weighted into four main categories. Waste management pattern was studied based on a checklist extracted from national guidelines. Then, hospitals were ranked from very poor to excellent classes. For data analysis, Excel soft ware was used. Results: Waste generation rate was on average 2.402± 0.163 Kg/bed.day in the studied hospitals. The generation rate of domestic waste, infectious waste, sharp wastes, and chemical - pharmacological waste was 1.432±0.059, 0.926±0.096, 0.029±0.0055, and 0.015±0.002 kg/day.bed respectively. The status of the waste management practices was determined as average. Conclusion: Waste generation rate in the hospitals of Zanjan was lower compared with the expected average value in other cities (e.g. 2.71 Kg/bed.day in Tehran). The percentage of medical waste in Zanjan hospitals was 34, which is higher than W.H.O. recommendations. Therefore, it is strongly recommended to reform and monitor certain solid waste management practices in order to reduce health and environmental issues.

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Background and Objectives: Dust phenomenon has adverse effects on the health of the population.Due to the increasing concentration of Kermanshah dust phenomenon in recent years, The aim of this study was to measure the concentration of the sensitivity coefficients between dust phenomenon hospitalization and mortality rates for heart and respiratory.

Materials and Methods: This was a descriptive study in which we studied the sensitivity coefficient of hospitalization and mortality rates for heart disease and respiratory to changes of dust concentration.. The study duration was during March-September 2010 and 2011. We collected the dust phenomenon data from Kermanshah Province Environmental Protection Department. The admissions and mortality of the cardiovascular and respiratory sufferers was collected from the Imam Ali, Imam Reza, and Imam Khomeini governmental hosiptals in Kermanshah.

Results: 1% increase in air pollution caused by the dust phenomenon will result in increasing about 0.5 % of the respiratory patients, 1% cardiac patients, and about 0.3% of the heart disease mortality. The relationship between dust phenomenon and respiratory sufferers was statistically not significant.

Conclusions: We found that respiratory and cardiovascular hospital admission has a high sensitivity to dust phenomenon. This sensitivity has increased from 2010 to 2011. This sensitivity was greater for males than females. At least, during March-September 2010, for every 100% increase in the concentration of dust phenomenon, cardiovascular mortality increased by 29%.

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Background and Objectives: Weather pollution, caused by Ozone (O3) in metropolitans, is one of the major components of pollutants, which damage the environment and hurt all living organisms. Therefore, this study attempts to provide a model for the estimation of O3 concentration in Tabriz at two pollution monitoring stations: Abresan and Rastekuche.
Materials and Methods: In this research, Artificial neural networks (ANNs) were used to consider the impact of the meteorological and weather pollution parameters upon O3 concentration, and weight matrix of ANNs with Garson equation were used for sensitivity analysis of the input parameters to ANNs.
 Results: The results indicate that the O3 concentration is simultaneously affected by the meteorological and the weather pollution parameters. Among the meteorological parameters used by ANNs, maximum temperature and among the air pollution parameters, carbon monoxide had the maximum effect.
Conclusion: The results are representative of the acceptable performance of ANNs to predict O3 concentration. In addition, the parameters used in the modeling process could assess variations of the ozone concentration at the investigated stations.

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Background and Aim: In this study, the removal of dye blue reactive-171 by combination of advanced oxidation processes UV/H₂O₂ and SBAR has been investigated. Methods: The efficiency of chemical and biological system was first investigated separately. In chemical system, the kind, power, initial dye concentration and hydrogen parasitize and in biological system, hydraulic detention time, aeration rate, initial dye concentration and the percent removal of dye and COD were investigated. In order to investigate the hybrid system, after determination of the optimum conditions and the capabilities of each system, the removed chemical system effluent from residual hydroxide peroxide, was entered into the biological reactor. Results: In the chemicals process, 100 ppm dye using 150 Watt-UV-C lamp and 0.1 mM hydrogen peroxide at pH= 9 was completely removed in 25 minutes. COD removal was 86.7 percent at the end of the experiment (135 min). Biological system with adsorption mechanism has shown 44 percent dye removal with initial COD of 50 mg/L that indicated the system inability in biodegradation and breaking down of the dye molecule. In comparison to separate chemical and biological processes, hybrid system has shown better dye removal efficiency. The results indicated that in addition to the complete dye removal achievement, 81% of COD in the first hybrid system and 52% of COD in the second hybrid system was removed, respectively. Conclusion: According to the results, because of complexity of dye structure, biological system was not able to remove the dye as efficient as hybrid system of advanced oxidation processes UV/H₂O₂ with SBAR.