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Background and purpose: Heterotrophic plate count (HPC) is commonly used to assess the general microbiological quality of drinking water. HPC must be less than 500 colonies per milliliter in drinking water. The aim of this study was to compare the heterotrophic bacteria of bottled water and drinking water distribution system and their relationship with water quality parameters. Materials and methods: In this study 21 samples of bottled water belonging to seven domestic brands and 15 samples of drinking water from water distribution system in Semnan were analyzed and compared for HPC. The Relationship between HPC with pH, temperature, turbidity and free residual chlorine were also determined in drinking water distribution system. Results: The results showed that HPC was lower in bottled water compared with that of the tap water. HPC has increased when the temperature increased. In contrast, HPC has decreased when free residual chlorine increased. Turbidity and pH did not influence the HPC in drinking water distribution system. Conclusion: The quality of all bottled water was consistent with the Iranian drinking water standards and also the standard levels proposed by World Health Organization. However, HPC was found more in some parts of distribution system where the residual chlorine was low.

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Introduction: Water quality has directly related to personal and public health. Therefore monitoring of water supplies and theirs sanitary conditions is very important. The aim of this study was to investigate the chemical quality of drinking water in Khoy city (West Azarbaijan province, Iran) during 2008 and 2009. Materials & Methods: This resach was a descriptive study. All data of water quality was received from Water and Wastewater Co in Western Azerbaijan province. Collected data was for 24 months from March 2008 to February 2009. The data were analyzed by using Spss and Excel software and then compared with the national standards. Results: the results showed that the mean concentration of nitrate was18.9 ± 9.4 mg / l during two years. The mean concentration of EC was 589 ±120µs/cm in the all studied wells. The mean concentration of fluoride was 0.39 ± 0.1 mg /l. The average hardness of water was 293 ±64 mg/l as calcium carbonate. Conclusion: Although the electrical conductivity and nitrate concentrations in Khoy city drinking water were lower than the standard values, the concentration had the increasing trend in two years consequently. According to average annual temperature of weather in the region, the fluoride content is lower than the standard value in all wells. The drinking water of Khoy city is calssifed in hard and very hard categories. The relation between hardness and electrical conductivity is a direct linear ratio.

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Introduction: The amount and composition of municipal solid waste, as basic data, require to design, operation and optimization of waste management systems. The aim of this study was to investigate the qualitative and quantitative of municipal solid waste in tabriz city. Materials and Methods: This is a cross-sectional study. The samples were collected from all regions (10 regions) of Tabriz city. The samples have chosen according random cluster sampling during a year. 12 samples were collected in each season. Then, the data were analyzed by SPSS and Excel softwares. Results: The results indicated that amount of MSW was 1200 tons per day. The content of organic material, paper & cardboard and recyclable (plastic, metal, glass and etc) was 52%, 13.15% and 19%, respectively. The maximum and minimum production rate was in august and January, respectively. Conclusion: Approximately, 85% of wastes included the recyclable and organic materials which the reuse of this material prevents the environmental pollution. The citizens believed that the most important of MSW program should be the promoting awareness, waste reduction and recycling.

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Background and purpose: Corrosion is a physicochemical reaction between metal and its surrounding that lead to changing in water quality. Corrosion causes to solve the pipelines that release the pollutants in the water. The objective of this study was to assess the scale formation and corrosion of drinking water supplies in Yasuj (Iran) in 2012 Materials and methods: This research was a descriptive and cross-sectional study. Experiments were conducted according to standard methods for water and wastewater experiment in the Water and Wastewater Co. The data were analyzed by using of Excel and Water Stability analyzer softwares. The results were compared with national and international standards. Results: The results showed that the calcium and TDS contents are not in the recommended range of national and WHO standards. The Langelier Index ranged from -0.91 to -0.43 in summer and -0.66 to -0.25 in the winter. The average of Rayznr index was 8.61±0.23 and 8.48±0.07 in the summer and the winter, respectively. The average of aggression, Puckorius and Larson indexes were 11.58, 8.13 and 0.29 respectively, which indicates the most of water supplies don’t tend to scale formation, however tend to mild corrosion. Conclusion: The results showed that water supplies of Yasuj city was mild corrosive. Therefore water quality should be control. Also water pipelines should be preserved with several modes of corrosion inhibition.

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Background and purpose: Maintenance of safety in housing is among concerns of the urban and rural healthy life in our country. Disregarding of safety issues and probability of occurrence of accident impose many costs on the families and Ministry of Health and Medical Education. This study aimed to determine safety status of residential housing in rural families of Ramian Township in 2011. Materials and methods: This cross-sectional study was conducted on 12965 residential housings (all households) in Ramian township (Golestan Province, Iran) in 2011 according to credible safety checklist of Ministry of Health (five parts: kitchen, bedroom, bathroom, balcony and roof, and the staircase). After completing the checklist, the overall home safety score and scores of its five parts were calculated and were graded. Then data were analyzed by SPSS version 16, Excel and descriptive statistics . Results: Results showed that five sections of home had acceptable safety, including kitchen (96.64%), bedroom (96.49%), staircase (95.53%), yard, balcony, parking lot and roof (94.27%), and the bathroom (93.42%). Overall, 0.72% homes (93 households), 2.43% homes (315 households) and of 96.85% homes (12,548 households) had poor, average and acceptable safety score, respectively. Also, Ghareghach and Saadabad health care centers had subsequently minimum and maximum overall home safety score. Conclusion: The results indicated that houses of eight rural health care centers had significantly different safety overall and five parts scores. The results also showed that the overall home safety in rural families of Ramian Township, in contrast to previous studies, even in the central area and the outskirts of the city, has been higher or close to equal. For maintaining and improving the safety of residential homes, other mechanisms are presented, such as increasing of public awareness, strengthening inter-sectorial cooperation and participation, and encouraging of households evaluated as safe.

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Introduction: Bisphenol A is an aromatic compound that has many applications in various industries and is known as persistent pollutants. The aim of this study was to investigate bisphenol A removal by using activated carbon and shell eggs from aqueous solution by response surface experimental designs. Materials and Methods: In this study, activated carbon and eggshell were used as adsorbents. The adsorbents were prepared using standard methods and then were sized. The variables were pH, retention time, concentration bisphenol A and adsorbent dose. All experiments were performed by standard methods, and sample size determined by Box Behnken method. Results: The results showed that adsorption efficiency of both adsorbents increased with increasing in time, BPA concentration and lower pH. Maximum adsorption of activated carbon and eggshell was 92 and 33 percent, respectively. The maximum of adsorption rate was occured at the 120 min retention time. ANOVA statistical test data showed that the surface response model had statically significant liner relationship in the case of activated carbon and liner, square and interaction in the case of eggshell. Conclusion: Bisphenol adsorption by the eggshell adsorbent is low and insignificant compared to activated carbon. Activated carbon is a good adsorbent for bisphenol A.

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Background and purpose: Solid waste leachate including different physical, chemical and biological pollutants is one of the most contaminated wastewater types. The limitations of conventional biological method for leachate treatment are the high energy consumption, nutrient requirement, sludge production, and cost. In this research, the efficiency of anaerobic baffled reactor modified by anaerobic filter (ABR-AF) was studied in solid waste leachate treatment located in Sari. Materials and methods: In this study, two glass reactors (six cells) were used. Each cell in upward section was equipped with a sampling port (and also a gas exit) and the volume of each reactor was 5.7 L. The initial cell was used for suspended solid settling and the last cell acted as an anaerobic filter in ABR-AF. The blank reactor characteristics were the same as the initial one except that it was without sludge and filter media. The interior temperature of the cells was adjusted by four electrical elements. After reaching the equilibrium, the leachate with different organic loading entered the reactor. Then, different parameters (COD, BOD5, TSS, o-phosphate, nitrate, ammonia, pH, etc.) were measured in different places of the reactors. All analyses were performed according to the “Standard Methods for the Examination of Water and Wastewater”. To analyze the data, analysis of variance and regression tests were performed in SPSS version 16. Results: The system efficiency for COD removal varied in the range of 39-96%. The maximum efficiency for COD removal was related to three days detention time and 10.72(Kg COD/m3.d) organic loading, while the minimum efficiency for it before the filter was related to one day detention time and 1.96 (Kg COD/m3.d) organic loading. The average efficiency for BOD5 removal varied from 39 to 58% and it ranged from 4 to 16% for o-phosphate removal. Conclusion: The ABR-AF system alone is not able to provide the effluent discharge requirement to surface and groundwater, but it can meet the needs of effluent discharge requirement to agricultural waterways.

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Background and purpose: Ammonia in form of ammonium ions pollutes the acceptor water through industrial, domestic and agricultural wastewater. Ammonium ions are toxic and could decrease the dissolved oxygen in water and endanger the aquatic life. One of the conventional methods for removing ammonia from water and wastewater is exchanging the ions using zeolites. The aim of this study was to assess the efficacy of zeolite Clinoptilolite in removing ammonia from water, in both batch and continuous systems. Materials and methods: In this study batch experiments were exposed to different concentrations of natural Clinoptilolite (5, 10, and 50 g/l) with aqueous solution containing ammonium ions (1, 5and, 10 mg/l) in different exposure times (10 to 240 minutes). The continuous experiments were also conducted at ammonium concentrations of 5 and10 mg/l. Results: The maximum ammonium absorption occurred at pH=7 and in 60 minutes exposure time. Increase in initial concentration of ammonium increased the sorption capacity. Also, sorption capacity decreased when the absorbent material increased. Considering higher correlation coefficient (R2) the isotherm obtained in this study matches the Freundlich isotherm model. The results of column tests showed longer time to reach the breakpoint when initial concentration of ammonium decreased. Breakpoints for ammonium concentrations of 5 and 10 mg/l were 6.45 and 6.32 mg/g, respectively. Conclusion: This study proved that ion exchange using zeolite Clinoptilolite is a low cost method that could result in complete removal of ammonium from water.

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Background and purpose: Cadmium is a very toxic metal that have adverse effects on human health and aquatic environments even at low concentrations, therefore, efforts should be made to eliminate this metal from aquatic ecosystem. The aim of this study was to investigate the efficacy of L-cysteine functionalized single-walled carbon nanotubes in removing cadmium from aqueous environments. This study also assessed the role of some parameters such as pH, adsorbent dose, contact time and concentration of cadmium. Materials and methods: Single-walled carbon nanotubes were functionalized with L-cysteine. Then the optimum level of pH, carbon nanotubes dose, contact time, and cadmium concentration were determined during the adsorption process. The experimental data were compared with the Langmuir and Freundlich adsorption isotherm models. Results: qe increased when the pH level increased, while contact time and Cd concentration decreased by increase in the number of carbon nanotubes. The Langmuir adsorption model agreed well with the experimental data (R2 = 0.997). Efficiency of single-walled carbon nanotubes in optimal condition was 94.26%. Conclusion: The results showed that L-cysteine functionalized single-walled carbon nanotubes could be effective for the removal of cadmium.

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Background and purpose: There are limited studies on the natural systems of wastewater treatment by artificial wetlands subsurface in Northern Iran. The goal of this study was determining the efficiency of the artificial wetlands pilot system and the efficiency of horizontal subsurface flow systems for a variety of pollutants. Materials and methods: This study used artificial wetlands pilot system for removal of BOD, COD, TSS, TKN and TP in wastewater. Dimensions of reactors used in this study were 4 to 6 m length, 1.5m width and 0.8 m depth. Reactor No. 2 was used as a blank (unplanted) reactor. Reactors were located in parallel and Phragmites Australis -a commonly found plant in the area- was used in this study. Samples of wastewater were taken from the input and output of constructed wetland’s subsurface and tested in laboratory of faculty of health in Mazandaran University of Medical Sciences based on the standard reference method for experiments in water and wastewater. Results: Average removal using subsurface wetland showed that the unplanted reactor efficiency for removal of BOD,COD,TSS,TKN and TP was 47.11, 70.26, 50.83,19.69 and 91.69 percent and for reactors with Phragmitis Australis the percentage was 81.47, 78.5 ,87.87,76.18 and 97.80, respectively. Optimum hydraulic detention time was six days and gravel size 10 mm was better than 20 mm. Conclusion: This system as an efficient system can reduce the conventional pollutants of wastewater to the standards of secondary wastewater treatment. Furthermore, this system can remove nitrogen and phosphorus from effluent discharges more than conventional systems.

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Background and purpose: Safe drinking is water that does not have any chemical and microbial contamination. According to the World Health Organization (WHO) guideline standards for drinking water total and fecal coliform the indicator of fecal contamination must not be detectable in any 100 ml samples. Pollution indicator bacteria such as coliforms and fecal coliforms were enumerated using a multiple-tube fermentation method. Therefore, this study aimed to determine the microbial quality of domestic water wells in rural areas around Sari, Iran with most probable number (MPN) test. Materials and methods: In this cross-sectional study, the microbial quality of water samples from 23 domestic water wells in some villages of Sari were randomly tested in twice to determine the presence of total coliform (TC) and fecal coliform (FC) by the MPN. Sampling and sample transportation and sample analysis were done according to water and wastewater standard methods. Results: The results showed that 87 and 70% of the samples presented total and fecal coliforms, respectively. Water samples of 16 wells were bacteriologically nonpotable. Besides, the results showed that the bacteriological quality of the 3 wells was within the acceptable limits set by WHO guidelines and therefore was safe for human consumption. Conclusion: The results of the study suggested that the level of fecal contamination in domestic water wells was very high. The bacteriological quality of water was not according to the standard of WHO guidelines for drinking water. Therefore, using and drinking water from domestic water wells can pose a great threat and risk of waterborne epidemics by bacterial pathogens to the population consuming it. Water supplying authorities should consider this situation and take measures for the provision of contamination free drinking water to prevent waterborne disease outbreaks.

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Background and purpose: Furfural compound is very harmful to health that is used or generated in many industries such as oil refineries, petrochemical, pharmaceutical, paper, etc. The composition is one of the critical pollutants that is difficult to remove using the biological methods therefore, the aim of this study was to evaluate the performance of TiO2 nanoparticles in the removal of furfural in the presence of sunlight and UV radiation. Materials and methods: In this study, TiO2 was prepared by sol – gel method and the properties of nanoparticle were determined using SEM. The number of samples was determined through the central composite statistical methods. The samples with definite concentration of furfural and nanoparticle in different operational conditions were exposed to sunlight and UV radiation, individually. The furfural concentration was measured using HPLC. Data analysis was performed using Minitab 16 software. Results: The results showed that the removal efficiency of furfural increased with rising staying time, nanoparticle dose and pH and decreased with rising of the furfural concentration in both methods. The highest removal efficiency of TiO2/UV and TiO2/sun methods were 87 and 45 percent, respectively. Conclusion: The rate of degradation and elimination furfural in both sunlight and ultraviolet radiation photocatalytic methods increased. The efficiency of TiO2/sun method in comparison with TiO2/UV method is negligible.

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Background and purpose: Fluoride in drinking water can be either beneficial or detrimental to health depending on its concentration. Its high concentrations leads to dental and skeletal fluorosis and lesions of the endocrine glands, thyroid and liver. This paper describes the removal of fluoride from water using lemna minor. Material and methods: This research was a lab study. The lemna minor plants were collected and dried in the oven at 105 in 24 h and sieved in 18-30 mesh. The optimum values of pH, contact time and adsorbent dosage were determined and the different concentrations of fluoride were experimented in lab scale conditions for modified lemna minor. The fluoride concentration was measured in wavelength of 518 nm by spectrophotometer. Also, the found data of this research were fitted with Variety Isotherm and kinetic models. Results: The results showed that by increasing pH solution, removal efficiency decreased and optimum pH was 5. Increasing of contact time and adsorbent dose can lead to the increase of the removal efficiency.Adsorption isotherm data show that the fluoride sorption followed the Langmuir No 2. Fluoride sorption is better agreed with pseudo- second order of Kinetics model which was well described by pseudo- second order model. Conclusion: The result of the present work shows that lemna minor can be used as an effective and cheap adsorbent for fluoride removal.

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Background and purpose: Nitrate is one of the pollutants of groundwater resources which is easily found in agricultural and wastewater disposal areas. The aim of this study was to determine the spatial and temporal variations of nitrate and nitrite in drinking water resources of Kohgiluyeh -a city in Iran- using Geographic Information System (GIS). Materials and methods: This cross-sectional study was carried out in 2011 in which 18 sources of drinking water (108 samples) and results of five-year-archived analysis in Water and sewage Co of Kohgiloyeh were studied applying GIS software ver. 9.3, SPSS ver. 16, and Pearson correlation test. Results: The results showed that the mean of nitrate concentration in 2007 was 18.5 ± 1.5 and in the summer and fall of 2011 was 20 ± 4.6 and 20.83 ± 2.2 ppm, respectively which indicates a direct correlation between years and the increase in nitrate concentration (R= 0.92, P= 0.01). However, the nitrite concentration was found steady in most years. The spatial variations represent worse quality of northwest. Ordinary kriging is the best interpolation method for nitrate and nitrite. Conclusion: According to the results, the concentration of nitrite and nitrate has increased during the past years and in some parts are even rising more than the standard levels. The reasons could be regional geology and agricultural and to prevent such problems protecting the wells, using river water for agriculture, and construction of wastewater treatment plants could be of great benefit.

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Background and purpose: Mercury is a toxic heavy metal which causes irrevocable intense nerve-recognition disturbance to human. Excess contact to mercury causes diseases like tremor, losing sensation, decreasing vision and hearing or growth. WHO recommended the most amount of mercury absorption about 0.3 mg per week and the most concentration in water about 1µg/L. The purpose of this study was to investigate the efficiency of Lcysteinefunctionalized single-walled carbon nanotubes (SWCNs) in mercury removal from aqueous solutions. Materials and methods: In this study, single-walled carbon nanotubes was used as absorbent. The effects of some parameters such as pH, absorbent dose, contact time and mercury concentration were assessed. All experiments have been done according to standard methods. The sample size was determined by Box-Benkan method. Results: The result showed that absorption rate increased by increasing of pH, contact time and mass CNTs dose. The Hg removal efficiency decreased by increasing of initial Hg concentration.The maximum and the minimum of absorption rate are 95 and 22 percent, respectively. ANOVA showed that RSM has a significant relationship for single-walled carbon nanotubes with linear conditions. Conclusion: The study demonstrated that SWCNT-Cysteine is a well absorbent for Hg removal from aqueous solutions Therefore, it can be effective for the removal of mercury from aqueous solutions.

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Background and purpose: Radon is a colorless inert gas which decay products are the main component of natural radioactive elements that are naturally produced in under layers of earth crust by decay of radium and uranium. It enters through buildings via gaps and cracks. Alpha particle emissions as a radon gas decay product can increase the incidence of lung cancer in human. Every person spends 65 to 95 percent of his life in closed environments, therefore, elevated concentrations of radon could negatively influence human health. This study aimed at measuring the indoor radon concentration in the dwelling of Gorgan and compare it with EPA standards. Material and Methods: The indoor radon concentration was measured in 212 homes in Gorgan using solid-state nuclear track detectors (CR-39). Each CR-39 detector was mounted 50-90 cm from the bottom bedroom and living rooms, away from doors and windows. After about three months of exposure, the detectors were collected and transported to the laboratory. In next step, they were etched in 6.25N NaOH solutions at 85 C˚ for three hours. Finally, track densities were analyzed using an optical microscope scanning system. Results: The radon concentration in three percent of the houses was found higher than 148 Bq/m3 receipted by EPA as the action level. Conclusion: The result of this study could be used in mapping of national radon level.

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Background and purpose: Nitrate is probably the most widespread groundwater contaminant in the world, due to its high water solubility. It imposes a serious threat to human health and contributes to eutrophication. The objectives of this study were set to explore how the factors of ultraviolet light and ionic strength could influence the nano zero valent iron (NZVI) system for nitrate removal. Material and methods: In this study, response surface methodology was employed for the design and analysis of experiments .Experiments were carried out as per Box–Behnken) BBD) surface statistical design with four input parameters namely NZVI dose (0.5–2g/L), initial concentration (50–150mg/L), contact time (15–60min), and ionic strength (1000-5000μmho/cm). All experiments were performed in the presence and absence of UV irradiation. Results: The Maximum reduction efficiency for experiments in the presence and absence of UV irradiation was 85.3% and 91.6% in nano zero valent iron dose 2g/L, initial concentration 100mg/L, Contact time 60, and ionic strength 3000μmho/cm. The proposed model was essentially in accordance with the experimental case with correlation coefficient R2 = 0.9992, 0.9946 and Adj-R2 = 0.9982, 0.9884, respectively. Conclusion: Removal efficiency of nitrate increased with increase in time and NZVI dosage. In contrast, it decreased when ionic strength and initial concentration increased. Also, UV irradiation accelerated the removal of nitrate.

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Abstract Background and purpose: Nowadays, tendency to consume bottled water shows significant growth due to increase of demand for safe drinking water, limited resources of fresh water and the public beliefs about the quality of bottled water. The aims of this study were to evaluate the microbial and physicochemical quality of bottled water in Mazandaran province and their heavy metal concentration. Materials and methods: This descriptive-cross sectional study was done in 60 types of 1.5 lit bottled water from 15 different brands which have been bottled in different seasons in Mazandaran province in 2012. We assessed 33 microbial and physicochemical characteristics and concentrations of heavy metals applying standard method and compared them with those recommended by WHO and Iran National Standard Organization. Results: The analyzed samples were 100% in the range of Iran National Standard regarding microbial and physicochemical quality. Among chemical parameters, fluorine (0.01 mg/l) was the least while nickel (0.08 mg/l) and boron (1 mg/l) were the most common. Compared to standard guidelines, among heavy metals, mercury, chrome and lead were found with maximum level (0.001, 0.01 and 0.05 mg/l, respectively). There was no significant difference between the measured and listed values on the labels of bottled water (P<0.05). Conclusion: Results showed that the values of all parameters except Nickel were acceptable and did not exceed the standard guidelines for bottled water quality. However, continuous monitoring of bottled water is necessary since there is an increasing trend in consumption of bottled water and new brands are being distributed in the market.

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Background and purpose: Appropriate and efficient disinfection is an important aspect of hospital infections control. The aim of this study was to investigate the effects of common disinfectants used for Escherichia coli bacteria separated from two teaching hospitals in Sari, 2014. Materials and methods: Escherichia coli were taken from different wards in Zare and BouAli hospitals. E.Coli was identified by standard plant methods, differential test and biochemical isolation. Deconex plus53, Creolin and Cidex were used as disinfectants in various concentrations. Their effects were determined by Standard disc diffusion method. Data was analyzed using regression in Minitab V.17. Results: A total of 120 samples were investigated of which 48 (40%) were found contaminated and 15 (13%) of these isolates were positive for E.coli. The most effective disinfectants against E.coli were Cidex 2%, deconex Plus53 2%, and Creolin 3.5%, respectively. Conclusion: Performing pretests is necessary for choosing the most appropriate disinfectant and increasing its efficacy. Also, it is important to consider common infectious bacteria in hospitals and effective factors on disinfectants such as concentration and time.

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Background and purpose: Medical wastes are amongst the main problems of solid waste management and have some serious health risks. Their management is of great importance since they could threaten human health. The aim of this study was to determine the quality, quantity and the method of medical waste disposal in Gachsaran. Materials and methods: A cross-sectional study was conducted in healthcare settings in Gachsaran including 20 doctor’s offices, seven clinics, five health stations, four outpatient clinics, three laboratories, nine health centers, and 51 health houses. Census sampling was performed in which three samples were chosen during three months from each healthcare setting. The mean of three samples was considered as the final weight. Excel and SPSS software and descriptive statistics were applied to analyze the data. Results: The mean amounts of total waste, infectious waste, and non-infectious waste generated in Ghachsaran health settings were 625, 201, and 424 kg per day, respectively. Total amount of referrals was 2031 and the amount of waste produced per capita was 307.7g. Doctor’s offices and health houses generated the highest and lowest amount of infectious wastes (70 and 4.5 kg, respectively). Conclusion: Infectious wastes are produced at a high rate in healthcare settings. Moreover, there are different types of healthcare settings that generate many wastes, therefore, it is necessary to perform continues monitoring, on their management, particularly on collection and disposal process. These measures could maintain and enhance the health of exposed people and other people in the society.