IRANIAN JOURNAL OF HEALTH AND ENVIRONMENT
Year:2018 | Volume:11 | Issue:2 |Papers Count:12

Background and Objective: Food-borne diseases are among the most important public health problems. Among them, Salmonella is one of the most important food pathogens. Different Salmonella serotypes enter body through food and causes food infections in consumers. One of the most important evaluation criteria for health is to determine the microbial load of food.Materials and Methods: In this study, 245 shrimp samples supplied in Khuzestan province were taken randomly. The samples kept on ice were transferred to the laboratory and immediately tested microbiologically.Results: In this study, in 50.2 percent of the samples, the average number of bacteria per mL of the rinse water used to rinse the shrimps was 2200 bacteria, in 29.8 percent of the samples, it was 13600 bacteria and in 20.0 percent of the samples, the average number of bacteria per mL of the rinse water, it was 36700 bacteria. Based on these results, the average number of bacteria in the total samples was 20000 bacteria per mL rinse water.Out of the total samples assessed 33 samples were positive and 212 were negative forSalmonella, showing a 13.4 percent prevalence of Salmonella contamination in the shrimp production in Khuzestan Province.Conclusion: Due to the microbial load and Salmonella contamination in shrimp supply in the province of Khuzestan raw or undercooked consumption of shrimps can increase the possibility of problems for consumers.

Background and Objective: Today, landfill management of municipal waste and soil pollution with heavy metals are major environmental problems.This research was conducted to evaluate the effect of Shazand municipal waste compost and Saveh pomegranate peel biochar on decreasing Pb availability in soil and sorghum plant.Materials and Methods: Treatments consisted of applying Shazand municipal waste compost (0, 10 and 20 ton/ ha) and Saveh pomegranate peel biochar (0 and 15 g/ kg) in a Pb polluted soil (0, 600, 800 and 1000 mg Pb/ kg soil). After 8 weeks of sorghum planting (Kimya CV.), the soil physio-chemical properties and soil and plant Pb concentration were measured.Results: Applying 20 ton/ha municipal waste compost with 15 g/ kg biochar increased soil pH by 0.4 units and decreased soil Pb availability by 11%. The similar results were observed for the root and shoot Pb concentrations, when the same amount of manure in a Pb polluted soil was applied (1000mg Pb/ kg soil) that decreased the root and shoot Pb concentration by 1.8 and 2.2 times, respectively.Conclusion: The result of this experiment showed that applying Shazand municipal waste compost and biochar can increase soil sorption properties and decrease soil or plant Pb concentration. However, the role of these organic amendments on supplying plant nutritional needs cannot be ignored.

Background and Objective: Water quality is one of the issues that is of great importance to economic and social development due to the high costs of providing healthy drinking water and its risk to human health and the environment. For instance, although only a short time has passed since the construction of the Shirin-darreh dam, the problems arising from its exploitation have challenged the environmental sector and the health of the water.Materials and Methods: Water quality is affected by complex processes and various variables. Accordingly, NSFWQI input variables at monthly intervals collected at the dam reservoir during December 2011 - November 2012 was used to evaluate the water quality of the reservoir based on the grey relational analysis process. The results were compared with the results of the NSFWQI method.Also, the Shannon Entropy method was used, considering the importance of weight of variables in different methods.Results: The results showed that the water quality in the grey analysis method from November 2011 to May 2012 and in the NSFWQI method from October 2011 to April 2012 was moderate and in the remaining months was bad. In the grey analysis method, the highest reservoir value was related to Station 3 and month of February 2012 with a value of 64.2 and the worst water quality was related to Station 4 and month of August 2012 with a value of 39.2. Also, In NSFWQI method, the highest reservoir value was related to station 3 and month of February 2012 with a value of 68.7, and the worst water quality was related to Station 1 and month of August 2012 with a value of 39.1.Conclusion: Although there was no significant difference between the two methods, due to the greater adaptability of the results of the gray analysis method with the weather events and upstream conditions of the dam, this method is recommended.Due to the relative inadequacy of Shirin-darreh reservoir water in some months, it is essential that the source of pollutants from upstream areas is identified. After identification of the hotspots and preparation of the critical areas map, the appropriate control measures could be implemented.

Background and Objective: Chromium is present in two oxidation forms of Cr (III) and Cr (VI). Cr (III) is less toxic than Cr (VI). The aim of this article was to optimize an artificial neural network structure in modeling the photocatalytic reduction of Cr (VI) by TiO2-P25 nanoparticles.Materials and Methods: In this work, an artificial neural network (ANN) for the modeling photocatalytic reduction Cr (VI) by TiO2-P25 nanoparticles were used and its structure was optimized. The operating parameters were initial concentration of chromium, amount of photocatalyst, ultraviolet light irradiation time and pH. All the experiments were conducted in a batch photoreactor. The Cr (VI) concentration was measured with a UV/Vis spectrophotometer. ANN calculations were performed using Matlab 7 software and the ANN toolbox.Results: The results show that the optimization of the ANN structure and the use of an appropriate algorithm and transfer function could significantly improve performance. The proposed neural network in modeling the photoactivity of TiO2-P25 nanoparticles in reducing Cr (VI) was acceptable, based on a good correlation coefficient (0.9886) and a small mean square error (0.00018). All the input variables affected the reduction of Cr (VI), however the effect of pH with an impact factor of 34.15 % was more significant than the others. The results indicated that pH=2 was the best pH for photocatalytic reduction of Cr (VI).Increasing photocatalyst dosage and irradiation time in the investigated range increased Cr (VI) photocatalytic reduction.Conclusion: Optimized structure of the ANN includes a three-layer feedforward back propagation network with 4: 10: 1 topology and the most appropriate algorithm is a scaled conjugate gradient backpropagation algorithm.

Background and Objective: Water pollution due to heavy metals is a critical and increasing problem worldwide. In this study, removal of cadmium and lead heavy metals using a graphene oxide (GO) adsorbent was examined.Materials and Methods: GO nanosheets were synthesized through Hummer’s method, and its characterizations were examined using FTIR, XRD, and SEM.The effect of independent variables pH, contact time and initial concentration of the solution on removal efficiency of Cd2+and Pb2+using response surface methodology was evaluated according to Box-Behnken experimental design.Applying quadratic model, adsorption rate of Cd2+and Pb2+achieved 99%.ANOVA was applied for statistical analysis of responses.Results: According to SEM images, the average size of graphene oxide sheets was 1 to 3 μm. After optimization through RSM, the adsorption capacity for Pb2+ and Cd2+was 136 mg/g and 68 mg/g, respectively. Examination of the isotherms suggested that Cd2+and Pb2+adsorption follows Langmuir and Freundlich isotherm, respectively.Conclusion: the results show that the graphene oxide performed well in removing both Cd2+and Pb2+ions from aqueous solutions. The most influential parameters on the above-mentioned heavy metals adsorption were pH of the solution and the initial concentration.

Background and Objective: Heavy metals as a main group of aquatic pollutants cause poisoning and concern in fish consumption. The aim of the present study was to assess cadmium (Cd) and lead (Pb) concentration in liver and muscle of rainbow trout (Oncorhynchus mykiss). Additionally, the relationship between the heavy metals concentration with weight and length and the consumption risk of the species were assessed.Materials and Methods: Thirty specimens of rainbow trout were obtained from a fish farming ponds that is located in Sanandaj City. After acidic digestion of the specimens, concentration of Cd and Pb were determined by using atomic adsorption spectrophotometer.Results: The average concentration of Cd and Pb were 0.62 and 26.31 mg/g wet weight (ww) in liver and 0.16 and 23.65μg/g ww in muscle, respectively. The amount of Pb was higher than the maximum acceptable level that is permitted by most international organizations. There was a significant correlation between Cd and Pb with length and total weight of liver. Also, a significant relationship was found between Cd and length and total weight of muscle (p<0.01). The amount of THQ, Daily and weekly intake of Cd and Pb were lower than the allowable proposed dose. The maximum allowable consumption rate of Cd and Pb were 0.16 and 0.09 kg/day for adults and 0.01 and 0.002 kg/day for children, respectively.Conclusion: The results of the present study showed that the amount of Cd and Pb in the rainbow trout is safe to consume and does not threaten the health of consumer with current consumption rate.

Background and Objective: Due to the vulnerability of water resources, quality control of surface water is one of the key issues in environmental conservation programs. In recent years, Anzali wetland has been exposed to numerous threats, including environmental pollutants. TOPSIS is an efficient and reliable way to assess the quality of water resources.Materials and Methods: In order to evaluate water quality condition, Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), temperature, pH, turbidity, Total Suspended Solid (TSS), phosphate (PO4-), nitrate (NO3) and Fecal Coliforms (FC) were measured seasonally from 10 sites of Anzali International Wetland in 2014 and the water quality condition was estimated using TOPSIS method.Results: The highest BOD5, phosphate, temperature and fecal coliform were measured at station 8. Comparison of TOPSIS values in different sampling stations showed the minimum (0.339) and maximum values (0.689) at the stations 5 and 8, respectively. According to the result, the station 5 (Sorkhankal) had the best water quality condition and station 8 (Pirbazar) had the lowest one.Also, seasonal results of TOPSIS values showed that the maximum value was at spring (0.742).Conclusion: Discharge of effluents from land uses, agricultural and industrial activities located along the stream, could be considered as important reasons for decreasing water quality. Our results showed that TOPSIS method was clearly able to demonstrate the qualitative changes of water resources, indicating a moderate water quality for Anzali international wetland.

Background and Objective: In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production.Materials and Methods: Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA.Results: The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl2 of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl2 (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester.Conclusion: The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of biogas.

Background and Objective: Climate change in recent years has led to a crisis of drought in many countries around the world, including Iran. In such a situation, the supply of safe drinking water is very important and knowing the climate impacts on the chemical quality of these resources can play a significant role in their proper exploitation.Materials and Methods: Using GIS geomorphology models, the effect of climatic factors including minimum and maximum temperatures, mean precipitation, evaporation, transpiration and vegetation index on the quality of groundwater resources of Varamin Plain include pH, electrical conductivity, total dissolved solid, anions and cations concentrations and total hardness were studied and their maps were produced. Correlation between these factors was investigated using spatial correlation analysis tool at a confidence level of 0.95 (p=0.05).Results: The results showed that these parameters (except pH) along the plain are highly variable and the spatial distribution of data in this region is not normal around the mean, and the frequency of pixels with values less than the spatial mean of the region is higher. Spatial distribution of the factors showed that their amounts (except pH) are low in the central area of the plain and reach its peak in the western and northwest regions. The spatial distribution of pH was almost uniform in all the plain.Conclusion: Correlation analysis showed that the quality of water resources is influenced by climatic factors and the maximum temperature has the highest impact.

Background and Objective: Ethylene oxide (EO) is a very toxic and dangerous substance with a high potential for explosion and fire. Ethylene oxide units are among the most hazardous units in petrochemical industries. This study was designed to analyze and model the consequences of ethylene oxide storage tanks explosion in one of Iran’s petrochemical industries.Materials and Methods: In this study, the consequences of the ethylene oxide storage tanks explosion in a petrochemical industry was identified and analyzed.This study was conducted in 2017 using PHAST software version 6.54. For this study, two climate conditions including the first climate conditions (spring and summer) and the second climate conditions (autumn and winter) were considered.Results: The results of the modeling for the first and second climate conditions showed that there were possibility of severe damages due to the explosion consequences up to 204 and 256 meters, respectively. In addition, based on the criteria for assessing the consequences of accidents associated with damage levels, such as the explosion wave, the wind speed and direction due to the sudden release scenario and the numerical results related to the modeling, the consequence of this scenario in the second climate conditions (autumn and winter) was higher than the first climate conditions (spring and summer).Conclusion: The findings of the study indicated that, in addition to the high risk of explosion of ethylene oxide storage tanks, the modeling scenarios in different climate conditions have different consequences. Thus, more attention should be paid to safety of these equipment as risk centers in the petrochemical industry and similar industries.

Background and Objective: Nowadays, the increasing use of antibiotics to control diseases and mismanagement and inappropriate disposal of medicinal wastes cause environmental problems and threatens human health. The present study was conducted to determine removal of antibiotic Metronidazole as one of the most used drugs during the process of composting.Materials and Methods: In this experimental study, a mixture of livestock manure, fruit, straw and sludge were used for the preparation of compost.Duration of the process was 40 days. Metronidazole was added to the compost reactors at three concentrations of 20, 50 and 100 mg/kg. Totally, 42 Samples were taken weekly. HPLC was used to analyze the samples. The experiment was repeated twice. SPSS22 software was used to analyze the results.Results: The rate of Metronidazole removal after day 21 and end of the thermophilic phase was 99.9, 96.73 and 93.48 % in the reactors contained 20, 50 and 100 mg/kg, respectively. Increasing concentrations in the reactors caused the removal rate to decrease, while increasing removal time caused to increase the removal rate. At the end of the process, the removal rate for all three reactors was 99.99 %. The physico-chemical properties of the final compost were within the national standard.Conclusion: The use of an aerobic composting process to degrade antibiotic Metronidazole is an economical, effective and, environmentally friendly method.At the end of the process, 99.99 % of Metronidazole was degraded.

Background and Objective: Bacterial exposure in hospitals due to the presence of pathogens in hospitals is one of important health problems for medical staff.The World Health Organization (WHO) reported a global outbreak of hospital infections from 5.7% to 19.1% in the 2011 report. The aim of this study was to identify bacterial bioaerosols in nursing stations in a public hospital in Tehran to determine the occupational hazards of them.Materials and Methods: This cross-sectional study was conducted three times at fifteen nursing station in 15 different departments of a public hospital in Tehran.45 samples were prepared on three culture media including Mackangi Agar, nutrient agar and Manitol Salt Agar. Air samples were prepared according to NIOSH 0800 method by a bacterial sampler with a flow rate of 28.3 L/min for 5 min. Samples were analyzed by microbial screening test.Results: Mean of the bacterial infection was 180.03±125.27 CFU/m3. The results showed that there were gram positivestaphylococcus aureus in the all air samples of nursing stations. Moreover, in 26.7% of occupational exposure nursing stations withAcinetobacter Iwoffii was observed as the most common gram negative bacteria.. Maximum bacterial number was found in orthopedic nursing station (399.99 CFU/m3) and heart transplant nursing station had the minimum bacterial infection (43.73 CFU/m3).Conclusion: Eighty percent of occupational exposure in the samples had higher exposure to bacterial pathogens than the standards set by ACGIH (75 CFU/m3).Due to the presence ofStaphylococcus aureus, E. coli and Acinetobacter Iwoffii in nursing stations, there was a risk of hospital infections in health care workers.It seems unsuitable surface sterilization and lake of useful engineered controlling methods has led to bio aerosol scattering in the air of studied stations.