90 research outputs found
Noise pollution in urban environments: a study in Yazd city, Iran
One of the most important sources of noise pollution in urban areas is traffic noise. The aim of the present study was to determine noise pollution in the different parts of Yazd city in 2010 and to compare them with current standard levels.In total, 135 samples were obtained from both residential and commercial areas according to the ISO 1996-2002 method in order to measure noise pressure levels. Locations included 10 streets and 5 squares of the city and the measurement times were considered in the morning, afternoon, and the evening. Noise level was determined in A-weighted by sound level meter model 2232. Results showed that the rate of background noise in Yazd city was high, as it was 71.2±4.4, 66.2±3.7, and 60.3±4 in the L10, L50, and L90, respectively. The mean level of maximum noise pressure was 74.3 dB(A)(Lmax), and the mean continuous sound equivalent level was 66.7 dB(A) (Leq). Comparing the noise level obtained in the present study to the standard level, it can be obviously concluded that the noise levels are higher than that of acceptable levels in most parts of the city. So, different preventive countermeasures such as increasing public awareness through educational programs and technical controls for the future development of the city are crucial
Application of novel Modified Biological Aerated Filter (MBAF) as a promising post-treatment for water reuse: Modification in configuration and backwashing process
Biological Aerated Filter (BAF) reactors due to their plentiful biomass, high shockability, high efficiency, good filtration, availability and lack of need for large land areas, are enjoying from great importance in advanced wastewater treatment. Therefore, in this study, Polystyrene Coated by Sand (PCS) was produced as a novel media and its application in a modified down-flow BAF structure for advanced wastewater treatment was assessed in two steps. In step one, the backwash effluent did not return to the system, while in step two backwash effluent returned to increase the water reuse efficiency. The backwash process was also studied through three methods of Top Backwashing (TB), Bottom Backwashing (BB), as well as Top and Bottom Backwashing Simultaneously (TBBS). The results showed that return of backwash effluent had no significant effect on the BAF effluent quality. In the second step similar to the first one with slight differences, the residual average concentrations of TSS, BOD5, and COD at the effluent were about 2.5, 8.2, and 25.5 mg/L, respectively. Additionally, in step two, the mean volume of disposal sludge/volume of treated water (v(ds)/v(tw)) decreased a large extent to about 0.088. In other words, the water reuse has increased to more than 99.91. The backwash time in methods of TB and BB were 65 and 35 min, respectively; however, it decreased in TBBS methods to 25 min. The concentrations of most effluent parameters in this system are in concordance with the 2012 EPA Agriculture Standards, even for irrigation of Non-processed agricultural crops and livestock water consumption. (C) 2017 Elsevier Ltd. All rights reserved
Anxiety as a consequence of modern dietary pattern in adults in Tehran-Iran
Food intake patterns in relation to mental health have already been revealed. To investigate the relationship between processed food consumption behavior and anxiety disorder, a cross sectional study was conducted. Overall, 1782 young adults aged 18-35 years were randomly selected using cluster sampling method from 22 districts of Tehran Iran in 2011. Diet assessment was done using a 24 hour recall questionnaire in two times with a week interval. Anxiety level was determined using the validated Speilburger test (Persian version). A proportional odds regression model was used to assess the effect of processed food consumption on anxiety variables. A significant statistical difference was found between men and women in terms of processed food consumption (p<0.001). Adjusting for age, total calorie intake, gender, body mass index, socioeconomic status, and history of sedative drug consumption as well as mental health disorders, the proportional odds regression model showed a significant relationship between increased consumption of processed foods and anxiety (OR = 4.73, 95 CI: 2.89-12.54 for state and OR = 4.91, 95 CI: 2.88-13.99 for trait). Identification, modification and adjusting incorrect food patterns in the community could be considered as valuable steps to turn down nutritional-based health difficulties. (C) 2012 Elsevier Ltd. All rights reserved
Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology
Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)
Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology
Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)
Assessment of the association between body composition and risk of non-alcoholic fatty liver
Non-alcoholic fatty liver disease (NAFLD) is defined as the condition of fat accumulation in the liver. This cross-sectional study aimed to investigate the relationship between body composition and fatty liver and determine of cut-off point for predicting NAFLD. Samples were selected from the nutrition clinic from 2016 to 2017 in Tehran, Iran. The liver steatosis was calculated using the CAP score through the FiroScan� and body composition was measured using the dual-energy X-ray absorptiometry scan method. A total of 2160 patients participated in this study, 745 (34.5) subjects had NAFLD. We found that fat-free tissue was inversely and fat tissue was directly correlated with the risk of NAFLD in almost all factors and the risk of developing NAFLD increases if the total fat exceeds 32.23 and 26.73 in women and men and abdominal fat exceeds 21.42 and 13.76 in women and men, respectively. Finally, we realized that the total fat percent had the highest AUC (0.932 for men and 0.917 for women) to predict the risk of NAFLD. Overall, the likelihood of NAFLD development rose significantly with increasing the amount of total fat and abdominal fat from the cut-off point level. Copyright: © 2021 Ariya et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Survey of Knowledge, Attitude and Practice of Yazd University of Medical Sciences Students about Solid Wastes Disposal and Recycling
The risk of unhealthy disposal of solid waste is one of the important
problems in many societies, and recycling is considered as a solution
for managing solid wastes. Environmental knowledge and attitude of
young people (like students) appears to be crucial as their point of
view ultimately plays an important role in providing solution to future
environmental problems. In this study the knowledge, attitude and
practice of Yazd University of Medical Sciences students in respect of
disposal of solid wastes and the important factors were studied. Two
hundred thirty seven students were included in this cross-sectional
study, selected from 5 schools of this university. Data collected by a
self administered questionnaire containing four sections, were analyzed
using SPSS for Windows. The mean grade of knowledge of men and women
was 13.53 and 12.38, of 20, respectively. The difference between the
knowledge of males and females was significant (P< 0.016). On the
whole the knowledge of the students was not appropriate. About 66% of
students did not have any action in segregation and recycling of solid
wastes. It is concluded that all students must take part in formal and
informal education classes to promote their knowledge in this regard
Type of fuel consumed and frequency of lorry passing associated with allergic rhinitis and asthma symptoms in children
Allergic diseases are prevalent in children and their prevalence and
severity are different in dissimilar areas of the world. Many studies
have been carried out regarding the inspection of the causative
environmental factors such as air, foods and environmental allergens.
In this study, using the ISAAC standardized method, the relation
between asthma and allergic rhinitis symptoms with the kind of fuel
consumed at homes and the frequency of lorry passing through the
streets next to the houses in 3000 children aged 6-7 years and 3000
children 13-14 years was investigated. The results indicated that in
the children aged 6-7 years, the prevalence of asthma and allergic
rhinitis had a meaningful relation with the type of fuel consumed at
homes (P<0.05), so that the less pollutant fuel resulted in less
symptoms. The evidence suggested that in both age group, when there was
lorry passing all day long, there were more wheezing and allergic
rhinitis symptoms, and the difference was meaningful regarding allergic
rhinitis (P< 0.05). The study reveals that indoor and outdoor air
pollution is associated with increase in the prevalence of allergic
diseases in children. Therefore, it seems that these types of air
pollution can be a cause of increase of the allergic cases in
childhood
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