Iranian Journal of Health and Environment
Year:2009 | Volume:2 | Issue:2 (4)|Papers Count:8

Backgrounds and Objectives: Due to importance of ionizing radiation on human health, many studies have been performed to measure the background gamma radiation all around the world as well as some cities in lran. According to this fact that everybody spends almost 80% of his time in indoor areas, this study was carried out to measure the amount of background gamma radiation in indoor areas in Zanjan city located in northwest of Iran to determine the annual effective dose of the city residents.Materials and Methods: To determine the dose rate of background gamma radiation in indoors, 30 dwelling (in the main geographical directions and in the downtown areas) were selected. All of them were one floor and iron roofed. A Geiger-Muller detector (RDS-110) calibrated by Cs-137 was used in each livings room of each dwellings that performed in one meter far from the earth. In 30 minute 30 values was recorded. The mean value was considered as indoor gamma dose rate in each dwelling.Results: The mean value of dose rate in Zanajn indoor areas due to gamma background radiation was determined 146±25 nGy/h. According to the results and findings in our previous study about gamma background radiation in outdoor areas in Zanjan, the annual effective dose was determined and 0.87 mSv for Zanjan city residents.Conclusion: The annual effective dose of Zanjan city residents due to the gamma background radiation is 0.87 mSv that in comparison with UNSCEAR-2000 report is higher than the mean value for the world (0.48 mSv).

Backgrounds and Objectives: Municipal Solid Waste (MSW) management and planning without adequate and reliable data about its physical components and generation rate are not obtainable. Because of MSW collection and landfilling expenses, in last decades, reuse and recycle of its components as an environmental object have been considered.Materials and Methods: In this research, in order to determine the possibility of source recycling application in Malayer and physical composition of MSW, samples were taken by Truck-Load method and cluster random sampling from autumn 2006 until summer 2007 and analyzed for physical components percents. The obtained data were analyzed by One-Way ANOVA and Tuky statistical test. Also, public partnership was investigated. Public opinion deliberation was accomplished by dividing the city into several clusters. Questionnaires were filled by oral interview conversation.Results: The results showed that average daily generation rate was 138 Tons and 0.88 Kg per person per day. The average percent of recyclable materials was about 11% of total daily generated wastes. Also 99% of residents had positive response to source recycling plans.Conclusion: In general, by planning of enforceable reuse and recycling programmes, could avoid of 15 Tons of recyclable materials burial and save 19 millions Rials each day.

Backgrounds and Objectives: Dyes are organic materials with complex structures, toxic, carcinogenic, teratogenic, nonbiodegredable properties and the most important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC) as a sorbent for the removal of methylene blue (MB) from synthetic wastewater. The sub goals of the research were to determine the adsorption isotherm, effects of primary concentration of dye, adsorbent dose, contact time, and pH for the adsorption of MB with BC.Materials and Methods: BC was prepared under laboratory conditions by using of electrical furnae at 400oC for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16 mesh (1.18-2 mm). The chemical composition and solid structure of BC was analyzed using X-ray diffraction (XRD) and scanning electronic microscopy (SEM). Measurement of the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric method (663nm).Results: Predominant composition of BC is calcium hydroxyl apatite (Ca5 (PO4)3OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12) would lead to increasing of adsorption/removal of MB dye. Equilibration of dye adsorption was reached at lapse of 2h and optimum pH for adsorption of MB with BC found in the rage of 8.5-12. Adsorption of MB with BC complies with freundlich isotherm (R2: 0.99).Conclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile industrial wastewaters have an alkaline pH, this adsorbent can be used for the removal of dyes from these wastewaters.

Backgrounds and Objectives: Leachate is one of the landfill products and also a wastewaterbearing the most advers effects on the environment. Biological methods are usually employed fortreatment of young leachate (1-2 years) wich is of high concentration of organic compounds withlow molecular weight. However these methods are not approprate for mature leachate (5-10years) due to having high rate of compounds with molecular weight and the presence of materials resistant to biodegradation and toxic compounds. Advanced oxidation process such as Fenton reagent used in treatment or biodegrability improvement of strong wastewater. In the present study the degrabilityimprovement of mature leachate through oxidation fenton process in bench scale and in batch reactor has been investigated.Materials and Methods: The samples have been taken from Ahwaz landfill and factors such as initial COD and BOD, pH, BOD5/COD were studies as degradability, the amount of Hydrogen Peroxide, Fe(II), optimal reaction time and optimal pH.Results: The highest amount of COD removal was observed in PH=3-3.5 and 90 minutes of reaction time. H2O2=29700mg/land Fe2+=16500 mg/l in [Fe2+]/[H2O2]=1/14.8 molarity ratio were obtained as optimal amounts BOD5/COD was equal to 0.38.Conclusion: This study indicates that Fenton oxidation enhances the biodegradability of leachate.

Backgrounds and Objectives: Noise in large cities is considered by the World Health Organization to be the third most hazardous type of pollution. Buses are an interesting object of study in the theme of noise pollution. They are at the same time a source of urban environmental (traffic) noise and occupational noise exposure source for drivers. The object of this study is Occupational noise exposure evaluation in drivers of bus transportation of Tehran city.Materials and Methods: Noise levels in 90 buses were sampled in three separate sub-sample including (1)30 Ikaroos buses (2)30 Man buses (3)30 Shahab buses, which were selected by simple random sampling. Noise exposure level was normalized to a nominal 8-h working day (LEX, 8h). Simultaneous Octave Frequency Analysis were measured and sound intensity level (SIL) for bus drivers were calculated. Results, which are obtained from separate buses were compared together and too with standard levels.Results: the normalized noise exposure levels (LEX, 8h) in Ikaroos bus drivers (82dB A) were higher than that of in Man bus drivers (77/6dB A) and this Values were higher than that of in Shahab bus drivers (75dB A).SIL values for Ikaroos bus drivers were higher than other that of other bus drivers. Results obtained of Frequency Analysis showed that age of buses in mid frequencies ws a meaningful on noise increase.Conclusion: Results showed that type and age of buses were effective factors in drivers. Noise exposure levels (LEX, 8h), which was consistent with previous studies in this field.

Backgrounds and Objectives: Safe drinking water providing is one of the main purposes in the community. Development and improvement of community is related to the public health. In this study we studied the bacteriological quality of 116 villages under coverage of the water and wastewater companies in rural areas of Saqqez in 1386.Material and Methods: Drinking water of these rural areas have provided of deep, semi-depth-wells and spring water sources. Because in numerous rural areas both sources of drinking water and in some of them different sources of drinking water were used (old and new storage water source), in general, 359 samples were collected and transferred to the laboratory for testing to evaluate its quality. We also used linear Regression statistical analysis for collected data.Results: results show that residual chlorine in drinking water in 33.88 percent of rural areas population were in range 0.2-1 mg/l. For 98.3 percent of the seqqez rural population, the turbidity was lower than the maximum permissible levels of drinking water standards of Iran (5 NTU). There was no any E.coli contamination in 88 percent of drinking water in saqqez rural areas.Conclusion: Based on WHO guidelines concerning the microbial quality of water published in 2006! the average indicator for lack of E.coli in water of rural areas of seqqez was 88 percent and water is safe or good for drinking.

Backgrounds and Objectives: A number of different technologies have recently been studied to determine the best use of biogas, however, to choose optimize technologies of using biogas for energy recovery it is necessary to monitor and predict the methane percentage of biogas. In this study, a method is proposed for predicting the methane fraction in landfill gas originating from Labscale landfill bioreactors, based on neural network.Materials and Methods: In this study, two different systems were applied, to predict the methane fraction in landfill gas as a final product of anaerobic digestion, we used the leachate specifications as input parameters. In system I (C1), the leachate generated from a fresh-waste reactor was drained to recirculation tank, and recycled. In System II (C2), the leachate generated from a fresh waste landfill reactor was fed through a well-decomposed refuse landfill reactor, and at the same time, the leachate generated from a well-decomposed refuse landfill reactor recycled to a fresh waste landfillreactor.Results: There is very good agreement in the trends between forecasted and measured data. R values are 0.999 and 0.997, and the obtained Root mean square error values are 1.098 and 2.387 for training and test data, respectively.Conclusion: The proposed method can significantly predict the methane fraction in landfill gas originating and, consequently, neural network can be use to optimize the dimensions of a plant using biogas for energy (i.e. heat and/or electricity) recovery and monitoring system.

Backgrounds and Objectives: Today the crisis rising from over consumption energy and material and environmental pollution pose serious problems that challenges present resources of man. Sustainable development is probably an inevitable strategy for human being in such a way that the least possible damage be inflicted to the environment.In this way, the role played by universities in reaching the objectives of sustainable development is crucial. In this paper, we examine the present state of consumption energy resources (Electricity and natural gas) in the central main campus of Tehran University and so we calculate the extent of environmental pollutants resulted of these energy consumptions.Materials and Methods: For surveying of our objectives the first step is a survey of the current state of campus by way of reexamination of Gas and Electricity bills and distribution of a questionnaire. Second is an estimate of the entering pollutants to the environment with online software in site of http://www.abraxasenergy.com/emissions.Results: annual consumption of 16.5 million KWHS of electricity along with 4312392 m3 of natural gas leads to 0.0218 million tones Co2, 778 kg VOCS, 374.6 tones NOX, 2.41 tones CO, 65.341 tones So2, 93 kg Mercury compounds and 868 kg particles.Conclusion: It is shown that there is no objective effort and green management in this part of university officials. This project suggests that the implementation of green management in the framework of programs such as green university can be crucial in reaching the objectives.