خيارات البحث
النتائج 51 - 60 من 4,302
Assessment of indoor environmental impacts on human health (Case study: Glass city, Firozabad (India)(
2017
Bano, Nikhat
The present study aims to analyze the existing indoor environmental conditions of Firozabad City along with its impact on people’s health by going through the correlative index of indoor environment’s determinant and different diseases, faced by the people. In order to measure spatial disparities, the statistical technique, i.e. the standard score additive model (Z- score), has been applied to develop a composite score for each set of indicators in order to arrive at the general environmental and health condition of the study area as a whole. The analysis reveals that high intensity of indoor pollution and disease are reported in peripheral and old parts of the city. Preventive measures, likely to have deleterious health effects and improve such harmful environmental conditions, should be adopted. Enhanced use of clean fuel and national uniform housing codes or guidelines that address factors, affecting indoor air quality, makes up the current need.
اظهر المزيد [+] اقل [-]Removal of heavy metals and hardness from groundwater via electro-coagulation method
2017
Vosoogh, Ali | Baghvand, Akbar | Saghakhaneh, Hatef
Groundwater makes up an important part of global freshwater resources, though it is often threatened by overuse of natural resources along with abundant production of wastes in modern society. This study aims to investigate the removal of three heavy metals including nickel, cadmium, and lead from groundwater via electrocoagulation, a suitable method for treatment of water-soluble compounds, dealing with the impact of this process on three major groundwater parameters, namely TDS (Total Dissolved Solid), TH, and EC at a laboratory scale. The experiments have been performed using four aluminum electrodes. In this research, the efficiency of contaminants removal and the parameters of interest have been investigated under several conditions such as the distance among the electrodes, potential difference among the electrodes, and different initial concentrations of heavy metals with a detention time of 20 min. Afterwards both results and observations have been analyzed, using diagrams and data tables. Results indicate that this method has had no significant effect on TDS and EC; however, in case of TH, the removal has increased by up to 29.17%. As for the heavy metals, all three contaminants have achieved an increase of the potential difference to 15 V, a decrease in the distance among the electrodes to 2.2 cm, as well as a removal of over 90%. Furthermore, result analysis shows that this process has had a better removal efficiency, concerning lead.
اظهر المزيد [+] اقل [-]Natural radioactivity and heavy metal distribution in reservoirs in Ghana
2017
Darko, Godfred | Ansah, Eugene | Faanu, Augustine | Azanu, David
The present paper has determined the radioactivity concentrations, which are due to natural occurrence of radionuclides along with heavy metal concentration in water, sediment, and fish from 2 reservoirs in Ghana. Heavy metal concentrations in all samples were generally within the WHO safe limits with the average activity concentrations of 238U, 232Th, and 40K in water being respectively 0.42±0.20, 0.33±0.31, and 1.59±1.07 Bq/L in case of Lake Bosomtwe and 0.26±0.14, 0.67±0.34 and 1.47±0.62 Bq/L for Bui Dam in Ghana. The average annual effective dose due to ingestion of radionuclides in water ranged from 20.5 to 156 for Lake Bosomtwe and 26.5 to 162 μSv/year for Bui dam and the absorbed dose rate and annual effective dose, measured for Lake Bosomtwe, was 15.45±2.00 nGy/year and 18.95±2.95 mS/year respectively while in case of Bui dam it accounted to 10.44±4.11 nGy/year and 12.88±5.01 mS/year respectively, found to be within the UNSCEAR recommended limits of 59 nGy/year and 100 mS/year respectively. The observed metal concentrations, within safety limits, imply that metal-associated diseases cannot be expected among patrons of these reservoirs. Therefore, radionuclides and heavy metals levels in the reservoirs are not expected to cause any significant health problem for humans.
اظهر المزيد [+] اقل [-]Capabilities of data assimilation in correcting sea surface temperature in the Persian Gulf
2017
Abbasi, Mahmud Reza | Chegini, Vahid | Sadrinasab, Masoud | Siadatmousavi, Seyed Mostafa
Predicting the quality of water and air is a particular challenge for forecasting systems that support them. In order to represent the small-scale phenomena, a high-resolution model needs accurate capture of air and sea circulations, significant for forecasting environmental pollution. Data assimilation is one of the state of the art methods to be used for this purpose. Due to the importance of thermal structure in monitoring the variations of environmental phenomena, the present study has used Sea Surface Temperature (SST) in data assimilation method to optimize this parameter. SST is one of the most important factors to conduct researches on the ocean, the atmosphere, and their interaction, not to mention monitoring and forecasting air and ocean phenomena as well as commercial and fishing communities and weather forecasts. This study has aimed to present a satellite-derived SST based on pathfinder advanced very high resolution radiometer (AVHRR) data assimilating in FVCOM (finite volume community ocean model) on the Persian Gulf to examine the effect of data assimilation by using the Cressman scheme. The performance of this method has been compared to the optimal interpolation SST (OISST) data, via both visual comparisons and statistical parameters. Applying assimilation method improves correlation coefficient of the model from 0.92 to 0.99. Results demonstrate that the modeled SST has been completely reconstructed by the data assimilated experiment via the Cressman scheme for this region. The spatial and temporal pattern of SST reveals a significant improvement in the entire domain during the investigated period in the gulf.
اظهر المزيد [+] اقل [-]Risk assessment of exposure to released BTEX in district 12 of Tehran municipality for employees or shopkeepers and gas station customers
2017
Faraji, Afsaneh | Nabibidhendi, Gholamreza | Pardakhti, Alireza
Owing to environmentally-destructive impact of aromatic hydrocarbons, such as benzene, benzene ethyl, toluene, and xylenes or BTEXs, these materials are classified as hazardous pollutants in the air. This study studies cancer and non-cancer risk in District 12 of Tehran Municipality, through these components for two groups of employees or storekeepers and gas station customers. By measuring pollutant concentrations along with doing related calculations, the areas and gas stations of the study area with the highest risk have been found. Results show that Station 7, located in Zone 4, is one of the most dangerous spots in terms of cancer and non-cancer risk to employees or storekeepers in the area. Additionally, there is no risk of non-cancerous disease for the customers, using these stations, during their lifetime. Finally, the study proposes some solutions for making appropriate decisions, concerning the sustainable management plan.
اظهر المزيد [+] اقل [-]Provisional Evaluation of Composting as Priority Option for Sustainable Waste Management in South-West Nigeria
2017
Olukanni, David | Aremu, Damilola
The management of Municipal Solid Waste (MSW) in Nigeria and most developing countries has remained a major public health challenge, thus creating the need for reliable and environmentally-acceptable alternatives. This study focuses on composting assessment as a viable recovery alternative for MSW in six States of Southwest Nigeria, namely: Ekiti, Osun, Ondo, Ogun, Oyo, and Lagos. Extensive literature review has been carried out to understand the waste generation patterns in these states. Reported literature data has been assessed for sustainability of composting strategy in terms of organic waste streams, amenable of biotransformation as well as in terms of return through energy saving and material recovery. A life-cycle framework has been used to estimate GHG emissions, available nutrients, and potential compost production, instead of landfill in each region. Results show significant potential compost production of 895,659-, 255,267-, 153,423-, 117,468-, 113,094- and 112, 397-m3/yr for Lagos, Oyo, Ogun, Osun, Ondo, and Ekiti, respectively. It has been deduced from the study that composting would be very beneficial to the economy as its product would boost agriculture production while reducing the budget spent on fertilizer annually.
اظهر المزيد [+] اقل [-]Assessment of the presence of metals and quality of water used for irrigation in Kwara State, Nigeria
2017
Aliyu, Taiye | Balogun, Olusegun | Namani, Chineye | Olatinwo, Lateefat | Aliyu, Abubakar
In Nigeria irrigated agriculture is an important tool for economic growth, food security, and poverty reduction during dry periods of rain-fed agriculture. The concentration and composition of dissolved constituents in water determines its quality for irrigation use. Water quality studies strongly suggest that agriculture is a leading source of water quality problems, due to pesticides and other agro-inputs, widely used by farmers to improve agricultural productivity. Poor quality irrigation water would therefore obviously affect soil quality and crop productivity. This study was carried out in 2015 to assess the presence of metals and physical properties of water, used for irrigation in Kwara state, Nigeria. Samples were randomly collected from thirty irrigation sources in three senatorial zones of Kwara State. The samples were analyzed for the presence of metals and water quality parameters, using standard procedures. Results showed that the highest concentration of Sulphate (7.0mg/L), Nitrate (8.9mg/L), Sodium (31.6mg/L), Calcium (3.1mg/L), and Magnesium (0.7) ions were within acceptable limits. The Sodium Adsorption Ratio, an indicator for water suitability in agricultural irrigation as well as a standard diagnostic parameter for the sodicity hazard of a soil, was significantly the highest (22.7) in Kwara North. Results of the study point to the need for an effective irrigation water quality assessment to curb nonpoint source pollution that could be caused by improper use of chemicals and pesticides by farmers.
اظهر المزيد [+] اقل [-]Synoptic approach to forecasting and statistical downscaling of climate parameters (Case study: Golestan Province)
2017
Ghanghermeh, Abdolazim | Roshan, Gholamreza | Nasrabadi, Touraj
The present study attempts to introduce a method of statistical downscaling with a synoptic view. The precipitation data of Golestan Province has been used for the years 1971 to 2010. Employing multivariable regression, this study models the precipitation gauges in the station scale, by making use of 26 predicting components of model HadCM3, on the basis of two A2 and B2 scenarios. However, the minimum predicting components for precipitation in station scale included 26 components for one grid to 390 atmosphere circulation components for the 15 suggested grids. Nevertheless, results indicate minimum error, related to the precipitation models, based on projecting components of the studies of 15 grids. By applying this selected method, the precipitation gauges for 2020 to 2040 has been simulated. General results of the precipitation changes for the yearly decennial average of Golestan Province indicates additive stream of this component, based on both A2 and B2 scenarios. Yet this yearly decennial addition of precipitation go with seasonal and annual changes, i.e. getting drier in summer as well as its subsequent increase in draught issue on one hand, and increased centralization of precipitations in the winter and lack of its proper distribution during year on the other. As a result, changes in local patterns of precipitations throughout the province is promising for maximum increase of precipitation for the farthest southwest area of Golestan, greatly potential for decreasing precipitation of sub eastern area.
اظهر المزيد [+] اقل [-]Acute toxicity of povidone-iodine (Betadine) in common carp (Cyprinus carpio L. 1758)
2017
Forouhar Vajargah, Mohammad | Mohammadi Yalsuyi, Ahmad | Hedayati, Aliakbar
Organisms in aquatic environments are exposed to a number of pollutants such as pharmaceutical residues. As such, the aim of the present study is to achieve the Lethal Concentration (LC50) of Povidone-iodine (Betadine) for Cyprinus carpio. To do so, the study employs samples, weighing 4±1 [mean±SD] gr, and carries out an experiment in static condition. Based on OECD instructions, after a period of 4 days under controlled water, the physicochemical factors give the following results: pH= 8-8.3, BOD= 690 mg/l, total hardness= 210 mg, and CaCo3 and temperature= 17±0.1 °C. All fish are acclimatized for 10 days in an aquarium, 60×55×30 cm in size, which included the control group (no toxic concentration) as well as the treated aquariums, with Betadine concentration of 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 400, and 600 mg/l. LC10, LC20, LC30, LC40, LC50, LC60, LC70, LC80, LC90, and LC95 have been measured for 6, 12, 18, and 24 hours. LC50 24h Betadine for C. carpio has been 158.273 ml/l, showing no mortality after 24 hours (i.e. 48h, 72h, and 96h). Results of the present study suggest that Betadine is practically nontoxic and not irritant at low concentrations for this species and it has a short half-life in aquatic environments.
اظهر المزيد [+] اقل [-]Evaluation Euro IV of effectiveness in transportation systems of Tehran on air quality: Application of IVE model
2017
Ghadiri, Zahra | Rashidi, Yousef | Broomandi, Parya
The quick growth of vehicles is due to fast urbanization in mega cities during last decades. This phenomenon has serious impacts on air quality, as emission from mobile vehicles is the major source of air pollution. As a result, any attempt to reduce the emitted air pollutants is needed. This study aims at improving the fuel quality in transporting system with particular emphasis on taxis in Tehran in 2014. As a clean fuel, Euro IV is being used to reduce the emission of pollution, toxic substances, and greenhouse gases. A bottom-up approach to evaluate vehicular emission, using IVE (International Vehicle Emission) model in Tehran, has been presented, which employs the local vehicle technology and its distributions, vehicle soak distributions, power based driving factors, and meteorological parameters to evaluate the emission, itself. Results show that the most abundant air pollutant (CO) has been reduced by 87.6% due to the clean fuel consumption (Euro IV). Also, the emission rates of the predominant toxic pollutant (Benzene) decreased by 98.7%. As a clean fuel, Euro IV managed to increase the emitted amount of CO2 and NH3. It can be concluded that upgrading transportation system with updated fuel quality is an essential step to improve air quality in Tehran.
اظهر المزيد [+] اقل [-]