Journal of Environmental Studies
Year:2008 | Volume:34 | Issue:45|Papers Count:15

Polybrominated diphenyl ethers as flame retardants prevent the branching mechanism of free radicals in gas phase during the combustion. Therefore, they are used in electric and electronical instruments. These supplies are entering the landfills after use. The existing flame retardants in these landfills enter the air, water and soil and pollute them. In this paper a mass-transfer model is developed with respect to the reactions and transfer processes of these chemicals in the various parts of environment. The curves of concentration versus time are also presented for three different compartment and four commercial PBDEs. The results show that concentrations of these chemicals are rather constant in the soil and so these pollutant chemicals are persistent in soil. Although concentrations of these pollutants in water have increasing trend, but the amount of concentration is lower than that of soil and it may be due to their hydrophobic structure. Incidentally, the concentration of these pollutants in air decreases with passing time.

Maragheh-Bonab active cultivated plain is located in south east of east Azarbaijan and consists of valuable groundwater resources. Maragheh Industrial Park is nearly located in the recharge area of this plain. Kaveh soda and paper mill factories that are located in this Park produce high volume of wastewater is continually recharged in the plain. In this article, the effect of industrial wastewater on the quality of groundwater has been considered. For this purpose, 92 water samples were collected from wells, springs, qanats and wastewaters in two periods and were analyzed chemically. The electric conductivity of wastewater in October 2006 has been measured as 167384 ms/cm and on the basis of hydro chemical analysis, the most important ions in wastewater are, Cl- , Ca2+, Na+ and SO42-, respectively. The concentration of these ions has unusually increased in samples taken from wells which located in 1.5 and 2 km far from wastewater site and two other drinking water wells (the Khoshe Mehr village water wells) which located in the central part of the Plain. Hydro chemical properties of these samples are the same as industrial wastewaters. Therefore, the chemical anomalies created in the plain are resulted from wastewater recharge into groundwater resources.

Many constants and coefficient effect on the modeling results. In many cases, it is possible these constants and coefficients differ from their real values in the environment, but the modeling results adapted with real boundary conditions due to other factors adjustment during modeling. Uncertainty analysis is a tool for assessing the effect of uncertainty of various factors on the modeling results. As well, it can show the need for more data to improve load estimations, initial conditions or decay rates, etc. The effect of decay coefficient of CBOD uncertainty on the dissolved oxygen concentration in Zarjoob River (Gilan) was studied by QUAL2E model. Sampling for water quality parameters, flow rates, depths, and cross sections was done in August and September for model calibration and October for its verification in six stations during year 2005. Meteorological data was obtained from the nearest station in Rasht city. The effect of algae, sediment oxygen demand, and NBOD was considered as part of other DO coefficients. Decay and reaeration coefficients obtained by model calibration. Single factor method used for uncertainty analysis. The results show sensitivity level of Dissolved oxygen to decay coefficient in downstream was about -0.6 in August and in fifth station, the sensitivity level was -6 before the DO reaches to zero in July. The reason of high sensitivity is sharp reduction of DO from station 4 to 5 and its low level in this station. It shows the need for more time and money for measuring or more precise estimation of decay rates.

The macro invertebrate and physico-chemical characteristics on 21 sites (upstream, downstream and around cities) of 12 rivers discharging into Anzali wetland were assessed. Margalef and Menhinic richness, Shannon and Simpson Diversity indices, EPT/Chir and Hilsenhof family level biological index were calculated for each study site. The sites located near the populated city Rasht showed the least diversity and richness indices and the upstream demonstrate the highest values during the whole survey period. Based on Hilsenhof biotic index, stations near the urban area and just before entering the wetland had a poor to very poor water quality, indicating high organic enrichment in these regions. Only a few upstream stations were classified as "good" water quality (4.5>HBI>5). High phosphorous and nitrogen of water confirmed the observed classification. This result reveals the role of urban and agricultural activities in increasing organic pollution of the Inlet Rivers can accelerate the eutriphication of Anzali wetland. According to the study, there is an urgent need for well developed technologies and managements to reduce the organic pollution and its environmental impacts on the Anzali Lagoon.

Lead has been recognized as an environmental pollutant of cancer for humans for livings for years. The lead concentration in biological cycles seems to depend on several factors, such as soil properties, plants species, and water properties as well as other factors. The objective of this study was to assess the rate of mobility and determine its effect on blood indices around the feyz abad – lead mine. The first part of this study showed a high lead level in water, soil and plant samples (compaired with anther area). To check the details, a blood sample of the male workers who were selected by a questionnaire was gathered (n=24 as the experimental group). Then, HCT, MCV, MCHC, MCH, Hg and RBC factors were measured. Finally, a comparison was made between the sampling data and 24 males unexposed to lead who were from Ravar (as the control group).The results indicated that HCT and Hg were significantly lower in the experimental group than the control group. RBC, MCV, MCHC and MCH showed no significant variation. It is concluded that the lead compounds in Feyz Abad can enter the biological cycle and then absorbed by tissues such as bone marrow and induce variation on blood indices.

Marine environment of the Caspian Sea, due to extensive human exploitation and discharge of large magnitudes of urban, industrial and agricultural waste, is under extensive pressure. Nutrients such as phosphate and nitrate, and other human wastes are introduced into the Caspian Sea by river inflows and by direct waste dumping threatening marine life and eco system of the sea. High concentration of phytoplankton in marine environments occurs in response to introducing of nutrients by human activities and results in several harmful effects on the marine environment. Therefore, distribution and concentration of chlorophyll a as an indicator of the biomass of phytoplankton is very important in the study of water quality and ecological characteristics of marine environments. This paper presents distribution and seasonal variations of the concentration of chlorophyll a over the continental shelf of the Caspian Sea adjacent to Iran. The chlorophyll data were collected down to 200m depth in two areas in east (off Bipolar in Mazandaran) and west (eastern coast of Anzali in front of Sepidrood River) of the southern coast of the Caspian. The data were collected using a flourometer sensor of a CTD probe in autumn 2003, autumn 2004, and winter and spring 2005. The results showed that the chlorophyll a concentration in the study area ranged between 0.91-0.99 mg/m3. Above the thermo cline the chlorophyll concentration mainly varied between 0.93-0.96 mg/m3. Below the thermo cline the concentration of chlorophyll a was mainly 0.91 mg/m3 with small variation with depth and no significant seasonal variation. The observed chlorophyll a concentrations in the southern coastal areas of the Caspian Sea were high and indicated large inputs of nutrients into this area. The results show the necessity of certain measures for the decrease of nutrient inputs into the Caspian Sea in particular from urban sewage and agricultural waste.

End of life vehicles, cause serious environmental impact owing to present end of life treatment practice and abandonment in the nature. The enormous volume of vehicle waste and accompanying environmental impacts encourage seeking an environmentally effective policy solution to control the problem of end- of – life vehicle. This research attempt to explore and discuss the determinant factors, which may contribute to the development of effective and efficient end of life vehicle policy. In this research six countries were studied, the main focus was on legislation, use of various policy instruments in system, financial mechanism and the same factors. This research identified several factors that influence the success or failure of the ELV system. Deregistration of ELVs was initiated from 200 in Iran. There are two systems in Iran: number one system, last owner takes ELVs to authority centers and ELV will be deregistrated. Remain parts will be disposed in land fill. Environmental problems of relative parts were not being observed. In number two systems, last owner gives ELVs to producers and will receive about 15 million Rails. In this system has initiated its activity only in filed of collection and ELVs collected have not been treated. Discussion on these determinant factors may provide better understanding of end of life vehicle issues. Finally, with considering above factors, a systemically discussion for ELV in Iran was presented.

This research is focused on evaluation of environmental impacts of the dense and high-rise urban developments in Elahie neighborhood, Tehran by applying the Ecological footprints analysis. The primary analysis of the land use changes from 1979 till 2005 showed that the built areas increased by 250% whereas the open and green spaces decreased by more than 1.7 times. The degradation of open and green areas by the built areas has been determined as one of the most significant environmental impacts of the high-rise neighborhood development. In addition, it was discovered that the real ecological footprints of neighborhood (to meet its resident's needs) is 5 times more than its statistical area and 1.6 times more than Tehran city. Based on our results, it can be concluded that the Elahie neighborhood is being consumed by more than its real environmental carrying capacity. Furthermore, it seems that there was no plan for green space developments to compensate for the increase in construction of the high-rise buildings during the studied period. Finally it was demonstrated that the Ecological footprint analysis based on the "land consuming" criteria (as a common and measurable criterion) can be applied to and developed as a suitable environmental impact assessment tool of small scale urban developments.

Tehran the capital city of Iran, with a population of about 8 million and an area of over 700 Km2 is one of the most polluted metropolises in the world. Tehran is suffering from a tremendous reduction in its sink capacity for absorption and assimilation of pollution which is generally due to uncontrolled urban sprawl and failure in consideration of ecological aspects into regional land use planning. In order to quantify the configuration and composition of green spaces, Land sat satellite images (dated 1988 & 2002) and land use map (1:2000) were applied. Landscape metrics such as NP, MPS, MNN and CAP were used for the analysis of landscape structure (both configuration and composition) in two landscape scales. Findings revealed that, Tehran has been experiencing severe alterations in the form of perforation and fragmentation as a result of extension of patchy settlements and lack of proper connectivity in the mosaic network of green spaces.

In this study, the environmental effects of land use changes on vegetation cover and emitted land surface temperature in two urban and non-urban areas of Ardakan in Yazd province, Iran, were studied and compared temporally, using remote sensing technique. For this purpose, contemporary Land sat satellite images in 1990 and 2002 were acquired and used. Then vegetation cover maps were generated using NDVI derivation and also classified into six categories (very good, good, medium, poor, very poor, non-covered) in 1990 and 2002. For quality evaluation of temporal changes in emitted land surface temperature, Land sat thermal infrared band (band 6) was used and calibrated and finally classified into four temperature classes (very cool, cool, warm, very warm). The occupied area of all classes were calculated and compared, temporally. Results show that in non-urban areas, both vegetation cover and emitted surface temperature changes are negligible. On the other side, in urban areas, total vegetation cover decreased by 36.2 %, whereas emitted surface temperature has increased, significantly. Consequently, land use changes in urban areas has important role in surface temperature regulation. Therefore, this key subject has to be attended by decision makers.

Human activities often adversely affect natural landscapes and ecosystems. Natural landscapes consist of habitats, and habitat loss and fragmentation are major threats to biodiversity. Environmental Impact Assessment (EIA)as a systematic and well documented procedure to identify, describe and assess the direct and indirect effects of a developmental project in different environments does not comprise a well – developed method for quantifying and predicting impacts of ecosystem loss and fragmentation on biodiversity. In this context, this paper is dealt with the environmental impacts of Tehran – Pardis Highway Project on biodiversity of two protected areas, Khojir and Sorkhehesar that are located in Tehran province in Iran. Two type of impact were considered in the assessment, the direct loss of ecosystems and the fragmentation on ecosystems. For computing ecosystem – loss, a space- occupation buffer was estimated for road layout and the ecosystem- loss impact was computed by over laying such a buffer map with the ecosystem map. The expected result of this stage was represented by a table showing project alternative project (in this study with and without project), and the estimated loss in area caused on each ecosystem type. Furthermore, three patch indicators were selected to predict the effects of fragmentation: core area, isolation and disturbance. These indicators were used as indirect measures to describe the ecosystem viability. Viability can be defined as the capability of an ecosystem to preserve its integrity and to accommodate its original biodiversity. Finally, above mentioned impacts were predicted and for valuing ecosystems as a part of impact assessment procedure, rarity of each ecosystem was computed. The ratio between actual cover and potential cover of each natural ecosystem type were selected as indicators to express ecosystem's rarity. Consequently, by applying this methodology, the biodiversity assessment approved the construction of Tehran – Pardiss highway.

Deciding a proper scale for Environmental Impact Assessment (EIA) is crucial, and a function of several parameters such as budgeting, location of study area, types of impacts, map resolution, and data availability. Scale can be categorized into three dimensions namely temporal, mass, and spatial scales. However, in each dimension of scale, the exact expression of the scale refers to the theories that might be examined. Therefore, in the EIA studies that are referred to changing scales of mass or spatial information in the study unit(s), the outcomes of the EIA report might be influenced by changing scales. Thus, the question is "to what extent the findings of an EIA report can be influenced by changing their scales"? Developing the idea, 10 study units were delineated in a sub watershed in Japan. Then, via applying zooming (changing the resolution of a map) and panning (moving the framework on a map) within degradation modeling for an EIA it was cleared that how changing spatial scales can influence the results of the EIA. For example, those areas with high degradation number in high resolution maps were classified as low degraded areas in low resolutions maps, while the exact location was unchanged. Improving the impacts of changing mass scale in an EIA, another different in size dam in Iran was selected to compare the influence of mass change on the EIA. Then, an ad hoc scaled-weighted matrix was developed for two dams. It is cleared that the evaluation of changing mass-scale can be conducted more quantitatively than changing spatial scales, due to possibility of mass impact-factor delineation via water weight of the reservoir. Changing scale can also be divided into two different levels that are project and planning levels. In a project, the EIA assessors are dealing with temporal, mass, or spatial effects of data accuracy, but in planning level the approach focuses on different landscapes, types of planning, or different strategies.

In less developed or developing countries like Iran, the developing plans, due to the governance of non-scientific approaches in the feasibility study phase, provoke destroying environment, Nonsustainably development and ruining the Land Use Planning of districts. Countless experiences show that usually the solutions to solve the problems do not function properly as these unpleased consequences took place with delay. In this article, the causes and consequences of occurrence of environment depletion cycle in Kelardasht is diagnosed by systemic approach using the grounded theory and referring to the environment depletion cycle of Mr. Gladvin. . The emergence of three new scientific theories in the field of environment management is of the other artifacts of this research and because it takes into account wider span of Iran specific realities about depletion phenomenon, have more power to describe the behavior of the phenomenon in contract with other existing theories of experts and international institutes. In these three theories, the uncontrolled growth of population, lack of vision and the governance of non-linear thinking in people mental models and managers of less developed countries, the main cause of the environment depletion are identified.