Health risk assessment of PAHs in fruit juice samples marketed in city of Tehran,Iran

Environmental Science and Pollution Research - The objective of the present study was to investigate the level of 16 PAHs in fruit juice samples (orange, apple, peach, pineapple, and mango) with...     

Biodegradation of low-density polyethylene (LDPE) by isolated fungi in solid waste medium

In this study, biodegradation of low-density polyethylene (LDPE) by isolated landfill-source fungi was evaluated in a controlled solid waste medium. The fungi, including Aspergillus fumigatus, Aspergillus terreus and Fusarium solani, were isolated from samples taken from an aerobic aged municipal landfill in Tehran. These fungi could degrade LDPE via the formation of a biofilm in a submerged medium. In the sterilized solid waste medium, LPDE films were buried for 100 days in a 1-L flask containing 400 g sterile solid waste raw materials at 28 °C. Each fungus was added to a separate flask. The moisture content and pH of the media were maintained at the optimal levels for each fungus. Photo-oxidation (25 days under UV-irradiation) was used as a pretreatment of the LDPE samples. The progress of the process was monitored by measurement of total organic carbon (TOC), pH, temperature and moisture. The results obtained from monitoring the process using isolated fungi under sterile conditions indicate that these fungi are able to grow in solid waste medium. The results of FT-IR and SEM analyses show that A. terreus and A. fumigatus, despite the availability of other organic carbon of materials, could utilize LDPE as carbon source. While there has been much research in the field of LDPE biodegradation under solid conditions, this is the first report of degradation of LDPE by A. fumigatus.     

Cypress tree (Cupressus semervirens L.) bark as an indicator for heavy metal pollution in the atmosphere of Amman City,Jordan

Bio-monitoring of air quality in Amman City was investigated by analyzing 36 cypress tree (Cupressus semervirens L.) bark samples from three sites of different anthropogenic activities at the end of summer season 2001. Cypress barks were found to be a good bio-indicator for air pollution in arid regions. Variation in Pb, Zn, Mn, Cr, Ni, Cd, and Cu contents between sites was observed due to different types of activities. Traffic emissions were found to be the main source of heavy metal pollution in the atmosphere of Amman. Lead content was found to be the highest in highly traffic density areas. The industrial part of the city was characterized by high Zn, Mn, Cr, Ni, and Co contents. No significance variations were found in pH values of the bark between the sites. This was attributed to buffering effect of carbonate in the atmosphere originated from soil of the area.     

Predictive modelling of piezometric head and seepage discharge in earth dam using soft computational models

Environmental Science and Pollution Research - Predictions of pore pressure and seepage discharge are the most important parameters in the design of earth dams and assessing their safety during the...     

Determination of mercury and arsenic levels in fish caught in the Beheshtabad River,Chaharmahal and Bakhtiari Province,Iran

Mercury and arsenic pollution has been recognized as a potential environmental and public health problem for over 40 years. The major source of exposure to mercury for humans is the ingestion of fish. This study was conducted with the aim of determining the levels of mercury and arsenic in the muscles of four fish species caught in the Beheshtabad River and comparing the results with the maximum tolerance levels for mercury and arsenic. The samples of 90 fish were used for the determination of both the metals by graphite furnace atomic absorption spectrometry. The results showed that the concentrations ranged from 1.5 to 3.8 µg kg^?1 for mercury and from 35 to 70 µg kg^?1 for arsenic, with means of 2.7 ± 0.5 and 57 ± 12 µg kg^?1, respectively. Both mean levels were lower than the threshold limits acceptable by WHO standards.     

Using Design-Expert to Optimize the Properties of a Polyethersulfone Ultrafiltration Membrane Through the Incorporation of NH2-MIL-53(Fe) and PVP for Maximum Cr(VI) Removal and Flux

Journal of Polymers and the Environment - In this study, an NH2-MIL-53(Fe) functionalized membrane was fabricated for Cr(VI) removal from contaminated groundwater. Design-Expert was employed to...     

Survey of quantity and management condition of end-of-life tires in Iran: a case study in Tabriz

Journal of Material Cycles and Waste Management - Once a tire is removed from a vehicle without the possibility of being remounted for continued on-road use, it is defined as waste and called...     

Land surface temperature estimating in urbanized landscapes using artificial neural networks

Scenario-based land surface temperature (LST) modeling is a powerful tool for adopting proper urban land use planning policies. In this study, using greater Isfahan as a case study, the artificial neural network (ANN) algorithm was utilized to explore the non-linear relationships between urban LST and green cover spatial patterns derived from Landsat 8 OLI imagery. The model was calibrated using two sets of variables: Normalized Difference Built Index (NDBI) and Normalized Difference Vegetation Index (NDVI). Furthermore, Compact Development Scenario (CDS) and Green Development Scenario (GDS) were defined. The results showed that GDS is more successful in mitigating urban LST (mean LST?=?40.93) compared to CDS (mean LST?=?44.88). In addition, urban LST retrieved from the CDS was more accurate in terms of ANOVA significance (sig?=?0.043) than the GDS (sig?=?0.010). The findings of this study suggest that developing green spaces is a key strategy to combat against the risk of LST concerns in urban areas.     

Survey of discomfort glare from the headlamps of cars widely used in Iran

Objective: On 2-lane roads, discomfort glare can cause annoyance, discomfort, inconvenience, stress, and fatigue to drivers, posing a risk of accidents. The aim of this study is to evaluate discomfort glare from the headlamps of cars widely used in Iran.

Methods: The discomfort glare of new vehicles including Pride Saba model GTX, Pride Model 131SL, Samand Soren, Peugeot 405, Megane, and Peugeot Pars was examined at distances of 5 to 100 m at a background luminance of 50 cd/m² (late twilight/early dawn lighting) and 1 cd/m² (nighttime) using Schmidt-Clausen and Bindels model and de Boer's subjective scale.

Results: According to the de Boer scale, at a background luminance of 50 cd/m², the discomfort glare for all studied vehicles was between 1.98 and 4.05 in high-beam mode and between 3.5 and 5.4 in low-beam mode. At a background luminance of 1 cd/m², discomfort glare was between 0.41 and 2.48 in high-beam mode and between 1.93 and 3.84 in low-beam mode. In high-beam mode, the average levels of discomfort glare of these vehicles gradually increased when the distance between cars was reduced by up to about 20 m. In low-beam mode, there was no discomfort glare up to a vehicle distance of 40 m. In addition, at an angle of 1.15°–5.73° between the line of sight and light of vehicles in high-beam mode, the level of discomfort glare was increased, but at an angle of 5.73°–22.9° the level of discomfort glare was reduced. In low-beam mode at an angle of 2.86°–22.9°, the level of discomfort glare was almost identical. The results show that in high-beam mode and with a 100-m distance between vehicles as well as in low-beam mode at intervals of less than 40 m between cars, discomfort glare is created.

Conclusion: It can be concluded that by providing solutions such as installing road lighting system, an increase in luminance of roads, separating or widening road lanes, increasing the lateral distance between vehicles, and increasing the angle between lighted vehicles and drivers can noticeably reduce discomfort glare.