Iranian Journal of

Backgrounds and Objectives: Quantity of trace metals in the wet precipitation can illustrate the environmental pollution of different urban areas. Up to now, there is no study regarding the chemistry of wet precipitation in Tehran .The objectives of this study are: measurement of heavy metal concentrations and identification of the main factors affecting the heavy metal concentrations in wet precipitation using factor analysis method.

Materials and Methods: This was a cross-sectional study in which measurements of heavy metals were performed in 53 wet precipitation samples collected from a central site of Tehran City, capital of Iran. The samples were collected during November to May in 2010, 2011 and 2012 on the roof of the student’s dormitory building of Tehran University of Medical Sciences and then the concentration of heavy metals in each sample was measured with ICP-MS.

Results: pH ranged from 4.2 to 7.1 with a mean value of 5.1 indicating in acidic range. Result of EF calculations revealed that samples were not enriched with Fe and Cr but were enriched with Zn, Cd, Ni, Pb and Cu. Factor Component Analysis with Varimax normalized rotation showed Al, Fe and Cr are originated from crustal source and Zn, Cd, Ni, Pb and Cu are originated from anthropogenic sources. 

Conclusion: EF and acidic pH values indicate Tehran is under the influence of extremely anthropogenic activities. Large number of vehicles and industrial activity in the city are undoubtedly responsible for the emission of a wide range of pollution.

Background and Objectives: Street dust reflects one of the most important indicators of pollution in the urban environment. Most studies carried out in the world on heavy metal pollution are related to cities and metropolitans, while less attention has been paid to towns. Masjed-e- Soleiman, the most oil-rich town is located in the north eastern part of Khuzestan Province in Iran. This town contains geogenic pollutants such as gas and oil sources, oil and gas activities, oil and gas combustion, industries, and heavy traffic, which make it important from the viewpoint of environmental impact assessment.

Materials and Methods: For monitoring and management of pollution, 11 samples of street dust were collected and prepared from different stations within the town during the dry season (June 2013). Each sample was analyzed using ICP-OES instrument.

Results: Possible sources of the heavy metals were identified by multivariate analyses such as Principal Component Analysis (PCA) and Cluster Analysis (CA). In addition, factors such as the Index of Geo-accumulation (Igeo), Pollution Index (PI), Integration Pollution Index (IPI), and Enrichment Factor (EF) were assessed to determine the degree of heavy metals pollution in street dust of the Masjed-e- Soleiman Town. The results of PCA and CA indicated that the region is mostly affected by oil pollution (both natural and combustion of fossil fuels), traffic, and industrial activities (PI revealed high levels of Pb, Cd, Cu, and Zn pollution in samples and the average level of Ni, As, and V pollution in other samples). Igeo indicated the moderate to severe pollution of some samples to Pb, Cd, Cu, and Zn while no to moderate pollution against Ni, As, and V in other samples. EF for Pb, Cd, Cu, and Zn showed a significant pollution in some samples and other samples represented the least pollution against Ni, As, and V.

Conclusion: Results showed that the concentrations of heavy metals in dust samples were higher than control samples in Masjed-e- Soleiman. Thus, the classification of pollution in street dust in Masjed-e- Soleiman is as follows: IPI> EF> Igeo ≈ PI.

Background and Objective: The aim of this study was to investigate the physico-chemical properties, size distribution and shape of the falling mineral dusts over Masjed Soleyman and to identify their origins. Also, seasonal and annual variations of climatic parameters and their relation with dust storm occurrence were investigated.

Materials and Methods: The collected samples were as result of dry deposition process during warm season in 2013. Particle size distribution was determined by laser size diffraction. Chemical and mineralogical compositions were measured with atomic absorption spectrophotometer (AAS) and X-ray diffraction (XRD). Crustal and non-crustal origins for elements in the dust samples were determined using enrichment factor (EF). In addition, dust storm sources were identified using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT.4).

Results: The study of the annual and seasonal changes in meteorological parameters associated with the occurrence of dust storms indicated an agreement between the occurrence of dusty days, temperature and rainfall in summer. The chemical and mineralogical analysis of dust particles demonstrated that the likely origin of these particles is of neighboring countries in the South West of Iran. Also, some of the detected trace elements had non-crustal sources.

Conclusion: Using HYSPLIT.4 results, it was concluded that the main origin of dust storms are North West of Iraq and East of Syria in Masjed Soleyman.

Background and Objective: The aim of the present study was to investigate the concentration, enrichment factor, Nemrow integrated pollution index, and potential ecological risk of heavy metals including (Pb, Ni, Cu, Zn, Cd, V and Cr) in surface soils of Ahvaz oil filed.
Materials and Methods: For this purpose, 49 soil samples with a systematic scheme from Ahvaz oil field were analyzed by atomic absorption method.