Concerns about dust contamination with potentially toxic elements are especially important in environments such as schools (particularly elementary schools) because children are more vulnerable to contaminants than adults. Therefore, due to the diversity of air pollution sources in Tehran, the present study was conducted to determine the severity of pollution, origin and health risk assessment of some potentially toxic elements in the dust of elementary schools in three districts of Tehran. For this purpose, 27 dust samples were collected from the indoor and outdoor areas of schools, and the concentration of elements was measured by induced coupled plasma mass spectrometer (ICP-MS). Calculation of different geochemical indices showed that the four elements Cu, Zn, Sb and Pb have the highest enrichment and pollution compared to other elements. The results of calculating the health risk index revealed that As, Cu, Ni, Pb and Zn have similar hazard quotient (HQ) values in children and adults. Also, the health risk of exposure to Cr and Mn through dermal contact is higher in adults than in children, and the total hazard index (HI) of all elements in children is higher than in adults. Among the studied elements, two elements, lead and chromium, threaten the health of children more than others. Based on principal component analysis and positive matrix factorization (PMF) model, traffic and urban pollution sources, industries such as asphalt, plating and plastic factories, and indoor sources including wall painting and chair coatings, along with local background of elements are the main factors of the elements concentration in school dust.

Karst springs in the western and eastern regions of Ilam province have different physical and chemical properties. The springs of  the western regions, are sulfuric and thermal with high salinity; while, springs in the eastern regions, are fresh and cold. Geological, hydrogeological, hydrogeochemical and isotope studies were performed to compare and determine the factors affecting the physical and chemical properties of these springs. Monitoring of springs including measurement of discharge, temperature, acidity, amount of hydrogen sulfide gas,  dossolved oxygen in the field and analysis of major ion chemistry was performed monthly for two years. Deuterium and oxygen 18 stable isotopes were measured in two dry and wet periods to determine the source of water. Field studies showed that the geology of the eastern and western regions of Ilam province is different. Deep faults have affected the western regions and some calcareous formations have changed facies; so that they have anhydrite members. The deep faults of the western regions of Ilam province have caused the hydraulic connection of karst formations with the old and lower evaporite formations. The ratios of Na/Cl, SO4/Cl and TDS/Br showed that the salinity of sulfur springs is originates from the dissolution of evaporite formations and not related to the oilfields brines. The results of deuterium (2H) and oxygen 18 (18O) stable isotopes analysis in thermal and sulfur springs demonstrated that the origin of these springs is the local meteoric precipitations. The origin of hydrogen sulfide (H2S) of sulfur and thermal springs was attributed to the activity of sulfate reducing bacterias. According to the hydrograph of the springs, rainfall affects  the discharge increase of fresh and cold springs less than one month; while, the discharge of sulfur and thermal springs increases about two months after rainfalls. In other words, the infiltrating waters that recharge the sulfur springs have a deep circulation. Therefore, the high temperature of the springs in the western regions of Ilam province is  attributed to the deep circulation of infiltrating waters from local precipitation along the faults.

The continuous development of the oil industry has led to a significant increase in the number of wells that are simultaneously analyzed. For this reason, it is important to develop methods that improve the integration of all well information at different scales, while reducing the time required for studies. This article examines the integration of image log (FMI) with other conventional logs (gamma, density, neutron, sonic log) to determine electrofacies in the Gadwan formation in one of the wells of Abadan plain fields. Due to the high resolution, the image logs can provide important information regarding sedimentology, texture, and porosity distribution. This information is very valuable in situations where it is not possible to core from the formation. To accurately estimate, the necessary environmental corrections were made on conventional logs. In the next step, electro-facies were created by integrating conventional logs and image log using the graphical clustering method (MRGC) in Geolog software and using the FACIMAGE™ module, and finally, the model with 8 facies was selected as the optimal model. Among the determined facies, the electrofacies number 8 was recognized as the best reservoir facies (due to high effective porosity and low shale volume). Comparing the results of lithology, shale volume, porosity and water saturation with the facies determined by the cluster analysis method showed that the use of image logs improves the separation of electrofacies.

The aim of this study was to determine the ambient concentration, content of heavy metals and morphology and mineralogy of PM2.5 samples collected from air pollution monitoring station in Haft-Tir square (central Tehran). For this purpose, PM2.5 samples were collected by means of low-volume sampling device during five months (April-August 2019). Based on the obtained results, there is more loading of PM2.5 on June higher that 10 μgm−3 and showed high to very high pollution level. Variations in metal concentration in the sampling months are less and more the same showing order of Zn>Ni>Pb>Cr>Cu>Cd. Comparing the mean concentration of metals with international permissible limits the concentration of Pb and Cr in PM2.5 samples was lower than that of recommended by the WHO while the average concentration of Cd and Ni was higher than those of USEPA recommended limit. Calculations of enrichment factor and results of principal component analysis revealed that Cr is of geogenic origin, Cd and Zn are derived from anthropic sources and Pb, Cu and Ni is probably of mixed sources. Based on scanning electron microscopy images, PM2.5 are observed as a shapeless or irregular, rod-shaped, irregular spherical, completely spherical, sheeted, as well as long chain aggregates or single crystals. According to the results of X-ray diffraction analysis, clay minerals, quartz and calcite were found as major minerals, gypsum and dolomite minerals were identified as minor minerals and wüstite and halite minerals were identified as rare mineral phases.

The Naft anticline with NW-SE trend is located in north of the Lurestan sub-zone and the Zagros fold and thrust belt. Thrust and basement strike-slip faults and detachment levels play an important role in the structural geometry of the folded structures in this is sub-zone.  In this research, deformational pattern and structural geometry of the Naft anticline hane been studied using constration a cross-section perpendicular to the anticline axis in the central part and relenat analysis. Two upper (Amiran Formation) and Middle (Garau Formation) detachment levels and deelpy thrust fault in the southwestern limb have the main affect on folding geometry and led to the formation of disharmonic folding. An N-S basement strike-slip fault in the middle part of the anticline has shifted the anticline axis from N70W in the northwest to N50W in the southeast. In addition, the shallow thrust fault and detachment levels caused the formation of an axis of two kink and curved hinges in the middle part of the Naft anticline. Measurement of geometrical parametrical of the Naft anticline indicate that this anticline is an asymmetrical, noncylindrical fold and from tightness view is open is half-angle round.