Environmental Geochemistry of Potentially Toxic elements in thermal springs in the Sabalan Volcanic Field, NW Iran

Thermal springs are widely used by tourists for treatment of dermal diseases and other therapeutic applications. In Iran, thermal springs occur in Northwestern part mainly surrounding the Mount Sabalan which attract hundreds of thousands of tourists annually. Two clusters of springs in Neer and Meshkinshahr areas including 16 thermomineralic springs have been studied in this research and they were sampled twice in May and November in order to investigate the seasonal changes of trace elements in dry and wet seasons. The samples were analyzed in Acme Lab, Canada for 72 elements. Trace element concentrations indicate that most of the elements show concentration well beyond the guideline values for drinking water. While the two sets of samples were taken within a 6 months interval, the elements show slight or no variation from first period to the second and in some cases. Arsenic shows a variation of 5-5834μg/l and the mean As value is 160 times the guideline values (10 μg/l). Other toxic elements with high concentration are B, Fe, Mn, Sb, and Si. Mn and Sb shows exeedance of 12 and 11.5 times respectively. Correlation coefficient and principal component analysis of analytical data indicate that Cl, As, B, Ba, Br, and V show very strong mutual correlation coefficients implying their relationship and common source and fate in the hydrothermal fluid carrying them. These elements fall in the component 1 of PCA. This group of elements is supposed to be derived and sourced from the magmatic-hydrothermal system and through the interaction of hydrothermal fluids with rocks they passed through. Because of discharge of the thermal springs into the nearby streams intended to be used for drinking water and also vast application of spring waters in balneological uses, they may have adverse environmental and health impacts on tourists that expose themselves to this contaminants through balneological applications

Assessing the contamination level, sources and risk of potentially toxic elements in urban soil and dust of Iranian cities using secondary data of published literature

Research in urban geochemistry has been expanding globally in recent years, following the trend of the ever-increasing human population living in cities. Environmental problems caused by non-degradable pollutants such as metals and metalloids are of particular interest considering the potential to affect the health of current and future urban residents. In comparison with the extensive global research on urban geochemistry, Iranian cities have not received sufficient study. However, rapid and often uncontrolled urban expansion in Iran over recent years has contributed to an increasing number of studies concerning contamination of urban soil and dust. The present work is based on a comprehensive nationwide evaluation and intercomparison of published quantitative datasets to determine the contamination levels of Iranian cities with respect to potentially toxic elements (PTEs) and assess health risks for urban population. Calculation of geoaccumulation, pollution, and integrated pollution indices facilitated the identification of the elements of most concern in the cities, while both carcinogenic and non-carcinogenic risks have been assessed using a widely accepted health-risk model. The analysis of secondary, literature data revealed a trend of contamination, particularly in old and industrial cities with some alarming levels of health risks. Among the elements of concern, As, Cd, Cu, and Pb were found to be most enriched in soils and dusts of the studied cities based on the calculated geochemical indices. The necessity of designing strategic plans to mitigate possible adverse effects of elevated PTE concentrations in urban environments is emphasized considering the role of long-term exposure in the occurrence of chronic carcinogenic and non-carcinogenic health problems. © 2021, The Author(s), under exclusive licence to Springer Nature B.V

Trace and rare earth elements distribution and mobility during diagenetic alteration of volcanic ash to bentonite in Eastern Iranian bentonite deposits

The chemical composition of the source magma along with the physiochemical conditions of the depositional environment are the main controlling factors in determining the behavior and mobility of trace elements and rare earth elements (REEs) during the transformation of volcanic ash to bentonite. The purpose of the present study was to determine the distribution pattern and mobility of trace elements and REEs in several bentonite deposits formed by diagenetic alteration of volcanic ash in shallow alkaline water in eastern Iran. Using geochemical and statistical data, the degree of weathering in the parent rocks and the distribution and mobility of trace elements and REEs during the alteration process at seven deposits (Chah-Taleb, Chah-Keshmir, Chah-Golestan, Chah-Pirouz, Gholeh-Gelia, Kharman-Sar, and Khal-Kooh) were studied. None of the parent rocks showed an advanced degree of depositional reworking and, therefore, their chemical composition is representative of the volcanic ash from which the bentonites were formed. In the chondrite-normalized REE patterns of both parent rocks and bentonites, the light rare earth elements (LREEs) were found to be enriched relative to the heavy rare earth elements (HREEs). The variation in δEu and δCe values suggested a high-temperature (<200°C), suboxic, aquatic environment in which the conversion of volcanic ash to bentonite occurred. In the bivariate correlation analysis, Si showed a strong inverse relationship with Al and LREEs, while large ion lithophile elements (LILEs), high field strength elements (HFSEs), HREEs, and LREEs displayed a positive correlation between the elements of their respective groups. The R values in the binary diagram of potential immobile elements against Al suggest a qualitative classification in which Ti, Gd, Ga, Pr, Tb, Nd, Sm, Ce, and Nb are considered immobile, and U, Dy, In, Sc, Hf, Zr, La, and Eu are considered to have had poor mobility during formation of the Eastern Iranian bentonite deposits.This research was partly funded by the Iran National Science Foundation (contract no. 90004849), Spanish Group CTS-946 (Junta de Andalucia), and MINECO project CGL2016-80833-R. The authors acknowledge the School of Geology of the University of Tehran for sample preparation and some geochemical tests. The authors express their gratitude to Shaghayegh V. Navabpour for assisting with the statistical analyses. They also sincerely thank the reviewers for their careful reading of the manuscript and their many insightful comments and suggestions which certainly helped to improve the manuscript

Genesis of the Eastern Iranian bentonite deposits

Numerous bentonite deposits are located in Southern Khorasan (Eastern Iran), especially in Ferdows and Sarayan counties. We studied the genesis of these bentonites at seven deposits (Chah-Taleb, Chah-Keshmir, Chah-Golestan, Chah-Pirouz, Gholeh-Gelia, Kharman-Sar and Khal-Kooh) using petrological, mineralogical and geochemical data (including X-ray diffraction and fluorescence, and inductively coupled plasma-mass spectrometry) from both bentonites and parent rock samples. The deposits mainly consist of Na-montmorillonite and opaline silica, with lesser amounts of quartz, feldspars, carbonates, halite, zeolites, and illite. The studied deposits formed in a volcanic arc setting and their magma series are calc-alkaline, except for the Kharman-Sar deposit, which is tholeiitic in composition. The presence of significant amounts of opaline silica indicates a low fluid flow rate in these systems, in spite of the high leaching of alkalis. The strata-bound nature of the studied deposits, as well as the high amount of montmorillonite, the presence of gypsum layers alternating with those of bentonite and the lack of hydrothermal alteration suggest that these Iranian bentonite deposits were formed through diagenetic processes in lagoon environments, by means of the alteration of intermediate to acidic precursors, trachy-andesite to rhyolite, belonging to two volcanic provinces: one pyroclastic realm in Ferdows, and another volcaniclastic in Sarayan.This research was partly funded by the Iran National Science Foundation (contract no. 90004849 ), Spanish Group CTS-946 (Junta de Andalucia) and MINECO project CGL2016-80833-R . We also acknowledge the School of Geology of the University of Tehran for sample preparation and some geochemical tests

Genesis of the Eastern Iranian bentonite deposits

Numerous bentonite deposits are located in Southern Khorasan (Eastern Iran), especially in Ferdows and Sarayan counties. We studied the genesis of these bentonites at seven deposits (Chah-Taleb, Chah-Keshmir, Chah- Golestan, Chah-Pirouz, Gholeh-Gelia, Kharman-Sar and Khal-Kooh) using petrological, mineralogical and geochemical data (including X-ray diffraction and fluorescence, and inductively coupled plasma-mass spectrometry) from both bentonites and parent rock samples. The deposits mainly consist of Na-montmorillonite and opaline silica, with lesser amounts of quartz, feldspars, carbonates, halite, zeolites, and illite. The studied deposits formed in a volcanic arc setting and their magma series are calc-alkaline, except for the Kharman-Sar deposit, which is tholeiitic in composition. The presence of significant amounts of opaline silica indicates a low fluid flow rate in these systems, in spite of the high leaching of alkalis. The strata-bound nature of the studied deposits, as well as the high amount of montmorillonite, the presence of gypsum layers alternating with those of bentonite and the lack of hydrothermal alteration suggest that these Iranian bentonite deposits were formed through diagenetic processes in lagoon environments, by means of the alteration of intermediate to acidic precursors, trachy-andesite to rhyolite, belonging to two volcanic provinces: one pyroclastic realm in Ferdows, and another volcaniclastic in Sarayan

Investigation of Geological and Environmental Factors of Airborne Suspended Particles from Sand and Gravel Quarries in The West of Tehran, Iran

Introduction: Particulate matter (PM) is known as the most common cause of air pollution in the world. Activities of sand quarries are known as one of the emission sources in Tehran. This study aimed at investigating the geological and environmental factors of airborne particles in an active quarry in the west of Tehran. Material and Methods: Three methods of dust sampling were used. totally, 32 samples were analyzed by Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX). The data were analyzed through Principal Component Analysis (PCA), Enrichment Factor (EF) and Geo-accumulation Index (Igeo). Results: The results showed the presence of Si, Ca, Al, Na, Fe, K, Zn, Pb, P, S, Mg, Cu, Ti, Mn, Cl and V in dust of the quarry. Also, the elements of Mn, V, Zn, Cu and Pb were shown to have moderate to extremely enrichment and contamination from anthropogenic origin. The silicon and potassium were found to have a natural source originated from igneous and alluvial rocks. Conclusion: In this study, it was shown that fugitive dust generated from sand quarries and related activities have higher concentration of elements than those in the Earth crust due to anthropogenic activities. Further studies on transfer of fugitive dust from sand and gravel quarries to Tehran and assessment of its health impact are suggested

Circular RNAs: New players in thyroid cancer

The prevalence of thyroid cancer the most frequent endocrine malignancy, is rapidly increasing. Most of thyroid cancers are relatively indolent, however, some cases still possess a risk of developing into lethal types of thyroid cancer. Regarding its multistep tumorigenesis, the determination of the underlying mechanisms is a vital issue for thyroid cancer therapy. Circular RNAs (circRNAs) are a type of non-coding RNAs with a closed loop structure. Numerous circRNAs have been identified in cancerous tissues. Mounting data recommends that the biological activities of circRNAs, such as serving as microRNA or ceRNAs sponges, interacting with proteins, modulating gene translation and transcription, suggesting that circRNAs will be potential targets as well as agents for the prognosis and diagnosis of diseases, including cancer. Given that circular RNAs acts as oncogenes or tumor suppressors in the thyroid cancer. Several studies documented that circular RNAs via microRNA and protein sponges could regulate a sequences of cellular and molecular mechanisms e.g., apoptosis, angiogenesis, tumor growth, and invasion that are involved in thyroid cancer pathogenesis. Herein, we summarized the role of circular RNAs as therapeutic and diagnostic biomarkers in the thyroid cancer. Moreover, we highlighted the role of these molecules in the pathogenesis of various cancers. © 2020 Elsevier Gmb

Synthesis and characterization of exopolysaccharide encapsulated PCL/gelatin skin substitute for full-thickness wound regeneration.

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