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

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

International audienc

Caspian Sea is eutrophying:the alarming message of satellite data

Abstract The competition over extracting the energy resources of the Caspian Sea together with the major anthropogenic changes in the coastal zones have resulted in increased pollution and environmental degradation of the sea. We provide the first evaluation of the spatiotemporal variation of chlorophyll-a (Chl-a) across the Caspian Sea. Using remotely sensed data from 2003 to 2017, we found that the Caspian Sea has suffered from a growing increase in Chl-a, especially in warmer months. The shallow parts of the sea, near Russia and Kazakhstan, especially where the Volga and Terek rivers discharge large nutrient loads (nitrogen- and phosphorus-rich compounds) into the sea, have experienced the highest variations in Chl-a. The Carlson's trophic state index showed that during the study period, on average, about 12%, 26%, and 62% of the Caspian Sea's area was eutrophic, mesotrophic, and oligotrophic, respectively. The identified trends reflect an increasing rate of environmental degradation in the Caspian Sea, which has been the subject of conflict among its littoral states that since the collapse of the Soviet Union have remained unable to agree on a legal regime for governing the sea and its resources