heavy metal deposition
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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pei-Wen Wu ◽  
Ta-Jen Lee ◽  
Shih-Wei Yang ◽  
Yenlin Huang ◽  
Yun-Shien Lee ◽  
...  

AbstractMaxillary sinus fungal balls (MSFBs) mostly occur in older individuals and demonstrate female predominance. Early diagnosis is important to avoid treatment delays. Intralesional hyperdensity (IH) indicates the presence of heavy metal deposition within fungal hyphae and has been the most specific characteristic of MSFB on computed tomography (CT). For those without IH on CT, the diagnosis of MSFB remains challenging. This study aimed to characterize clinical presentation of MSFB with and without IH and to study factors contributing to MSFB with no IH formation. We retrospectively identified 588 patients with MSFB. The clinical characteristics and CT findings were reviewed. Patients with unilateral MSFB had a mean age of 57.4 years and demonstrated female predominance (64.63%). The female-to-male ratio was highest at 51–60 years (2.02) and rose to 2.60 in MSFB with IH only. Compared to those with IH, MSFB without IH was significantly more common in males (OR = 2.49), in those with diabetes mellitus (DM) (OR = 1.87), adjacent maxillary odontogenic pathology (OR = 1.75). Complete opacification on CT was less common in MSFB without IH (OR = 0.60). Patients with MSFB without IH were more likely to have DM, no female predominance, adjacent maxillary odontogenic pathology, and partial opacification of the sinus, compared to those with IH. These may be helpful in better understanding of the formation of MSFBs without IH, early identification of them and prevention of post-operative recurrence.


Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1455
Author(s):  
Angela Schlutow ◽  
Winfried Schröder

The protection against eco- and human-toxicological impairments caused by atmospheric deposition of heavy metals requires legally defined assessment values. Since such values are missing for Luxembourg, the aim of this investigation was to evaluate different approaches to derive assessment values for the regulation of heavy metals that are in accordance with scientific and legal standards. To this end, assessment values for heavy metals were derived from the compilation of respective values implemented in European countries. In addition, (1) precipitation-related assessment values for the protection of soil for Cr, Zn, and Cu and (2) precautionary assessment values (critical loads for Cr, Zn, and Cu, as well as As, Cd, Ni, and Pb) for the protection of human health and ecosystems were calculated. The calculation of the regionally differentiated precipitation-related assessment values resulted in ranges of 17–272 g Cu ha−1 a−1, 167–2672 g Zn ha−1 a−1 and 17–272 g Crtotal ha−1 a−1. The critical loads for drinking water protection vary in the ranges from 1.23 to 2.14 g Cd ha−1 a−1, from 4.05 to 8.63 g Pb ha−1 a−1, from 2.6 to 5.9 g As ha−1 a−1, from 258 to 564 g Cu ha−1 a−1, from 1292 to 2944 g Zn ha−1 a−1, and from 12.9 to 29.9 g Crtotal ha−1 a−1. Ecosystems are significantly more sensitive to Pb, Cu, and Zn inputs than humans. For As and Cr, humans react much more sensitively than ecosystems. For Cd, the critical loads for drinking water, ecosystems, and wheat products are about the same.


2021 ◽  
Author(s):  
Alejandra Vicente de Vera García ◽  
Fernando Barreiro Lostres ◽  
Ana Moreno Caballud ◽  
María del Pilar Mata Campo ◽  
Juan Pablo Corella Aznar ◽  
...  

<p>High altitude mountain lakes archive high-resolution records of environmental variability (climatic and anthropic). The REPLIM project funded by the INTERREG program (POCTEFA 2014-2020) has implemented a network to understand current and past changes in Pyrenean lakes. In this work, we compare six high altitude lake records along a W- E transect in the South Central Pyrenees: Acherito (1877 m.a.s.l.), La Sierra (2022 m.a.s.l.), Sabocos (1900 m.a.s.l.), Marboré (2600 m.a.s.l), Urdiceto (2364 m.a.s.l.) and Cregueña (2633 m.a.s.l.).</p><p>In each lake we have analyzed short sediment cores across transects applying sedimentological (facies, grain size, sediment composition, thin sections), geochemical (XRF scanner, elemental and trace metals) physical (Magnetic Susceptibility), isotopic (δ<sup>13</sup>C and δ <sup>15</sup>N of bulk organic matter) and biological (diatoms) techniques. The age models have been constructed with <sup>137</sup>Cs, <sup>210</sup>Pb and <sup>14</sup>C dates.</p><p>The sedimentary dynamics and heavy metals depositional history for the last 2000 years provides a temporal context for recent changes. Sedimentary facies variability correlates with climate phases and reflect varied human pressures. In general, during the colder and more humid periods, usually associated with glacier advances (LIA and Late Antiquity LIA), higher surface runoff was generated and, therefore, sediment delivery to the lake increased, in some cases with deposition of coarser facies. Intense watershed disturbances due to human impact were noticeable in lower altitude lakes since early medieval times. All lakes show larger sediment rate variability during the last centuries, but the timing of the onset varies. Lakes located at higher altitudes (Marboré and Cregüeña) show larger changes in sedimentation rates and dynamics around the end of the LIA (ca. 1850 CE), while in lower altitude lakes (Sierra, Sabocos, Acherito) occurred later (ca. 1950 CE).  In most lakes, a significant increase in organic matter accumulation started at the end of the 19th century and the trend accelerated since mid 20th century. Diatom and isotopes analyses suggest an increase in lake primary productivity during the last decades. The results indicate that the combined impacts of climate change and increased human pressure in the Pyrenees at the end of the LIA had a greater impact on high-altitude lakes, but recent changes in the 20th century have affected the lakes at all altitudes</p><p>All lakes show a similar heavy metal deposition pattern, with enrichment during Roman and Medieval times and a progressive increase since the end of the 18<sup>th</sup> century (industrialization) and reaching its peak in the middle and late 20<sup>th</sup> century. Some metals, such as Pb, show a subsequent decline at the end of the 20<sup>th</sup> century related to the reduction of industrial emissions and the ban on leaded gasoline.</p><p>This integrated approach demonstrates the sensitivity of high altitude lake systems to record past changes and highlights the need for multi-archive studies to support regional reconstructions of past environmental and climate changes.</p>


2021 ◽  
Vol 16 (1) ◽  
pp. 187-197
Author(s):  
Najla LASSOUED ◽  
◽  
Essaid BILAL

A field experiment was conducted to demonstrate the beneficial and negative aspects of sewage sludge application on wheat and to determine the way of heavy metals in the sludge-soil-plant system. Two types of sewage sludge (urban and industrial) were applied at different rates (5, 25, 50 and 100 t dry matter (DM) per ha). Results showed that growth and yield have been improved by sewage sludge use. However, sewage sludge applications modified the content of heavy metals in plant tissues especially for industrial sewage sludge and high rates where significant accumulations including Co, Cr and Pb, were detected mainly in the roots. This has been coupled by an alteration of the root cellular ultra-structure and the presence of heavy metal deposition as electron-dense granules and crystals.


2020 ◽  
Vol 27 (2) ◽  
pp. 195-210
Author(s):  
Paweł Świsłowski ◽  
Jan Kříž ◽  
Małgorzata Rajfur

AbstractIn the year 2016, passive biomonitoring studies were conducted in the forest areas of southern and north-eastern Poland: the Karkonosze Mountains (Kark), the Beskidy Mountains (Beskid), Borecka Forest (P. Bor), Knyszynska Forest (P. Kny), and Białowieza Forest (P. Bia). This study used bark from the tree, Betula pendula Roth. Samples were collected in spring (Sp), summer (Su), and autumn (Au). Concentrations of Mn, Fe, Ni, Cu, Zn, Cd, and Pb were determined for the samples using the atomic absorption spectrometry method with flame excitation (F-AAS). Based on the obtained results, the studied areas were ranked according to level of heavy-metal deposition: forests of southern Poland > forests of north-eastern Poland. Some seasonal changes in the concentrations of metals accumulated in bark were also indicated, which is directly related to their changing concentrations in the air during the calendar year, for instance, the winter heating season produces higher concentrations of heavy metals in the bark samples taken in spring. When deciding to do biomonitoring studies using bark, but also other biological materials, it is necessary to take into account the period in which the conducted research is done and the time when the samples are taken for analysis, because this will have a significant impact on the obtained results.


2020 ◽  
Vol 210 ◽  
pp. 106414
Author(s):  
R. Scott Van Pelt ◽  
Eugenia G. Shekhter ◽  
Melanie A.W. Barnes ◽  
Sara E. Duke ◽  
Thomas E. Gill ◽  
...  

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