scholarly journals Mecanismos de tolerancia a elementos potencialmente tóxicos en plantas

2017 ◽  
pp. 53 ◽  
Author(s):  
Daniel González-Mendoza ◽  
Omar Zapata-Pérez
Keyword(s):  
Heavy Metals ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Free Proline ◽  
Potentially Toxic Metals ◽  
Cellular Mechanisms ◽  
Mycorrhizal Associations ◽  
Broad Overview

Plants possess a wide array of potential cellular mechanisms that may be involved in the tolerance to potentially toxic elements. These mechanisms include mycorrhizal associations, heavy metals binding to cell wall, precipitation by extracellular exudates; reduction in uptake or efflux pumping of metals at the plasma membrane, chelation of metals in the cytosol by peptides such as phytochelatins, metallothionein, histidina free, proline free , and the compartmentation of metals in the vacuole by tono-plast- located transporters. This review provides a broad overview of the evidence of the involvement of each mechanism in plants' tolerance to potentially toxic metals.

scholarly journals It’s Time to Replace the Term “Heavy Metals” with “Potentially Toxic Elements” When Reporting Environmental Research

2019 ◽  
Vol 16 (22) ◽  
pp. 4446 ◽  
Author(s):  
Olivier Pourret ◽  
Andrew Hursthouse
Keyword(s):  
Heavy Metals ◽  
Toxic Elements ◽  
Chemical Elements ◽  
Natural Sciences ◽  
Potentially Toxic Elements ◽  
Toxic Element ◽  
Environmental Research ◽  
Environmental Sciences ◽  
Common Term ◽  
Pollution Impacts

Even if the Periodic Table of Chemical Elements is relatively well defined, some controversial terms are still in use. Indeed, the term “heavy metal” is a common term used for decades in the natural sciences, and even more in environmental sciences, particularly in studies of pollution impacts. As the use of the term appears to have increased, we highlight the relevance of the use of the term “Potentially Toxic Element(s)”, which needs more explicit endorsement, and we illustrate the chemical elements that need to be considered.

scholarly journals Terrestrial Biota as Bioindicators for Microplastics and Potentially Toxic Elements

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1152
Author(s):  
Jamila S. Al Malki ◽  
Nahed Ahmed Hussien ◽  
Ehab M. Tantawy ◽  
Yassir Khattab ◽  
Amaal Mohammadein
Keyword(s):  
Inductively Coupled Plasma ◽  
Toxic Elements ◽  
Lumbricus Terrestris ◽  
Potentially Toxic Elements ◽  
Metallic Elements ◽  
Potentially Toxic Metals ◽  
Inductively Coupled ◽  
Plastic Bags ◽  
Terrestrial Biota ◽  
Eobania Vermiculata

Plastic products used in our daily life remain in the environment for a long time. Plastics decompose gradually into smaller fragments (<5 mm) known as microplastics. There are different sources of microplastics contamination, including plastic bags, masks, synthetic textiles, and various coatings. Microplastics’ smaller size enhances toxic pollutants’ adsorption, through which they are easily digested by small biota and finally accumulated along the food chain. Many studies are found concerning marine microplastic distribution and pollution; however, rarely do they address terrestrial contamination. The terrestrial species Eobania vermiculata, Rumina decollata, Porcellio, Armadillo, Lumbricus terrestris, and Scolopendra were evaluated as bioindicators for soil pollution by microplastics and some potentially toxic metallic elements. Microplastics were isolated with the help of caustic potash. The particles were characterized by infrared spectroscopy (FTIR); some associated potentially toxic metals were assessed in the filtrate by inductively coupled plasma spectrometry (ICP). The following polymers were present in all studied samples: copolyamide, nylon, high- and low-density polyethylene, polyamide, and polyester. In addition, the metallic elements antimony, iron, aluminum, selenium, and zinc were determined with different concentrations. Thus, terrestrial biota can serve as bioindicators for microplastic pollution of soil, which could act as a vector for potentially toxic elements.

scholarly journals Carcinogenic and Non-carcinogenic Health Risk Assessment of Heavy Metals in Njaba River, Imo State, Nigeria

2021 ◽  
Author(s):  
Victor Eze ◽  
Chidiebere Ndife ◽  
Miracle Muogbo
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Health Risk ◽  
Health Risk Assessment ◽  
Toxic Elements ◽  
Risk Estimation ◽  
Hazard Index ◽  
Potentially Toxic Elements ◽  
Tolerable Risk ◽  
Sample Points

Daily exposure to potentially toxic elements (heavy metals) through the oral ingestion of water has been a major concern to human health due to its detrimental effects. Studies focusing on health risk assessment of potentially toxic elements in surface and ground waters have been conducted, but none has been reported in Njaba River. Few studies conducted have focused only on the assessment of its water quality. Therefore, this study assessed the carcinogenic and non-carcinogenic effects of the potentially toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) in Njaba River. Overall, a total of 135 water samples was collected for this study and were analyzed using Agilent FS240AA AAS. The potentially toxic elements concentrations were: As (0.015±0.001 to 0.021±0.001 mg L-1), Cd (0.006±0.002 to 0.018±0.002 mg L-1), Cr (0.027±0.001 to 0.074±0.001 mg L-1), Cu (0.016±0.002 to 0.033±0.001 mg L-1), Ni (0.031±0.001 to 0.053±0.002 mg L-1), Pb (0.050±0.002 to 0.092±0.001 mg L-1), and Zn (0.061±0.002 to 0.097±0.002 mg L-1). As, Ni and Pb recorded concentrations above their respective maximum permissible limits. Physicochemical parameters were appraised using the American Public Health Association standard method (APHA). The evaluation of the carcinogenic and non-carcinogenic health risks of the analyzed elements was carried out based on the guidelines of the USEPA. The hazard index values for children via upstream, midstream and downstream sample points were 0.0000128, 0.00000895 and 0.0513 respectively, while the hazard index values for adults via upstream, midstream and downstream sample points were 0.00000551, 0.00000395 and 0.00000581 respectively. The health risk estimation showed that the hazard quotients were within acceptable limits. The total cancer risks of potentially toxic elements were generally within the range of tolerable risk for adults and above the range of tolerable risk for children.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

Heavy metals pollution potentials in the National Iron Ore Mining Company, Itakpe

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Cyril Ocheri ◽  
A. D. Omah ◽  
C. N. Mbah ◽  
R. E. Njoku ◽  
N. A. Urama ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sea Level ◽  
Toxic Elements ◽  
Iron Ore ◽  
Pollution Potential ◽  
Extraction Techniques ◽  
Mining Company ◽  
Mining Sites ◽  
Metals Pollution ◽  
Heavy Metals Pollution

Heavy metals pollution potential in National Iron Ore Mining Company, Itakpe was investigated. Two mining sites located at the east mining pits such as M3O, which is 370 m above sea level and M2O, which is 350 m above sea level were studied.  Sequential extraction techniques was utilised to examine the distribution effect of the heavy metals pollution potential on the environment. Twelve representative (six-soil, two-sediment, two-plant and two-water) samples were collected, pre-treated and prepared for this study. The atomic absorption spectrometer was used to analyse the concentration of the metals after the sequential and single-stage extractions were determined. Results showed that Chromium, Arsenic, Cadmium and Copper are more bioavailable in the study area than Lead and Iron. This findings indicate that human, animals and plants are exposed to toxic elements (metals and metalloids).

Hydrogeochemistry of Toxic Elements in Urbanized Geotechnical Systems

1997 ◽  
Vol 32 (3) ◽  
pp. 523-550
Author(s):  
S.N. Volkov
Keyword(s):  
Heavy Metals ◽  
Toxic Elements ◽  
Life Support ◽  
Alkylating Agents ◽  
Pollution Sources ◽  
The Urals

Abstract In urbanized geotechnical systems (UGSs), the majority of problems related to the ecological hydrochemistry of Cd, Pb, Ni and other heavy metals are the result of emergent characteristics of a system as a whole as opposed to individual pollution sources. In petrochemical UGSs, pollution of the environment from compounds containing methylating or alkylating agents results in an increase in the mobility of Cd, Pb, Ni, Cr and As. This process is controlled by environmental and microclimatic factors rather than by pollution sources. Under conditions of predominant dust and element effects, geo-chemically paradoxical associations of Cd with Ni, Mn and Cr can be formed in the main life support media in mining and metallurgical UGSs. Uncontrolled processes of hydrochemical interactions take place in complex multifunctional UGSs, leading to a change in speciation of heavy metals, particularly cadmium. This report is part of a 5-year study of the geotechnical systems in the Urals.

Sign in / Sign up

Export Citation Format

Share Document