scholarly journals Electrochemical attributes and availability of nutrients, toxic elements, and heavy metals in tropical soils

2006 ◽  
Vol 63 (6) ◽  
pp. 589-608 ◽  
Author(s):  
Mauricio Paulo Ferreira Fontes ◽  
Luís Reynaldo Ferracciú Alleoni
Keyword(s):  
Heavy Metals ◽  
Electrochemical Properties ◽  
Toxic Elements ◽  
Chemical Speciation ◽  
Surface Complexation ◽  
Tropical Soils ◽  
Metal Availability ◽  
Ionic Exchange ◽  
Weathered Soils ◽  
Highly Weathered Soils

Electrochemical properties of soils are very important for the understanding of the physico-chemical phenomena which affect soil fertility and the availability of nutrients for plants. This review highlights the electrochemical properties of tropical soils, the behavior and the availability of nutrients, toxic elements and heavy metals in the soil, especially for soils with predominant variable charge minerals. Availability of the elements is related to ionic exchange, solution speciation, and electrostatic and specific adsorptive soil properties. Empirical and surface complexation models are briefly described, and some results of their application in tropical soils are presented. A better understanding of the role of the double diffuse layer of charges and CEC on nutrient cation availability for highly weathered soils is required, as well as a solid comprehension of surface complexation models, in order to improve the knowledge regarding the behavior of anions in soils. More studies have to be conducted to generate results that enable the use of chemical speciation concepts and calculation of several constants used in surface complexation models, especially for highly weathered soils from the humid tropics. There has to be a continuing development and use of computer softwares that have already incorporated the concepts of chemical speciation and adsorption models in the study of nutrients, toxic elements and heavy metal availability in the soil-plant system.

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.

scholarly journals Toxic Elements in Traditional Kohl-Based Eye Cosmetics in Spanish and German Markets

2021 ◽  
Vol 18 (11) ◽  
pp. 6109
Author(s):  
Elisabet Navarro-Tapia ◽  
Mariona Serra-Delgado ◽  
Lucía Fernández-López ◽  
Montserrat Meseguer-Gilabert ◽  
María Falcón ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Prior Distribution ◽  
Inductively Coupled Plasma ◽  
Toxic Elements ◽  
Optical Emission ◽  
The European Union ◽  
Inductively Coupled ◽  
Women And Children ◽  
Harmful Effects ◽  
The Eu

Kohl is a traditional cosmetic widely used in Asia and Africa. In recent years, demand for kohl-based eyelids and lipsticks has increased in Europe, linked to migratory phenomena of populations from these continents. Although the European legislation prohibits the use of heavy metals in cosmetics due to the harmful effects to human health, particularly to pregnant women and children, these elements are still present in certain products. The European Union recommended levels are Pb < 20 ppm, As < 5 ppm, Cd < 5 ppm, Sb < 100 ppm, and Ni < 200 ppm. In Germany, levels are more restrictive: Pb < 2 ppm, As < 0.5 ppm, Cd < 0.1 ppm, Sb < 0.5 ppm, and Ni < 10 ppm. Here, we analyzed 12 kohl-based cosmetics in different presentations (powder, paste, and pencil) that were purchased in Spanish and German local shops. An inductively coupled plasma optical emission spectrophotometer was used to identify toxic elements and heavy metals. Levels of Pb ranged between 1.7 and 410,000 ppm in six of the study samples, four of which had levels above the recommended limit of at least two heavy metals. Arsenic (a carcinogenic element) values were within the range allowed by the EU in only 58% of the studied samples. Moreover, two products doubled this limit, reaching levels of 9.2 and 12.6 ppm. In one of the products, cadmium, related to toxic keratitis, was four times higher (20.7 ppm) than that allowed, while in two other products, these limits were doubled (11.8 and 12.7 ppm). Our results indicate the need to supervise the manufacture of kohl-based traditional products and the analysis of their composition prior distribution in European countries.

Research on the stability of heavy metals (Cu, Zn) in excess sludge with the pretreatment of thermal hydrolysis

2015 ◽  
Vol 73 (4) ◽  
pp. 890-898 ◽  
Author(s):  
Huimin Wu ◽  
Meng Li ◽  
Lei Zhang ◽  
Chao Sheng
Keyword(s):  
Heavy Metals ◽  
Anaerobic Digestion ◽  
Chemical Speciation ◽  
Stable Form ◽  
Thermal Hydrolysis ◽  
Excess Sludge ◽  
The Stability ◽  
Cu And Zn

Thermal hydrolysis (TH) has been used to improve anaerobic digestion performance as well as the stability of heavy metals in sludge. Because the toxicity of heavy metals is closely related to both the concentration and the chemical speciation, more exhaustive studies on speciation distribution are urgently needed. This research aimed to investigate the effects of TH treatment (especially the time and temperature) on the concentration and stability of heavy metals in sludge, and to define the optimal TH conditions. The TH experiment indicated that the content of the stable form of Cu and Zn reached 83% and 47.4%, respectively, with TH at 210°C and 30 min. Compared with the raw sludge, the proportion of Cu and Zn increased by 11.88% and 7.3%, respectively. Results indicated that the heavy metals were combined with sludge in a more stable form with the pretreatment of TH, which improved the stability of heavy metals.

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 Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open wastewater channels in Nairobi, Kenya

2021 ◽  
Author(s):  
Geoffrey Kariuki Kinuthia ◽  
Veronica Ngure ◽  
Luna Kamau
Keyword(s):  
Heavy Metals ◽  
Green Algae ◽  
Toxic Elements ◽  
Tap Water ◽  
Aquatic Organisms ◽  
Industrial Area ◽  
Metal Exposure ◽  
Water Control ◽  
Filamentous Green Algae ◽  
Us Epa

Abstract Background Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) in samples of wastewater, filamentous green algae (spirogyra) and urban mosquitoes obtained from open wastewater channels in Nairobi industrial area, Kenya, was established. Industrial wastewater may contain hazardous heavy metals upon exposure. Aquatic organisms in wastewater may accumulate the toxic elements with time. Therefore, human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms can be key in metal exposure assessment. Results Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/L while Tl, Hg, & Cd levels ranged from 0.05 to 0.12 µg/L in wastewater. Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Metals in tap water (control) which ranged from 0.01 to 0.2 µg/L was below WHO, US EPA, & Kenya standard limits. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3 to 2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/L & 1.8 mg/L respectively) was higher than in field mosquitoes (0.048 mg/L & 0.12 mg/L respectively). Pb, Cr, Ni, & Cd levels in green filamentous algae were 110.62, 29.75, 14.45, & 0.44 mg/L respectively and above WHO limits for vegetable plants. Hg level in algae samples (0.057 mg/L) was below WHO standard limits but above Kenya & US EPA limits in vegetables. Correlations for Pb & Hg (r = 0.957; P < 0.05); Cd & Cr (r = 0.985; P < 0.05) in algae samples were noted. The metal concentrations in the samples were in the order, wastewater < mosquitoes < filamentous green algae. Conclusion Samples of wastewater, mosquitoes and filamentous green algae from open wastewater channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Urban mosquitoes and filamentous green algae can play a role of metal biomonitoring in wastewater. The possibility of urban mosquitoes transferring the heavy metals to their hosts when sucking blood should be investigated.

Epilepsy and Stroke Emerging From Climate Change-Related Neurotoxicity

2019 ◽  
pp. 322-347
Author(s):  
Hind Benammi ◽  
Omar El Hiba ◽  
Abdelmohcine Aimrane ◽  
Nadia Zouhairi ◽  
Hicham Chatoui ◽  
...  
Keyword(s):  
Climate Change ◽  
Heavy Metals ◽  
Nervous System ◽  
Toxic Elements ◽  
Neurological Diseases ◽  
Quality Of Water ◽  
Wide Range ◽  
The Impact ◽  
Shed Light

Climate change has an important impact on the environment. As it degrades the quality of water, soil, and area, it also spreads the distribution of many toxic elements, specifically heavy metals and pesticides. The impact of climate change on contamination with heavy metals and pesticides has been well investigated and discussed. The influence of these elements on human health is obviously exacerbated following their extended distribution. Moreover, a wide range of health problems have been associated to such intoxication, among which impairment and dysfunction of the nervous system are prominent. In this chapter, the authors will shed light on two most common neurological diseases such as epilepsy and stroke affecting people worldwide arising from food and water contaminations, mainly with heavy metals and pesticides.

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