Heavy Metals and 2, 4-Dinitrophenol Impact on Some Physiological and Biochemical Parameters in Capsicum Species

Abstract The accumulation of heavy metals and of pesticides in the soil have a negative impact on Capsicum chinense var. Aji Mochero and Capsicum baccatum var. pendulum Bishop's Crown species, the present work highlighting the exerted influence on the superoxid-dismutase activity, catalase and peroxidase - as enzymes implied in the removal of H2O2, of O2- radical and of ion HO- that have devastating effects on the vegetable cell, on the Krebs cycle's dehydrogenases - as main way to produce energy, respectively of the chlorophyll a, b and carotenes - as photoassimilatory pigments, but also as biologic antioxidants.

Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation

Abstract Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil.

El cabello, fuente de información del estado de salud / The hair, source of health information

El cabello y especialmente el localizado en la cabeza provee importante información sobre posibles exposiciones ambientales y/o laborales a diferentes elementos. El pelo puede ser considerado como un producto excretor, y su estudio reflejaría el metabolismo de minerales en el cuerpo. Nuestro propósito en el presente estudio es conocer si datos existentes dan información poblacional sobre la presencia de elementos tóxicos o no a través del análisis del cabello humano. RESULTADOS: Fue analizada la información proveniente de 241 muestras de cabello, de los cuales 163 (67,6%) corresponden al sexo femenino y 78 (32,4%) al masculino. Fueron analizados 22 elementos esenciales y 17 elementos de tóxicos. Entre los elementos esenciales presentaron resultados elevados Calcio (Ca), Magnesio (Mg), Manganeso (Mn), Molibdeno (Mo), Vanadio (V), Estroncio (Sr) y Circonio (Zr); entre los elementos tóxicos tuvieron valores elevados Aluminio (Al), Arsénico (As), Bario (Ba), Bismuto (Bi), Cadmio (Cd), Níquel (Ni), Plomo (Pb), Mercurio (Mg), Plata (Ag), Estaño (Sn). CONCLUSIÓN. Nuestro estudio muestra a nivel poblacional, no individual, puntos de alerta por la carencia o exceso de algunos elementos analizados debiéndose continuar con estudios locales interdisciplinarios en los cuales exista información sobre enfermedades, hábitos alimentarios, hábitos tóxicos, actividad laboral y exposición ambiental a los diferentes elementos. (AU)

Hair, especially localized in the head, provides important information on possible environmental and/or labor exposures to different elements. Hair can be considered as an excretory product, and its study would reflect the metabolism of minerals in the body. Our purpose in this study was to determine whether existing population data provide information on the presence of toxic and non-toxic elements by analizing human hair. RESULTS: We analyzed information from 241 hair samples, of which 163 (67.6%) are from females and 78 (32.4%) are from males. There were analyzed 22 essential elements and 17 toxic elements. Among the essential elements that had elevated results there were: Calcium (CA), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), strontium (Sr) and zirconium (Zr); among the toxic elements, those with higher values were: Aluminum (Al), arsenic (As), barium (BA), bismuth (Bi), Cadmium (Cd), Nickel (Ni), lead (Pb), Mercury (Mg), silver (Ag), tin (Sn). CONCLUSION. Our study shows at population level, not individual, warning points due to the lack or excess of some elements analyzed. It is reccommended to continue the research with local interdisciplinary studies which include information on diseases, eating habits, toxic habits, work activity and environmental exposure to different elements. (AU)

Análisis climático de la concentración de metales pesados asociados al sedimento depositado sobre vías urbanas / Climatic analysis of heavy metal concentration associated with urban road-deposited sediment

Objetivo Realizar una evaluación climática (diaria) de la concentración de metales pesados (Pb y Cu) asociada con el sedimento depositado sobre las superficies viales de las localidades de Kennedy y Puente Aranda (Bogotá D.C., Colombia). Adicionalmente, se evaluaran las concentraciones detectadas con respecto a la legislación seleccionada como de referencia para la protección de la salud humana en suelo urbano. Métodos La concentración se determinó mediante espectrometría de absorción atómica con llama; previamente las muestras fueron digeridas en una mezcla de ácido clorhídrico y nítrico (3:1; agua regia). Resultados Se evidencia con respecto a la fracción de tamaño del sedimento vial más cercana a la potencialmente inhalable desde el punto de vista de la salud pública (≤ 10 µm), que las concentraciones metálicas en promedio tienden a aumentar en tiempo seco (29 %). Al respecto, las concentraciones durante estos períodos de tiempo son en promedio 1,69 veces superiores al valor límite más bajo fijado por la normatividad de referencia. No obstante, se sugiere que las concentraciones metálicas están dominadas por el uso del suelo antes que por las condiciones climáticas. Conclusiones Los hallazgos se constituyen en un punto de referencia a nivel colombiano para la discusión y publicación de normatividad ambiental asociada con la protección de la salud humana por metales pesados, y para visualizar futuras líneas de investigación acerca del efecto del cambio climático sobre las concentraciones metálicas en ambientes urbanos.(AU)

Objective To climatically assess (daily) the concentration of heavy metals (Pb and Cu) in sediment deposited on road surfaces of the localities of Kennedy and Puente Aranda (Bogota, D.C., Colombia). Additionally, the detected concentrations are to be evaluated with respect to the legislation chosen as reference point for the protection of human health in urban areas. Methods The concentration was determined by flame atomic absorption spectrometry. The samples were previously digested in a mixture of hydrochloric and nitric acid (3:1; aqua regia). Results The results show, with respect to road sediment closest to the size that could be potentially inhaled from the point of view of public health (≤ 10 µm), that the metal concentrations on average tend to increase in dry weather (29 %). In this regard, the concentrations during these time periods are on average 1.69 times higher than the lowest limit value set by the reference legislation. However, it is suggested that the metal concentrations are mostly due to the use of the land rather than weather conditions. Conclusions The findings are a reference point in Colombia for the discussion and publication of environmental regulations associated with the protection of human health from heavy metals and for visualizing future lines of research about the effect of climate change on metal concentrations in urban environments.(AU)

Platinum nanoparticles-manganese oxide nanorods as novel binary catalysts for formic acid oxidation

The current study proposes a novel binary catalyst system [composed of metal/metal; oxide nanoparticles] as a promising electrocatalyst in formic acid oxidation. The electro-catalytic oxidation of formic acid is carried out with binary catalysts of Pt nanoparticles [nano-Pt] and manganese oxide nanorods [nano-MnO[x]] electrodeposited onto glassy carbon [GC] electrodes. Cyclic voltammetric [CV] measurements showed that unmodified GC and nano-MnO[x]/GC electrodes have no catalytic activity. While two oxidation peaks were observed at nano-Pt/GC electrode at ca. 0.2 and 0.55 V [corresponding to the direct oxidation of formic acid and the oxidation of the poisoning CO intermediate, respectively]. The combined use of nano-MnO[x] and nano-Pt results in superb enhancement of the direct oxidation pathway. Nano-MnO[x] is shown to facilitate the oxidation of CO [to CO[2]] by providing oxygen at low over-potential. This leads to retrieval of Pt active sites necessary for the direct oxidation of formic acid. The higher catalytic activity of nano-MnO[x]/nano-Pt/GC electrode [with Pt firstly deposited] compared to its mirror image electrode [i.e., with MnO[x]. firstly deposited, nano-Pt/nano-MnO[x]/GC] reveals that the order of the electrocldeposition is an essential parameter

Cultivo a escala de laboratorio de bacterias sulfato reductoras ácidófilas y su aplicación en procesos de biorremediación utilizadas para la precipitación de metales pesados / Lab-scale culture of acidofilic sulfate reducing bacteria and applications for heavy metal precipitation

En el mundo uno de los mayores contaminantes para el medio ambiente son los drenajes ácidos de mina (DAM), los cuales están caracterizados por presentar elevadas concentraciones de metales pesados, sulfatos que contribuyen a la acidez del efluente.

Synthesis and physico-chemical studies of some polymers for removing of some heavy metal ions of industrial wastewater

The chemical contaminations of wide range of toxic derivatives in water, in particular heavy metal ions and dyes is a serious environmental problem owing to their potential human toxicity. Therefore, there is a need to develop technologies that can remove toxic pollutants from the wastewater. Adsorption is one of choices used for treating industrial effluents and a useful tool for protecting the environment. In particular, adsorption on synthetic, natural polymers and their derivatives is known to remove pollutants from water. The importance of the synthetic polymers has increased due to their high selectively, stability at elevated temperature and sensitivity to the high concentration of ions. One of the major applications of epoxy and its many derivatives is based on its ability to bind strongly heavy and toxic metal ions. This study will focus on the synthesis of two types of polymers, the first one was carried by suspension polymerization of epoxy resin, methyl methacrylate [MMA] and divinyl benzene [DVB] mixtures which have been modified though epoxy functions in two steps: [i] by treating with polyamine and [ii] by subsequent reaction with potassium chloroacetate. The second type which is a new low cost adsorbent was prepared by modified polysaccharides for example resin was polymerized epoxy resin and cross linked starch mixtures in two steps; [i] by treating with polyamine and [ii] by subsequent reaction with potassium mono chloroacetate, that to increase the efficient sorbet for removal of Cu[II] and Ni[II] ions

Heavy metal induced oxidative stress & its possible reversal by chelation therapy.

Exposure to heavy metals is a common phenomenon due to their environmental pervasiveness. Metal intoxication particularly neurotoxicity, genotoxicity, or carcinogenicity is widely known. This review summarizes our current understanding about the mechanism by which metalloids or heavy metals (particularly arsenic, lead, cadmium and mercury) induce their toxic effects. The unifying factor in determining toxicity and carcinogenicity for all these metals is the generation of reactive oxygen and nitrogen species. The toxic manifestations of these metals are caused primarily due to imbalance between pro-oxidant and antioxidant homeostasis which is termed as oxidative stress. Besides these metals have high affinity for thiol groups containing enzymes and proteins, which are responsible for normal cellular defense mechanism. Long term exposure to these metals could lead to apoptosis. Signaling components affected by metals include growth factor receptors, G-proteins, MAP kinases and transcription factors. Chelation therapy with chelating agents like calcium disodium ethylenediamine tetra acetic acid (CaNa(2)EDTA), British Anti Lewisite (BAL), sodium 2,3-dimercaptopropane 1-sulfonate (DMPS), meso 2,3-dimercaptosuccinic acid (DMSA) etc., is considered to be the best known treatment against metal poisoning. Despite many years of research we are still far away from effective treatment against toxicity caused due to exposure to heavy metals/metalloids. The treatment with these chelating agents is compromised with number of serious side-effects. Studies show that supplementation of antioxidants along-with a chelating agent prove to be a better treatment regimen than monotherapy with chelating agents. This review attempts a comprehensive account of recent developments in the research on heavy metal poisoning particularly the role of oxidative stress/free radicals in the toxic manifestation, an update about the recent strategies for the treatment with chelating agents and a possible beneficial role of antioxidants supplementation to achieve the optimum effects. We have selected only arsenic, lead, mercury and cadmium for this article keeping in view current concerns and literature available.

Estudio del pH y presencia de metales pesados de un trióxido mineral / Study of the pH and the presence of heavy metals from a mineral trioxide

El propósito del presente trabajo fue comparar in vitro la capacidad de alcalinización por inmersión en agua destilada de dos trióxidos minerales y analizar su polvo para determinar la presencia de metales pesados como arsénico y cromo en su composición. Se prepararon tres muestras para cada grupo. Se registró el pH del agua destilada, se sumergió cada muestra y se volvió a realizar la medición inmediatamente a la hora, a las tres horas y a los 7 días, mateniéndolñas en una estufa a 37ºC. Se determinó la presencia de arsénico por espectrometría de absorción atómica con generación de hidruros y de cromo por espectrometría de absorción atómica con horno de grafito. Los resultados del pH fueron evaluados en función del tiempo. El pH inicial de CPM fue 10,14 y a los 7 días 10,94, en tanto que para ProRoot MTA fue 8,98 y 11,87 respectivamente, determinando que el incremento del pH de CPM y MTA fue diferente en cuanto a tiempo y valores de pH. El análisis estadístico mostró el efecto significativo de los factores material, tiempo y su interacción (p<0,01). Los resultados del análisis químico determinaron la presencia de arsénico y cromo en ambos materiales; CPM: As (2,1mg/kg), Cr (3,2mg/kg); ProRoot-MTA As (2,0mg/kg), Cr (3,5mg/kg).

Effect of bread making process on heavy metals content of Egyptian breads

A total of 105 samples of flour, dough and bread from 35 bakery units were selected from various areas of Cairo The contents of lead [Pb], cadmium [Cd], cupper [Cu] and iron [Fe] were determined using atomic absorption spectrophotometer. Effect of breadmaking process was evaluated regarding heavy metals content. Results showed that slight increase of heavy metals content in flour compared to [Codex], i.e., Pb ranged between 0.177 - 2.98mg/kg m. Balady bread and ranged between 0.480 - 2.860mg/kg in Fino bread [0.5 mg/kg] while Cd ranged between 0.093 - 0.197 mg/kg in Balady bread and ranged between 0.071-0.176mg/kg in Fino bread [0.1 mg/kg]. Heavy metals increased as flour extraction increased .Also heavy metals content affected by breadmaking process. Breads had higher content of heavy metals than its dough or flour. Balady bread had higher content of determined heavy metals than Fino bread

Avaliação da concentração de metais pesados em tecido de ostras Crassostrea gigas (Molusca, bivalve) cultivadas na baía da Barbitonga, literoal norte de Santa Catarina / Evaluation of heavy metal concentration in tissue of Crassostrea gigas (Molusca, bivalve) oysters cultivated in Babitonga Bay, north coast of Santa Catarina state, Brazil

Este trabalho objetivou avaliar a concentração de metais pesados em tecidos de ostras Crassostrea gigas cultivadas em 4 pontos da Baía da Babitonga, litoral norte do estado de Santa Catarina. Para tanto, foram instaladas estruturas de cultivo em cada ponto no sistema longline. Durante um anos foram medidos os parâmetros físico-químicos da águas, quinzenalmente, e realizadas análises químicas bimensais dos metais pesados arsênio, cádmio, cobre, níquel e zinco no sedimento, na águas e no tecido de ostras. Os resultados da concentração de metais pesados mostraram teores acima do permitido pela legislação brasileira para arsênio, níquel, cobre, cádmio e zinco durante o período do verão. Entretanto, foi observada a presença de concentrações significativas de zinco para todos os pontos ao longo do ano. Constatou-se que as ostras apresentaram assimilação de contaminantes, indicando a biodisponibilidade no ambiente, no entanto, também foi observada a capacidade de autodepuração por parte dos organismos

Composição química de diferentes fontes de fósforo e deposição de metais pesados em tecidos de suínos / Chemical composition of different phosphorus sources and heavy metal deposition in tissues of swines

Foram utilizados 112 leitões com peso inicial de 28,68kg, distribuídos em blocos ao acaso, em esquema fatorial 8 2 (oito tratamentos x dois sexos), sete repetições e dois animais por baia. As dietas foram formuladas com base no fósforo total, sendo estas à base de milho e de farelo de soja. O fósforo foi suplementado utilizando-se os fosfatos: bicálcico (FBC); monobicálcico (MBC); supertriplo (ST); supersimples (SS); rocha Catalão (ROCHA); mistura de fontes (MIST) e ácido fosfórico (AcF); e dieta-controle, sem o fósforo suplementar (CONT). Avaliou-se previamente a composição química de amostras de fontes de fósforo disponíveis no mercado. Os fosfatos MBC, FBC e AcF apresentaram baixo nível de contaminação por metais pesados. Observou-se variação no teor de metais pesados entre as marcas comerciais de supertriplo. O consumo do fosfato resultou em acúmulo de cobre nos músculos. A dieta-controle provocou acúmulo de chumbo e zinco no fígado, e a mistura de fontes e supertriplo ocasionou acúmulo de cádmio no fígado. A utilização de fontes alternativas de fósforo menos elaboradas influenciou a deposição de minerais no fígado e nos músculos dos suínos.

Separation and recovery of radioactive and non-radioactive toxic trace elements from aqueous industrial effluents.

An update is presented on liquid membrane-based processes as viable and relevant alternatives to conventional approaches such as precipitation, solvent extraction, ion exchange processes and electrochemical techniques for the removal and recovery of some toxic and/or valuable trace metal ions including some actinides and fission products e.g. U, Am, Y etc and As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn etc from radioactive as well as non-radioactive aqueous waste solutions respectively. In particular, results of experiments aimed at developing supported liquid membrane(SLM)-based process using commercially available porous membranes and indigenously prepared track--etch membranes (TEMs) have been critically examined in laboratory studies to generate basic data needed to evaluate their utility for continuous operation without regeneration. These include effect of pore size, porosity, optimum pore size and their reusability. It is clearly demonstrated that indigenously prepared 10 microm thick TEMs with a porosity in the range of 2-5% give comparable transport rates for metal ions-matching with that of commercial membranes of much higher thickness (160 microm) and higher porosity of 60-85%. The smaller thickness of TEMs more than compensates for their lower porosity. It is shown that because of their well defined pore characteristics TEMs could serve as model supports in SLM studies. By comparing the values of permeability coefficient (P) for TEM and polytetraflouroethylene (PTFE) supports for the transport of Pb2+ chosen as a typical divalent metal ion, and using di-2 ethyl hexyl phosphoric acid (D2EHPA) as the carrier, it is unambiguously proved that diffusion of the metal complex across the membrane is the rate controlling step in metal ion transport in SLM-based processes. An overview of the experimental findings along with future outlook and suggestions for further work are presented in this paper.

Microbes in heavy metal remediation.

Heavy metal contamination due to natural and anthropogenic sources is a global environmental concern. Release of heavy metal without proper treatment poses a significant threat to public health because of its persistence, biomagnification and accumulation in food chain. Non-biodegradability and sludge production are the two major constraints of metal treatment. Microbial metal bioremediation is an efficient strategy due to its low cost, high efficiency and ecofriendly nature. Recent advances have been made in understanding metal--microbe interaction and their application for metal accumulation/detoxification. This article summarizes the potentials of microbes in metal remediation.

Teste de AMES como uma ferramenta para detecçäo de citotoxidade e mutagenicidade causadas por metais pesados e radicais livres / Ames test as a tool for detection of citotoxicity and mutagenicity caused by heavy metals and the free radicals

Considerando a interaçäo complexa entre diferentes compostos químicos e metais, a influência desses fenômenos sobre o meio ambiente e consequentemente, sobre o ser humano, esta revisäo tem como objetivo mostrar que o Teste de Ames ainda hoje, é uma ferramenta importante na detecçäo de mutágenos