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El artículo tiene como objetivo revisar las metodologías existentes para evaluar la contaminación por metales pesados (MP) asociada con el sedimento vial, la cual es descargada sobre cuerpos hídricos urbanos. La revisión sistemática de literatura utilizó un índice de frecuencia de citación (Q) para establecer la importancia de las variables consideradas. Los resultados indican que las variables clave a considerar son las siguientes: Precipitación (Q = 0,83), sólidos totales (0,70), metales pesados (0,61), hidrocarburos (0,32), Residuos sólidos (0,27) y Escorrentía (0,23). Los MPs de mayor relevancia son los siguientes: Zn (0,79), Cu (0,76), Ni (0,68), Cr (0,65) y Pb (0,46). Las metodologías de evaluación detectadas son las siguientes: Análisis químico (0,30), impacto biológico (0,29), modelización numérica (0,29), análisis granulométrico (0,29) y simulaciones en laboratorio (0,22). Los MPs mayoritarios en ambientes viales son Zn y Ni, y los sólidos totales pueden ser utilizados como indicadores de MPs en la escorrentía vial.

RESUMO A companhia Siderúrgica Nacional (CSN) vem desenvolvendo estudos para disposição adequada dos seus resíduos no Aterro de Resíduos Sólidos Industriais (ARSI). Com objetivo de avaliara movimentação de Pb, Zn, Ni e Cd provenientes das misturas de resíduos alcalinos e ácidos da CSN, amostras dessas misturas foram colocadas sobre as amostras de solo empacotadas, em colunas de vidro, na proporção 1:4 (resíduo:solo). Após a lixiviação com 50 volumes-poro, as colunas foram seccionadas em quatro partes iguais e os teores de Pb, Zn, Ni e Cd determinados em todas profundidades. O pH do resíduo alcalino resultou na diminuição da vazão nas colunas, na baixa solubilidade do Pb do resíduo e na retenção do Zn, Ni e Cd na camada superficial de 0-5cm. Entretanto, no resíduo ácido a mobilização desses metais foi muito superior à do resíduo alcalino, sendo, inclusive, detectados no efluente em concentrações superiores ao permitido pela FEEMA.

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O cobre em elevada concentração no solo, causa toxidez nas plantas, sendo necessário o desenvolvimento de estudos que reduzam, ou imobilizem esse elemento. Nesse sentido, o biocarvão poderia ser uma alternativa para a imobilização de cobre no solo, visando menores teores deste elemento na biomassa e nos grãos do feijão preto (Phaseolus vulgaris) utilizado para consumo humano. Contudo, há variações na reatividade do biocarvão em decorrência do seu material de origem e tempo de pirólise. Portanto, o objetivo deste trabalho foi determinar o efeito do biocarvão de eucalipto na disponibilidade de cobre no solo e nos teores em feijão cultivado em solo contaminado. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 5 × 2, sendo cinco doses de biocarvão (0, 0.5, 1, 1.5 e 2% mm-1 de solo seco), solo sem e com adição de cobre (1.000 mg kg-1 de solo seco), com oito repetições. Avaliou-se o teor de cobre disponível no solo, teor de cobre na raiz, na parte aérea e no grão do feijão; índice de clorofila e fatores de bioconcentração e de translocação de cobre na planta. O biocarvão derivado de resíduos de eucalipto diminui a disponibilidade de cobre em solo contaminado. Os teores de cobre na raiz, parte aérea e nos grãos de Phaseolus vulgaris são reduzidos com a aplicação de biocarvão no solo, mantendo-se nos grãos, a partir da dose 1,66% mm-1, abaixo do limite máximo tolerável pela legislação brasileira.

Copyright of CULCyT: Cultura Científica y Tecnológica is the property of Cultura Cientifica y Tecnologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La presencia de cadmio en la cadena productiva del cacao ha establecido una barrera comercial que afecta considerablemente las exportaciones de los países latinoamericanos a Europa. Debido a que las plantas de cacao tienden a acumular trazas de cadmio en sus estructuras y tejidos, los países europeos han fijado los límites permisibles máximos de concentración de cadmio para los productos derivados del cacao, mediante el reglamento 488/2014 para contaminantes de alimentos, esto, buscando mejorar la trazabilidad de la materia prima desde su origen. En esta revisión, se destacan los estudios que buscan determinar las concentraciones de cadmio actuales en suelo y en la planta en diferentes países latinoamericanos, buscando cumplir con los estándares que rige la normativa. Tales estudios son necesarios como diagnóstico inicial para brindar soluciones de remediación que permitan mantener el comercio con los países europeos.

Introduction. In Peru, municipal solid waste in 2021 reached 8,215,355.9 tons and only 61.28 % is disposed of in sanitary landfills to be treated through composting; however, its implementation is deficient and requires studies to obtain a usable product as a substrate or amendment and reduce environmental pollution. Objective. The study determined the levels of nutrients, heavy metals, fecal microorganisms, and the quality of compost based on solid urban organic waste produced at the Shapajilla Valorization Plant in the Leoncio Prado province of Peru. Materials and methods. Four piles of organic solid waste were composted and evaluated for nutrients, heavy metals, fecal microorganisms, and quality based on Chilean Standard 2880 and Spanish Standard 824. Results. 95 % of the composted materials were food waste, fruit and peelings, and there were no differences between the piles evaluated. During processing, the temperature reached the different stages and the pH increased. High pH levels (>7.50) and low levels of Ca, Mg and K (< 1 %) were found; heavy metals presented differences and low levels, with absence of microorganisms of fecal origin, and the composts were of intermediate quality (B). Conclusions. The compost produced is of intermediate quality, free of metals and pathogenic microorganisms, and can be used as a substrate or amendment with some limitations, due to the high pH levels and low levels of Ca, Mg and K. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

User demographics, perceptions, and motivation data obtained from actual observation and experience surveys provide contextualized and first-hand information for game designers. However, this type of information can be misinterpreted if it is presented as numbers. Contextual Design (CD) is a user-centered method that allows a better understanding of the user’s work environment, as well as the requirements that the interactive systems must have to cover their needs. According to the CD, the user Personas (also called archetypes) are representations of users created to establish behaviors, likes and motivations of a representative group of users who share common patterns. These types of profiles can represent user groups during the design and development process of a videogame, thus allowing a more focused design. This paper describes step by step the process of designing user Personas for a group of 25 participants with stroke. This information was obtained from contextual interviews and gaming experience surveys, which allowed a more homogeneous interpretation of the dislikes, limitations and motivations of the participants. The CD methodology showed to be very useful, generating four user profiles, which were used for the creation of a serious video game in virtual reality that allows therapeutic support in a physical rehabilitation process for people with stroke. Finally, this work presents the preliminary design of the videogame and the importance of the information in the creation of user models. [ABSTRACT FROM AUTHOR]

(Em cobre no solo, o cobre Cu) é tóxico para o desenvolvimento dos vegetais. Simbiose veicular entre microrganismos e vegetais são da minimização da toxicidade das plantas contaminadas com cobre. O trabalho teve como objetivo selecionar as espécies de fungos microscópicos arbusculares para o desenvolvimento de plantas de trigo em solo contaminado com cobre. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 4 × 6, sendo quatro espécies de fontes inóculos: espécies de micorrizas arbusculares (Acaulospora, Gigaspora margarita e Rhizophagus clarus) e semculo (testemunha) e seis doses de cobre no solo (0 , 80 , 160, 240, 320 e 400 mg kg -1), com sete repetições. Padrão-se a altura de plantas, comprimento de raiz, volume de raízes, massa seca de raiz,é superficial específico, diâmetro de raiz, teor de cobre na média, na parte aérea e no grão e grande de colonização. A massa de raiz e o conector foram identificados com altas doses de umidade. Os isolados Acaulospora Colombia e Gigaspora Margarita apresentam maior altura, comprimento de raiz e área superficial específica e menor teor de Cu no grão na cultura do trigo. A colonização micorrízica com os fungos Acaulospora Colombiana, Gigaspora Margarita e Rhizophagus clarus resulta em menor teor de cobre na parte aérea e nos grãos do trigo. Os isolados Acaulospora Colombia e Gigaspora Margarita apresentam maior altura, comprimento de raiz e área superficial específica e menor teor de Cu no grão na cultura do trigo.A colonização micorrízica com os fungos Acaulospora Colombiana, Gigaspora Margarita e Rhizophagus clarus resulta em menor teor de cobre na parte aérea e nos grãos do trigo. Os isolados Acaulospora Colombia e Gigaspora Margarita apresentam maior altura, comprimento de raiz e área superficial específica e menor teor de Cu no grão na cultura do trigo. A colonização micorrízica com os fungos Acaulospora Colombiana, Gigaspora Margarita e Rhizophagus clarus resulta em menor teor de cobre na parte aérea e nos grãos do trigo.

Copyright of Diversitas Journal is the property of Diversitas Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lead (Pb) is a heavy metal considered one of the major soil pollutants. Phytoremediation is a sustainable and economically viable biological method for reducing Pb content in the environment. Inga uruguensis is a tree legume species that has characteristics favorable to phytoremediation, such as rapid growth and high biomass production. The objective of this work was an initial evaluation of tolerance and phytoremediation potential of I. uruguensis to Pb. The experiment was carried out in a greenhouse. In addition to the control, soil contamination was carried out with the following Pb doses: 100, 200, 300, 400, and 500 mg.dm?, with 5 repetitions in each treatment, totaling 30 vases. We assessed growth, number and mass of nodules, chlorophyll content, ureids, amino acid, protein and soluble carbohydrates in leaves, roots and nodules, tolerance index, dry matter, and tissues Pb content of I. uruguensis. The data were analyzed by the Tukey test using R and SISVAR software. There was no negative effect of Pb in soil on I. uruguensis growth, the symbiotic relationship with rhizobia was kept, even at high Pb content and the tolerance index was not lower than 0.69. Inga uruguensis has initial tolerance and potential to be used as phytoremediation in soils contaminated by Pb. [ABSTRACT FROM AUTHOR]

Copyright of Revista CIENCIA UNEMI is the property of Universidad Estatal de Milagro (UNEMI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O cobre em elevada concentração no solo torna-se tóxico ao desenvolvimento das plantas e microrganismo. O trabalho objetivou selecionar fungos micorrízicos arbusculares eficientes para o desenvolvimento e produtividade da soja cultivada em solo contaminado com cobre. O delineamento experimental foi em Inteiramente casualizado em arranjo fatorial 7 × 4, sendo, sete doses de cobre (0, 80, 160, 240, 320, 400 e 480 mg de cobre kg-1de solo), quatro inóculos (testemunha sem inoculação e três fungos micorrízicos: Acaulospora colombiana, Dentiscutata heterogama e Rhizophagus clarus), com 7 repetições. Avaliou-se a altura da parte aérea, diâmetro do colo, número de grão por planta, massa seca da parte aérea e sistema radicular, área foliar, área superficial específica de raízes, teores e acúmulo de cobre na parte aérea, radicular e no grão, parâmetros da clorofila, e porcentagem de colonização micorrízica. A inoculação com fungos micorrízicos arbusculares Acaulospora colombiana, Dentiscutata heterogama, Rhizophagus clarus aumenta os parâmetros fenológicos e fisiológicos da soja e a sua produtividade soja em solo contaminado com até 480 mg kg-1de cobre aplicado no solo. O isolado Rhizophagus clarus promove maior desenvolvimento da soja e aumenta sua produtividade em solo contaminado com até 480 mg kg-1de cobre aplicado no solo em relação aos demais isolados.

Las elevadas concentraciones de plomo (Pb) en el suelo limitan el establecimiento de las plantas, por lo que es importante identificar especies tolerantes. El objetivo del presente estudio consistió en determinar el efecto de PbCl2 y Pb(NO3)2 en la germinación y crecimiento temprano de Parkinsonia aculeata. En laboratorio se imbibieron las semillas en soluciones de PbCl2 y Pb(NO3)2 a concentraciones de 0.0, 0.1, 0.2, 0.5, 1.0 y 2.0 mM. Las semillas se pesaron al inicio y al final (48 h); posteriormente, se incubaron y regaron con sus respectivas soluciones (7 días). En invernadero, las semillas se sembraron en arena y se regaron (15 días) para determinar el porcentaje de germinación (laboratorio) y emergencia (invernadero); las variables consideradas fueron: longitud de vástago, radícula y peso seco (ambas condiciones). Bajo condiciones controladas, PbCl2 y Pb(NO3)2 no afectaron la imbibición, pero al aumentar sus concentraciones, redujeron significativamente la germinación en 18 y 26 %, respectivamente, así como el peso seco del vástago (40 y 49 %), y radícula (40 y 57 %). En invernadero, los compuestos de Pb no redujeron la emergencia, pero inhibieron el crecimiento de radícula; mientras que el Pb(NO3)2 inhibió en mayor proporción su peso seco. El efecto del Pb puede diferir en función del compuesto de Pb utilizado. El Pb(NO3)2 presenta una mayor toxicidad.

Um dos principais metais explorados no mundo é o cobre (Cu), um elemento nativo, que dificilmente é encontrado puro na natureza. A lavra e beneficiamento do cobre geram debates ambientais devido à formação de agentes poluidores nas áreas de concentração, fundição e refino, além dos impactos negativos na vegetação e topografia da área minerada. Este trabalho teve como objetivo investigar o desempenho morfométrico inicial do ipê-branco (Tabebuia roseo-alba (Ridl.) Sandwith) em substrato composto por rejeito de mineração de cobre e percentuais crescentes de matéria orgânica, bem como, avaliar seu potencial fitorremediador e o Índice de Qualidade de Dickson (IQD). O delineamento experimental foi o inteiramente casualizado, onde se coletou dados morfométricos dos tratamentos referentes à altura, diâmetro do caule e número de folhas da espécie vegetal que posteriormente foram submetidos à análise estatística e ao IQD, além dos cálculos relacionados ao índice e fator de translocação do cobre na planta e sua capacidade fitoextratora. A fitomassa compartimentalizada em raízes e parte aérea foi coletada, colocada em estufa, moída e enviada ao laboratório para as devidas avaliações do metal cobre nos compartimentos da espécie vegetal, além da avaliação química do substrato. Concluiu-se que o ipê-branco possui potencial fitoestabilizador do elemento cobre proveniente de rejeito de mineração, bem como atingiu um IQD satisfatório no tratamento composto por 90% de rejeito de mineração e 10% de matéria orgânica.

Las problemáticas ambientales asociadas al incremento de metales pesados como el plomo han promovido la búsqueda de bioindicadores eficientes; Vicia faba es uno de los más utilizados, sin embargo, su aprovechamiento a nivel mundial ha provocado el uso indistinto de sus variedades silvestres y domesticadas, sin considerar las implicaciones del proceso de domesticación. Por tal motivo, la presente investigación tiene como objetivo evaluar el efecto genotóxico y citotóxico del plomo en células meristemáticas de raíz de semillas de V. faba silvestre y de la variedad Major (domesticada) a través de la presencia de micronúcleos y la determinación del índice mitótico, con la finalidad de conocer sus respuestas ante este metal y su relación con la domesticación, así como sugerir el uso de la variedad más sensible como bioindicador. Para ello, los meristemos radiculares se sometieron a tratamientos con 0, 0.005, 0.01 y 0.02 g L-1 de acetato de plomo y se realizaron tinciones con aceto-orceína; se obtuvo la frecuencia de micronúcleos y el índice mitótico por cada 1000 células observadas. Los resultados obtenidos indican que el acetato de plomo tiene un efecto genotóxico y citotóxico diferencial entre ambas variedades, siendo V. faba var. Major la que presenta una alta sensibilidad al metal pesado, debido a una pérdida en la resistencia al estrés, por lo que se sugiere su uso como bioindicador; mientras que en las semillas silvestres mostraron mayor tolerancia al tener un bajo grado de domesticación.

O ne of the main metals explored in the world is copper (Cu), a native element, which is rarely found pure in nature. The mining and processing of copper generates environmental debates due to the generation of polluting agents in the areas of concentration, smelting and refining, in addition to the negative impacts imposed on the vegetation and topography of the mined area. The study aimed to investigate the initial morphometric performance of the white ipe (Tabebuia roseo-alba (Ridl.) Sandwith) in a substrate composed of copper mining tailings and increasing percentages of organic matter, evaluate its phytoremediator potential and the Dickson's Quality Index (IQD). The experimental design was the entirely randomized one. Morphometric data of the treatment were collected regarding height, stem diameter and number of leaves of the plant species where they were later submitted to statistical and IQD analysis, in addition to calculations related to the index and translocation factor of copper in the plant and its phytoextracting capacity. The phytomass compartmentalized in roots and aerial part was collected, placed in a drying oven, ground and sent to the laboratory for the proper evaluation of the copper metal in the compartments of the plant species, in addition to the chemical evaluation of the substrate. It was concluded that white ipe has the potential to phytostabilize the copper element coming from mining tailings, as well as achieving a satisfactory IQD in treatment composed of 90% of mining tailings and 10% of organic matter. [ABSTRACT FROM AUTHOR]

This research evaluated the phytotoxic effects of cadmium on the germination development and initial growth of Gossypium hirsutum L. The ecotoxicological effects of 13 experimental concentrations of cadmium (0.0-50.0 mM) on variables like germination percentage, GSI, average germination time (AGT) and root length were evaluated. G. hirsutum seeds exposed to cadmium showed a decrease in germination percentage and an increase in the number of normal plantules from the concentrations 18.0 and 3.0 mM, respectively. It also inhibited root growth and increased the AGT from the exposure to the concentration 0.5 mM, reducing the GSI. G. hirsutum is tolerant to cadmium during its germinal stage. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study uses the experimental research by phytoremediation technique, with the use of Canavalia ensiformis as a soil phytoremediation contaminated by slag, the analysis was done in five treatments under different doses of the contaminant (0, 32, 64, 128 and 256 grams). The results were submitted to analysis of variance and the means compared by 5% Tukey test. It can be concluded that the plant growth pattern was affected by the contaminant and the treatment 02 showed further development of the branch and biomass production compared to the others, and the Treatment 04 had lower branch growth rate followed by lower production biomass compared to other witnesses. [ABSTRACT FROM AUTHOR]

Copyright of Revista Facultad de Ingeniería - UPTC is the property of Universidad Pedagogica y Tecnologica de Colombia, Facultad de Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the effects of heavy metals in aquatic ecosystems is of significant importance due to their potential to bioaccumulate at various trophic levels and induce damage in DNA. Mercury is considered one of the most dangerous heavy metals, causing chromosomal breakage (clastogenic event) or spindle dysfunction (aneugenic event), that can lead to the formation of encapsulated chromatin into a separate smaller nucleus, generally referred to as a micronucleus. We evaluated the sensitivity of the micronucleus test in the neotropical cichlid Andinoacara rivulatus (Günther 1860). The fish were divided into four groups of 16 individuals, and each group was placed in separate aquaria (140 L) provided with filtered water and constant aeration. Fish were exposed to mercury chloride (HgCl2) at doses 0.1, 0.25, and 0.50 mg/kg body weight, administered by intraperitoneal (IP) injection. Fish from the control group were injected with a physiologic solution. The following erythrocyte anomalies were identified: erythrocytes with micronuclei varying to some extent in size and position in the cytoplasm, blebbed nucleus, binucleated cell, nuclei showing a deep invagination toward the center (notched nuclei). Examination of blood smears demonstrated a higher level of micronucleus and notched erythrocytes in fish injected with HgCl2 than in the controls. There were significant differences in the frequency of micronucleated and notched erythrocytes among the groups exposed to mercury. Linear regression analysis revealed a positive relationship between the frequency of micronucleated and notched erythrocytes (P< 0.0001), with a moderately strong correlation coefficient (R= 0.737). We propose that, in addition to the two so far known mechanisms of micronucleus formation (spindle apparatus damage and chromosomal ruptures), chromatin fragmentation in notched nuclei resulting from a combination of the cytotoxic effects of mercury and mechanical stress, may be a third mechanism of micronuclei genesis. [ABSTRACT FROM AUTHOR]

The presence of arsenic in irrigation water and its accumulation in agricultural soil increases in areas with intensive farming and negatively affects the health and economy of the producers. Plants absorb arsenic in the form of arsenate and can translocate it to the seeds; thus, we can find arsenate in the flour of species like wheat (Triticum durum). The plant cellular mechanisms do not differentiate phosphorous from arsenic due to the similarity between them; this generates metabolic disorders that restrict the plant development and its physiological performance from its first phenological stages, and can even limit the productive plot establishment. This study aimed to evaluate the physiological modifications and antioxidant components due to arsenate in wheat seedlings. We hypothesized that the response depends on the concentration of arsenate and the tolerance of the varieties. In the Bárcenas and Cortázar varieties seedlings, we evaluated concentrations of arsenate (100, 200, 500, and 700 mg L-1) and distilled water, using a randomized complete block experimental design. We considered each variety as a block and the treatments corresponded to the block combinations with the concentrations of arsenate and the control, with five repetitions per germination test. The Bárcenas seedlings were the most vigorous and presented the highest antioxidant activity, and with high concentrations of arsenate they synthesize greater concentrations of proline and phenolic compounds. With this variety, it could be possible to obtain tolerant lines that allow the cultivation of wheat plants in high concentrations of arsenic. [ABSTRACT FROM AUTHOR]

Introduction: Metals are called the chemical elements on the left and center of the periodic system. They are simple, solid elements (except mercury), conductors of heat and electricity, with a special shine once polished, and crystalstructure in solid state. Lead (Pb) is a heavy metal, which belongs to subgroup IV B of the periodic table and is the 82nd element. It has an atomic mass of 207.19 and its usual state of oxidation in inorganic compounds is +2. Acute poisoning is not common, the chronicism is called Saturnism: derived from the ancient name of the Pb "Saturn". The toxicity of this metal was recognized by Nicander of Colofon in 200 BC, with B. Ramazini in 1700 the first to study it. No benefit is known for the organism and is neurotoxic. Objective: Describe lead poisoning, as well as sources of exposure, clinical manifestations, preventive and pharmacological treatment. Methods: A bibliographic review was conducted on lead poisoning based on a telephone consultation carried out by professionals of the Pedro Soto Alba Pediatric Hospital to the Medical Guard of the National Center of Toxicology, by a patient diagnosis of lupus poisoning. [ABSTRACT FROM AUTHOR]

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Phytoremediation is an alternative technique used to treat copper-contaminated soils. The objective of this research was to explore the behavior of nine summer cover crops regarding the growth, absorption and translocation of copper in soils with contamination levels exceeding the Value of Prevention, with a view to selecting plants for phytoremediation programs. In the experiments the Cambisol was contaminated with copper, added in doses of 0, 100, 200, 400, 500 and 600mg kg-1, in which the following nine plants were cultivated under greenhouse conditions: Canavalia ensiformis, Cajanus cajan, Dolichos lablad, Mucuna cinereum, Mucuna aterrima, Crotalaria juncea, Crotalaria spectabilis, Pennisetum glaucum and Paspalum notatum. At 90 days after sowing the plants were evaluated for dry mass of shoot and root, Cu, N, P, K, Ca, Zn, and Fe levels in the shoot and Cu in the roots. High soil Cu levels induced a decline in the phosphorus absorption by the plants. Canavalia ensiformis displayed high potential for phytoextraction as these plants could translocate high copper concentrations to the aerial plant parts, while the Mucuna cinereum and M. aterrima are indicated for the copper phytostabilization programs, due to the high copper accumulation in their root systems. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of increasing concentrations of lead (Pb) in the nutrient solution on growth and macronutrient and organic solute contents of Helianthus annuus plants. The experimental design was completely randomized with four replications. The dry mass yield was not affected by the treatments up to a Pb concentration of 0.6 mM, indicating that H. annuus was tolerant to this Pb concentration in the growth medium. The reductions in leaf, stem and root dry masses at a Pb concentration of 0.8 mM were 74, 84 and 85%, respectively. Lead stress did not reduce the levels of nitrogen (N), phosphorus (P) and potassium (K), indicating that the growth reduction observed at 0.8 mM Pb could not be attributed to deficiencies of these nutrients. On the other hand, Pb significantly reduced calcium (Ca) and magnesium (Mg) contents in leaves, stems and roots, which might, at least in part, explain the Pb-induced growth reduction in the H. annuus plants. Pb increased soluble carbohydrate, free amino acid and proline contents in leaves, and soluble protein and proline contents in roots, showing stress-induced changes in cell metabolism. The data also suggest that Ca and Mg concentrations may be used as nutritional indicators and the proline content may be used as a biochemical indicator of Pb toxicity in H. annuus.

A preocupação ambiental permeia os diferentes âmbitos de ensino e pesquisa tanto nacional como internacional. Não obstante, ainda é possível observar a presença de experimentos, em instituições de ensino superior, que provoque impacto visual como, por exemplo, a precipitação do iodeto de chumbo, um produto químico que contém metal pesado. Evitar a geração de rejeitos químicos perpassa a formação do profissional como parte do seu dia-a-dia. Este artigo relata uma proposta de substituição de um experimento nas aulas de química geral experimental do ensino superior que tem como produto o metal pesado chumbo (Pb) envolvendo uma reação de oxidação-redução com a formação de precipitado sem a presença de um metal pesado.

The increasing amounts of heavy metals entering aquatic environments can result in high accumulation levels of these contaminants in fish and their consumers, which pose a serious risk to ecosystems and human health. We investigated the concentrations of mercury (Hg), cadmium (Cd), zinc (Zn), chromium (Cr), and lead (Pb) in muscle, liver, and spleen tissues of Pseudoplatystoma corruscans specimens collected from two sites on the Paraopeba River, Brazil. The level of heavy metals concentrations in the tissues was often higher in viscera (i.e. liver and spleen) than in muscle, and thus, the viscera should not be considered for human consumption. Correlations between metal concentrations and fish size were not significant. Although the levels of muscle bioaccumulation of Hg, Cd, Zn, Cr, and Pb, generally do not exceed the safe levels for human consumption, the constant presence of heavy metals in concentrations near those limits considered safe for human consumption, is a reason for concern, and populations who constantly consume fish from polluted rivers should be warned. Our findings also indicate that in a river network where certain areas are connected to other areas with high rates of environmental pollutants, people should be cautious about the regular consumption of fish, even when the fish consumed are caught in stretches of the basin where contamination levels are considered low, since many of the freshwater fish with high commercial value, such as the catfish surubim, are migratory.

A aplicação de fungicidas foliares em vinhedos incrementa o teor de cobre (Cu) no solo, que pode modificar parâmetros fisiológicos de videiras jovens transplantadas em solos de vinhedos erradicados. A inoculação com fungos micorrízicos arbusculares (FMA) pode reduzir a disponibilidade de Cu às videiras e, com isso, reduzir o efeito tóxico do Cu nas células de plantas jovens. O trabalho objetivou avaliar alterações fisiológicas no porta-enxerto de videira ‘P1103’ (Vitis berlandieri x Vitis rupestris) cultivado em solo com alto teor de Cu e inoculado com espécies de FMA. O experimento foi conduzido em casa de vegetação. As videiras foram acondicionadas em vasos. No momento do transplante, as raízes foram inoculadas com os FMA: Dentiscutata heterogama, Acaulospora morrowiae e Rhizophagus clarus, além de um tratamento controle, não-inoculado. O experimento foi conduzido em blocos ao acaso com sete repetições. O cultivo foi realizado durante 76 dias, ao final do qual foi avaliado a altura de planta, a área foliar, as taxas de trocas gasosas, colonização micorrízica, matéria seca de raízes, caule e folha; número de folhas, diâmetro de colmo, teores de carboidratos solúveis totais, amido total, clorofila a, b e total, carotenoides, teores de Cu e P nas plantas. Dentre os FMA avaliados, o R. clarus promoveu maior benefício para o crescimento das plantas e reduziu o teor de Cu nos tecidos. As maiores taxas de assimilação de CO2 e condutância estomática ocorreram nas plantas inoculadas com D. heterogama. Os FMAs estudados amenizaram a toxicidade do cobre às videiras jovens.

In this work we investigated whether priming with auxin, cytokinin, gibberellin, abscisic acid and ethylene, alters the physiological responses of seeds of pigeon pea germinated under water and cadmium stress. Seeds treated with water or non-treated seeds were used as control. Although compared to non-treated seeds we found that the hormone treatments improve the germination of pigeon pea under cadmium stress, however, these treatments did not differ from water. However, we also observed a trend of tolerance to the effects of cadmium in the presence of ethylene, suggesting that the use of this hormone may be an efficient method to overcome seed germination under metal stress.

Despite the considerable environmental importance of mercury (Hg), given its high toxicity and ability to contaminate large areas via atmospheric deposition, little is known about its activity in soils, especially tropical soils, in comparison with other heavy metals. This lack of information about Hg arises because analytical methods for determination of Hg are more laborious and expensive compared to methods for other heavy metals. The situation is even more precarious regarding speciation of Hg in soils since sequential extraction methods are also inefficient for this metal. The aim of this paper is to present a technique of thermal desorption associated with atomic absorption spectrometry, TDAAS, as an efficient tool for quantitative determination of Hg in soils. The method consists of the release of Hg by heating, followed by its quantification by atomic absorption spectrometry. It was developed by constructing calibration curves in different soil samples based on increasing volumes of standard Hg2+ solutions. Performance, accuracy, precision, and quantification and detection limit parameters were evaluated. No matrix interference was detected. Certified reference samples and comparison with a Direct Mercury Analyzer, DMA (another highly recognized technique), were used in validation of the method, which proved to be accurate and precise.

A espectroscopia de raios-X por reflexão total (TXRF) é uma técnica promissora para análise de elementos-traço (ETs), principalmente por não ser necessária a digestão das amostras, reduzindo assim a geração de resíduos e emissão de vapores tóxicos. Este trabalho comparou os teores dos ETs: Cr, Mn, Ni, Zn, Cu, As, Se, Hg e Pb, coletados em solos de área de agricultura intensiva e vegetação nativa, determinados por TXRF e por espectrometria de absorção atômica de chama ou forno de grafite (FAAS/GFAAS). Adicionalmente, compararam-se os teores dos ET com valores de referência para solos não contaminados. As amostras de solo foram coletadas na profundidade 0,0-0,2 m em municípios representativos de cada região agrícola do Estado de Mato Grosso (Rondonópolis, Alto Garça, Primavera do Leste, Campo Novo, Nova Mutum, Lucas do Rio Verde, Sorriso, Sinop, Campo Novo dos Parecis, Campos de Julho e Vila Bela da Santíssima Trindade). Em cada município, foram selecionadas seis áreas, totalizando 72 amostras, todas georreferenciadas. Para a leitura dos teores de ET no aparelho de TXRF S2 Picofox™, foram preparadas suspensões de solo usando Triton X-100 a 5 % v/v utilizando gálio como padrão interno, enquanto no FAAS/GFAAS as amostras foram submetidas à digestão ácida pelo método 3051A. Considerando área cultivada e área nativa, respectivamente, os teores médios dos ET por TXRF, em mg kg-1, foram: Cr, 69 e 62; Zn, 16 e 8; Pb, 28 e 21; Mn, 56 e 42; As, 2 e 2; Cu, 9 e 8; e Ni, 2 e 2. O Cd, Se e Hg não foram detectados por TXRF nas amostras analisadas. Para As, Cr, Mn, Zn, Ni, Cu e Pb, houve correlação linear (p

A correlação entre as características físicas e químicas do solo e o teor de mercúrio natural é importante para identificar aquelas que mais influenciam na retenção desse elemento nesses solos e sua distribuição nos diversos compartimentos ambientais. Esse estudo teve por objetivos determinar o teor de Hg de solos sem influência antropogênica e correlacionar esse teor com as características físicas e químicas dos solos. A relevância deste trabalho se deve ao fato que a maioria das pesquisas é focada em solos contaminados e, em caso de solos tropicais, as pesquisas são ainda mais escassas. As características físicas e químicas de diferentes solos de mata natural do Estado de Minas Gerias e de um solo do Estado do Rio de Janeiro foram correlacionadas com os teores naturais de Hg dos solos. O teor de Hg foi determinado empregando-se o analisador direto de Hg DMA-80. A faixa de concentração de Hg encontrada foi de 0 a 215 µg kg-1 com média de 81 µg kg-1. O teor de Hg dos solos correlacionou-se principalmente com o teor de argila e o pH do solo. Não houve correlação entre o teor de Hg e o de C. Para solos com teores mais altos de Hg e mesma textura, a capacidade de troca catiônica passa a ser uma variável importante.