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1.
Chemosphere ; 262: 128248, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32962839

RESUMO

Urban cemeteries on a global scale raise concerns due to their potential to concentrate differing levels of hazardous pollutants in their native soils due to the unnatural concentration of burials in a limited space. It is paramount for sustainability that designers of future cemeteries take this into account in order to minimize the deposition and movement of these contaminants within the soil profile. The objective of this manuscript is to identify the levels of certain hazardous element contamination, specifically heavy metals, in the soil of horizontal urban cemeteries that do not utilize herbicides for weed control. In this, solutions were sought for the construction of future urban cemeteries capable of mitigating further contamination of the environment by the increase in interments. The soils of three urban cemeteries (A, B and C) in the Brazilian city of Carazinho, in Rio Grande do Sul State, were sampled with 5 monitoring points in the internal area and 5 points in the external area of the cemeteries. At each point, 3 replications were performed at two depths (0-20 and 20-40 cm), totaling 180 samples in all, to determine the concentration of the following metals: copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), and chromium (Cr) (g kg-1). In addition, online interviews with 15 architects who design cemeteries were conducted. Architectural design solutions to mitigate environmental contamination were modeled utilizing the Building Information Modeling system (BIM). The results showed an excess of Cu in the soil of cemeteries A, B and C, surpassing the standards allowed by Brazilian federal regulations. A total of 80% of the interviewed architects expressed their preference for the vertical cemetery, with gas and effluent treatment systems to mitigate environmental impacts.


Assuntos
Cemitérios , Monitoramento Ambiental , Substâncias Perigosas/análise , Poluentes do Solo/análise , Brasil , Cromo/análise , Cidades , Cobre , Meio Ambiente , Poluição Ambiental , Ferro , Manganês , Metais Pesados/análise , Solo , Zinco/análise
2.
Chemosphere ; 254: 126852, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957277

RESUMO

This study reports the environmental fate and ecological hazard of the three heavy metals (HMs), viz. copper (Cu), manganese (Mn) and zinc (Zn) in soil influenced by municipal solid waste (MSW) dumping. The experimental site is situated in the vicinity of Deepor Beel, a Ramsar site located in Guwahati, India. This study assessed (i) the distribution pattern of Cu, Mn and Zn in six geochemical fractionations; (ii) the mobility, bioavailability and toxicity of Cu, Mn and Zn based on eight contamination and ecological indices, and (iii) the impact of Cu, Mn and Zn on soil quality. Altogether, 18 soil samples were collected and analysed from the study site using stratified random sampling. Pollution indices and multivariate statistics were applied on the data to identify the level and source of analysed HMs. Sequential extraction has revealed that the binding strength of Cu, Mn and Zn had a uniform trend. Mobility and potential bioavailability of studied HMs were in the order Mn > Cu > Zn. Analysed HMs were dominantly associated with non-bioavailable fractions. The observed low values of various contamination factors indicated the lesser contamination load posed by these metals. Conversely, their high enrichment factor and geo-accumulation index values indicated the sources of these metals were anthropogenic. Overall, the pollution and ecological indices registered lower contamination. Yet, it would be prudent to adopt efficient MSW management strategies for eliminating any future risk emanating out of this dumping site and posing threat to nearby Deepor Beel and its associated flora and fauna.


Assuntos
Metais Pesados/análise , Medição de Risco , Poluentes do Solo/análise , Cobre/análise , Monitoramento Ambiental , Poluição Ambiental/análise , Índia , Manganês/análise , Zinco/análise
3.
PLoS One ; 15(9): e0239739, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986755

RESUMO

Rice is critical for sustainable food and nutritional security; however, nominal micronutrient quantities in grains aggravate malnutrition in rice-eating poor populations. In this study, we evaluated genetic diversity in grain iron (Fe) and zinc (Zn) contents using trait-linked simple sequence repeat (SSR) markers in the representative subset of a large collection of local and exotic rice germplasm. Results demonstrated that aromatic fine grain accessions contained relatively higher Fe and Zn contents in brown rice (BR) than coarse grain accessions and a strong positive correlation between both mineral elements. Genotyping with 24 trait-linked SSR markers identified 21 polymorphic markers, among which 17 demonstrated higher gene diversity and polymorphism information content (PIC) values, strongly indicating that markers used in current research were moderate to highly informative for evaluating the genetic diversity. Population structure, principal coordinate and phylogenetic analyses classified studied rice accessions into two fine grain specific and one fine and coarse grain admixture subpopulations. Single marker analysis recognized four ZnBR and single FeBR significant marker-trait associations (MTAs) contributing 15.41-39.72% in total observed phenotypic variance. Furthermore, high grain Fe and Zn contents linked marker alleles from significant MTAs were also identified. Collectively, these results indicate a wide genetic diversity exist in grain Fe and Zn contents of studied rice accessions and reveal perspective for marker-assisted biofortification breeding.


Assuntos
Grão Comestível/química , Grão Comestível/genética , Ferro/análise , Micronutrientes/análise , Repetições de Microssatélites/genética , Oryza/química , Oryza/genética , Polimorfismo Genético , Zinco/análise , Alelos , Biofortificação , Biomarcadores , Grão Comestível/classificação , Genes de Plantas , Genótipo , Oryza/classificação , Fenótipo , Filogenia , Melhoramento Vegetal , Locos de Características Quantitativas
4.
Sci Total Environ ; 740: 139648, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927528

RESUMO

Soybean is recognized as one of the most important prospective protein sources for human nutrition under conditions of climate change and population growth. Occurrence of Se and Zn deficiency in vast areas over the globe inhabited by up to 2 billion people, induced search for a comprehensive solution to these problems through the efficient Se/Zn biofortification of soybean seeds (beans). To assess the Se/Zn accumulation efficiency and the physiological status of soybean plants, a pot experiment on Se and Zn enrichment in beans was conducted. It consisted of applying 15 different Se-deficient soil treatments with these elements during the flowering phase, alone or in dose combinations. Application of Se alone, besides Se accumulation in soybean, reduced Zn uptake from soil, but caused alterations in Zn translocation, and its multiple enrichment in beans. Addition of Zn alone promoted both Zn and Se enrichment in beans. Joint Se/Zn application in increasing doses appeared to have a strong synergistic effect on accumulation of these elements in beans and enhanced the physiological functions of the soybean. This manifested itself in the growth of photosynthetic production and soybean biomass, and in the improvement of lipid peroxidation status (REC, MDA and proline content indices). Toxicity symptoms indicated the maximum Se/Zn doses. Several-fold higher contents of Se and Zn in soybean straw compared to spiked soil suggest its possible use as Se/Zn-rich soil amendment in accordance with the circular economy goals. These novel findings may significantly contribute to human health improvement in Se and Zn deficient regions.


Assuntos
Solo , Soja , Biofortificação , Humanos , Estudos Prospectivos , Zinco/análise
5.
Mar Pollut Bull ; 158: 111094, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753165

RESUMO

Concentrations of Fe, Mn, Zn, and Cu in the muscle, lung, liver, and kidney tissues of 49 cetaceans, including 11 Kogia sima (Ks), 10 Lagenodelphis hosei (Lh), 14 Grampus griseus (Gg), and 14 Stenella attenuata (Sa) from 1994 to 2012 in Taiwan were measured. Ks exhibited the highest Fe, and the lowest Zn, Cu and Mn tissue concentrations. The Kogiid and Delphinid groups were significantly categorized by nMDS analysis. Fe muscle concentrations were found to be positively correlated with Ks, Lh, and Gg but not Sa body length. The different levels of Zn-, Cu-, and Mn- tissue concentrations of the two families were due to their different SOD systems. Their calves contained higher Cu liver concentrations. The four essential elements in cetaceans regulate homeostasis to meet their eco-physiological demand. The baseline levels for these four elements in these four tissues in the Delphinid group are defined.


Assuntos
Golfinhos , Oligoelementos/análise , Animais , Bovinos , Fígado/química , Taiwan , Baleias , Zinco/análise
6.
Sci Total Environ ; 738: 140311, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806385

RESUMO

Trace element concentrations in the rhizosphere were quantified to better understand why soil liming often fails to reduce cadmium (Cd) uptake by plants. Maize seedlings were grown on a soil with natural background levels of Cd and zinc (Zn). Soil liming increased soil pH from 4.9 to 6.5 and lowered the soil solution free ion activities by factor 7 (Cd) and 9 (Zn). In contrast, shoot Cd concentrations were unaffected by liming while shoot Zn concentrations were lowered by factor 1.9. Mapping of labile soil trace elements using diffusive gradients in thin films (DGT) in combination with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) revealed an almost complete depletion of Cd in the rhizosphere in all soil treatments, showing that Cd uptake is controlled by diffusion. The flux of Cd from soil to the DGT, with direct contact between the soil and the binding gel, was unaffected by liming whereas it decreased by factor 3 for Zn, closely mimicking the contrasting effects of liming on Cd and Zn bioavailability. This evidence, combined with additional flux data of freshly spiked Cd and Zn isotopes in soil and with modelling, suggests that the diffusive transport of Cd in unsaturated soil is more strongly controlled by the labile adsorbed metal concentration than by its concentration in solution. This is less the case for Zn because of its inherently slower desorption compared to Cd.


Assuntos
Poluentes do Solo/análise , Oligoelementos , Cádmio/análise , Rizosfera , Solo , Zea mays , Zinco/análise
7.
Leg Med (Tokyo) ; 47: 101768, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32738701

RESUMO

We investigated the application of energy-dispersive X-ray fluorescent spectrometry (EDX) analysis to the detection of aluminum (Al), tin (Sn) and zinc (Zn) as the electric conductor in experimental electrical injury. Experimental electrical injury was caused by exposure to alternating current at 100 V for 10 s. The peaks of Al, Sn, and Zn were detected by EDX in formalin-fixed skin samples of each current exposure group. Histological examination revealed blister formation in all samples of each current exposure group. EDX analysis technique can be applied to detect Al, Sn, and Zn as the electric conductor, and is useful in the diagnosis of electrocution.


Assuntos
Alumínio/análise , Traumatismos por Eletricidade/diagnóstico , Traumatismos por Eletricidade/metabolismo , Eletricidade/efeitos adversos , Resposta Galvânica da Pele , Pele/metabolismo , Espectrometria por Raios X , Estanho/análise , Zinco/análise , Animais , Traumatismos por Eletricidade/patologia , Masculino , Ratos Wistar , Pele/patologia
8.
Bull Environ Contam Toxicol ; 105(3): 405-410, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32776280

RESUMO

The accumulation of zinc (Zn) in Cichorium intybus and effects of phytotoxicity during 90 days of growth on (natural) non-contaminated and Zn-contaminated soils were studied. The phytotoxicity effects were monitored by evaluating the leaf area, leaf biomass, leaf length and root length of the vegetable. The Zn concentrations ranged from 5.35 ± 1.05 to 37.5 ± 3.89 mg kg-1 in leaves of plants grown on natural soil, and from 334.0 ± 25.6 to 2232 ± 16.7 mg kg-1 when grown on Zn-contaminated soils. Zn accumulation caused a decrease in growth on contaminated soils and an increase in phytotoxicity. These effects were associated to high metal concentration, mobility and bioavailability in the soil as well as changes in the translocation mechanism from the roots to the leaves. Then, it must be avoided the organic fertilization of soils with either animal manure or other agricultural inputs containing high zinc concentrations.


Assuntos
Chicória/efeitos dos fármacos , Poluentes do Solo/toxicidade , Zinco/toxicidade , Animais , Disponibilidade Biológica , Chicória/metabolismo , Fertilizantes , Metais , Folhas de Planta/química , Raízes de Plantas/química , Plantas , Solo , Poluentes do Solo/análise , Verduras , Zinco/análise
9.
Environ Sci Pollut Res Int ; 27(36): 45513-45526, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32794095

RESUMO

Cadmium (Cd) and zinc (Zn) toxicity causes physiological disorders and harms plants, interfering with the rehabilitation of areas affected by mining activities. This study evaluated how the exposure to Zn and/or Cd affects the growth of native andropogon grass (Andropogon gayanus Kunth) plants originally found in areas contaminated with Cd and/or Zn due to zinc mining activities. Plants were cultivated for 7 weeks in a nutrient solution treated with Zn (142.3-854.0 µM) or Cd (0.9-13.3 µM) separately or combined with a molar ratio of 64:1 (Zn:Cd). A control treatment was grown in a complete Hoagland and Arnon solution (without Cd). Plant height, stem diameter, internode length, dry weight, Cd and Zn concentration, and accumulation in shoots/roots, as well as ultrastructure of roots and leaves were analyzed at the end of the experiment. The root dry weight was not significantly affected by the addition of the metals. Moreover, Zn provided higher shoot dry weight (up to 160%) relative to control. Andropogon grass tolerated both metals better separately than when applied together. Transmission electron microscopy analyses showed modifications such as vesiculation and vacuolation in the ultrastructure of andropogon tissues by Cd and/or Zn. The andropogon grass was tolerant to the doses tested, evidencing that it has potential for recovering areas contaminated with Zn and/or Cd.


Assuntos
Andropogon , Poluentes do Solo , Bioacumulação , Cádmio/análise , Hidroponia , Raízes de Plantas/química , Poluentes do Solo/análise , Zinco/análise
10.
Aquat Toxicol ; 227: 105604, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32846286

RESUMO

River sediment is the ultimate sink for heavy metal pollution. Copper (Cu) and zinc (Zn) are consistently found at environmentally significant levels in sediments worldwide. We hypothesized that the bioavailability and potential ecological risk of Cu and Zn in river sediments may be affected by seasonal variations and spatial distribution. In this study, we tested our hypothesis using highly industrialized river sediments (Laojie River) as an example. The concentration of heavy metals, pollution indexes, and risk indexes were evaluated and multivariate statistical analyses were performed. We found that seasonal variations affect heavy metal contamination, pollution indexes, and potential ecological risk in sediments and this effect was more severe in the dry season. In addition, higher levels of metal contamination, pollution indexes, and potential ecological risk were observed midstream and downstream of the Laojie River. We found that Cu and Zn were the primary contaminants in Laojie River sediments and may originate from common anthropogenic sources. Analysis of the chemical fractions further revealed that Cu and Zn exhibited high mobility and potential bioavailability risk. In addition, a high percentage and amount of Cu and Zn were found in exchangeable fractions, suggesting they pose a great risk to aquatic organisms. Our results indicate that seasonal variations and spatial distribution affect the bioavailability and potential ecological risk of Cu and Zn in river sediments. These findings suggest that seasonal variations and spatial distribution are important parameters to consider for environmental monitoring and environmental management in aquatic environments.


Assuntos
Cobre/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Zinco/análise , Disponibilidade Biológica , China , Poluição Ambiental/análise , Sedimentos Geológicos/química , Metais Pesados/análise , Medição de Risco , Rios/química , Estações do Ano , Poluentes Químicos da Água/toxicidade
11.
Bull Environ Contam Toxicol ; 105(3): 428-432, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740744

RESUMO

The accumulation of Cd and Pb in rice grains poses a potential threat to human health, which is a subject of increasing concern across the globe. We examined the effect that foliar spraying of Zn-ethylenediaminetetraacetate (Zn-EDTA) (0.3% and 0.5% w/v) during the early-grain filling stage has on rice grain yield and Cd, Pb, Zn and Fe contents in rice tissues via a field experiment. The grain yield significantly decreased with the foliar application of 0.5% Zn-EDTA. In rice grain, foliar spraying of 0.5% Zn-EDTA significantly decreased the Cd and Pb contents, but increased the Zn and Fe contents. The main reasons for the decrease in the Cd and Pb content in grain were the inhibition of Cd and Pb by roots and the increased Fe content in grain via Zn-EDTA application. The foliar spraying of Zn-EDTA decreased the grain yield and Cd and Pb contents, while increased the Zn and Fe contents in grains.


Assuntos
Cádmio/análise , Ácido Edético/química , Chumbo/análise , Oryza/fisiologia , Poluentes do Solo/análise , Grão Comestível/química , Humanos , Oryza/efeitos dos fármacos , Folhas de Planta/química , Raízes de Plantas/química , Solo , Zinco/análise
12.
Environ Sci Pollut Res Int ; 27(35): 43942-43957, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32748358

RESUMO

This study investigates the contents of lead, zinc, and cadmium in 109 near-surface soil samples collected around the abandoned mine of Fedj Lahdoum, northern Tunisia, to assess the risk of pollution they generate. The study involved some analytical procedures such as pH measurements, X-ray diffraction techniques, sequential fractionation, and geostatistical mapping using the ordinary Kriging techniques. The sequential fractionation revealed that the bioavailability of Pb, Zn, and Cd follows the orders F5 > F3 ¼ F4 > F2 ¼ F1, F5 > F3 ¼ F4 ¼ F2 > F1 and F5 > F2 ¼ F4 > F1, respectively; their associations with organic matter and residual sulfides (F4) are relatively low. However, their high cumulated contents are dominantly associated with the residual (F5) and reducible (F3) fractions. The geostatistical mapping was endeavored to predict the spatial distribution of the studied heavy metals at unsampled sites and to produce a cumulated risk map of soil pollution. The latter is discussed with emphasis of the main factors responsible for the scattering of the pollution as much as the landscape conditions, the chemical composition of the mine tailings, the surface drainage of meteoric water and the wind. This study provides insight into the delineation of the spatial spreading of Pb, Zn, and Cd around the abandoned mine Fedj Lahdoum and their surrounding urban areas. It reveals that the mine infrastructure areas encompassing both extraction and processing and tailing deposition areas are the main sources of contamination. And the landscape conditions together with the surface drainage of meteoric water and the wind are the main factors responsible for the scattering of the pollution.


Assuntos
Metais Pesados , Poluentes do Solo , Monitoramento Ambiental , Poluição Ambiental , Chumbo , Metais Pesados/análise , Poluentes do Solo/análise , Tunísia , Zinco/análise
13.
S Afr Med J ; 110(5): 409-415, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32657727

RESUMO

BACKGROUND: Atopic dermatitis (AD) is a common chronic inflammatory skin condition that disproportionately affects children and is associated with reduced quality of life. Zinc deficiency may contribute to the pathogenesis of AD because zinc plays a role in epidermal barrier integrity and the immune system. Systematic review evidence suggests that low zinc is associated with AD, but limitations of included studies support further investigation. OBJECTIVES: To investigate hair zinc concentrations in children with AD v. healthy controls in a low- to middle-income country setting. METHODS: One hundred and five children aged 1 - 12 yea-rs participated in a frequency-matched for age case-control study. The outcome variable, AD, was confirmed by a clinician and corroborated using the UK Working Party criteria. The primary predictor, long-term average zinc concentration, was determined by measuring hair zinc using inductively coupled mass spectrometry. Baseline demographic characteristics, anthropometry and measures of socioeconomic status were included in our logistic regression analysis. Subgroup analysis was performed where interaction terms suggested effect modification. RESULTS: Using data from the overall sample, population median hair zinc was not significantly different between children with AD and healthy controls. However, subgroup analysis suggested a clinically and statistically significant difference in median zinc between children with AD (175.35 µg/g) and healthy controls (206.4 µg/g) in the older age group (5 - 12 years) (p=0.01). In this age group, multivariable logistic regression analysis also found significantly decreased hair zinc concentrations in AD (odds ratio 0.83; 95% confidence interval 0.66 - 0.96; p=0.046). CONCLUSIONS: The inverse association between zinc status and AD in children aged 5 - 12 years in our setting is consistent with the international literature. The clinical importance of decreased zinc levels in AD is not yet known. Further investigation into relevant underlying mechanisms seems warranted given the global reach of AD, its effect on quality of life, and the low cost of potential zinc-based interventions.


Assuntos
Dermatite Atópica/epidemiologia , Cabelo/química , Zinco/análise , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , África do Sul/epidemiologia
14.
Ecotoxicol Environ Saf ; 202: 110893, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615495

RESUMO

Leaching of the hazardous electric arc furnace (EAF) dust containing mainly zinc ferrite and zinc oxide, accompanied by minor concentrations of arsenic compounds, was investigated using sulfuric acid. In order to reach the maximum recovery of zinc, the leaching solution was adjusted to recover both iron and zinc at their maximum possible values. To obtain a high recovery value of zinc and iron, analyzed by AAS, the optimum leaching condition was found to be the temperature of 90 °C, the sulfuric acid concentration of 3 M, the particle size of 75 µm, the S/L ratio of 1:10 g/mL and the leaching time of 2 h. The percentages of the zinc and iron recovery under the optimum condition were ca. 98.6% and 99.1% respectively, which were verified by a confirmation test and were very close to the predicted values of 100% based on the optimized model, obtained through the software. From the thermodynamics' point of view, it has been found that Zn2+ is the predominant species (90%) under the leaching condition applied. Moreover, the predominant species of iron are FeSO4+, FeHSO42+, Fe(SO4)2- and Fe3+ in the magnitudes of 65.8%, 25.6%, 4.4% and 4.0%, respectively. According to the kinetic results, the controlling step in the leaching was the chemical reaction at the most of the operating temperatures and times. In order to purify the zinc solution for electrowinning, iron and arsenic were removed through the jarosite formation process as confirmed by the XRD results. The speciation of arsenic in the precipitated jarosite was explored by XPS. Finally, the low concentrations of arsenic (less than 0.1 ppm) and iron (less than 50 ppm) were determined by the ICP analysis.


Assuntos
Compostos Férricos/química , Metalurgia/métodos , Reciclagem , Sulfatos/química , Zinco/análise , Poeira/análise , Eletricidade , Ferro/química , Tamanho da Partícula , Ácidos Sulfúricos , Temperatura , Óxido de Zinco
15.
Sci Total Environ ; 745: 140926, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32712499

RESUMO

Arsenic, copper, and zinc are common elements found in contaminated soils but little is known about their combined effects on plants when presented simultaneously. Here, we systematically investigated the phytotoxicity and uptake of binary and ternary mixtures of As, Cu, and Zn in a soil-plant system, using wheat (Triticum aestivum) as model species. The reference models of concentration addition (CA) and response addition (RA) coupled with different expressions of exposure (total concentrations in soil ([M]tot, mg/kg), free ion activities in soil solution ({M}, µM), and internal concentrations in plant roots ([M]int, µg/g)), were selected to assess the interaction mechanisms of binary mixtures of AsCu, AsZn, and CuZn. Metal(loid) interactions in soil were estimated in terms of solution-solid partitioning, root uptake, and root elongation effects. The partitioning of one metal(loid) between the soil solution and solid phase was most often inhibited by the presence of the other metal(loid). In terms of uptake, inhibitory effects and no effects were observed in the mixtures of As, Cu, and Zn, depending on the mixture combinations and the dose metrics used. In terms of toxicity, simple (antagonistic or synergistic) and more complex (dose ratio-dependent or dose level-dependent) interaction patterns of binary mixtures occurred, depending on the dose metrics selected and the reference models used. For ternary mixtures (As-Cu-Zn), nearly additive effects were observed irrespective of dose descriptors and reference models. The observed interactions in this study may help to understand and predict the joint toxicity of metal(loid)s mixtures in soil-plant system. Mixture interactions and bioavailability should be incorporated into the regulatory framework for accurate risk assessment of multimetal-contaminated sites.


Assuntos
Arsênico/toxicidade , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Cobre/toxicidade , Solo , Triticum/efeitos dos fármacos , Zinco/análise , Zinco/toxicidade
16.
Chemosphere ; 260: 127652, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32688325

RESUMO

Cadmium (Cd) contamination in soil negatively impacts crop productivity, grain quality, and human health. Wheat seeds, with different concentrations of intrinsic zinc (Zn): low Zn (35 mg kg-1), medium (42 mg kg-1), and high Zn (49 mg kg-1), were planted in artificially contaminated soil (10 mg Cd kg-1 soil). Zinc (5 g kg-1) and biochar (20 g kg-1 soil) were applied alone or in combination at sowing. Cadmium contamination reduced wheat growth, productivity, and grain Zn concentration, relative to the respective no-Cd treatments, with greater reductions in plants with low intrinsic Zn. Among the soil amendments, Zn and/or biochar improved wheat productivity and grain Zn and reduced grain Cd concentration in plants grown from seed with varying intrinsic Zn levels. Plants from high intrinsic Zn seeds performed better under Cd stress with the application of soil amendments than seeds with low or medium intrinsic Zn levels. The combined application of Zn and biochar had the highest increases in grain yield (9.51%) and grain Zn concentration (12.2%), relative to the control (no Cd, no Zn, and no biochar). This treatment also decreased the Cd concentrations in straw (7.1%) and grain (95.6%). The sole application of Zn or biochar improved wheat productivity and grain Zn concentration and deceased grain Cd concentration under Cd stress, but more improvements resulted from the combined application of Zn and biochar. Plants grown from seed with high Zn were better able to tolerate Cd stress than the plants raised from seeds with medium and low Zn levels.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Triticum/fisiologia , Zinco/análise , Pão , Cádmio/química , Carvão Vegetal , Grão Comestível/química , Poluição Ambiental , Humanos , Sementes/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/química , Triticum/crescimento & desenvolvimento
17.
Acta Clin Croat ; 59(1): 154-160, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32724287

RESUMO

The prevalence and importance of male infertility make it a serious worldwide medical and social problem. The aim of this study was to determine if there were any significant differences in zinc concentrations in seminal fluid in men diagnosed with infertility compared to control group, and if there were, to determine how it affected the number and percentage of sperm cells with normal motility and morphology. A case-control study was conducted in the Osijek-Baranja County from January 2014 to June of 2015. The study included 276 subjects referred to biochemistry laboratory of the Osijek University Hospital Centre, 100 (36.2%) of them with low sperm count confirmed by spermiogram after 3 months. Semen samples were processed according to the World Health Organization criteria, and zinc concentrations were determined using spectrophotometry and direct colorimetry without deproteinization on a chemistry analyzer (Olympus AU 680, Beckman Coulter, Tokyo, Japan). Study results showed the men with low sperm count to be significantly older (Mann Whitney U test: p=0.013) and to have lower zinc levels (χ2-test: p<0.001). Further analysis included 100 (36.2%) patients with low sperm count. In the group of infertile men, those with low sperm count had higher zinc levels compared to men with azoospermia (Mann Whitney U test: p=0.036), suggesting a connection between lower zinc level in seminal fluid and male fertility. Zinc as a biological marker and an antioxidant affects sperm count, motility and morphology. Zinc supplemental therapy could improve seminal parameters in patients diagnosed with low sperm count. Dietary habits of the subjects differ regionally, and future research could make a solid foundation for complementary approach to treatment of male infertility.


Assuntos
Infertilidade Masculina , Sêmen , Zinco , Adulto , Estudos de Casos e Controles , Humanos , Infertilidade Masculina/diagnóstico , Masculino , Sêmen/química , Contagem de Espermatozoides , Motilidade Espermática , Zinco/análise
18.
Chemosphere ; 260: 127505, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32683021

RESUMO

Competitive and non-competitive batch experiments were conducted on flax fibers to study Zn2+, Cu2+, and Pb2+ ions biosorption performance. Biosorption efficiency was dependent on contact time, pH, and biosorbent concentration. The results under competitive conditions were different from those obtained in non-competitive form. A high affinity of lead, with a selectivity sequence in general of Pb > Cu > Zn was observed. The biosorption data fitted very well the Langmuir model for lead in both types of solutions and for zinc and copper in the monometal form. The fit with the Freundlich model was not as successful, except for copper in the ternary system. Regarding zinc under competitive conditions, the sorption process was quite difficult and thus the equilibrium data could not fit well the adsorption models. The maximum adsorption capacities (mmol.kg-1) were respectively 112, 122 and 71, for Pb, Cu and Zn in the single metal ion solution and 82, 57 and 8 only in the ternary, showing thus a high competition between metal ions when added simultaneously. Overall, lead could still be efficiently removed in spite of the presence of other ions while zinc would be overcome in the presence of lead and copper.


Assuntos
Cobre/análise , Linho/química , Chumbo/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Zinco/análise , Adsorção , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Teóricos , Soluções , Propriedades de Superfície
19.
J Environ Sci Health B ; 55(9): 844-853, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32657218

RESUMO

A greenhouse pot experiment was conducted to evaluate the effect of biochar on the growth and uptake of Pb and Zn by tomato plants (Solanum lycopersicum, L.) cultivated in two highly contaminated Kosovo soils, A and B. Plants were cultivated in the biochar amended and unamended soils. As expected, the biochar addition to the two polluted soils has contributed to significantly improve the crop yields, in terms of both fresh and dry weight. Further, results indicated that the effect of biochar on metal mobility is closely related, besides its properties, to soil's native characteristics. In fact, the addition of biochar to soil B had also beneficial effects on the uptake of both metals, halving in some cases the values of the biological accumulation and transfer coefficients, while it did not show the same efficacy on soil A.


Assuntos
Carvão Vegetal , Chumbo/farmacocinética , Lycopersicon esculentum/efeitos dos fármacos , Poluentes do Solo/farmacocinética , Zinco/farmacocinética , Kosovo , Chumbo/análise , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Poluentes do Solo/análise , Zinco/análise
20.
Proc Natl Acad Sci U S A ; 117(32): 19528-19537, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723821

RESUMO

Zinc starvation in mycobacteria leads to remodeling of ribosomes, in which multiple ribosomal (r-) proteins containing the zinc-binding CXXC motif are replaced by their motif-free paralogues, collectively called C- r-proteins. We previously reported that the 70S C- ribosome is exclusively targeted for hibernation by mycobacterial-specific protein Y (Mpy), which binds to the decoding center and stabilizes the ribosome in an inactive and drug-resistant state. In this study, we delineate the conditions for ribosome remodeling and hibernation and provide further insight into how zinc depletion induces Mpy recruitment to C- ribosomes. Specifically, we show that ribosome hibernation in a batch culture is induced at an approximately two-fold lower cellular zinc concentration than remodeling. We further identify a growth phase in which the C- ribosome remains active, while its hibernation is inhibited by the caseinolytic protease (Clp) system in a zinc-dependent manner. The Clp protease system destabilizes a zinc-bound form of Mpy recruitment factor (Mrf), which is stabilized upon further depletion of zinc, presumably in a zinc-free form. Stabilized Mrf binds to the 30S subunit and recruits Mpy to the ribosome. Replenishment of zinc to cells harboring hibernating ribosomes restores Mrf instability and dissociates Mpy from the ribosome. Finally, we demonstrate zinc-responsive binding of Mpy to ribosomes in Mycobacterium tuberculosis (Mtb) and show Mpy-dependent antibiotic tolerance of Mtb in mouse lungs. Together, we propose that ribosome hibernation is a specific and conserved response to zinc depletion in both environmental and pathogenic mycobacteria.


Assuntos
Mycobacterium tuberculosis/metabolismo , Ribossomos/metabolismo , Zinco/deficiência , Animais , Antibióticos Antituberculose/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Tolerância a Medicamentos/genética , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Camundongos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas/metabolismo , Zinco/análise , Zinco/metabolismo
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