Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.022
Filtrar
1.
Rev Environ Contam Toxicol ; 249: 153-197, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30900073

RESUMO

Lead (Pb) is an extremely toxic metal for all living forms including plants. It enters plants through roots from soil or soil solution. It is considered as one of the most eminent examples of anthropogenic environmental pollutant added in environment through mining and smelting of lead ores, coal burning, waste from battery industries, leaded paints, metal plating, and automobile exhaust. Uptake of Pb in plants is a nonselective process and is driven by H+/ATPases. Translocation of Pb metal ions occurs by apoplastic movement resulting in deposition of metal ions in the endodermis and is further transported by symplastic movement. Plants exposed to high concentration of Pb show toxic symptoms due to the overproduction of reactive oxygen species (ROS) through Fenton-Haber-Weiss reaction. ROS include superoxide anion, hydroxyl radical, and hydrogen peroxide, which reach to macro- and micro-cellular levels in the plant cells and cause oxidative damage. Plant growth and plethora of biochemical and physiological attributes including plant growth, water status, photosynthetic efficiency, antioxidative defense system, phenolic compounds, metal chelators, osmolytes, and redox status are adversely influenced by Pb toxicity. Plants respond to toxic levels of Pb in varied ways such as restricted uptake of metal, chelation of metal ions to the root endodermis, enhancement in activity of antioxidative defense, alteration in metal transporters expression, and involvement of plant growth regulators.


Assuntos
Chumbo/toxicidade , Fenômenos Fisiológicos Vegetais , Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Antioxidantes , Espécies Reativas de Oxigênio
2.
J Photochem Photobiol B ; 197: 111551, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31306954

RESUMO

Heavy metal pollution as one of the most serious pollution problems of marine environment, seriously threatens the safety of marine organism and human health, and will lead to potential risks for the marine ecological environment. In order to develop a rapid and sensitive toxicity detection method for marine heavy metals, in this study, marine diatom Nitzschia closterium was used as the test organism, and the effects of different concentrations of lead (Pb) on the five chlorophyll fluorescence parameters of N. closterium including the maximum photochemical quantum yield of PSII (Fv/Fm), the effective quantum yield of PSII photochemical energy conversion (ΦPSII), the effective absorption cross section of PSII photochemistry (σPSII'), the relative electron transfer rate of PSII (rP), and the PSII electron flux per unit volume (JVPII) at different exposure times were investigated based on chlorophyll fluorescence technology. By comparing with the photosynthetic activity fluorescence parameter Fv/Fm which is commonly used for toxicity analysis of pollutants using algae as test organisms, the optimal chlorophyll fluorescence parameter that could rapidly and sensitively determine Pb toxicity to N. closterium was selected. The results indicate that all the five chlorophyll fluorescence parameters of Fv/Fm, ΦPSII, σPSII', rP and JVPII showed good dose-response relationships with Pb within 8 h exposure time, and they all could be used as endpoints to rapidly determine Pb toxicity to N. closterium. Among the five chlorophyll fluorescence parameters, JVPII was the most sensitive fluorescence parameter for detecting the toxicity of Pb to N. closterium within 6 h exposure. And for JVPII, the median effective concentration (EC50) values of Pb at 2, 4 and 6 h were 0.329, 0.068 and 0.040 mmol L-1, respectively. However, when the exposure time was 8 h, ΦPSII was the most sensitive fluorescence parameter for the toxicity detection of Pb, and the EC50 value of Pb at 8 h was 0.038 mmol L-1. This study will provide an important basis for the development of a rapid and sensitive detection method for the biological toxicity of marine heavy metals, and those results will be helpful for ecological risk assessment in marine environment.


Assuntos
Clorofila/química , Chumbo/toxicidade , Microalgas/efeitos dos fármacos , Microalgas/química , Microalgas/metabolismo , Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/metabolismo , Teoria Quântica , Espectrometria de Fluorescência , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
3.
Environ Sci Pollut Res Int ; 26(22): 22736-22746, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31172438

RESUMO

The Thymus vulgaris (T. vulgaris) has been used in foods for the flavor, aroma, and preservation and in folk medicines. The objective of the present work was to determine the antioxidant and protective effects of T. vulgaris extract against lead (Pb)-intoxicated rats. A thirty-two male Sprague-Dawley were randomly assigned into 4 equal groups and treated for six weeks as follows: group I (GP-I), served as negative control; GP-II, -III, and -IV received either Pb acetate in drinking water (500 mg/L), T. vulgaris extract (500 mg/kg/day) by oral gavage or Pb acetate with T. vulgaris extract, respectively. Blood samples were collected at the end of the study week 6 to measure the hepatic and renal biochemical markers, complete blood count alongside the serum levels of interleukin (IL)-1ß, IL-6, IL-10, tumor necrosis (TNF)-α, and interferon (IFN)-γ. Additionally, liver and kidney tissue specimens were collected for histopathology as well as to measure the antioxidant-reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) alongside the lipid peroxidation marker, malonaldehyde (MDA). The results indicated that Pb toxicity increased the serum levels of IL-1ß, IL-6, and TNF-α, whereas IL-10 and IFN-γ were reduced. The results showed disturbed liver and renal functions; increased serum levels of ALT, AST, ALP, total bilirubin, creatinine, and urea; and decreased total protein, albumin, and calcium. The GSH, Gpx, and CAT levels were significantly decreased in the Pb-administrated group, while MDA was increased. However, regarding the hepatorenal markers, those animals treated with T. vulgaris alone did not induce any significant changes. Moreover, the combined treatment with T. vulgaris extract together with Pb showed significant improvement in Pb-induced toxicity in all the tested parameters compared to the negative control group. We investigated the potential protective effects of the medicinal plant T. vulgaris in vivo, since there are no publications that address the potential protective effect of this leaf extract against Pb-induced hepatorenal toxicity. Our studies concluded that the T. vulgaris extract reduces Pb overload in hepatorenal tissues, and that this has a potential immunomodulatory role, antioxidant activity, and a protective effect against Pb toxicity.


Assuntos
Antioxidantes/metabolismo , Chumbo/toxicidade , Extratos Vegetais/metabolismo , Thymus (Planta) , Animais , Catalase/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Interleucina-10 , Rim/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
4.
Ecotoxicol Environ Saf ; 181: 146-154, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31177079

RESUMO

The impact of lead (Pb) on Spirodela polyrhiza was studied to determine the subcellular distribution, chemical forms, and resulting morphophysiological modifications after treatments with 20 or 80 µM Pb(NO3)2 for 10 days. At the subcellular level, the Pb uptake by S. polyrhiza was mainly compartmentalized in the cell walls (70%), and the majority of Pb (approximately 70%) was extracted using 1 M NaCl and 2% acetic acid (HAc). Visual symptoms of phytotoxcity, surface roughness and closure of stomata, were observed in Pb-treated fronds. Electron-dense precipitates were present in cell walls, and changes to the ultrastructure were most noticeably exhibited in organelle shape, internal organization, and size of the plastoglobules of chloroplasts. Toxic concentrations of Pb induced oxidative stress in fronds, characterized by an accumulation of malondialdehyde (MDA) and decreased chlorophyll and unsaturated fatty acid contents. Pb exposure increased ABS/RC, TRo/RC, DIo/RC, Vj, and φDo (Fv/Fm), indicating that reaction centers were transformed to dissipation sinks, leading to a decrease in the efficiency of photosystem II, which was evident from the decreased values of Fv/Fo, Fv/Fm, ψEo, φEo, RC/ABS, and PIabs. These results indicated that decreased photosynthesis in Pb-treated fronds was partially ascribed to the lower pigment content, inhibition of electron transport, inactivation of the reaction centers, damage to the chloroplast ultrastructure, and stomatal closure. The physiological implications of subcellular distribution and chemical forms are discussed in relation to Pb accumulation and detoxification. However, Pb accumulation significantly impaired photosynthesis and membrane integrity in the fronds of S. polyrhiza.


Assuntos
Araceae/efeitos dos fármacos , Chumbo/toxicidade , Araceae/anatomia & histologia , Araceae/metabolismo , Araceae/ultraestrutura , Clorofila/metabolismo , Cloroplastos/efeitos dos fármacos , Cloroplastos/ultraestrutura , Transporte de Elétrons/efeitos dos fármacos , Ácidos Graxos Insaturados/metabolismo , Chumbo/farmacocinética , Malondialdeído/metabolismo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo
5.
Chemosphere ; 233: 579-589, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31195263

RESUMO

Complex interactions have been established between nanoparticles (NPs) and heavy metals in real environments. Herein we used zebrafish embryos to investigate the influence of titanium dioxide NPs (n-TiO2) on the uptake, bioconcentration, and depuration, and toxicity of Pb. The formation of n-TiO2-Pb complexes was confirmed in an exposure suspension. An increase in Pb bioconcentration was observed in zebrafish embryos upon co-exposure to n-TiO2 and Pb; moreover, n-TiO2-Pb complexes could be found in the embryos, indicating the bioavailability of NPs. However, there was no difference in the depuration rates of Pb in the presence of n-TiO2. Metallothionein (MT) content was significantly increased upon exposure to Pb alone, and the content significantly increased even further upon co-exposure. A downregulation in the expression levels of the neurodevelopment-related genes gfap, syn2α, and elavl3 was observed in the embryos, and we also noted a reduction in the swimming speed of and the total distance traveled by the larvae. To summarize, our results indicate that n-TiO2 can act as an effective carrier of Pb to enhance its uptake, bioavailability, and toxicity in zebrafish embryos.


Assuntos
Embrião não Mamífero/fisiologia , Chumbo/toxicidade , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Disponibilidade Biológica , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Larva/metabolismo , Metalotioneína/metabolismo , Nanopartículas/toxicidade , Peixe-Zebra/metabolismo
6.
Environ Pollut ; 249: 1091-1105, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146315

RESUMO

Lead (Pb) both in paints and children's Polyvinyl chloride (PVC) toys is a major public health concern which has attracted attention of the international community. Concentrations of Pb both in lead-based paints and children's PVC toys have been assessed through various studies across the globe. Therefore, the purpose of this article was to summarize the results reported in these studies and provide some comprehension on their implications to human health for law enforcement as well as for awareness raising to the general public. Highlights on identified gaps have been provided to pave ways for further research interventions in order to establish comprehensive information on the subject. Regardless of regulatory limits on the content of lead, both in paints and children's PVC toys existing in different countries in the world, some of the reviewed articles have revealed significant levels of lead in these two items far above the permissible limits. High lead levels in paints have been recorded in China (116,200 ppm), Cameroon (500,000 ppm), South Africa (189,000 ppm), Tanzania (120,862.1 ppm), Uganda (150,000 ppm), Thailand (505,716 ppm) and Brazil (170,258.4 ppm) just to mention a few. Lead poisoning cases in children have been reported in several countries including France, Morocco, South Africa and United States. Countries where high levels of lead in children's PVC toys have been recounted include; China (860,000 ppm), South Africa (145,000 ppm), United States (22,550 ppm), Thailand (4,486.11 ppm), Palestine (6,036 ppm) and India (2,104 ppm). Awareness raising among parents is vital to impart them with knowledge on the matter so that they can take strenuous measures to protect their children from lead poisoning emanating from playing with toys and paint dust. Law enforcement on phasing out lead-based paints and control of lead content in children's PVC toys worldwide is also highly recommended.


Assuntos
Intoxicação por Chumbo/etiologia , Chumbo/toxicidade , Pintura/análise , Jogos e Brinquedos , Cloreto de Polivinila/toxicidade , Criança , Humanos , Chumbo/análise , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/prevenção & controle , Cloreto de Polivinila/análise
7.
Chemosphere ; 232: 430-438, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158638

RESUMO

Long-term effects of Pb2+ on the operating performance and membrane fouling of two hydrolytic-anoxic-oxic-membrane bioreactors treating synthetic electroplating wastewater were investigated. The COD, NH4+-N and TN removal efficiencies decreased by 5.5%, 10.4% and 7.9% with long-term exposure of 2 mg L-1 Pb2+, while serious decreases achieved 25.4%, 35.0% and 26.2% with 6 mg L-1 Pb2+ exposure, respectively. 2 mg L-1 Pb2+ mitigated the cake layer fouling rate by 25.4% but increased the pore blocking rate by 69.1%, which was contributed by the increase of low and moderate molecular weight (MW) components in the soluble and colloidal foulants (SCFs). 6 mg L-1 Pb2+ accelerated the cake layer fouling rate by 101.1%, but mitigated the pore blocking rate by 6.4% due to the increase of high MW SCFs (especially polysaccharides). Thermodynamic analyses showed that Pb2+ regulated the concentration and protein/polysaccharide ratio of loosely bound extracellular polymeric substances, thus changing the flocs hydrophobicity and aggregation capacity, leading the cake layer fouling rate variation.


Assuntos
Incrustação Biológica , Reatores Biológicos/microbiologia , Galvanoplastia , Chumbo/toxicidade , Membranas Artificiais , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Aerobiose , Anaerobiose , Chumbo/análise , Poluentes Químicos da Água/análise
8.
Artigo em Chinês | MEDLINE | ID: mdl-31189237

RESUMO

Objective: To investigate the dynamic changes of copper and iron contents in brain tissue, body fluids and barriers of rats exposed to lead at different periods in order to provide a theoretical basis for the study of the mechanism of lead nerve injury. Methods: Sixty-four healthy adult SPF male SD rats were randomly divided into control group and lead exposure group, after one week of adaptive feeding, rats in the lead exposure group were treated with 250 mg/L lead acetate, and rats in control group were treated with ordinary drinking water, the experimental period was 12 weeks. After exposure for 3, 6, 9 and 12 weeks, the samples including blood, choroid plexus, cerebrospinal fluid, cortex, hippocampus, striatum, hypothalamus, amygdala, substantia nigra and cerebellum were obtained. Lead, copper and iron content in all kinds of samples were detected by Inductively Coupled Plasma Mass Spectrometry(ICP-MS). The measurement data were presented as Mean±SD, Comparison of metal contents in different tissues of rats at different time analyzed using repeated measurement analysis of variance, Two-variable correlation analysis using Spearman correlation test.The relationship between lead exposure experiod and copper and iron in samples was studied by using trend test. Results: After 12 weeks of lead exposure compared with the control group, lead contents in cortex, hippocampus, striatum, hypothalamus, amygdala, substantia nigra and cerebellum of rats were 2.21, 2.44, 2.95, 3.53, 4.01, 1.85 and 2.86 folds of control group, and the differences were statistically significant(P<0.05). At the same time, lead content in blood, cerebrospinal fluid,choroid plexus, brain microvessels and bones increased. The increase rate in the amygdala and cerebrospinal fluid ranked first among brain tissue or barrier,which were 4.01 and 3.0 folds respectively. Compared with the control group, Compared with the control group, copper content in cortex,hippocampus, striatum, hypothalamus,amygdala, cerebellum,blood,cerebrospinal fluid,choroid plexus and cerebral microvasculature showed an increasing trend among rats following 3,6,9,12 weeks of lead exposure. Copper content change in the striatum was highest among all brain tissue. The increase rate of copper content in the striatum was at the top among brain tissues. After 12 weeks of lead exposure,copper content in brain microvessels was 4.98 folds higher than that of the control group (P<0.05). After lead exposure at different periods,the iron content in the cortex, hippocampus, striatum,cerebrospinal fluid,choroid plexus and brain microvessels of experimental rats all increased(P<0.05). And the iron increase rate in the hypothalamus or cerebrospinal fluid increase ranked first among brain tissues or body fluid the most obviously. Conclusion: With the increase of exposure time, lead exposure can changes in the contents of copper and iron in different brain tissues,body fluids and barriers in rats,among which, the contents of copper and iron in the amygdala,cerebrospinal fluid and brain microvessels increase significantly. This may be related to nerve damage from lead exposure.


Assuntos
Química Encefálica , Cobre , Ferro , Chumbo , Animais , Encéfalo , Cobre/farmacocinética , Ferro/farmacocinética , Chumbo/toxicidade , Masculino , Ratos , Ratos Sprague-Dawley
9.
Environ Monit Assess ; 191(7): 465, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243568

RESUMO

The germination capacity of poplar seeds has never been studied in the context of metal(loid)-contaminated soils, even though poplars are present over a vast geographical area. In this study, black poplar seeds from the Loire Valley (France) were grown for 28 days in mesocosm on a heavily polluted soil that was subjected to different amendments. This phytomanagement process aimed to allow the revegetation of an As and Pb-contaminated mining soil by adding appropriate amendments, resulting in metal(loid) soil stabilisation and efficient plant growth. The objectives were to evaluate the effect of three amendments (garden soil, compost and biochar) when added alone or combined to a technosol on (i) the soil physicochemical properties, (ii) the mobility of As and Pb in the soil pore water (SPW), (iii) the capacity of poplar seeds to germinate and to grow and (iv) the metal(loid) distribution within the plant organs. The addition of amendments alone or combined allowed a 90% decrease in SPW Pb concentrations, while the arsenic concentrations were between 18 and 416 times higher. However, we were only able to obtain seed germination and plant growth on amended soils. These promising results will allow us to explore the use of such amendments in rehabilitating areas that are sources of significant metal(loid) dissemination, as well as allowing a natural plant recolonisation of these sites by seeds from the surrounding environment.


Assuntos
Carvão Vegetal/química , Compostagem , Germinação/efeitos dos fármacos , Mineração , Populus/efeitos dos fármacos , Poluentes do Solo/análise , Solo/química , Arsênico/análise , Monitoramento Ambiental , França , Chumbo/análise , Chumbo/toxicidade , Populus/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Poluentes do Solo/toxicidade
10.
Ecotoxicol Environ Saf ; 180: 396-402, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31108416

RESUMO

Pb2+ pollution and poisoning are serious environmental and pharmacological concerns. The World Health Organization reported that Pb has resulted in 540,000 deaths in 2016 alone. Therefore, effective drugs or supplements that can alleviate or offset Pb2+-induced toxicity are badly needed. Through screening biocompatible natural compounds, we discovered that chicoric acid exhibited potent protective activities against Pb2+-induced toxicity both in BV-2 microglial cells and in zebrafish from the first days of development. Chicoric acid was able to reduce Pb2+-induced increases in levels of reactive oxygen species and tumor necrosis factor alpha, restoring the cell cycle in BV-2 cells. In the zebrafish model, chicoric acid significantly alleviated the Pb2+-induced serious mortality and malformation of zebrafish larvae in a concentration-dependent manner. These protective activities of chicoric acid were mainly from its alleviation of Pb2+-induced dysregulation of oxidative response pathways, including key genes such as Aox1, Gclm, Hmox1, Nqo1, Scd1, and Srxn1, as well as HO-1 protein. Since Pb2+ is difficult to be completely eliminated from the body and chelating agents may cause serious adverse effects, chicoric acid is likely a potential supplement therapy, in addition to current clinical practices.


Assuntos
Ácidos Cafeicos/farmacologia , Poluentes Ambientais/toxicidade , Larva/efeitos dos fármacos , Chumbo/toxicidade , Microglia/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Succinatos/farmacologia , Peixe-Zebra/metabolismo , Animais , Antioxidantes/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Larva/metabolismo , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
11.
Chemosphere ; 231: 315-325, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31132538

RESUMO

Environmental lead (Pb) exposure is a great hazard to the public health. Although environmentally relevant Pb poisoning is preventable, insidious Pb contaminants are still a major threat to human health. Herein, we reported that exposure to Pb at environmentally relevant concentration level (1 µg/L, 10 µg/L and 100 µg/L), disturbed the courtship behavior of adult male zebrafish and further altered the transcriptional patterns of key genes involved in testicular steroidogenesis (igf3, amh, piwil1, lhcgr, fshr, cyp11c1, star, cyp19a1a, cyp19a1b) and apoptosis (bax, cytoC, caspase 9, caspase 3, puma). Both the behavioral and the transcriptional profiles share a similar biphasic dose response, with stimulatory effects after low-level exposure and inhibitory effects after high-level exposure. This results revealed the endocrine disrupting effects of Pb even at an environmentally relevant level within the concentration range of ambient water quality criteria (AWQC) and the reliability of locomotion fingerprint as the indicator for detecting the risk induced by Pb pollution. Current research, for the first time, employed the ZebraTower system as the biological early warning system (BEWS) to find that Pb exerted biphasic effects on the courtship behavior and endocrine regulation of male adult zebrafish. Methodologically, we firstly propose an efficient solution to monitor and assess the risk of Pb exposure by combining the (BEWS) and data analyzing methods such as zebrafish phenomics, which would make a contribution to the detection and prevention of environmentally relevant Pb poisoning.


Assuntos
Disruptores Endócrinos/toxicidade , Chumbo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Caspase 3 , Sistema Endócrino/efeitos dos fármacos , Poluição Ambiental , Humanos , Masculino , Reprodutibilidade dos Testes , Testículo/efeitos dos fármacos , Peixe-Zebra/fisiologia
12.
Environ Sci Pollut Res Int ; 26(18): 18554-18564, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31054054

RESUMO

The study was conducted on a model of dairy cows of the Holstein breed. At the first stage of research, the elemental composition of cow hair was studied (n = 198). Based on this study, the percentile intervals of chemical elements concentrations in hair were established; values of 25 and 75 percentiles were determined, and they were considered as "physiological standard." At the second stage, the elemental composition of hair from the upper part of withers of highly productive Holstein cows during the period of increasing milk yield was analyzed (n = 47). The elemental composition of biological substrates was studied according to 25 indicators, using the methods of atomic emission and mass spectrometry (AES-ICP and MS-ICP). An assessment of productivity parameters of cows depending on the level of toxic elements in hair revealed a negative statistically significant relationship with the level of lead. Lead content in hair was negatively correlated with the yield of fat (r = - 0.50), protein (r = - 0.37), and dry matter (r = - 0.48) in milk. Based on these data, cows were divided into three groups: group I, with Pb concentration in hair 0.0245-0.0449 mg/g, group II-between 0.0495 and 0.141 mg/kg, and in group III-between 0.145 and 0.247 mg/g. It was established that increasing Pb content decreases daily production of milk fat by 18.8 (P ≤ 0.05) and 25.3% (P ≤ 0.05), protein by 9.7 (P ≤ 0.05) and 10.7% (P ≤ 0.05), and dry matter by 8.0 and 13.0% (P ≤ 0.05) in cows. Average daily milk yield, adjusted for 1% of fat, decreased by 19.2 (P ≤ 0.05) and 25.3% (P ≤ 0.05), respectively. As the concentration of lead in hair increased, the content of toxic elements (Al, As, Cd, Hg, Pb, Sn, Sr) increased from 0.07 to 0.235 mmol/kg in group I, in group II from 0.082 to 0.266 mmol/kg, and in group III-from 0.126 to 0.337 mmol/kg. It was concluded that it is necessary to further study the use of physiological standard indicators of the content of toxic chemical elements in hair of dairy cows to increase productivity and maintain animal health and to create an effective system of individual health monitoring of highly productive cattle.


Assuntos
Cabelo/química , Lactação , Chumbo/análise , Metais Pesados/análise , Leite/química , Oligoelementos/análise , Animais , Bovinos , Dieta/veterinária , Feminino , Lactação/efeitos dos fármacos , Chumbo/toxicidade , Metais Pesados/toxicidade , Oligoelementos/toxicidade
13.
J Agric Food Chem ; 67(27): 7716-7725, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31131603

RESUMO

Plasmalogens derived from dietary phospholipids are considered to be potential protectors against oxidation-related disorders, while lead (Pb) is an environmental contaminant worldwide and is known to induce oxidative stress. However, the protective and antilipid oxidative effects of individual plasmalogen species against Pb damage have received little attention. In this study, six plasmalogen species (with either choline or ethanolamine as the headgroup and p16:0/18:1, p16:0/18:2, or p16:0/20:5 as the side chains) were evaluated in human hepatoma cells. Plasmalogen species showed a remarkable recovery in cell viability as well as elimination of reactive oxygen species and suppressed the accumulation of phosphatidylcholine hydroperoxides (from 63.6 ± 1.8% to 80.3 ± 2.9%) and phosphatidylethanolamine hydroperoxides (from 25.7 ± 9.3% to 76.1 ± 3.7%). Moreover, plasmalogens significantly upregulated the gene expression levels of a series of antioxidant enzymes that are regulated via the Nrf-2-dependent pathway. This study suggested that choline and ethanolamine plasmalogens could prevent Pb-induced cytotoxicity and lipid oxidation in HepG2 cells.


Assuntos
Chumbo/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Plasmalogênios/farmacologia , Antioxidantes/análise , Antioxidantes/farmacologia , Poluentes Ambientais/toxicidade , Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/genética , Células Hep G2 , Humanos , Fígado/enzimologia , Fígado/metabolismo , NAD(P)H Desidrogenase (Quinona)/genética , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Regulação para Cima/efeitos dos fármacos
14.
Int J Occup Environ Med ; 10(2): 89-93, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31041926

RESUMO

Lead exposure is associated with several health hazards among workers with different individual responses. We conducted this study to determine the possible effects of lead exposure on hematological parameters and kidney function of a group of Egyptian ammunition workers and the interaction of aminolevulinic acid dehydratase (ALAD) G177C gene polymorphisms as an effect modifier. Significant differences were observed between exposed workers with ALAD1-1 and ALAD1-2 genotypes in terms of blood lead level, hematological parameters and kidney function. It seems that δ-ALAD gene polymorphism may be an effect modifier and a marker of genetic susceptibility to lead toxicity.


Assuntos
Chumbo/sangue , Exposição Ocupacional , Polimorfismo Genético , Sintase do Porfobilinogênio/genética , Biomarcadores/sangue , Estudos Transversais , Egito , Predisposição Genética para Doença , Humanos , Rim/efeitos dos fármacos , Testes de Função Renal , Chumbo/toxicidade , Masculino , Pessoa de Meia-Idade
15.
Environ Pollut ; 251: 221-229, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31082606

RESUMO

Toxicity of hazard materials to organism is different between larvae and adult zebrafish. However, this different effect was seldom considered in toxicological modeling. Here, we measured Cd and Pb toxicity for larvae and adult zebrafish (Danio rerio) and assessed whether metal toxicity can be better simulated by the one-compartment or two-compartment toxicokinetic (TK) and toxicodynamic (TD) models with assumption of stochastic death (SD) and individual tolerance (IT), respectively. Results showed that, for larvae, the one-compartment model generally fitted the observed accumulation and survival better than two-compartment model. In contrast, for adult, the two-compartment model simulation satisfied the observed accumulation and survival better than one-compartment model. In addition, both the SD and the IT models generally described the Cd or Pb toxicity well, although the IT model predictions were slightly better than the SD model in adult fish, the opposite phenomenon was observed in larvae. Our results suggested that variations in both TK and TD parameters might be needed to quantify the toxicity sensitivity in larvae and adult zebrafish, and accounting these variations in mechanistic toxicological effect models (e.g. TK-TD) will allow more accurate predictions of hazard materials effects to organisms.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Modelos Biológicos , Toxicocinética , Poluentes Químicos da Água/toxicidade , Animais , Larva , Peixe-Zebra
16.
Environ Sci Pollut Res Int ; 26(20): 20610-20618, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31104244

RESUMO

The present study was designed to investigate the protective role of dietary supplementation of Spirulina platensis (SP) against cytotoxic and genotoxic effects of lead nitrate in Clarias gariepinus. Four groups of fishes were used: first group as control which fed on basal diet, second group fed on basal diet and exposed to (1 mg/L of lead nitrate), third group fed on diet containing 0.25% SP and exposed to (1 mg/L of lead nitrate), and fourth group fed on diet containing 0.5%SP and exposed to (1 mg/L of lead nitrate). Fish samples were taken at 2nd and 4th week of exposure. The hematological indices of lead nitrate-exposed group were decreased significantly compared to the control group at 2nd and 4th week of exposure. Lead nitrate caused a significant increase in the percentage of poikilocytosis, micronuclei, and apoptotic cells as well as comet tail length and olive tail moment compared with the control group at 2nd and 4th week of exposure. The highest level of damage was found on 4th week of exposure with all parameters. Dietary inclusion of SP ameliorated these cytotoxic and genetic changes, as well as this amelioration was concentration and time dependent. Consequently, the present study proposed that the addition of SP to the fish diet can be used as a promising protective agent to oppose cytotoxic and genotoxic effects of lead nitrate in aquaculture. Graphical abstract.


Assuntos
Peixes-Gato/metabolismo , Chumbo/toxicidade , Nitratos/toxicidade , Substâncias Protetoras/farmacologia , Spirulina/fisiologia , Poluentes Químicos da Água/toxicidade , Ração Animal/análise , Animais , Biomarcadores/sangue , Peixes-Gato/sangue , Peixes-Gato/genética , Dano ao DNA/efeitos dos fármacos , Suplementos Nutricionais , Chumbo/metabolismo , Nitratos/metabolismo , Substâncias Protetoras/análise , Poluentes Químicos da Água/metabolismo
17.
Environ Sci Pollut Res Int ; 26(15): 15653-15664, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30949946

RESUMO

Biocementation of hazardous waste is used in reducing the mobility of contaminants, but studies on evaluating its efficacy have not been well documented. Therefore, to evaluate the efficacy of this method, physicochemical factors affecting stabilized hazardous products of in situ microbially induced calcium carbonate precipitation (MICP) were determined. The strength and leach resistance were investigated using the bacterium Pararhodobacter sp. Pb-contaminated kiln slag (KS) and leach plant residue (LPR) collected from Kabwe, Zambia, were investigated. Biocemented KS and KS/LPR had leachate Pb concentrations below the detection limit of < 0.001 mg/L, resisted slaking, and had maximum unconfined compressive strengths of 8 MPa for KS and 4 MPa for KS/LPR. Furthermore, biocemented KS and KS/LPR exhibited lower water absorption coefficient values, which could potentially reduce the water transportation of Pb2+. The results of this study show that MICP can reduce Pb2+ mobility in mine wastes. The improved physicochemical properties of the biocemented materials, therefore, indicates that this technique is an effective tool in stabilizing hazardous mine wastes and, consequently, preventing water and soil contamination.


Assuntos
Chumbo/toxicidade , Poluentes do Solo/análise , Resíduos Perigosos , Chumbo/química , Poluentes do Solo/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-30930206

RESUMO

During the past decade, the total population and overall reproductive performance of the oriental river prawn (Macrobrachium nipponense) in the Anzali international wetland and its basin rivers has been severely reduced. This seems to be caused by an increase in heavy metal pollution from industrial wastewaters. We investigated the effects of chronic levels of lead (Pb) and cadmium (Cd) on reproductive success, hemato-immunology, crustacean hyperglycemic hormone (cHH), Pb/Cd bioaccumulation and histopathology of hepatopancreas of oriental river prawn. The present study was separately carried out using four chronic treatments for Pb (0 (control), 0.024, 0.072 and 0.12 µM/l) and Cd (0 (control), 0.026, 0.053 and 0.08 µM/l) in experimental tanks during 60 days. The broodstock were fed by commercial shrimp diet, ad libitum, twice a day. The results revealed that reproductive activities ceased when Pb levels were 0.072 and 0.12 µM/l and also when Cd levels reached 0.08 µM/l. At 0.024 µM/l Pb, 0.026 and 0.053 µM/l Cd, the prawns showed initial reproductive activity but after spawning, the egg-clutches were found detached from the pleopods of the brood females. Hemato-immunology results showed that by increasing the Pb and Cd concentrations, large granular hemocyte (LGH) and cHH values also increased. However, small granular hemocyte (SGH) count was inversely affected. A significant increase in mortality (P < 0.05) was observed as both Pb and Cd concentrations increased. Histological observations are indicative of increased necrosis, lumen size, melanization, vacuolation and abnormal lumen shape, as the heavy metals concentrations increased. In conclusion, obtained results can help to elucidate effects of Pb and Cd on freshwater decapod crustaceans reproductive performance and related physiological parameters.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Palaemonidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cádmio/administração & dosagem , Relação Dose-Resposta a Droga , Esquema de Medicação , Chumbo/administração & dosagem , Poluentes Químicos da Água/administração & dosagem
19.
Sci Total Environ ; 675: 367-379, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31030143

RESUMO

Bioindicators have been widely used to assess the contamination of lead/zinc (Pb/Zn) in smelter areas, mining waste disposal areas and in areas containing slags from Pb ore smelting. In this context, the analysis involving microorganisms has gained prominence as a complementary tool in studies aimed at assessing contaminated sites. Therefore, the objective of this study was to assess the contamination of Pb, Zn and cadmium (Cd) in an area where a PbZn smelter operated, using the integration of geochemical and microbial data. The experimental analysis was conducted to characterize the soil collected at three different sites (samples NS, EW and EP). The analysis conducted was physicochemical, metal concentration, metal speciation and analysis of the microbial community through high-throughput sequencing technique. Through the results it was observed that the high concentrations of metals altered the bacterial community present in the soil. Differences were noted between the microbial communities according to the sampling site, especially in sample EP, collected at the margin of the dirt road, which presented higher metal concentrations and microbial diversity. The main phyla detected in the samples were: Proteobacteria, Bacteroidetes and Acidobacteria. Bacteria tolerant to the presence of potentially toxic metals (PTM), such as Rhodoplanes, Kaistobacter, Sphingomonas and Flavisolibacter were identified in the analyzed samples. The phylogenetic groups identified in the study area are similar to those obtained in other studies in metal contaminated areas. The differences between the bacterial communities in each sample indicate that the concentration of PTM may have influenced the microbial community in the soil. Thus, it is noted the importance of the integration of geochemical and microbial data to evaluate the impact of the improper disposal of high PTM concentrated slags in natural soils.


Assuntos
Monitoramento Ambiental , Chumbo/análise , Microbiologia do Solo , Poluentes do Solo/análise , Zinco/análise , Chumbo/toxicidade , Microbiota , Mineração , Poluentes do Solo/toxicidade , Zinco/toxicidade
20.
Environ Pollut ; 250: 676-685, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31035150

RESUMO

Phytostabilization of sulfidic PbZn tailing landscapes may be one of interim options of tailings management, but which is limited by acute phytotoxicity of heavy metals in the tailings. The present study aimed to investigate the effectiveness of soluble phosphate (i.e., K2HPO4) in immobilizing soluble Pb, Cd and Zn and lowering their acute phytotoxicity. The addition of soluble phosphate improved the growth of native plants Acacia chisholmii and survival rate of A. ligulata, where the latter exhibited 100% survival rate. This was in contrast to effects of conventional organic amendment in the tailings on metal solubility (e.g., elevated metal levels in porewater) and plant survival (e.g., only 42%). Organic amendment with mulch did not lower the levels of water-soluble Cd, Pb and Zn and their concentrations in plant tissues after 56 days of plant growth in the treatment. In contrast, the tailings amended with K2HPO4 significantly decreased metal concentrations in the porewater and plant tissues by about 80-92% and 56-88%, respectively. The metal immobilization by phosphate was due to the formation of insoluble or sparingly soluble metal (Pb, Cd and Zn)-phosphate minerals in the tailings with circumneutral pH conditions, as revealed by using X-ray diffraction and scanning electron microanalyses. The reduced metal concentrations in roots and shoots of Acacia species after direct root contact with the K2HPO4 amended tailings suggested that metals (i.e., Pb, Cd and Zn) were effectively immobilized by the phosphate treatment of the tailings. These findings indicate that addition of high dosage of soluble phosphate may provide a low cost option to treat sulfidic PbZn tailings for rapid phytostabilization of the tailings surface, as an interim option to manage environmental risks of sulfidic PbZn tailings.


Assuntos
Acacia/efeitos dos fármacos , Cádmio/toxicidade , Chumbo/toxicidade , Fosfatos/farmacologia , Poluentes do Solo/toxicidade , Zinco/toxicidade , Acacia/crescimento & desenvolvimento , Cádmio/análise , Chumbo/análise , Mineração , Modelos Teóricos , Poluentes do Solo/análise , Sulfetos , Zinco/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA