Navegando por Palavras-chave "Lead"

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    Association between heavy metal exposure and poor working memory and possible mediation effect of antioxidant defenses during aging
    (Elsevier Science Bv, 2017) Souza-Talarico, Juliana Nery; Marcourakis, Tania; Barbosa, Fernando, Jr.; Moraes Barros, Silvia Berlanga; Rivelli, Diogo Pineda; Pompeia, Sabine [UNIFESP]; Caramelli, Paulo; Plusquellec, Pierrich; Lupien, Sonia J.; Catucci, Raphael Fernandes; Alves, Andrea Regiani; Suchecki, Deborah [UNIFESP]
    Background: Inverse associations have been observed between memory performance and blood concentrations of cadmium (Cd) and lead (Pb). Low antioxidant cell activity has also been linked to decline in memory due to aging. However, it has not yet been established whether the heavy metal-memory relationship is mediated by differences in antioxidant activity. Methods: We examined Cd and Pb levels, as well as oxidative stress parameters, in blood samples from 125 older adults (age range 50-82 years). The Counting Span Test (CST) was used to evaluate working memory capacity (WMC). The Monte Carlo Method for Assessing Mediation (MCMAM) was used to analyze the mediation role of antioxidant activity in the heavy metals-memory association. Results: High blood Cd (BCd) concentration alone, and in combination with elevated blood Pb (BPb) concentration, was associated with poor WMC (p = 0.001) and low enzymatic antioxidant defenses (p = 0.006). The variance in WMC accounted for by BCd or by BCd combine with BPb was 20.6% and 18.6%, respectively. The MCMAM revealed that the influence of BCd and BPb concentrations on WMC was mediated by low antioxidant capacity (confidence interval -CI: 0.072 to -0.064 for BCd
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    Avaliação da exposição ao chumbo em trabalhadores de cooperativas de reciclagem da região metropolitana de São Paulo
    (Universidade Federal de São Paulo, 2013-11-29) Regina, Carlos Alberto Conde [UNIFESP]; Assunção, Nilson Antonio de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    In this study the availability and quantification of lead in recycling cooperatives and in nails of collectors of recyclable materials was performed in the metropolitan São Paulo, assessing the possible metal impacts on the behavioral health of the collectors due to their chronic contact with heavy metals during incorrect handling of electronic waste. Lead was analyzed in soils, in locals of public contact in cooperatives and in nails. The analyses were conducted using a Field Portable Spectrometer-Ray and the nails were analyzed in laboratory by Atomic Absorption Spectroscopy Graphite Furnace. A socio-behavioral questionnaire was applied to these workers to check if in some way, inside the socio-cultural scenario experienced by them, the presence of lead in these workplaces interfered in their everyday behavior. Concentrations of lead in situ were found at a range 10-10.437 ppm in routine places of such workers, and 11.170-240.872 ppm in electronic materials incorrectly stored in the field. In nails, lead concentrations were found to range from 0.12 to 15.8 mg/g. According to the methodology applied to evaluate the workers behavior, 40% of respondents had performance of anxiety and depression, 38% reported aggressive behaviors, 68% suffer from internalizing problems and 52% from externalizing problems.
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    Avaliação da influência de polimorfismos do gene da metalotioneína MT2A sobre as concentrações de chumbo (Pb) no sangue, plasma e urina de trabalhadores expostos ao metal
    (Universidade Federal de São Paulo, 2020-05-28) Faria, Jéssica Ramalho [UNIFESP]; Barcelos, Gustavo Rafael Mazzaron [UNIFESP]; http://lattes.cnpq.br/3494181017350657; http://lattes.cnpq.br/4521716627642528; Universidade Federal de São Paulo (UNIFESP)
    O chumbo (Pb) é o segundo elemento mais tóxico, atrás apenas do arsênio (As), e está presente em abundancia na crosta terrestre. O metal é utilizado principalmente na fabricação de baterias automotivas. A exposição ao Pb pode causar diversos efeitos nocivos à saúde tais como distúrbios gastrointestinais, neurológicos e no sistema antioxidante. Com o objetivo de minimizar os efeitos nocivos causados durante a jornada de trabalho o Ministério do trabalho classificou a exposição ao Pb inorgânico como insalubridade de grau máximo, além de estabelecer os biomarcadores de toxicidade, entretanto os valores limites estão desatualizados. Há grandes variações nas concentrações de biomarcadores de toxicidade associados à exposição ao chumbo (Pb), apesar de níveis semelhantes de exposição, hipoteticamente relacionados às diferenças genéticas nas enzimas que metabolizam o metal. Entretanto, pouco se sabe a respeito dos efeitos genéticos sobre o metabolismo e toxicidade induzida pelo Pb. As metalotioneínas (MTs) são proteínas de transporte e distribuição de metais essenciais tais como o zinco (Zn), cobre (Cu) e ferro (Fe); porém, devido a sua alta quantidade de grupamentos sulfidril, metais não essenciais podem ligar-se a ela, como o Pb, cádmio (Cd), dentre outros. Sendo assim, o objetivo do estudo foi avaliar o impacto de polimorfismos do tipo Single Nucleotide Polymorphisms (SNP) do gene MT2A (UTR-3 (3’-Untranslated Region), G → C; rs10636 e UTR-5 (5’-Untranslated Region), A→ G; rs28366003) sobre as concentrações de Pb no sangue (Pb-s), plasma (Pb-p) e urina (Pb-u), em 236 trabalhadores de fábricas de baterias automotivas expostos ao metal. As concentrações de Pb-s, Pb-p e Pb-u foram quantificadas por espectrometria de massa com plasma acoplado indutivamente (ICP-MS) e as genotipagens dos polimorfismos do gene MT2A foram realizadas através do método TaqMan, por meio do da Reação em Cadeia da Polimerase (RT-PCR) em Tempo Real. Para a avaliação do impacto dos polimorfismos sobre as concentrações do metal, regressões múltiplas foram aplicadas e ajustadas por idade, IMC, tempo de trabalho, tabagismo, álcool, além das concentrações de 15 elementos químicos (Al, Sr, Sn, Se, Sb, P, Mo, Mn, Mg, Co, As, Cu, P, Cd, Fe, Pb) e o valor de p≤0,050 foi considerado significativo. A idade média foi de 38 anos e o tempo de trabalho variou de 1 mês até 27 anos; concentrações de Pb-s, Pb-p e Pb-u foram de 21,1 ± 11,9 µg/dL, 0,60 ± 0,71 µg/dL e 38,9 ± 48,4 mg/g creatinina, respectivamente. Associações positivas entre tempo de trabalho e concentrações de Pb-s e Pb-p foram observadas, indicando que o período de exposição influência nas concentrações de Pb absorvido. Associações positivas entre os elementos Manganês (Mn) e Selênio (Se) no sangue e Magnésio (Mg) no plasma com as concentrações de Pb-s e Pb-p podem sugerir uma co-exposição a esses elementos durante a jornada de trabalho. Foi observado associação negativa entre os elementos Fe e As e as concentrações de Pb-s, o que pode sugerir uma competição entre os elementos na fase de absorção. Ainda, Cobre (Cu) e Antimônio (Sb) se mostram associados negativamente ao Pb-p. O alelo C do SNP rs10636 não impactou nas concentrações de Pb-s (β= -1,0; p= 0,65), Pb-p (β= 0,03; p= 0,71) e Pb-u (β= 0,09; p= 0,40) e o genótipo raro (AG) do SNP rs28366003 não influenciou nas concentrações de Pb-p (β= 0,09; p= 0,46) e Pb-u (β= 0,03; p= 0,84). Entretanto o genótipo raro (AG) está associado a maiores concentrações de Pb-s (β= 7,9; p=0,04), quando comparados com os indivíduos portadores do genótipo prevalente (AA). O resultado do estudo sugere que elementos químicos podem influenciar nas concentrações de Pb-s e Pb-p e que o SNP rs28366003 localizado na região promotora 5’UTR do gene MT2A pode impactar na toxicocinética e na toxicodinâmica do Pb.
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    Avaliação da relação entre a disponibilidade de chumbo, baixo rendimento acadêmico e agressividade em estudantes
    (Universidade Federal de São Paulo (UNIFESP), 2016-02-29) Tavares, Letícia Fátima da Silva [UNIFESP]; Assunção, Nilson Antonio de [UNIFESP]; http://lattes.cnpq.br/4183619506352119; http://lattes.cnpq.br/6411404982882021; Universidade Federal de São Paulo (UNIFESP)
    This study was conducted to quantify lead in the school environment and nails of students between 11 and 15 years of the city of Diadema - SP and the correlation between this data and socio-behavioral profile of these students. The focus was the neurocognitive system, where it aimed to verify the existence of correlation between the levels of lead present in the school environment and nails of students, and low academic achievement levels and aggressiveness of the same. A control group of students from the city of Varginha - MG was also analyzed in order to compare the lead of availability at school and nails of the students, in addition to academic performance and aggressiveness thereof to academic performance and aggressiveness of Diadema students - SP, always correlating this data to lead poisoning. The lead of this analysis the environment have been carried out by Fluorescence Spectroscopy portable X-ray and biological samples (nails) collected were quantified by Atomic Absorption Spectroscopy in Graphite Furnace. They were also applied social and behavioral questionnaires acquired by Achenbach System of empirically based Assessment (ASEBA) that are suitable for the needs of this study. The questionnaires were applied to students, parents and teachers of these students investigated, in order to correlate behavioral attitudes, academic performance and lead contamination levels. Lead concentrations found in the school environment were in the range 10-12089 mg kg -1 to school in Diadema - SP and in the range 0-1000 mg kg-1 for school Varginha - MG. In nails, lead concentrations were found in the range 0,11 to 16,74 ± 0,001-0,57 mg Pb / g nail in the school of Diadema - SP and 0,22 to 11,36 ± 0,00 ? 0,73 g Pb / g nail in school Varginha - MG. According to the behavioral methodology, students of Diadema - SP exhibit more aggressive behavior and poorer cognitive performance compared to students Varginha - MG. We hope, with this work, contribute to the development of public policies that assist in the elimination of lead contamination especially in children and adolescents, with lead as one of the possible causes for the low academic performance and aggressiveness of the same.
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    Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy
    (Elsevier B.V., 2014-07-01) Nunes, Lidiane Cristina; Arantes de Carvalho, Gabriel Gustinelli; Santos Junior, Dario [UNIFESP]; Krug, Francisco Jose; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. the experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm(-2) (750 mu m spot size), 2.0 mu s delay time and 5.0 mu s integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. the limits of detection of 1 mg kg(-1) Cd, 2 mg kg(-1) Cr and 15 mg kg(-1) Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIES method can be recommended for the determination of these analytes in phosphate fertilizers. (C) 2014 Elsevier B.V. All rights reserved.
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    A forensic study: Lead determination in gunshot residues
    (Elsevier B.V., 2012-03-01) Salles, Maiara Oliveira; Naozuka, Juliana [UNIFESP]; Bertotti, Mauro; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Electrochemical lead analyses of gunshot residues (GSRs) were performed using an acidic solution with a bare gold microelectrode in the presence of chloride ions. GSRs from four different guns (0.38 in. revolver, 12 caliber pump-action shotgun, 0.38 repeating rifle, and a 0.22 caliber semi-automatic rifle) and six different types of ammunition (CleanRange (R), normal, semi-jacketed, especial 24g (R), 3T (R), CBC (R), and Eley (R)) were analyzed. Results obtained with the proposed methodology were compared with those from an atomic absorption spectrometry analysis, and a paired Student's t-test indicated that there was no significant difference between them at the 95% confidence level. With this methodology, a detection limit of 1.7 nmol L-1 (3 sigma/slope), a linear range between 10 and 100 nmol L-1, and a relative standard deviation of 2.5% from 10 measurements were obtained. (C) 2011 Elsevier B.V. All rights reserved.
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    Impacto da exposição ao chumbo (Pb) sobre o perfil de expressão de genes relacionados ao metabolismo do metal em indivíduos ocupacionalmente expostos
    (Universidade Federal de São Paulo, 2022-01-18) Araújo, Marília Ladeira [UNIFESP]; Barcelos, Gustavo Rafael Mazzaron [UNIFESP]; http://lattes.cnpq.br/3494181017350657; Universidade Federal de São Paulo (UNIFESP)
    O chumbo (Pb) é um metal versátil utilizado por humanos há mais de 9.000 anos e, sua exposição poderá influenciar no processo de regulação da expressão gênica o qual é composta por diversos eventos complexos, caracterizando-os como um processo biológico essencial. Além disso, a identificação de biomarcadores moleculares que podem preceder a efeitos adversos à saúde relacionados à exposição a toxicantes aumentou significativamente na última década. Diante deste contexto, a expressão de genes relacionados com a toxicocinética do Pb e a expressão de microRNAs (miRNAs) em indivíduos expostos a baixas concentrações de Pb podem gerar novas perspectivas na ampliação do entendimento dos mecanismos associados à toxicidade induzida pelo metal. Deste modo, o objetivo do presente estudo consistiu na avaliação do impacto da exposição ao Pb sobre o perfil de expressão transcricional (RNAm) de genes associados ao metabolismo do metal (VDR, SLC11A2, MT2A, ALAD, GCLM, GSS, GSR, GGT1) e sobre a expressão de dois miRNAs, hsa-miR-148a-5p e hsa-miR-23a-3p, em trabalhadores expostos ao metal, por RT-qPCR. Foram coletadas cerca de 10 mL de sangue e cerca de 30 mL de urina de 85 trabalhadores de fábricas de baterias automotivas no estado do Paraná, após esclarecimento detalhado sobre o projeto e assinatura do termo de consentimento livre e esclarecido (TCLE). Foram incluídos no estudo indivíduos com idade entre 19 a 69 anos, do sexo masculino e que declararam não possuírem doenças conhecidas no momento da coleta. As concentrações de Pb no sangue (Pb-s), no plasma (Pb-p) e na urina (Pb-u) foram determinadas por espectrometria de massas com plasma indutivamente acoplado (ICP-MS). Para as análises das expressões transcricionais dos genes de metabolismo e do miRNA hsa-miR-148a-5p foram realizadas a partir de extrações de sangue, enquanto que a extração do miRNA hsa-miR-23a-3p foi obtida pelo plasma e os ensaios de RT-qPCR foram realizados através do método TaqMan. As médias ± desvio padrão (DP) de Pb-s, Pb-p e Pb-u foram de 19 ± 11 µg/dL, 0,54 ± 0,65 µg/dl, 35,39 ± 40 µg/g creatinina, respectivamente, evidenciando que estes valores encontram-se abaixo do permitido pela legislação brasileira. Correlações de Spearman e as análises de regressões multivariadas apontaram para associações positivas entre Pb-s e a expressão dos genes GSR e SLC11A2 (β=0,053 p=0,045 e β= 0,052 p=0,048, respectivamente). As regressões múltiplas apresentaram associações inversas entre a expressão de hsa- miR-148a-5p e metilação global do DNA (%5-mC DNA), em função do Pb-p (β = -4,1; p =0,050). Ademais, em baixas concentrações de Pb, os miRNAs (hsa-miR-148a-5p e hsa-miR-23a-3p) não impactaram na alteração da expressão de genes alvo. Por fim, os dados obtidos colaboraram para uma melhor compreensão sobre a influência da toxicidade do Pb em baixas concentrações, através da ativação do gene carreador de soluto (responsável pela absorção e distribuição do metal no organismo), assim como uma ativação do papel antioxidante, caracterizando como um possível mecanismo de defesa.
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    Lead detection using micro/nanocrystalline boron-doped diamond by square-wave anodic stripping voltammetry
    (Elsevier B.V., 2014-10-01) Arantes, Tatiane M.; Sardinha, Andre [UNIFESP]; Baldan, Mauricio R.; Cristovan, Fernando H. [UNIFESP]; Ferreira, Neidenei G.; LAS INPE Natl Inst Space Res; Universidade Federal de São Paulo (UNIFESP)
    Monitoring heavy metal ion levels in water is essential for human health and safety. Electroanalytical techniques have presented important features to detect toxic trace heavy metals in the environment due to their high sensitivity associated with their easy operational procedures. Square-wave voltammetry is a powerful electrochemical technique that may be applied to both electrokinetic and analytical measurements, and the analysis of the characteristic parameters of this technique also enables the mechanism and kinetic evaluation of the electrochemical process under study. in this work, we present a complete optimized study on the heavy metal detection using diamond electrodes. It was analyzed the influence of the morphology characteristics as well as the doping level on micro/nanocrystalline boron-doped diamond films by means of square-wave anodic stripping voltammetry (SWASV) technique. the SWASV parameters were optimized for all films, considering that their kinetic response is dependent on the morphology and/or doping level. the films presented reversible results for the Lead [Pb (II)] system studied. the Pb (II) analysis was performed in ammonium acetate buffer at pH 4.5, varying the lead concentration in the range from 1 to 10 mu g L-1. the analytical responses were obtained for the four electrodes. However, the best low limit detection and reproducibility was found for boron doped nanocrystalline diamond electrodes (BDND) doped with 2000 mg L-1 in B/C ratio. (C) 2014 Elsevier B.V. All rights reserved.
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    Milk and Dairy Products Intake Is Associated with Low Levels of Lead (Pb) in Workers highly Exposed to the Metal
    (Humana Press Inc, 2017) Gomes, Willian Robert; Devoz, Paula Picoli; Araújo, Marília Ladeira; Batista, Bruno Lemos; Barbosa, Fernando, Jr.; Barcelos, Gustavo Rafael Mazzaron [UNIFESP]
    Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r s = 0.21; r s = 0.20; p < 0.010). Multivariable linear regressions showed a significant influence of MDP intake on B-Pb (β = −0.10; p = 0.012) and P-Pb (β = −0.16; p < 0.010), while no significance was seen on U-Pb. Our results suggest that MDP consumption may modulate Pb levels in individuals highly exposed to the metal; these findings may be due to the Pb-Ca interactions, since the adverse effects of Pb are partially based on its interference with Ca metabolism and proper Ca supplementation may help to reduce the adverse health effects induced by Pb exposure.
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    Voltammetric studies of the interaction between lead metal ion and the methyl parathion pesticide
    (Springer, 2018) Cardoso, Daisy Alves [UNIFESP]; Valle, Eliana Maira Agostini [UNIFESP]; Codognoto, Lucia [UNIFESP]
    In this work, the interaction of the pesticide methyl parathion (MP) with the lead metal ion was evaluated using a carbon electrode reused from a zinc battery. MP showed a reduction peak around - 0.57 V, with characteristics of irreversible processes, followed by a redox pair at 0.02 and 0.04 V. For the Pb2+ ion was observed a redox pair with the peaks at - 0.65 and - 0.44 V, with characteristics of quasi-reversible process. The evaluation of the MP interaction with the metal ion was performed by anodic stripping voltammetry and by UV-Vis spectroscopy. The studies indicated the formation of a new species in solution with a stripping peak at - 0.60 V, as well as a pronounced effect on the stripping peak of the methyl parathion. Since this change is in the hydroxylamine redox couple, it suggests that the interaction is through the sulfur atom present in the parathion molecule. Through titration studies, was suggested a possible 1:2 Pb:MP stoichiometry for the complex formed. Langmuir linearization algorithms of titration data with the metal allowed us to calculate the stability constant for the Pb:MP complex (log K' = 7.6). The confirmation of the interaction between the species in solution was evidenced by UV-Vis spectroscopy, with the reduction of the MP absorption band at 282 nm.