Deposition of Lead and Cadmium Released by Cigarette Smoke in Dental Structures and Resin Composite

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l(-1) HNO3 and in 1 + 1 v/v diluted wine using mixtures of Pd(NO3)(2) + Mg(NO3)(2) and NH4H2PO4 + Mg(NO3)(2) as chemical modifiers. With 5 mug Pd + 3 mug Mg as the modifiers and a two-step pyrolysis (10 s at 400 degreesC and 10 s at 600 degreesC), the formation of carbonaceous residues inside the atomizer was avoided. For 20 mul of sample (wine + 0.056 mol l(-1) HNO3, 1 + 1, v/v) dispensed into the graphite tube, analytical curves in the 0.10-1.0 mug l(-1) Cd and 5.0-50 mug l(-1) Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 mug l(-1) for Cd, 0.8 mug l(-1) for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 mug l(-1) and for Pb at 500 mug l(-1). The relative standard deviations (n = 12) were typically < 8% for Cd and < 6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Ph was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Disponibilidade de metais pesados em Latossolo com aplicação superficial de escória, lama cal, lodos de esgoto e calcário

O objetivo deste trabalho foi avaliar alguns atributos químicos do solo e a disponibilidade de cádmio (Cd), cromo (Cr), níquel (Ni), mercúrio (Hg), chumbo (Pb) e arsênio (As), por meio da extração pelo DTPA, em conseqüência da aplicação superficial de escória de aciaria, lama cal e lodos de esgoto centrifugados e de biodigestores, nas doses 0 (testemunha), 2, 4 e 8 Mg ha-1 e um tratamento adicional composto pela calagem superficial na dose 2 Mg ha-1. O experimento foi conduzido em delineamento de blocos ao acaso, em condições de campo, em área sob sistema plantio direto, durante 2003 e 2004. A aplicação superficial de escória de aciaria, lama cal, lodo de esgoto centrifugado e de biodigestor, até a dose 8 Mg ha-1, assim como o calcário na dose 2 Mg ha-1, não trazem problemas de disponibilidade ao ambiente, com relação aos metais pesados Cd, Cr, Hg, Pb, Ni e As, quando aplicados sobre a superfície em Latossolo Vermelho distrófico, no sistema plantio direto. A fitodisponibilidade de metais pesados às culturas da soja e aveia-preta foi nula, quando foram aplicadas doses de até 8 Mg ha-1 de lodo de esgoto, escória e lama cal sobre a superfície do solo, no sistema plantio direto.

Adsorption of Cu(II), Zn(II), Cd(II), Hg(II) and Pb(II) from aqueous solutions on a 2-mercaptobenzimidazole-modified silica gel

The chemically modified silica, obtained by reacting 2-mercaptobenz-imidazole with 3-chloropropyl silica gel, was used to adsorb Cu(II), Zn(II), Cd(II) and Pb(II) from aqueous solutions at various pH. Between pH 3-5, the order of selectivity was Hg(II) > Cd(II) ≫ Cu(II) ∼ Zn(II) ∼ Pb(II). Under batch conditions retentions of 100% were achieved for all metals except for Pb(II) where 93% was attained. Under column conditions recoveries of 100% were obtained for all metals. © 1990 Springer-Verlag.

Uso da técnica de difusão em filmes finos por gradientes de concentração (DGT) para determinação in situ de metais-traço nos rios da Bacia Amazônica Central

Pós-graduação em Geociências e Meio Ambiente - IGCE

Determinação de macroelementos, oligoelementos e contaminantes metálicos em própolis por espectrofotometria de absorção atômica em chama e em forno de grafite

Pós-graduação em Ciências Farmacêuticas - FCFAR

Determinação de alguns parâmetros indicadores de poluição por efluente líquido de um aterro sanitário

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Estudo da viabilidade de uma gestão ambiental de pilhas no campus da Unesp de Rio Claro

When exhausted, the batteries are classified as hazardous waste because it has potentially toxic heavy metals and bio-accumulators, such as mercury, cadmium and lead in their internal composition functional. Due to the high level of danger, such waste should be properly designed to not allow theses chemical components to cause significant impacts on the environment. Thus, the recycling of waste in question is the best destination. In this context, was wanted to know, through a questionnaire in interview format, how the graduates of the Universidade Estadual Paulista Julio de Mesquita Filho of Rio Claro / SP are involved with this environmental issue. Since then, has been developed and implemented an environmental management for internal batteries

Análises de solos e sedimentos de corrente, nas áreas das usinas de fundição de chumbo do Calabouço (CIEM-CPRM) e de beneficiamento de minério aurífero do Morro do Ouro (Parque Municipal Morro do Ouro), no município de Apiaí - SP

Located in Apiaí, Vale do Ribeira, southern region of São Paulo state, the Usina do Calabouço areas (CIEM / CPRM) and Morro do Ouro (Parque Municipal do Morro do Ouro), were targeted for stud ies due to its old buildings, respectively a foundry in lead ore, called Experimental de Chumbo e Prata (Usina Calabouço), and a gold mine with processing plant of the gold-bearing ore produced there. Nowadays, the areas are used for public visitation, and in both places the rests of the buildings remains. Particularly in the CIEM/CPRM, due to the materials witch was produced before, it can suggest the existence of anomalous amounts of the involved metals (CIEM / CPRM) and possible contaminations by chemical products used in the improvement of the auriferous ore (P. M. Morro do Ouro). These potential contamination were confirmed with geochemical survey of soils and current sediments accomplished in both areas, for the elements arsenic, cadmium, lead, copper, mercury, silver and zinc, which were used as parameters guiding values for soil and groundwater the state of São Paulo (CETESB), and watershed values stipulated by CPRM (poor, background and anomalous), in it rising geochemistry during Folha Apiaí's execution (SG-22-X-B-V).

Cádmio, chumbo, cromo, mercúrio e níquel nos rios do estado de São Paulo e em peixes do Rio Sorocaba (São Paulo, Brasil)

To verify the levels of concentration of some heavy metals in fishes from Sorocaba river (São Paulo, Brazil) and evaluate if this contamination offers health risks to the fishermen, 63 samples of fishes collected from four points along the river were studied for cadmium, lead, chromium, nickel and mercury, with emphasis in this last, since it is the most toxic and most probable as a fish contaminant. Analyzing muscle samples by cold vapor atomic absorption spectrometry it was shown that the fishes are not contaminated. None of the five metals studied were present in prohibitive level and the fishes could be judged secure for human consume. It was also analyzed data from four years of cadmium, lead, chromium, nickel and mercury monitoring made by CETESB, from 1997 to 2000, in water from the main rivers of the State of São Paulo. The study pointed out that the majority of the monitored rivers still present contamination by those metals in a level that requires an improvement of the pollution control actions.

Acúmulo de metais pesados em cana-de-açúcar mediante a aplicação de lodo de esgoto e vinhaça

O uso de resíduos agroindustriais pode acumular metais pesados no solo e na planta. O objetivo deste trabalho foi avaliar os efeitos do lodo de esgoto e/ou vinhaça, aplicados no solo, disponibilizando Cd, Cr, Ni e Pb ao solo e quantificar as respectivas concentrações em plantas de cana-de-açúcar, após três aplicações anuais sucessivas. O experimento foi conduzido em condições de campo, com parcelas experimentais de cinco linhas espaçadas de 1,5 m e 10 m de comprimento. O delineamento experimental adotado foi o de blocos casualizados, com três repetições. Os tratamentos avaliados foram: 1. Lodo de esgoto com 100% de N; 2. Lodo de esgoto com 200% de N; 3. Vinhaça com 100% de K; 4. Vinhaça com 200% de K; 5. Lodo de esgoto+vinhaça com 100% de N e K; 6. Lodo de esgoto+vinhaça com 200% de N e K; 7. Testemunha (fertilização mineral). Os baixos teores de metais pesados (Cd, Cr, Ni e Pb) disponíveis no solo e nas partes das plantas de cana-de-açúcar indicam que o lodo de esgoto e a vinhaça, empregados nas doses mencionadas, não apresentaram, após três aplicações anuais sucessivas, potencial de contaminação do sistema solo-planta.

Sediment grain size distribution and heavy metals determination in a dam on the Parana River at Ilha Solteira, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bioconcentration of Cd and Pb by the River Crab Trichodactylus fluviatilis (Crustacea: Decapoda)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de parâmetros indicadores de poluição por efluente líquido de um aterro sanitário

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantitative analysis of potentially toxic metals in alginates for dental use

Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them.