This work aimed to adapt the analysis of methemoglobin recommended by Evelyn - Malloy (visible spectrophotometry), in order to facilitate its application in the field, or to analysis in clinical laboratory, of existing sites of diflubenzuron application. The parameters changed included: centrifuge rotation speed; time between the collection of biological sample and analysis, and storage temperature of the samples; and the volume of reagents. The comparison of the rotation speed (rpm) of the reference methodology with the rpm of a "clinical centrifuge" did not reveal a statistically significant difference in the levels of methemoglobin. The time between the collection of biological sample and analysis was extended for a period of up to 48 hours for both conservation by refrigeration and ambient temperature, producing no statistically significant difference when compared to the standard duration of 2 hours. Regarding the reagents, the reference methodology already uses the volume necessary to ensure complete reaction, whereas a wider range from the recommended volume to a 5-fold reduction in comparison to the reference methodology could be used. It was concluded that the proposed changes to the methodology for adapting the analysis are applicable to studies of field / workplace exposure and ensure the reliability of results. The adapted methodology was inter-laboratory validated and the parameters changed can be selected according to the requirements of the laboratory at which the methemoglobin is to be measured.

Metabolic reactive intermediates can react with biomolecules such as DNA and proteins to produce adducts. Recently, research has shown that such adducts can act as precursors of some chronic diseases (cancer, Parkinson's, immunologic system diseases, etc.), and their determination is important because they are biomarkers of undesirable health effects. These compounds are produced at very low concentrations, but the development and dissemination of sensitive new analytical tools, especially those based on chromatography coupled to other analytical instruments, make such determinations possible. This mini review is focused on the formation of reactive intermediates, their reaction with biomolecules, and the importance of their determination.

OBJECTIVES: Manganese (Mn) is an essential element, but overexposure can have neurotoxic effects. METHODS: In this article, we review and summarize studies on exposure to Mn and nervous system impairments in children. RESULTS: We identified 12 original articles published between 1977 and 2007. Overexposure to Mn was suspected to occur through diverse sources: infant milk formula, drinking water, industrial pollution, and mining wastes. The most common bioindicator of exposure to Mn was hair Mn content, but some studies measured Mn in blood, urine, or dentin; one study on prenatal exposure measured Mn content in cord blood. Most studies indicate that higher postnatal exposure to Mn is associated with poorer cognitive functions and hyperactive behavior. CONCLUSIONS: The limitations of the existing studies are numerous: most were cross-sectional, had a modest sample size, and lacked adjustment for important confounders. Future investigations should be performed on a larger sample size and include a more detailed exposure assessment, addressing multiple sources of exposure such as food, water, and airborne particulates.

OBJETIVO: El manganeso (Mn) es un elemento esencial, pero la sobreexposición puede tener efectos neurotóxicos. MÉTODOS: En este artículo se hace una revisión y un compendio de los estudios publicados sobre la exposición al Mn y los trastornos del sistema nervioso en niños. RESULTADOS: Se identificaron 12 artículos originales publicados entre 1977 y 2007. La sobreexposición al Mn puede haber ocurrido a partir de diversas fuentes: leche en polvo o maternizada, agua de beber, polución industrial y desechos de la producción minera. El bioindicador de exposición utilizado con mayor frecuencia fue el contenido de Mn en el pelo, aunque algunos estudios lo midieron en la sangre, la orina o la dentina; un estudio sobre exposición prenatal midió su contenido en la sangre del cordón umbilical. La mayoría de los estudios indican que una mayor exposición posnatal al Mn se asocia con deficiencias en las funciones cognitivas y el comportamiento hiperactivo. CONCLUSIONES: Las limitaciones de los estudios publicados son numerosas: la mayoría de ellos eran transversales, se basaban en muestras pequeñas y en ellos no se ajustaron los resultados por importantes factores de confusión. Se requieren investigaciones adicionales con muestras mayores y que hagan una evaluación más detallada de la exposición, tomando en cuenta múltiples fuentes, como los alimentos, el agua y las partículas suspendidas en el aire.

Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.

Photodegradation of the PAHs anthracene, chrysene and benzo[k]fluoranthane on silica gel impregnated with TiO2 and over glass plates holding TiO2 was studied. Silica gel plates holding these substances were exposed to solar radiation, developed with hexane and photographed under ultra-violet light. The plates containing benzo[k]fluoranthene were also analysed by both diffuse reflectance and laser induced fluorescence. Diffuse reflectance spectra of the fluorescent spot from non irradiated plates showed small differences when compared with those obtained from irradiated plates. These spectral differences are compatible with formation of less conjugated compounds during irradiation. Fluorescence and time resolved fluorescence spectra observed after irradiation were identical to those obtained with benzo[k]fluoranthene in methanol. On plates holding silica, PAH degradation requires longer periods of solar irradiation when compared with those plates containing silica impregnated with TiO2. Glass plates impregnated with TiO2 also showed very rapid PAH degradation.

Neste trabalho, rochas fosfatadas brasileiras (PRs) foram usadas na imobilização de Pb2+, Cu2+ e Cd2+ de soluções aquosas. Concluímos que estes metais são principalmente imobilizados por fluorapatita, mas outros minerais tais com carbonatos de cálcio contribuem para esta imobilização. No caso do chumbo, dois mecanismos são propostos: a dissolução da Ca10(PO4)6F2 seguida pela precipitação de (Ca,Pb)10(PO4,CO3) 6(OH,F,Cl)2.56.1.5H2O e a dissolução de CaCO3 com formação de PbCO3. Este segundo mecanismo aumenta a eficiência do processo de remoção, mas contribui para tornar o chumbo mais biodisponível porque o carbonato de chumbo é mais solúvel que a fluorpiromorfita. Este fato pode limitar a utilização das rochas fosfatadas na regeneração de solos contaminados. A imobilização de Cu2+ e do Cd2+ pelas PRs é controlada por mecanismos de adsorção mas mecanismos de dissolução/precipitação também contribuem. No caso do Cu2+ a dissolução da fluorapatita é seguida pela precipitação da libetenita, Cu2(PO4)(OH).

In this work Brazilian phosphate rocks, PRs, were used to reduce Pb2+, Cu2+ and Cd2+ concentrations from aqueous solutions. We concluded that these metals were mainly immobilized by fluorapatite but other minerals such as calcium carbonate also contribute to their immobilization. In the case of lead two mechanisms are proposed: the Ca10(PO4)6F2 dissolution followed by the precipitation of (Ca,Pb)10(PO4,CO3) 6(OH,F,Cl)2.56.1.5H2O and CaCO3 dissolution with the formation of a PbCO3. The occurrence of this second mechanism improves the uptake efficiency but contribute to the increases of lead bioavailability because lead carbonate is more soluble than fluorpyromorphite. This fact could limit the use of PRs for remediation of contaminated soils and wastes. The Cu2+ and Cd2+ removal by PRs is controlled by adsorption mechanisms but dissolution /precipitation mechanisms also occur. In the case of Cu2+, fluorapatite dissolution followed by Cu2(PO4)(OH) precipitation.

Lead absorption is influenced by the species that are formed and the physicochemical characteristics of lead, among others. Lead plasma concentration is < 5% of total blood lead and represents the biologically active fraction able to cross the cell membranes. Health risks mainly depend on a specific metal and its species. Speciation analysis is the analytical activity of identifying and determining different metal species. Chromatographic methods are very useful in the identification of species and the techniques most used to determine metals in biological fluids are ICP OES/MS and AAS. Lead speciation analysis in blood plasma is fundamental for understanding and evaluating the interaction mechanisms between that analyte and its biological targets.

The aim of this work was to compare the performances of the L'vov and integrated platforms in order to overcome the interferences found on lead determination in zidovudine by ET AAS. Pyrolysis and atomization temperatures found with integrated platform were 700 and 1400°C, respectively. The characteristic masses were 12.7 ± 1.2 pg with integrated platform and 11.1 ± 1.3 pg with grooved platform. The ratio between the slopes of zidovudine and aqueous curves shows a decrease in the interferences when the L'vov platform is used (bAZT/b aq = 0.97 ± 0.10) and the detection limit found was 0.03 µg.g-1. That ratio was 0.85 ± 0.07 with the integrated platform.

As técnicas de reflectância difusa no estado fundamental e de fluorescência induzida por laser foram testadas na avaliação do teor total de hidrocarbonetos policíclicos aromáticos (PAHs) em particulado atmosférico não extraído e não fraccionado. Foi comparado o teor total de PAHs no particulado estimado por estes métodos e por cromatografia gasosa em amostras de particulado atmosférico coletado na cidade do Rio de Janeiro e ainda para o material padrão de referência (SRM) 1648. A reflectância difusa no estado fundamental provou ser uma boa técnica para estimar o teor total de PAHs em material urbano particulado, uma vez que os resultados se correlacionam diretamente com os dados obtidos pela técnica de cromatografia gasosa convencional. A fluorescência induzida por laser é também um método eficiente para estimar baixas concentrações. Ocorrem desvios aparentes na resposta da fluorescência devido à interferência do "black carbon" que têm de ser contabilizados. Estes métodos ópticos mostraram ser rápidos, de baixo custo, sensíveis e úteis como técnicas de monitoramento, permitindo medidas de campo.

Ground-state diffuse reflectance and laser-induced fluorescence techniques were tested on the evaluation of total polycyclic aromatic hydrocarbons (PAHs) in unextracted and unfractionated airborne particulate matter. The total particulate PAH content estimated from these methods and from gas-chromatography in air particulate samples collected in the Rio de Janeiro city and for standard reference material (SRM) 1648, were compared. Ground-state diffuse reflectance proved to be by itself a good technique for estimating total PAH content in urban particulate matter, since results directly correlate with data obtained by conventional gas-chromatographic techniques. Laser-induced fluorescence is also an efficient method for low concentration estimates. Apparent deviations of the fluorescence response do occur due to black carbon interference and have to be taken into account. These surface optical methods showed to be fast, low cost, sensitive and useful as screening techniques, allowing field measurements.

O impacto do uso de agrotóxicos sobre a saúde humana é um problema que tem merecido atenção da comunidade científica em todo o mundo, sobretudo nos países em desenvolvimento. O consumo de agrotóxicos na região sudeste do Brasil está estimado em 12kg de agrotóxico/trabalhador/ano. Em algumas áreas agrícolas do Estado do Rio de Janeiro, como na região da Microbacia do Córrego de São Lourenço, Nova Friburgo, o consumo de agrotóxico foi estimado em 56kg de agrotóxico/trabalhador/ano. Elevados níveis de contaminação humana e ambiental foram encontrados nesta região, como decorrência do uso extensivo destes agentes químicos. A avaliação do impacto sobre a saúde humana implica o conhecimento e a visualização da importância/magnitude relativa de cada uma das vias de contaminação. Inúmeros fatores, que, em geral, encontram-se inter-relacionados, contribuem para a situação encontrada na Microbacia do Córrego de São Lourenço e a forma mais adequada de se avaliar toda a dimensão deste problema é o uso de uma abordagem integrada.

Environmental and human difficulties caused by pesticides used in agriculture are important health issues worldwide, specially in the developing countries. Pesticide consumption in Southeast Brazil is estimated in 12kg/worker/year. In the São Lourenço Valley, Rio de Janeiro State, pesticide consumption is estimated at some 56kg/worker/year. High levels of human and environmental contamination caused by these products were found in the area. Many factors were shown as determinants of this situation, such as: pesticides with different formulations used with insufficient or even non-existent supervision or technical advice; intensive marketing activities place the responsibility for correct use and disposal of these chemicals on farm workers with low education levels typical of rural areas in Brazil, resulting in widespread human and environmental contamination. The evaluation of those loosely inter-related factors help shape the current situation in the São Lourenço Valley, indicating that the only way to really understand and assess the problem as a whole is through an integrative (transdisciplinary) approach.

O impacto do uso de agrotóxicos sobre a saúde humana é um problema que tem merecido atenção da comunidade científica em todo o mundo, sobretudo nos países em desenvolvimento. O consumo de agrotóxicos na região sudeste do Brasil está estimado em 12kg de agrotóxico/trabalhador/ano. Em algumas áreas agrícolas do Estado do Rio de Janeiro, como na região da Microbacia do Córrego de São Lourenço, Nova Friburgo, o consumo de agrotóxico foi estimado em 56kg de agrotóxico/trabalhador/ano. Elevados níveis de contaminação humana e ambiental foram encontrados nesta região, como decorrência do uso extensivo destes agentes químicos. A avaliação do impacto sobre a saúde humana implica o conhecimento e a visualização da importância/magnitude relativa de cada uma das vias de contaminação. Inúmeros fatores, que, em geral, encontram-se inter-relacionados, contribuem para a situação encontrada na Microbacia do Córrego de São Lourenço e a forma mais adequada de se avaliar toda a dimensão deste problema é o uso de uma abordagem integrada.

Environmental and human difficulties caused by pesticides used in agriculture are important health issues worldwide, specially in the developing countries. Pesticide consumption in Southeast Brazil is estimated in 12kg/worker/year. In the São Lourenço Valley, Rio de Janeiro State, pesticide consumption is estimated at some 56kg/worker/year. High levels of human and environmental contamination caused by these products were found in the area. Many factors were shown as determinants of this situation, such as: pesticides with different formulations used with insufficient or even non-existent supervision or technical advice; intensive marketing activities place the responsibility for correct use and disposal of these chemicals on farm workers with low education levels typical of rural areas in Brazil, resulting in widespread human and environmental contamination. The evaluation of those loosely inter-related factors help shape the current situation in the São Lourenço Valley, indicating that the only way to really understand and assess the problem as a whole is through an integrative (transdisciplinary) approach.

Polycyclic aromatic hydrocabons (PAHs) and their nitroderivatives (NPAHs) are ubiquitous in the environment and they are produced in several industrial and combustion processes. Some of these compounds are potent carcinogens/mutagens and their determination in biological samples is an important step for exposure control. A review of the analytical methodologies used for the determination of PAHs and their metabolites in biological samples is presented.

Várias substâncias químicas com atividade sobre o sistema endócrino têm sido amplamente utilizadas no Brasil tanto em atividades industriais quanto em outros ramos, como por exemplo, na agricultura. Alguns dados mostrando a contaminação de grupos populacionais brasileiros por substâncias supostamente possuidoras destas propriedades são apresentados neste trabalho. Entretanto, muito pouco, ou mesmo nada, se sabe sobre os efeitos que as mesmas têm sobre a saúde destas populações expostas, mostrando claramente a necessidade urgente de implementação de um programa destinado a esta finalidade.

Several chemical substances suspected of endocrine disruption are currently being used in industrial and agricultural activities in Brazil. This paper presents analytical data showing contamination of some population groups by these substances. Virtually nothing is known about the related health effects, highlighting the need to implement a national program to evaluate such impacts.

Várias substâncias químicas com atividade sobre o sistema endócrino têm sido amplamente utilizadas no Brasil tanto em atividades industriais quanto em outros ramos, como por exemplo, na agricultura. Alguns dados mostrando a contaminação de grupos populacionais brasileiros por substâncias supostamente possuidoras destas propriedades são apresentados neste trabalho. Entretanto, muito pouco, ou mesmo nada, se sabe sobre os efeitos que as mesmas têm sobre a saúde destas populações expostas, mostrando claramente a necessidade urgente de implementação de um programa destinado a esta finalidade.

Several chemical substances suspected of endocrine disruption are currently being used in industrial and agricultural activities in Brazil. This paper presents analytical data showing contamination of some population groups by these substances. Virtually nothing is known about the related health effects, highlighting the need to implement a national program to evaluate such impacts.

A produção de baterias chumbo-ácidas representa um dos segmentos industriais de maior consumo de chumbo, estando os trabalhadores expostos a riscos elevados. Neste trabalho são discutidos os resultados obtidos na avaliação da exposição ao chumbo de trabalhadores de uma fábrica de baterias da cidade do Rio de Janeiro, de acordo com as normas vigentes da legislação brasileira e com dados científicos atualizados. Os métodos empregados neste estudo foram a amostragem de ar-pessoal e a determinação de chumbo em sangue Pb-S). De acordo com a observação do processo de trabalho, das concentrações de chumbo no ar (todos acima de 0,1 mg/m³) e do grande percentual de trabalhadores contaminados (55% com Pb-S acima de 25 µg/dl), foi possível confirmar a ineficácia das práticas de controle usualmente adotadas. Isto permite a manuntenção de 46% dos trabalhadores, apresentando níveis de Pb-S na faixa de 25-60 µg/dl, nas áreas de maior risco. Dados científicos atuais mostram que nessa faixa de concentração já ocorrem alterações subclínicas importantes, que devem ser investigadas nos exames médicos. Propõe-se, finalmente, uma estratégia de monitoramento ambiental e biológica para prevenir, inclusive, os efeitos subclínicos.

In developing countries, lead-acid battery factories are one of the heaviest consumers of lead. Due to lead's toxicological properties and prevalent working conditions in such factories, workers are subject to high exposure and health risk. This study discusses results obtained by lead exposure assessment of workers from a Rio de Janeiro battery factory, in light of Brazilian legislation and recent scientific data. Evaluation methods used were environmental (personal air sampling) and biological (determination of lead in blood, Pb-B) monitoring, showing a high personal exposure both in air (>0.1 mg/m³) and blood (55% of Pb-B >25µg/dl). These results confirmed the inefficiency of current control measures, with a possible 46% of workers presenting a Pb-B range of 25-60 µg/dl in risk areas. Recent data suggest that Pb-B levels above 25 µg/dl are related to subclinical alterations in human body that should be investigated during clinical examination. Finally, we propose a strategy based on environmental and biological monitoring to prevent both clinical and subclinical effects.