To review the literature concerning the risks associated with exposure to lead and lead compounds, especially in children and in populations that are occupationally exposed. Using "chumbo" [lead] and "efeitos" [effects] as search terms, two large databases, namely PubMed (United States National Library of Medicine) and LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde [Latin American and Caribbean Literature in the Health Sciences]), were searched for studies on lead toxicity from 1988 to 2002. Other sources used to conduct the search include the web page of the United States Agency for Toxic Substances and Disease Registry, in Atlanta, Georgia, and the library of the Toxicology Laboratory of the Center for Workers' Health and Human Ecology at the National School of Public Health [Centro de Estudos da Saúde de Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública], Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. The toxic effects of lead and lead compounds have been extensively studied for over a century. In recent years, epidemiologic studies have focused primarily on the neurotoxic effects of lead on children, particularly in terms of impaired intellectual ability and behavioral problems. However, there is still insufficient information on the mechanisms of action that account for such toxicity. More in-depth studies are also needed on the effects of lead exposure on bone, the central nervous system, the cardiovascular system, the kidneys, the liver, the male and female reproductive systems, and the endocrine system. The potential teratogenicity and carcinogenicity of lead, as well as its effect on pregnancy outcomes and neonatal growth and development, also require further study.

The determination of Cd in whole blood and urine by electrothermal atomic absorption spectrometry using Pd-based modifiers and in situ decontamination was studied. The performance of Pd, Pd + NH₄NO₃, and Pd + Mg(NO₃)₂ as modifiers were compared with respect to maximum pyrolysis and atomization temperatures, background attenuation, linear calibration range and matrix interference. Samples were diluted (1 + 4) with 0.1% Triton X-100 (blood) or 0.2% HNO₃(urine), and introduced onto the graphite tube platform already containing the in situ dried and decontaminated modifier. The influence of modifier volume and concentration, as well as that of the dilution ratio was investigated. The proposed procedure involves the use of Pd(NO₃)₂+ Mg(NO₃)₂ as modifier, a pyrolysis temperature of 700 °C and an in situ decontamination step of 1200 °C. The atomization temperature was 1700 °C. The detection limit (n= 10, k= 3) was 0.22 µg l^–1 for both samples. Typical relative standard deviation values (n= 3) were below 3%. Using matrix-matched standards, good agreement was observed between experimental and reference values in the analysis of certified reference materials. Interlaboratory comparison data have confirmed the validity of the proposed analytical procedure.

Heart disease progression occurs in 30% of patients with chronic Trypanosoma cruzi infection. Supplementation with selenium (Se) in animal model of T. cruzi infection produced promising results. There is evidence that patients with Chagas heart disease have lower Se levels than healthy individuals and patients with T. cruzi infection without of cardiac disease. The aim of this investigation is to estimate the effect of Se treatment on prevention of heart disease progression in patients with chagasic cardiopathy. The Selenium Treatment and Chagasic Cardiopathy trial is a superiority, double-blind, placebo-controlled, randomized clinical trial. The eligibility criteria are as follows: (1) a Chagas disease diagnosis confirmed by serology; (2) segmental, mild or moderate global left ventricular systolic dysfunction; and (3) age between 18 and 65 years. The exclusion criteria are as follows: (1) pregnancy, (2) diabetes mellitus, (3) tobacco use, (4) alcohol abuse, (5) evidence of nonchagasic heart disease, (6) depression, (7) dysphagia with evidence of food residues in the esophagus, (8) dysphagia with weight loss higher than 15% of usual weight in the last four months and/or (9) conditions that may result in low protocol adherence. The intervention will be 100 μg of sodium selenite once daily for 365 consecutive days compared to placebo. The following are the primary outcomes to be measured: (1) the trajectories of the left ventricular ejection fraction in the follow-up period; (2) reduction of heart disease progression rates, with progression defined as a 10% decrease in left ventricular ejection fraction; and (3) rate of hospital admissions attributable to dysrhythmia, heart failure or stroke due to Chagas disease. One hundred thirty patients will be randomly allocated into either the intervention or placebo group at a ratio of 1:1. The sequence allocation concealment and blinding were planned to be conducted with the strategy of numbered boxes. Both patients and health-care providers will remain blinded to the intervention groups during the 5 years of follow-up. If Se treatment reduces the progression of Chagas cardiopathy, the inclusion of this micronutrient in the daily diet can improve the therapeutic regimen for this neglected tropical disease at low cost. Clinical Trials.gov ID: NCT00875173 (registered 20 October 20 2008).

O objetivo deste trabalho foi verificar se há correlação estatisticamente significativa entre as concentrações de chumbo no sangue (Pb-S) e urina (Pb-U). A espectrometria de absorção atômica eletrotérmica foi utilizada na determinação da concentração de chumbo no material biológico. As amostras de sangue e de urina foram coletadas entre trabalhadores expostos ocupacionalmente (95) e entre adultos (130) e crianças até 15 anos (22) expostos ambientalmente. Após um teste que mostrou diferenças significativas entre Pb-U e as três categorias previamente determinadas, pontos de corte em Pb-U puderam ser fixados para a predição dos valores de Pb-S pela curva ROC. Assim, para Pb-U até 0,55 µg.dL-1, pode-se esperar que Pb-S seja menor do que 10 µg.dL-1, ao passo que níveis de chumbo no sangue até 27,6 µg.dL-1 são esperados quando o teor do metal na urina é menor do que 2,05 µg.dL-1. Logo, a urina pode ser utilizada em substituição ao sangue para avaliação da exposição ocupacional ao chumbo. Contudo, recomenda-se cautela no caso da exposição ambiental, devendo-se utilizar o chumbo urinário como uma estimativa do conteúdo do metal no sangue.

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