Neurotoxicidad por exposición a metales pesados: evidencias y cuestiones por resolver / Neurotoxicity due to exposure to heavy metals: evidence and unresolved issues

Los metales pesados son un grupo de agentes químicos que están presentes en la corteza terrestre en concentraciones variables. Muchos de estos compuestos tienen una gran importancia en el mundo actual, ya que se emplean en numerosos procesos industriales. Debido a su abundancia en la naturaleza y considerando que las investigaciones realizadas durante los últimos años han demostrado la implicación de los metales pesados en el desarrollo de numerosos procesos patológicos, se ha realizado una revisión bibliográfica con el objetivo de evaluar la relación entre la exposición a determinados metales pesados y el desarrollo de neurotoxicidad. Este análisis se ha llevado a cabo empleando la base de datos Medline y, tras un primer screening de las referencias encontradas, se ha centrado en la evaluación de siete agentes: aluminio, plomo, arsénico, mercurio, cadmio, manganeso y talio. La neurotoxicidad desarrollada tras la exposición aguda o crónica se debe a su capacidad para atravesar la barrera hematoencefálica. Algunos de los mecanismos de toxicidad no se han podido definir completamente aún, pero en casi todas las investigaciones se han relacionado con la capacidad de interferir con los procesos biológicos y de inducir estrés oxidativo y apoptosis neuronal. Existen determinadas patologías para las que se ha encontrado una relación directa con la exposición. Sin embargo, en el campo de las enfermedades neurodegenerativas la evidencia encontrada es menos concluyente. (AU)

Heavy metals are a group of chemical agents that are present in the Earth crust in varying concentrations. Many of these compounds are of great importance in today’s world, as they are used in many industrial processes. Due to their abundance in nature and considering that research carried out in recent years has shown the involvement of heavy metals in the development of numerous pathological processes, a bibliographic review has been carried out with the aim of evaluating the relationship between exposure to certain heavy metals and the development of neurotoxicity. This analysis has been carried out using the Medline database and, after a first screening of the references, it has focused on the evaluation of seven agents: aluminum, lead, arsenic, mercury, cadmium, manganese and thallium. Neurotoxicity developed after acute or chronic exposure has been shown to be due to its ability to cross the blood-brain barrier. Some of the toxicity mechanisms have not yet been fully defined, but in almost all investigations they have been related to the ability to interfere with biological processes and to induce oxidative stress and neuronal apoptosis. There are certain pathologies for which a direct relationship with exposure has been found. However, in the field of neurodegenerative diseases, the evidence found is less conclusive. (AU)

Matriz diseñada en toxicología ocupacional / Matrix designed in occupational toxicology

Se diseñó una matriz para prevenir el riesgo en toxicología ocupacional, estructurada en 3 secciones de evaluación (riesgo presumible, riesgo de asesoría y riesgo de condiciones de trabajo y daños a la salud). Se consideraron 5 menús en la primera (sector, agentes químicos, toxicidad referida, biomarcadores y eventos centinelas); 6 en la segunda (frecuencia de la exposición, duración de la exposición, proximidad a la fuente, medios de protección e influencia de puestos) y 2 en la tercera (evaluación de las condiciones de trabajo y daños a la salud). Toda vez que constituye un nuevo instrumento de gestión para estimar el riesgo toxicológico, contribuye a preservar la salud laboral(AU)

A matrix was designed to prevent the risk in occupational toxicology, structured in 3 evaluation sections (presumed risk, advice risk and risk of working conditions and damages to health). Five menus were considered in the first section (sector, chemicals, referred toxicity, biomarkers and sentinel events); 6 in the second section (frequency of exposure, length of exposure, proximity to the source, means of protection and influence of posts) and 2 in the third one (evaluation of working conditions and damages to health). Given that it is a new management tool to estimate the toxicological risk, it contributes to preserve health in the work place(AU)

Matriz diseñada en toxicología ocupacional / Matrix designed in occupational toxicology

Se diseñó una matriz para prevenir el riesgo en toxicología ocupacional, estructurada en 3 secciones de evaluación (riesgo presumible, riesgo de asesoría y riesgo de condiciones de trabajo y daños a la salud). Se consideraron 5 menús en la primera (sector, agentes químicos, toxicidad referida, biomarcadores y eventos centinelas); 6 en la segunda (frecuencia de la exposición, duración de la exposición, proximidad a la fuente, medios de protección e influencia de puestos) y 2 en la tercera (evaluación de las condiciones de trabajo y daños a la salud). Toda vez que constituye un nuevo instrumento de gestión para estimar el riesgo toxicológico, contribuye a preservar la salud laboral.

A matrix was designed to prevent the risk in occupational toxicology, structured in 3 evaluation sections (presumed risk, advice risk and risk of working conditions and damages to health). Five menus were considered in the first section (sector, chemicals, referred toxicity, biomarkers and sentinel events); 6 in the second section (frequency of exposure, length of exposure, proximity to the source, means of protection and influence of posts) and 2 in the third one (evaluation of working conditions and damages to health). Given that it is a new management tool to estimate the toxicological risk, it contributes to preserve health in the work place.

Proposta de mudança no ensino de toxicologia do médico do trabalho no Brasil, a partir da análise de erros cometidos por profissionais na condução de casos atendidos / Proposal of change in the teaching of toxicology of the occupational physician in Brazil, based on the analysis of errors made by professionals in the management of cases attended

Em um universo de centenas de casos envolvendo problemas de toxicologia ocupacional atendidos ao longo de 17 anos (1984 a 2001) por uma instituição governamental especializada em Saúde e Trabalho, foi constado que a grande maioria deles tinha sido anteriormente conduzido de forma equivocada pelos médicos do trabalho. Isto mostrou uma falha no ensino deste conhecimento a estes profissionais, e a partir deste fato, o ensino de toxicologia para os médicos, e especialmente para os médicos do trabalho, foi estudado, assim como os conceitos fundamentais das boas práticas da toxicologia ocupacional. A fim de se propor maneiras objetivas de melhoria dos cursos, foram analisados em profundidade dez casos extraídos do universo existente através do método qualitativo de estudos de casos, muito utilizado na área de educação, e a partir da compreensão das causas que levaram aos conceitos equivocados, e que tiveram suas conseqüências nos erros cometidos, foram elaboradas propostas de mudança da forma de se ministrar o conhecimento de toxicologia aos médicos do trabalho no Brasil

In a universe of hundreds of cases related to occupational toxicology, assisted over 17 years (from 1984 to 2001) in a governmental institution specialized in Occupational Health, it was observed that the great majority of them had been inadequately managed by the occupational physicians previously. This fact showed a flaw in the knowledge to these professionals. Based on this finding, a study was designed to evaluate the teaching of toxicology for physicians, particularly occupational physicians, as well as to assess the essential concepts of the good practices of occupational toxicology. In order to suggest objective measures to improve the courses, ten cases were deeply analyzed using a case study, a qualitative research methodology frequently used in the Education area. Based on the understanding of the causes responsible by the equivocal concepts, a set of proposals for changing the teaching of toxicology to occupational physicians in Brazil has been created.