Análisis de la dispersión de las fibras de asbesto en dos talleres de mecánica de frenos de la ciudad de Bogotá.
No hay miniatura disponible
Fecha
Autores
Título de la revista
ISSN de la revista
Título del volumen
Editor
Resumen
Descripción
Introducción: Los productos de freno son una fuente de exposición a las fibras de asbesto. Durante su manipulación los mecánicos están expuestos a concentraciones de asbesto muy altas. Objetivo: Entender el comportamiento de las fibras dentro de los talleres de mecánica e identificar los factores que determinan la dispersión de las fibras en el ambiente. Metodología: Se seleccionaron 2 talleres de mecánica de Bogotá. Se tomaron muestras personales y de área en puntos distribuidos al interior de los talleres durante la jornada de trabajo, por una semana laboral. Las concentraciones de fibras fueron determinadas por Microscopía de Contraste de Fase (PCM), y con base en estas concentraciones se elaboraron curvas de isoconcentración y modelos estadísticos. Asimismo, se determinó la tasa de intercambio de aire en cada taller. Resultados: Curvas de isoconcentración: En las primeras horas del día, se presentan altas concentraciones de fibras en el área de manipulación, y bajas concentraciones de fibras en las demás áreas del taller. Durante el día, se observa un desplazamiento de fibras hacia zonas ventiladas del taller. Intercambio de aire: Talleres cerrados, de pequeñas dimensiones presentan niveles de ventilación más bajos que talleres semi-abiertos, de grandes dimensiones. Modelos estadísticos: Las muestras personales y las de área reportan concentraciones significativamente diferentes, evidenciando que la asociación entre estos 2 tipos de muestras es muy débil. Conclusiones: La liberación de fibras en espacios cerrados y de baja ventilación genera altas concentraciones de fibras dentro del taller, mientras que la liberación de fibras en espacios semi-abiertos y de alta ventilación promueve la rápida dispersión y desplazamiento de las fibras hacia zonas externas al taller. Es muy inexacto estimar la exposición personal de un trabajador a las fibras de asbesto utilizando muestras de área.
Introduction: Brake products are a source of exposure to asbestos fibers. During the manipulation of such products mechanics are exposed to very high concentrations of asbestos. Aim: Understand the behavior of fibers within brake repair workshops and identify the factors determining the dispersion of these fibers in the environment. Methodology: Two brake repair workshops were selected in Bogota. Personal and area samples were taken at different locations distributed inside the brake repair workshops during 8-hour work-days, throughout a work week. Fiber concentrations were determined by Phase Contrast Microscopy (PCM), and iso-concentration curves and linear regression models were prepared based on those concentrations. Additionally, the air exchange rate was determinated in each brake repair workshop. Results: Isoconcentration curves: During the first hours of the day, high fiber concentrations were reported in the manipulation area and low fiber concentrations in other areas of the brake repair workshop. During the day, movement of fibers to the workshop ventilated areas was observed. Air exchange: Small and enclosed facilities have lower ventilation levels than bigger and semi-open facilities. Statistical models: Fiber concentrations reported in personal samples and area samples are significantly different, showing that the association between these 2 types of samples is very weak. Conclusions: The release of fibers in enclosed and low ventilation facilities generated high concentrations of fibers within the brake repair workshop, while the release of the fibers in semi-open and high ventilation facilities promoted rapid dispersion and displacement of the fibers to the outside areas of the brake repair workshop. It is very inaccurate to estimate the personal exposure of the worker to asbestos fibers using area samples.
Introduction: Brake products are a source of exposure to asbestos fibers. During the manipulation of such products mechanics are exposed to very high concentrations of asbestos. Aim: Understand the behavior of fibers within brake repair workshops and identify the factors determining the dispersion of these fibers in the environment. Methodology: Two brake repair workshops were selected in Bogota. Personal and area samples were taken at different locations distributed inside the brake repair workshops during 8-hour work-days, throughout a work week. Fiber concentrations were determined by Phase Contrast Microscopy (PCM), and iso-concentration curves and linear regression models were prepared based on those concentrations. Additionally, the air exchange rate was determinated in each brake repair workshop. Results: Isoconcentration curves: During the first hours of the day, high fiber concentrations were reported in the manipulation area and low fiber concentrations in other areas of the brake repair workshop. During the day, movement of fibers to the workshop ventilated areas was observed. Air exchange: Small and enclosed facilities have lower ventilation levels than bigger and semi-open facilities. Statistical models: Fiber concentrations reported in personal samples and area samples are significantly different, showing that the association between these 2 types of samples is very weak. Conclusions: The release of fibers in enclosed and low ventilation facilities generated high concentrations of fibers within the brake repair workshop, while the release of the fibers in semi-open and high ventilation facilities promoted rapid dispersion and displacement of the fibers to the outside areas of the brake repair workshop. It is very inaccurate to estimate the personal exposure of the worker to asbestos fibers using area samples.