Silicosis en trabajadores expuestos aconglomerados de cuarzo / Silicosis in workers exposed to quartz conglomerates

Introducción: la silicosis, enfermedad crónica, causada por la inhalación de polvo de sílice cristalina, sigue siendo un problema de salud laboral vigente. El objetivo de la investigación consistió en estimar el riesgo de silicosis complicada y/o acelerada en trabajadores expuestos a polvo de sílice de conglomerados de cuarzo frente al riesgo de los trabajadores expuestos a roca ornamental. Método: se desarrolló un estudio analítico de casos y controles prevalentes en trabajadores cuya vigilancia de la salud se realizó en el instituto Nacional de Silicosis (España), entre el 1 de enero de 2008 y el 31 de diciembre de 2018 (N = 90). El valor de la significación de todos los contrastes de hipótesis realizados fue α = 0,05. Resultados: se determinó mayor riesgo de silicosis complicada en los trabajadores expuestos a polvo de sílice proveniente del uso de conglomerados de cuarzo mediante el cálculo de Chi cuadrado, con un total de 7 casos (46,67%) de silicosis complicada (p = 0,046). Conclusiones: existe mayor riesgo de silicosis complicada en los trabajadores expuestos a polvo de sílice proveniente del uso de conglomerados de cuarzo frente a los expuestos a polvo de sílice de roca ornamental. No se observó relación entre el riesgo de desarrollar silicosis acelerada y la exposición a conglomerados de cuarzo en la muestra analizada (AU)

Introduction: silicosis, a chronic disease caused by the inhalation of crystalline silica dust, continues to be a current occupational health problem. The objective of the research was to estimate the risk of complicated and/or accelerated silicosis in workers exposed to silica dust from quartz conglomerates compared to the risk of workers exposed to ornamental rock. Method: an analytical study of cases and controls prevalent in workers whose health surveillance was carried out at the National Institute of Silicosis (Spain), between January 1, 2008 and December 31, 2018 was developed (N = 90). The significance value of all the hypotheses tests performed was α = 0.05. Results: a higher risk of complicated silicosis was determined in workers exposed to silica dust from the use of quartz conglomerates by calculating Chi square, with a total of 7 cases (46.67%) of complicated silicosis (p = 0.046). Conclusions: there is a higher risk of complicated silicosis in workers exposed to silica dust from the use of quartz conglomerates compared to those exposed to silica dust from ornamental rock. No relationship was observed between the risk of developing accelerated silicosis and exposure to quartz conglomerates in the analyzed sample (AU)

Use of the fractal dimension for the analysis of electroencephalographic time series.

Electroencephalogram (EEG) traces corresponding to different physiopathological conditions can be characterized by their fractal dimension, which is a measure of the signal complexity. Generally this dimension is evaluated in the phase space by means of the attractor dimension or other correlated parameters. Nevertheless, to obtain reliable values, long duration intervals are needed and consequently only long-term events can be analysed; also much calculation time is required. To analyse events of brief duration in real-time mode and to apply the results obtained directly in the time domain, thus providing an easier interpretation of fractal dimension behaviour, in this work we optimize and propose a new method for evaluating the fractal dimension. Moreover, we study the robustness of this evaluation in the presence of white or line noises and compare the results with those obtained with conventional spectral methods. The non-linear analysis carried out allows us to investigate relevant EEG events shorter than those detectable by means of other linear and non-linear techniques, thus achieving a better temporal resolution. An interesting link between the spectral distribution and the fractal dimension value is also pointed out.