RESUMO
Mercury, lead, cadmium and arsenic are considered hazardous pollutants in the environment, which can result in a risk for human health. This study aimed to determine the contents of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn by ICP-MS, CVAAS and ICP-AES in paddy and brown rice, grown in different soils of Cuba. The interest to include Cr, Ni, Cu and Zn was because these elements are found in very high levels in agricultural soils. To assess the safety of the dietary intake of these metals, the estimated weekly intake was calculated. The contents of Cd and As were below the maximum limits. A higher value was obtained for Pb when compared to Codex Alimentarius limits. The weekly intake of Cr and Ni was higher than the maximum weekly intake recommended by FAO/WHO.
Assuntos
Metais Pesados , Oryza , Poluentes do Solo , Cuba , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análiseRESUMO
RESUMEN Se presentó la metodología seguida para la modelación de tres parámetros que caracterizan la calidad del agua: demanda bioquímica de oxígeno, oxígeno disuelto y amonio en un tramo del río Luyanó, empleando el software RIOSep® v.2.0. Durante el trabajo se combinaron acertadamente las técnicas de radiotrazadores para estimar los parámetros hidrodinámicos de la corriente del río con las técnicas de análisis fisicoquímico para determinar sus parámetros básicos. El levantamiento de los parámetros hidrodinámicos en la corriente se realizó con el empleo del 
. Simultáneamente con la determinación de caudales se muestreó en cinco estaciones en el cauce principal y dos tributarios, para determinar los parámetros físico-químicos de interés. Como resultado se obtuvo un modelo que describe en más del 90% el comportamiento de la demanda bioquímica de oxígeno y del oxígeno disuelto y en más del 65% el comportamiento del amonio, por lo que caracteriza adecuadamente los procesos de autodepuración y el balance de oxígeno en las aguas del río.
ABSTRACT The methodology for the modelling of three parameters that characterize water quality: biochemical oxygen demand, dissolved oxygen and ammonium in a Luyanó river stretch using the RIOSep ® v.2.0 software. The procedure combined the use of radiotracer techniques for estimating the hydrodynamic parameters of the stream with physicochemical techniques to determine its basic parameters. The survey of hydrodynamic parameters in the stream was conducted with the use of as a radiotracer. Simultaneously with flow determination, water was sampled at five stations in the main channel and two tributaries, in order to determine the physical and chemical parameters of interest. The result was a model that describes accurately the biochemical oxygen demand and dissolved oxygen behaviour (more than 90%), and showed a good result for ammonium, so it adequately characterizes the purification and oxygen balance processes in water.