Browsing by Autor "Lieven Bervoets"

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ACUMULACION DE METALES PESADOS EN LOS SEDIMENTOS y EN LARVAS DE QUIRONOMIDOS DEL RIO CAINE (COCHABAMBA, BOLIVIA)
(1998) Danilo Solis; Ana Romero; Lieven Bervoets; Paul Van Damme
ACCUMULATION OF HEAVV METALS IN SEDIMENTS AND IN CHIRONOMID LARVAE IN THE RIO CAINE (COCHABAMBA, BOLIVIA) Se estudio el efecto de la actividad minera sobre la acumulacion de metales en sedimentos y quironomidos en el rfo Caine (zona Mina Asientos). En un estudio preliminar; fueron colectados sedimentos superficiales en 8 puntos de muestreo a lo largo del rfo y en un estudio posterior; se colectaron sedimentos superficiales asf como larvas de mosquitos (Chironomidae, Diptera) en 5 puntos de muestreo. Se determinaron las concentraciones de los metales cadmio, cobre, cromo, niquel, plomo y zinc en sedimentos y organismos, mediante espectrometrfa de absorcion atomica. En el primer estudio, se analizaron las concentraciones de metales totales y en el segundo estudio, las muestras de sedimentos fueron tratadas por dos diferentes metodos de extraccion para conocer la concentracion total de metales(T) y de metal reducido (R). No se detectaron incrementos significativos en la concentracion de metales en los sedimentos hasta 20 km rfo abajo del centro de actividad minera. Probablemente, los metales no se sedimentan por ser arrastrados por el agua. Sin embargo, la concentracion de metales en las larvas de mosquitos se incremento hasta 4 km rfo abajo. Probablemente, las larvas acumulan metales por el agua, a traves de una ruta que no ha sido cuantificada. Palabras claves: Metales pesados, Rfo Caine, bio-acumulacion, polucion de rios, Chironomidae, Cochabamba, Bolivia ABSTRACT The effect of mining on metal accumulation in sediments and chironomids in the Rfo Caine was assessed. In a preliminar stud)f: surficial sediments were collected at 8 sampling sites and, in a subsequent stud)f: surficial sediments and midge larvae (Chironomidae, Diptera) were collected at 5 sites. Concentrations of the trace metals Cd, Cu, Cr; Ni, Pb, and Zn were measured in sediments and organisms by atomic absorption spectrometer In the first stud)f: total trace metals were detected while, in the second stud)f: sediments were subjected to two different extraction procedures to measure total trace metals and reducible trace metals. No significant increase in metal concentration in sediments could be measured over a distance of 20 km downstream from the mining activitr Probabl)f: sedimentation of metals does not occur in this area and metals are being carried further downstream. However; larval metal concentrations increased markedly within the first 4 km of the area under investigation. Probabl)f: larvae accumulate heavy metals by a non-measured exposure route such as the overlying water column. Key words: Heavy metals, Rfo Caine, bio-accumulation, river pollution, Chironomidae, Cochabamba, Bolivia
Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia)
(Elsevier BV, 2008) Paul A. Van Damme; Caroli Hamel; Alfredo Ayala; Lieven Bervoets
Trace element accumulation in different edible fish species from the Bolivian Amazon and the risk for human consumption
(Elsevier BV, 2022) Inti E. Rodriguez-Levy; Paul A. Van Damme; Fernando M. Carvajal‐Vallejos; Lieven Bervoets
Artisanal mining and erosion of metalbearing soils can contaminate aquatic ecosystems and affect the health of riparian human populations, through metal bio-accumulation processes and fish consumption. Concentrations of eight trace metals (Cd, Cr, Co, Cu, Pb, Hg, Ni, Zn) and a metalloid (As) were measured in the muscle tissue of different edible fish species collected from markets of two cities along the Beni River banks, in the Bolivian Amazon. Relationships between the size of fish belonging to different trophic levels (carnivores, omnivores, detritivores and herbivorous) from four different fishing zones were analyzed. The most relevant results corresponded to the detritivore group, whose members exhibited significant positive correlations between the fish size and the concentration of three metals (cadmium, cobalt and nickel). Furthermore, a 3 × 3 scenario-risk analysis was performed to assess local risk for human health. This was done by relating three different scenarios of local fish consumption collected from literature (maximum, average and minimum) and three different levels of trace element concentrations (95th, 50th and 5th percentile) derived from the present study and the Minimal Risk Levels suggested by the Agency for Toxic Substances and Disease Registry. Results of these calculations determined the amount of fish muscle per contaminant that could be consumed per day without risking human's health. Finally, Target Hazard Quotients were calculated for each trace element, aiming to indicate the potential exposure to each one and the concentration at which no adverse effects are expected. The obtained results made clear that mercury is the only trace element that represents an important health risk to humans within the studied region, considering most of the combinations in the 3 × 3 analysis. Chronic mercury intoxication could occur when consumption of fish in Riberalta or Rurrenabaque exceeded 83 g/day in females and 110 g/day in males.
Trace Metal Levels in Chironomid Larvae and Sediments from a Bolivian River: Impact of Mining Activities
(Elsevier BV, 1998) Lieven Bervoets; Danilo Solis; Ana Romero; Paul A. Van Damme; F. Ollevier