Browsing by Autor "Vandecasteele, Carlo"

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    CONTAMINACION DEL AGUA Y SUBSUELO POR EL USO DEL FLUROXIPIR METILHEPTIL ESTER EN CULTIVOS DE SOYA EN LA LOCALIDAD DE CHANÉ EN EL DEPARTAMENTO DE SANTA CRUZ
    (Rev. Bol. Quim, 2005) Vargas, Paul E.; de Groot, Walter; Vandecasteele, Carlo
    Starane® es un producto herbicida muy utilizado en el cultivo de soya, su componente activo es fluroxipir metilheptil éster (FMHE). Se colectaron muestras de suelo de Santa Cruz y Cochabamba. Los valores de Kd y Koc obtenidos para el FMHE fueron 8 ml g-1 y 401 ml g-1. Los ensayos de infiltración con 1,74 veces la dosis de FMHE aplicada en campo presentaron una recuperación de menos del 1% de FMHE. Solo suelos con abundancia de material grueso presentaron FMHE en sus respectivos infiltrados. Altos contenidos de materia orgánica y sales se asociaron con una mayor y menor sorción de FMHE en el suelo, respectivamente. FMHE fue detectado en cuatro ríos y un pozo poco profundo de Santa Cruz.
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    Elevated cadmium concentrations in potato tubers due to irrigation with river water contaminated by mining in Potosí, Bolivia.
    (2007) Oporto, Carla; Vandecasteele, Carlo; Smolders, Erik
    Risk of cadmium (Cd) in the human food chain in Cd-contaminated areas is often limited by phytotoxicity from zinc (Zn) that is associated with the Cd contamination. A semiarid area, 60 km downstream of a tin mine in Bolivia, was surveyed where irrigation with Cd-contaminated river water (65-240 microg Cd L(-1)) has increased median soil Cd to 20 mg kg(-1) while median soil Zn was only about 260 mg kg(-1). Cadmium concentrations in potato tubers increased from background values (0.05 mg kg(-1) dry wt.) in soils irrigated with spring water to a median value of 1.2 mg kg(-1) dry wt. in the affected area. Median concentration of Cd in soil solutions was 27 microg L(-1) and exceeded the corresponding value of Zn almost twofold. Soil-extractable chloride ranged from 40 to 1600 mg Cl(-) kg(-1) and was positively correlated with soil total Cd. Increasing soil solution Cl(-) decreased the solid-liquid distribution coefficient of Cd in soil. Soil total Cd explained 64% of the variation of tuber Cd concentration while only 3% of the variation was explained by soil extractable Cl(-) (n = 49). The estimated dietary Cd intake from potato consumption by the local population is about 100 microg d(-1) which exceeds the WHO recommended total daily intake. It is concluded that the food chain risk of Cd in the irrigation water of the semiarid area is aggravated by the association with Cl(-) and, potentially, by the relatively large Cd/Zn ratio.