Determinación de la toxicidad en dispersantes de petróleo mediante bioensayos para calcular el CL50

Abstract

Este tipo de experimentación se ha centrado en la estimación de la Concentracion Letal Media (CL50), que significa el cincuenta por ciento de organismos muertos en un tiempo determinado.

We have gotten concentrations between 1.36 and 52.88 ppm, these values represent the rank of Median Lethal Concentration (50%) of mortality and we considerate it as the maximum and minimun values of oil dispersants for Tetraselmis sp., phytoplankton microorganism that corresponds to the first link of marine and estuarine trophic chain. The exponential tendency and the less and high critic values of CL50 concentrations were determined to make up the toxic scale: 1 to 10 ppm toxic moderate; 11 to 30 ppm toxic media and 31 to 60 toxic low. Since 1990, the Institute Oceanographic of the Ecuadorian Navy carried out 60 toxic bioassays of oil dispersants with the purpose of determinate CL50, and gave us the ability to controlate the toxic grade of different kinds of detergent substances that are present in oil spills in different areas such as sea, estuaries and rivers.