Determinación de la toxicidad de eventos de precipitación en las UPZ Chapinero y Chicó Lago en la localidad de Chapinero de Bogotá D.C.

Abstract

The purpose of this project was to evaluate the toxicity of precipitation events in the Zonal Planning Units (UPZ) Chapinero and Chicó Lago in Bogotá through a bioassay in which the common grass species (Cynodon dactylon) was exposed to rainwater collected, with which an analysis of radicle lengths (root) and the first segment of seed germination was carried out, the effective concentration 50 (EC50) was determined. To capture rainwater, 8 monitoring stations 4 were located for each UPZ, the collected samples were measured conductivity and pH in situ and in the laboratory sulfate ion concentrations to establish the conditions in which the water was collected.

The bioassay design was 5x3 (five treatments and three replicates per each), dividing the treatments into: an original sample and 4 dilutions, made from 15 ml of collected water and 10, 20, 30 and 40 ml of distilled water; Each experimental unit had 10 seeds of the species and 5 ml of water, therefore 15 units were obtained per monitoring station and 120 plus 3 targets for a large total. Finally, to maintain the germination conditions of the seedlings, they were incubated for a period of 120 hours (5 days).

The UPZ did not show significant levels of acidity in rainfall except for the weeks of February and March that were declared in yellow alert by the mayor of Bogotá due to air pollution; in relation to the bioassay, the monitoring station that presented the highest sensitivity to the pH of the samples was the Nogal station of 78, which showed a decrease in seedling growth and high pH values