Methodological approaches to assessing the toxicity of compounds by changing the behavioral response of soil oligochaetes

Abstract

The methodological aspects of assessing the toxicity of surface-active substances (SAS) by changing the behavioral response of avoiding the substrate by earthworms Eisenia fetida andrei Bouche, 1972 were studied. The conditions for biotesting were selected, under which the method is more sensitive to the tested pollutants. In this method, 30 worms. placed in a Petri dish with a substrate unfavorable for worms (dry sand). Around it, Petri dishes with test samples of moistened sand contaminated with individual toxicants in various concentrations and their mixtures were placed radially. A control sample (wet sand) was also placed among the prototypes. When the worms selected the most favorable of the tested contaminated substrate samples, their movement from dry sand was observed. After 4 h from the start of the experiment, the number of worms in each of the compartments was counted. The toxic effect of the cationic surfactant cetyltrimethylammonium bromide (CTAB) was manifested when its content in the soil sample was from 0.001 g / kg; nonionic surfactant Tween-80 – from 1 ml / kg; anionic surfactant sodium lauryl sulfate – from 20 mg / kg.