Toxicity of fourteen herbicides has been determined for thirteen animal species: Planaria gonocephala, Tubifex sp., Lymnaea stagnalis, Daphnia pulex, Gammarus pulex, Asellus aquaticus, Micronecta minutissima, Esox lucius, Cyprinus carpio, Phoxinus phoxinus. Leucaspius delineatus, Perca fluviatilis, Rana temporaria, in 510 laboratory experiments. It was followed in three concentrations and expressed both in tables, by the value LT50 or by the various degree of damage of the organisms, and in graphs. The organisms were divided into four groups according to their sensitivity to herbicides: 1. organisms with high sensitivity; 2. sensitive; 3. medium sensitive; 4. little sensitive. From the point of view of the toxicity the herbicides were divided into three groups: 1. powerfully toxic; 2. medium toxic; 3. little toxic. A relationship between the intensity of toxicity and the chemical structure of herbicides was found. The first group includes herbicides on the basis of carbamates and phenols, the second group includes the derivates of phenoxyacetic acid, and the third group includes inorganic herbicides and those pertaining to the group of the chlorated organic substances. The mechanism of the toxic action was followed from the point of view of the mutual relationship of herbicide toxicity and the sensitivity of organisms. Eight basic types of this action were found. Special attention was paid to those types where significant reparation phases appeared during the experiments. Only inorganic herbicides and those from the group of the chlorated organic substances or eventually those on the basis of phenoxyacetic acid may be used for mass application in water economy. In all cases further complex investigations must be made concerning the influence on water biocenoses, as the recent data on the toxicity of herbicides with respect to several species of fish only are not sufficient. The use of herbicides from the group of phenols and carbamates should be prohibited in the neighbourhood of water bodies.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - ecologie animale, vegetale et microbienne