Some suggestions for the development of test to detect the subacute effects of chemicals

Alemán. The purpose of the act on the protection against dangerous substances (chemicals act) is no longer accounted for if there is only an unilateral research into the 'ecochemical behaviour' of a substance, if the selection of test organisms is only directed towards such aim, if only such tests are developed, introduced and stipulated by legislation which permit solety the establishment of acute damage from chemicals in individual animals of defined species in the laboratory, i.e. isolated from their biocoenotic associations. Based on the hypothesis that in the case of terrestric animals, the damaging influence of chemicals would results in a reduced metabolism within the natural cycle of a biocoenosis, there has been a search for methods permitting an early recognition of subacute damage in soil organismus which precedes acute disorders. These studies were aimed at finding indicators capable of showing the reduced performance of terrestric animals expressing subacute damage. The suitability of collemboles, larvae of diptera and Lumbricidae for use in tests to detect acute damages is discussed. The differences in sensitivity to one and the same chemical in the experiment has been shown for collembole species. Attention is drawn to the fact that a determination of the LD50 value is of no importance for the development of tests to detect acute damage. There should be no arbitrary limitation of the testing period. Process-dependent indicators should serve as yardsticks to evaluate a reduced performance of test organisms. It would be promising to develop a multiplication or feeding activity test for collemboles, a soil structure or plant growth test for Lumbricidae, e.g. L. rubellus, and a feeding activity test for soil Diptera. The latter has been demonstrated experimentally, using larvae of Neosciara modesta