A dynamic system for long-term toxicity studies in fish under laboratory conditions

For the evaluation of possible adverse effects of compounds in fish at sublethal doses a dynamic system is required. The design of such a system is presented including the methodology of performing long-term toxicity studies in fish using selected environmental chemicals (plant protection products). Chronic studies with Diazinon, Terburyn, Phosphamidon on carp and trout comprised 28 day treatment periods followed by 28-day recovery periods. In addition to the toxicity, the residues of the applied chemicals in fish, divided into muscle tissue and viscera, and in the test medium were determined during the experimental and recovery period. The results demostrate that the chemicals accumulated to a somewhat greater extent in the viscera than in the muscle tissue of the fish during exposure. In the course of the recovery period the concentration of the substances tested decreased to the limits of detection. It was concluded that following an adequate waiting period no measurable residues were formed from these plant protection products, that are carried in the food chain.