Avaliação da toxicidade aguda do Decis ® 25 EC em Daphnia magna

Abstract

The use of chemicals to control pests and diseases in crops began in antiquity. Over time, these products have come to be called pesticides and have become indispensable in intensive farming to increase production. The Brazil due to its intense production of primary products, is a major consumer of these products. How much of the pesticides applied to the soil and plants tends to move, especially for surface and groundwater, assessment of toxicity to aquatic organisms should also be considered for the determination of maximum concentrations of compounds and the application of care, handling and disposal of packaging. In this context, this study aimed to evaluate the acute toxicity on Daphnia magna the insecticide Decis ® 25 EC manufactured by Bayer S/A, consisting of a mixture of deltamethrin and aromatic solvent. According to the Material Safety Data Sheet - MSDS product Decis ® EC 25, EC50 (48h) of deltamethrin in Daphnia sp. is 0,0035 mg/L (3,5.10-3 mg/L). Acute toxicity testing was conducted employing the microcrustacean D. magna, the EC50 with informed by the manufacturer and the above concentrations (1,25 mg/L; 0,025 mg/L; 0,005 mg/L) and below (3,5.10-4 mg/L; 3,5.10-5 mg/L; 3,5.10-6 mg/L; 3,5.10-8 mg/L; 3,5.10-9 mg/L) thereof. The above EC50 concentrations showed 100% immobility after 24 hours, the test with the EC50 of deltamethrin provided by the manufacturer resulted in 93% of immobility in 24 and 100% of immobility in 48 hours. Only concentrations 3,5.10-5 mg/L and 3,5.10-6 mg/L was obtained immobility in the range 60-40%. The results demonstrate that the EC50 presented by the leaflet refers only deltamethrin the aromatic solvent, which is 40 to 50% of the concentration of Decis ® EC 25 increases the EC50, was found with an EC50 of 0.93 ng / L referring to Decis ® 25 EC.