Ecotoxicological assessment and environmental risk of inseticides temephos and diflubenzuron to Daphnia magna, Lemna minor and fishes

• Grant number: 11/21425-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2012
• End date: October 31, 2014
• Field of knowledge: Biological Sciences - Pharmacology - Toxicology
• Principal Investigator: Joaquim Gonçalves Machado Neto
• Grantee: Joaquim Gonçalves Machado Neto
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The use of pesticide temephos and diflubenzuron in agriculture, aquaculture and control of disease vectors can cause environmental imbalances, and the occurrence of these effects are analyzed by ecotoxicological studies and environmental risk assessments. This study aims to: i) determine the acute and chronic toxicity of pesticide temephos and diflubenzuron in the presence and absence of sediment to the microcrustacean Daphnia magna, fish pacu (Piaractus mesopotamicus) and mato grosso (Hyphessobrycon eques) and macrophyte Lemna minor, ii) to assess the concentration of residues in water from chronic toxicity tests and iii) classify the pesticides on the environmental risk in aquatic ecosystem. For acute toxicity tests will determine the median lethal concentration (LC50) of L. minor, P. mesopotamicus and H. eques and mean effective concentration (EC50) in D. magna in laboratory conditions. For chronic tests, will be assessed longevity, growth and fecundity of D. magna on growth rate of L. minor, and longevity and growth of P. mesopotamicus and H. eques. During the experimental periods will be valued variables physico-chemical water (pH, dissolved oxygen, temperature and electrical conductivity). The values found will be used to classify the pesticides on the toxic potential for these species. Will be calculated the risk of environmental comtamination by the method of quotient (Q). Also will be obtained the values of no observed effect concentration (CENO), observed effect concentration (CEO), and chronic value (VC). For the analysis of pesticide residues in water, water samples will be collected from the tests of H. eques and determined by high performance liquid chromatography (HPLC), using a chromatographic system equipped with ultraviolet detector and loop of 20 µL. (AU)