Monitoring the impact of pesticide mixtures with advanced biotests

• Grant number: 19/21098-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: March 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Gisela de Aragão Umbuzeiro
• Grantee: Rhaul de Oliveira
• Supervisor: Stefan Scholz
• Host Institution: Faculdade de Tecnologia (FT). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil
• Institution abroad: Helmholtz Association, Germany
• Associated to the scholarship: 18/03108-0 - Zebrafish embryo test as a tool for an integrated assessment of water quality in sugarcane impacted areas, BP.PD

Abstract

Pesticides are used in large amounts in modern agriculture to secure nutrition and biofuel production. Registration and authorization of pesticides requires that they can be used without harm to the environment and appropriate safety data have to be provided before marketing and application. However, the assessment is based on individual compounds while typically pesticides occur in the environment in mixtures. This could represent a major reason why an impact on freshwater ecosystems probably caused by pesticides can be observed on the continental scale. In order to identify the potential impact of complex pesticide mixture on the environment, chemical monitoring should be accompanied by bioanalytical assessment. Biotests are able to capture the combined effects and the effects of compounds not targeted by chemical assessment. The proposed project aims to analysis the impact of pesticide mixtures with a focus on pesticides used in Brazil and identified in fresh waters. Analysis will be conducted with two high-throughput/high-content organismic biotests: (1) An automated zebrafish embryo test with quantitative phenotype and behaviour assessment and (2) a diagnostic algae assay coupled to PAM (pulse amplitude modulated) fluorimetry and FACS (fluorescence activated cell sorter) analysis. By means of these two models, we will characterize the effect signatures of individual pesticides and their mixture. Focus will be on pesticides that are commonly used in sugar cane production, including areas of pasture convertment. It is important to mention that the two systems allow capturing major mode of actions of pesticides, i.e. neuroactive and potential teratogenic effects of insecticides and photosystem interaction of herbicides. We aim at a detailed understanding of mixture effects in these bioassays to improve prediction of pesticide mixture and interpretation of mixture effect patterns for hazard assessment. (AU)