Effect of cerium oxide (CeO2) nanoparticles and polyethylene terephthalate (PET) microplastics, isolated and in mixture, on the neotropical Cladocera Ceriodaphnia silvestrii.

• Grant number: 24/18501-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Maria da Graça Gama Melão
• Grantee: Maria Júlia Godoy de Carvalho
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 24/06037-8 - Aspects of the ecotoxicity of secondary fragments of the microplastic polyethylene terephthalate (PET) isolated and in mixture with metallic and organic pollutants as a function of concentration and size", AP.R

Abstract

Cerium nanoparticles are widely used in various sectors, including metallurgy, biomedicine, and electronics, valued for their properties of conductivity, magnetism, and fluorescence. Microplastics (MPs), resulting from the degradation of the vast amounts of plastics used in our society, are known for their widespread distribution and environmental impact, affecting human health and aquatic life. The disposal of these substances into aquatic ecosystems has raised concerns regarding their impacts on biota, especially due to their potential toxicity and bioaccumulation. This study aims to evaluate the ecotoxicological effects of cerium oxide nanoparticles (NPs-CeO2) and polyethylene terephthalate (PET) microplastics, isolated and in mixtures, on the Neotropical Cladocera Ceriodaphnia silvestrii, an important environmental bioindicator. To this end, C. silvestrii will be cultured and exposed to the xenobiotics under controlled laboratory conditions, to determine its immobilization and filtration and ingestion rates after the exposure to different concentrations of NPs and MPs. Respiratory rates will be determined using a micro-respirometer system. The tests will follow standardized protocols by ABNT. We expect that the results will provide information about the impacts of these materials on C. silvestrii, and it will support the understanding of their effects on the base of freshwater food chains.