Ecotoxicology of Underivatized Fullerenes (C60) in FishEPA Grant Number: R833333
Title: Ecotoxicology of Underivatized Fullerenes (C60) in Fish
Investigators: Henry, Theodore B. , Compton, Robert N. , Menn, Fu-Min , Sayler, Gary S.
Institution: University of Tennessee - Knoxville
EPA Project Officer: Lasat, Mitch
Project Period: May 15, 2007 through May 14, 2010
Project Amount: $396,807
RFA: Exploratory Research: Nanotechnology Research Grants Investigating Environmental and Human Health Effects of Manufactured Nanomaterials: a Joint Research Solicitation-EPA, NSF, NIOSH, NIEHS (2006) RFA Text | Recipients Lists
Research Category: Health , Safer Chemicals , Nanotechnology , Health Effects
Use of nanomaterials (e.g., C60 fullerenes) in various industries is projected to increase dramatically in the future and environmental contamination by these materials is expected. Aquatic ecosystems are likely to become contaminated by C60 in the future and the potential for toxicity in aquatic organisms should be investigated. Our objectives are to investigate characteristics of aqueous C60 aggregates, the impact of dissolved organic material on behavior of these aggregates, and to evaluate bioavailability and toxicity of C60 (both aqueous C60 aggregates and dietary C60) in fish by assessing changes in gene expression, histopathology, and bioaccumulation of C60 in tissues. Our hypotheses are: 1) bioavailability of aqueous C60 aggregates is impacted by nanoparticle characteristics and presence of dissolved organic material; 2) exposure of fish to C60 can be detected by changes in expression of biomarker genes; and 3) toxic effects of C60 in fish can be detected only after long-term chronic exposure. Zebrafish (Danio rerio) and channel catfish (Ictalurus punctatus) are the species that will be investigated in this research.
The initial phase of research will investigate the behavior of aqueous C60 nanoparticles and associate particle characteristics with bioavailability in larval zebrafish. Particle characteristics and the influence of dissolved organic material (humic, fluvic acid) will be investigated by integration of analytical techniques including HPLC, LC-MS, laser desorption MS, Raman spectroscopy under liquid nitrogen (RUN), FTIR, and transmission electron microscopy. A set of biomarker genes will be selected from microarray analyses and developed in an RT-PCR format to serve as biomarkers of C60 exposure in larval zebrafish. Chronic toxicity of aqueous C60 aggregates will be investigated in zebrafish exposed from embryos to adult life stages, and toxicity will be assessed by survival, growth, biomarker gene expression in specific tissues, and histopathology. Biomarker genes identified in zebrafish will be adapted for use in channel catfish in an RT-PCR format and gene expression will be assessed in specific tissues of fish chronically exposed to aqueous or dietary C60. In channel catfish, the bioaccumulation of C60 among tissues will be assessed and lesions will be examined by histopathology of specific tissues.
Expected results include clarification of the characteristics of aqueous C60 nanoparticles and the influence of dissolved organic material on their bioavailability and toxicity in fish. Genes identified as biomarkers of C60 exposure will be developed for use as tools to investigate C60 toxicity in fish. Chronic toxicity of C60 will be determined and the potential for C60 to bioaccumulate in specific tissues will indicate the potential for human exposure to occur after consumption of fish chronically exposed to C60 in the future.