Grantee Research Project Results

2007 Progress Report: Aquatic Toxicity of Waste Stream Nanoparticles

EPA Grant Number: R833317
Title: Aquatic Toxicity of Waste Stream Nanoparticles
Investigators: Gordon, Terry , Chen, Lung Chi , Wirgin, Isaac
Institution: New York University School of Medicine
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 2006 through September 30, 2009
Project Period Covered by this Report: October 1, 2006 through September 30,2007
Project Amount: $399,827
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: Nanotechnology , Safer Chemicals

Objective:

The objective of this study is to determine the biological consequences of nanoparticle contamination of the aquatic environment. We have hypothesized that there will be a particle-type dependent difference in the developmental toxicity of manufactured nanoparticles in aquatic species, and in testing this hypothesis, we will: 1) measure the differential toxicity of several types of nanoparticles in an estuarine species of fish, Atlantic tomcod; and 2) identify whether the embryo and larval stage of development of tomcod are particularly susceptible to carbon nanoparticle vs. nanotube toxicity. A number of investigators have clearly demonstrated that nanoparticle toxicity in the mammalian lung is governed, in part, by particle size. Little research has been published, however, on whether these physico-chemcial properties of nanoparticles influence their toxicity at developmental stages in aquatic species. Thus, while an evergrowing data base is being established to understand the influence of physico-chemical properties of nanoparticle toxicity, it will be critical to understand the ability of various nanoparticles to produce toxicity once they have entered the waste stream and the aquatic environment. In the proposed studies, a group of particle toxicologists are collaborating with a fish toxicologist to explore the toxicity of a variety of manufactured nanoparticles in an established fish model of aquatic toxicity.

Progress Summary:

We have studied the dose-and particle type-dependent early life-stage toxicity of nanoparticles in tomcod. Tomcod eggs were fertilized and exposed to 0.4 to 50 µg/ml carbon nanoparticles or 0.08 to 10 µg/ml carbon nanotubes. In one experiment, tomcod embryos were treated starting on day 17 after fertilization, and in the second experiment, larval-stage tomcod were treated beginning on day 3 after hatching. The test nanoparticles included carbon toner particles and the raw combustion soot material and the sludge byproduct that were obtained during the processing and purification of carbon fullerenes with metal catalysts. The surfaces of the carbon nanotubes were polyethylene glycol derivatized.

Clear toxicity was observed at the highest concentrations of some but not all nanoparticles types. Significant increases in embryonic death were observed with 50 µg/ml soot and sludge nanoparticles. In comparison, neither the carbon nanotubes nor toner nanoparticles had a significant effect on embryo survival. Significant effects on survival were also observed in embryos treated with 10 µg/ml sludge, a manufacturing process waste product which would have the greatest chance of entering the ecosystem.

Other endpoints demonstrated that embryonic toxicity occurred at the lowest concentration of nanoparticles used in our experiments. A significant delay in hatching occurred in embryos treated with 0.4 µg/ml of the 3 types of carbon nanoparticles. Thus, naïve young life-stages of tomcod have proven to be sensitive monitors of chemical contamination for a variety of toxicological endpoints.

Similar concentration-dependent effects on survival were observed in the second experiment in which 3 day-old larval stage tomcod were treated with nanoparticles. There was little mortality observed in the larval stage tomcod exposed to carbon nanoparticles but abnormal behavior, as seen by decreased activity, was observed at concentrations as low as 2 µg/ml for the sludge nanoparticles.

Significance of Findings: We have clearly demonstrated that the early life stages of fish are sensitive to the toxic effects of manufactured nanoparticles. We also observed toxic effects at lower concentrations than those which caused outright mortality. Thus, future studies are needed to validate the observed early life stage toxicity of manufactured nanoparticles. Importantly, as with our work in nanoparticle research in mice, there are clear particle type-dependent differences in toxicity in fish. This would suggest that the exposure and risk assessment of nanoparticles must consider particle shape and compostion.

Future Activities:

The second year will repeat the first year’s exposure to manufactured nanoparticles but will expand the number of particle types to include metal oxide nanoparticles and to validate the observed nanoparticle toxicity in another fish species (mummichug).

Study Conduct/Quality Assurance: SOPs were followed and no problems were encountered. There were no changes of key personnel involved in the project. The budget was utilized as planned, there were no costs which are higher than originally estimated, and the budget will remain as originally awarded for Year 2.

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this project

Supplemental Keywords:

nanoparticle, exposure, aquatic, bioavailability, fish, Health, Scientific Discipline, Health Risk Assessment, Risk Assessments, Biochemistry, bioavailability, nanomaterials, carcinogenic, genetic analysis, human exposure, biological pathways, nanoparticle toxicity, nanotechnology, human health risk, toxicologic assessment

Progress and Final Reports:

Original Abstract

2008

Final Report

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.