R1 PM Nanotechnology Environmental Remediation, Fate, and Transport
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in Ballroom 1

(MAD-1117-842672) Hazard assessment and sensitivity analysis for buckminsterfullerene in the environment.

Maddalena, R¹, MacLeod, M², McKone, T^{1, 3}, Sohn, M¹, ¹ Lawrence Berkeley National Laboratory, Berkeley, CA, USA² Swiss Federal Institute of Technology, Zürich, Switzerland³ University of California, Berkeley, Berkeley, CA, USA

ABSTRACT- A prospective assessment of ecological and human health hazards associated with nanomaterials is timely given the increasing commercialization of nanotechnology. Because relevant data for the environmental behavior of nanomaterials is lacking, the goal of this paper is to provide an initial assessment of hazard for an archetypal nano-molecule (Buckminsterfullerene) in the context of current fate and exposure models. We extend the traditional approach to hazard assessment, which focuses primarily on toxicity, to include properties of the chemical that are indicative of environmental hazard such as persistence, bioaccumulation, long-range transport potential and exposure potential, where the latter is characterized using the intake fraction metric. The prospective analysis is developed using a series of representative polycyclic aromatic hydrocarbons increasing in size from naphthalene to Buckminsterfullerene. The approach illustrates how experience with "conventional" organic pollutants can provide insight about plausible, or at least bounding environmental fate and exposure outcomes. As part of the illustrative analysis, we apply non-traditional Monte Carlo-based sensitivity analyses techniques to identify (i) influential input/output relationships and (ii) internal constituents of the fate and exposure model (e.g, modules, algorithms and imbedded assumptions) that influence the hazard estimates for fullerene. The analysis provides an opportunity to identify potentially important exposure scenarios for organic nanomolecules given our current modeling framework, and explore the relevance of these scenarios for engineered nanomaterials dispersed in the environment.

Key words: exposure, persistence, bioaccumulation, intake fraction