Risk Identification and Assessment Techniques in the Absence of Toxicology Data on Nanomaterials
A. Wardak, S. Deshpande, N. Swami and M. Gorman
University of Virginia, US
risk identification, risk assessment, nanotechnology, control banding, influence diagrams, hierarchical holographic modeling, expert opinion elicitation
A National Science Foundation-sponsored survey identified regulatory and safety issues as market entry barriers for nanotechnology. The limited availability of toxicological data on nanomaterials, especially from studies using standardized protocols (biological system to be studied) with technologically relevant nanomaterials (uniform nanomaterials in their product form with the necessary coatings and isolated from catalysts used in their synthesis) within their likely exposure pathways, will continue to hamper the commercialization of nanotechnology. It is hard to account for nanotechnology’s potential environmental health and safety risks in the $1 trillion market estimate by 2015. If potential risks are not addressed adequately with a comprehensive risk management strategy, the market potential of nanotechnology will not be realized. The main challenge in addressing nanotechnology risks is identifying potential risks. For nanomaterials, experts have pointed out reasons for increased toxicity, such as size, surface reactivity, and shape. In toxicity risk assessments, identifying hazards, or potentially harmful human health effects, is the first step. Risk assessment is a function of hazard identification and exposure assessment, the estimate of duration, type, and quantity of exposure to individuals of a given substance. Risk identification is a stepping-stone to risk assessment because it points out scenarios for further study. As risks currently cannot be evaluated using traditional risk assessment due to a lack of scientific data on hazards and exposure, near-term approaches will be required for risk management. Practical approaches to managing uncertain risks could be modeled after those developed previously for risk identification. This talk will cover the use of such methods like expert opinion elicitation, influence diagrams, control banding, and hierarchical holographic modeling, for a set of model nanotechnology products. Expert opinion elicitation uses tacit knowledge from experts to answer questions about uncertain risks. Influence diagrams are pictorial models used to represent relationships among different hazards and exposure pathways to facilitate risk identification. Control banding is a method for assigning exposure controls to different bands of uses. This is done through a high-level evaluation of exposure and hazardous nature of a given substance. Finally, hierarchical holographic modeling is a method of risk identification often used in the engineering field and promotes a systems analysis approach to risk assessment. These risk identification techniques can prioritize and tune the scope of further investigation needed for a risk assessment of nanotechnologies.
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Nanotech 2007 Conference Program Abstract