Approaching Risk Assessment of Nanoscale Materials

Developments in nanotechnology and nanomaterials (NM) are rapidly proceeding ahead of a clear understanding of their potential health effects and environmental impacts. Risk assessment will be an important tool for evaluating and potentially regulating NM to protect health and the environment. We are developing an adaptive risk assessment framework for NM that provides an approach for precautionary decision-making and considers the current toxicological uncertainties about NM. Critical NM properties that contribute to the toxicological uncertainties include: a large surface area relative to NM size, their reactivity, and the possibility that NM may translocate within an organism. Our step-wise approach integrates an evaluation of current toxicological information and sources of uncertainty about the specific NM of interest, identification of the potential exposure scenarios, and application of risk assessment tools to evaluate and prioritize management procedures for mitigating NM exposure risk. Our adaptive approach allows for input of new information about NM to revise and refine health and safety recommendations for NM use and handling and for decision-making under uncertainty. We combine elements of risk assessment with the practices of health and safety to provide relevant NM management procedures for minimizing potential health effects and environmental impacts. This approach offers an effective tool to evaluate potential NM impacts throughout their life cycle, ranging from research and development and product manufacturing, to consumer applications and uses, and ultimately to their disposal and fate in the environment. Identifying the key exposure pathways creates the opportunity to mitigate them, and to operate in a safer work environment. Understanding the environmental, health and safety risks allows effective management of them.