Development of a Preliminary Framework for Information the Risk Analysis and Risk Management of Nanoparticles
Vol. 25, Num. 6
As a Senior Advisor for risk analysis, Morgan reminds us that "decisions are often made even when there is uncertainty about the possible outcomes." She says that "safety assessment for a product containing engineered nano-scale particles" are, at present, "a very poorly structured problem."
There are many studies of fine particles and concomitant regulations that some legislators believe are applicable to nanotechnology, but Morgan says that nanoparticles have such unqiue properties that there may be no comparable studies. Borrowing may add to the confusion.
In such fields, "expert elicitation is used to fill the gaps." Another useful tool is the influence diagram, which is a representation of a complex problem relying upon "many different sources and types of information." Morgan's research used experts to create an influence diagram. The experts were asked "to identify a set of particle-related characteristics that have the potential to influence risk, or more specifically, exposure and toxicity."
Morgan found that assessment involved the presence of nano-materials, the uptake capacity, the transport and fate of nano materials and their toxic effects. Her model became more complex as experts identified, among other properties, surface reactivity, solubility, adsorption tendency, surface area, shape, degree of agreggation, and so on. Each model could be broken down into further specificities. "The diagram lays out a broad array of potential relationships that could be investigated, and it gives researchers a context within which to interpret and build on results from such studies." She notes that "this framework is designed to incorporate research results as they are generated, and therefore serve as a tool for estimating the potential for human health and environmental risk."