Use of Multi-Criteria Decision Analysis Tools to Facilitate Weight-of-Evidence Evaluation in Nanotechnology Risk Assessment

Keywords:
nanoparticles, toxicology, weight of evidence, decision support

Abstract:
Elucidation of nanomaterial toxicity requires multiple sets of information due to both the complexity of nanomaterials and the limited database of relevant experimental studies. The EPA and other agencies use a weight-of-evidence approach in evaluating the potential carcinogenicity and toxicity of environmental contaminants. Traditionally, assessors weigh various lines of evidence and apply professional judgment and/or calculations to decide where the weight of evidence lies – that is, whether the various lines of evidence point to potential risk in the case of each receptor or not. Even though weight-of-evidence considerations may use some quantification, this approach often results in arbitrary weight selection (e.g., conservative bias) and thus in risk estimates that include an unquantified degree of uncertainty and potential bias. We argue that weight-of-evidence approaches may be useful for assessing the toxicity of nanomaterials, but a limited knowledge base and high uncertainty and variability in their basic properties requires coupling traditional weight-of-evidence assessments with multi-criteria decision analysis (MCDA) to support toxicity assessment and regulatory decision making. MCDA offers a rigorous and consistent approach. Even though MCDA is often used to incorporate social factors into decision making processes, this presentation will illustrate the potential of MCDA to facilitate purely technical evaluation of the multiple lines of evidence used in typical human health risk assessment for nanomaterials.

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Nanotech 2006 Conference Program Abstract