Session 5 Chair: Stacey Harper
Oregon State University
Much of the primary research that feeds into risk decisions is currently focused on the study of pristine nanomaterials. To address the potential for adverse effects from occupational exposures, this approach makes sense and as such has become the basis for nanomaterial risk determination. However, the same materials are modified or transformed throughout their life cycle and do not resemble or behave in the same manner as the newly synthesized pristine nanomaterials. Thus, we have created an artificial knowledge gap with the current focus on pristine nanomaterials that needs to be addressed. This session will focus on current approaches to nanomaterial toxicity testing and what we legitimately need in future assessments to more robustly characterize potential nanomaterial exposure and hazards. The speakers in this session will tackle this issue from three unique and complementary points of view. Salik Hussain, a research fellow at the National Institute of Environmental Health Sciences, will present his work on the use of realistic exposures (e.g. linking ultrafine particles with human health effects) and realistic receptors (e.g. live human cell culture donor samples) to determine intra-cellular mechanisms of toxicity. David Hinton, an ecotoxicologist at Duke University, will share his research on nanomaterials biouptake and toxicity and how life stages of an aquarium model fish affect these processes. He will also highlight use of a novel transparent fish to better determine host responses prior to high resolution studies. Finally, Cecilia Tan, a research scientist with the Environmental Protection Agency, will provide a look at how the Aggregate Exposure Pathway frameworks can support translating nanomaterial toxicity testing results into hazard and exposure information. We will end the session with a provocative panel discussion to address the following questions: How can we incorporate extrinsic environmental factors in toxicological studies for properly assessing health risks in the general population? What considerations need to be taken into account to ensure assessments are robust enough to deal with nanomaterial transformations? What role can functional assays fill in support of risk decisions? Where would environmental factors and nanomaterial dynamic processes fit into cumulative risk frameworks; or should it? Can we employ complementary testing of transformed materials and environmentally realistic exposures alongside of traditional toxicological testing of pristine materials? What benefits would result if we were able to expand toxicological considerations beyond pristine materials?