Complete Workshop Report Available to Download

Developing Experimental Approaches for the Evaluation of
Toxicological Interactions of Nanoscale Materials
A workshop addressing the challenges of conducting and
interpreting studies of potential toxic effects of nanoscale materials

On November 3-4, 2004 a group of international experts met in Gainesville, Florida to identify and discuss issues associated with the proper conduct of studies to characterize the potential toxicities of manufactured nanoscale materials. The 75 invited participants represented expertise in biology, medicine, toxicology, physics, chemistry, and materials science drawn from government, industry, academic and public interest sectors. The participants heard presentations and addressed in breakout sessions; a) characterization and dosimetry of nanoscale materials, b) delivery of nanoscale materials to test systems, c) toxicology study protocols appropriate for nanoscale materials, d) detection and quantification of nanoscale materials in test systems/organisms and the environment, e) laboratory safety and disposal issues, and f) specific issues related to uptake and toxicity to the respiratory, skin, and immune systems.

Over the course of the two-day workshop, several central themes emerged from the presentations and discussions:

• It is essential that the physical and chemical characterization of nanoscale materials be much more complete than has been the case in the sparse toxicology literature appearing to date. State of the art analytical characterization techniques were described and their application to all phases of toxicology studies was considered. The use of currently available analytical techniques to detect and quantify nanoscale structures in biological systems was considered critical for both guiding the selection of the specific toxic endpoints of interest, and for following the movement of nanoscale materials in biological systems. The group recommended that scientific journal editors be urged to require proper physical and chemical characterization of nanoscale materials for all publications in the newly emerging field of “nanotoxicology”.
  
  
• Most participants agreed that “nanotoxicology” need not be a new scientific discipline. Based on our current understanding, the traditional approaches and study protocols now used for routine toxicological characterizations of chemicals or larger particles are sufficiently robust to provide meaningful toxicological characterizations of nanoscale materials. While nanoscale materials clearly have unique physical and chemical properties that may lead to unpredictable distribution and effects within biological systems, there was general agreement that the manifestation of biological interactions of nanoscale materials will likely be the same as for any potentially hazardous agent. The participants recognized that more suitable approaches for nanoscale material characterization, detection and/or toxicological evaluations may emerge with time and experience.
  
  
• Participants stressed the need to approach nanotoxicology studies from a multidisciplinary approach and recommended that government agencies explore ways to create and promote linkages between toxicologists and experts in materials science, physics, chemistry and other appropriate disciplines. Government agencies were also asked to provide assistance with the creation of standard reference materials, and in the development of accreditation programs for analytical laboratories engaged in the analysis and characterization of nanoscale materials.
  

The workshop was organized by the University of Florida and the U.S. Department of Health and Human Services’ National Toxicology Program. Workshop funding was provided by the Air Force Office of Scientific Research, the U.S. Environmental Protection Agency, the National Institute of Environmental Health Sciences, the National Science Foundation, and the University of Florida.