Nanotechnology: Human and Environmental Exposure Assessment of Nanomaterials Workshop

Determining whether a material or substance poses an occupational health risk depends on knowing not only the potential toxic characteristics of the material, but also the characteristics of exposure. To what concentrations are workers exposed, for how long, and in what ways? In research to answer the question of whether nanomaterials pose work-related health risks, exposure assessment is particularly vital. Because of the relative newness of nanotechnology, very little exposure data have been reported in the scientific literature. At this stage, measuring or determining risk becomes a little like trying to solve a mystery when major clues are missing. Scientists and engineers face this challenge even as the market for nanotechnology grows, and along with it, an increasing demand from diverse parties for guidance to underpin its responsible development.

As part of a national effort to stimulate new research and knowledge in this area, the National Institute for Occupational Safety and Health (NIOSH) collaborated with the U.S. Nanoscale Science, Engineering and Technology Subcommittee (NSET) to co-sponsor the workshop on Human and Environmental Exposure Assessment of Nanomaterials on Feb. 24-25, 2009, in Bethesda, Md. More than 165 scientists and other stakeholders from government, industry, labor and other segments participated in person. An additional 25 viewers joined from other locations through the webcast plenary session. The workshop focused on research needed for characterizing exposures to nanomaterials among workers, other populations, and environments by measuring and modeling exposure levels, and by monitoring indicators of biological responses through the product life of a nanomaterial. The objectives of NIOSH, NSET, and other partners were to review the state-of-the-science, identify critical gaps, and inform further development and adaptation of the interagency research strategy as appropriate.

Planning for the workshop began in February 2008 by the interagency Nanotechnology Environmental and Health Implications (NEHI) workgroup. The workgroup operates under the auspices of NSET and includes NIOSH as a member. It was established informally in 2003, and then formalized in 2005. One of the main tasks of the group was to develop strategy in close consultation with the public.The group released three documents for public review. The first NEHI document, Environmental, Health, and Safety Research Needs for Engineered Nanoscale Materials was released in 2006 and provides an evaluation of the science, groups research into five research categories (Instrumentation, Metrology and Analytical Methods; Nanomaterials and Human Health, Nanomaterials and the Environment, Human and Environmental Exposure Assessment of Nanomaterials, and Risk Management Methods) and describes research needs within each category. The second document, released in 2007, entitled Prioritization of Environmental, Health, and Safety Research Needs For Engineered Nanoscale Materials: An Interim Document For Public Comment was intended to elicit comments from the public, the scientific community, and other stakeholders, on how the NSET was proposing to approach prioritization of environmental health and safety research needs. That input was incorporated into the third document, Strategy for Nanotechnology-Related Environmental, Health, and Safety Research , released in 2008. The strategy describes adaptive management approach for addressing implication of nanotechnology through inter-agency efforts including identification of priority needs, assessing existing research, analyzing strengths and weaknesses and periodically updating and revising it. The strategy provides information to agencies that conduct and fund research on nanotechnology. It informs those agencies on critical research needs, and facilitates collaborative research activities to address them.

The strategy focuses on research supporting risk assessment and risk management of nanomaterials to meet needs of agencies with regulatory and oversight responsibilities. As needs of regulator decision makers change and as we learn more though basic research, the strategy should be updated. Therefore, the inter-agency group conducts periodic progress reviews and updates research needs and priorities, taking into consideration advances from private sector and international entities. This is accomplished in part through workshops for each of the research categories. Organizing workshops to inform further development and adaptation of the inter-agency strategy as appropriate in their research categories is one of the coordinating agency roles. NIOSH, in recognition of its leadership in conducting research on exposure assessment, is a coordinating agency for the Exposure Assessment research category and played a leading role in organizing the Human and Environmental Exposure Assessment of Nanomaterials Workshop.

Five plenary presentations provided state-of-the-science overviews for five research needs in the exposure assessment category, including needs for closing critical gaps in information necessary to adequately manage risk of nanomaterials, and for identifying emerging trends. These presentations served as catalysts for general open-floor discussions by the workshop participants. The plenary presentations were as follows:

1. Characterize Exposure among workers – Dr. Robert Herrick, Harvard University;
2. Identify population groups and environments exposed to engineered nanoscale materials – Dr. David MacIntosh, Environmental Health & Engineering, Inc.;
3. Characterize exposure to the general population from industrial processes and industrial and consumer products containing nanomaterials – Dr. Paul Lioy, Rutgers;
4. Characterize health of exposed populations and environments – Dr. William Halperin, University of Medicine & Dentistry of New Jersey;
5. Understand workplace processes and factors that determine exposure to nanomaterials – Dr. Susan Woskie, University of Massachusetts, Lowell.

The rest of the workshop was organized around six concurrent breakout sessions for five research needs and emerging trends. During the first day, breakout sessions focused on collecting information about where we are in addressing research needs, where we need to be in 5 years, are the current research needs framed correctly? Specific technical questions for each of the breakout sessions helped focus discussions. Discussions on the second day of the workshop centered on identifying paths forward in addressing critical research gaps identified in the first-day breakout sessions.

The main output of the workshop will be a workshop report which will further development and adaptation of the strategy. All presentation slides and video recording will be made available on the workshop website.

The workshop also provided valuable information that NIOSH will use in its research planning and allowed NIOSH to update participants about NIOSH research. The Human and Environmental Exposure Assessment of Nanomaterials workshop is the first in the series of workshops for each of the five research categories which will follow later in 2009 and 2010. We would like to encourage all stakeholders from government, industry, labor, non-governmental organizations and the general public to actively participate in these workshops to help update the strategy for the U.S. government program addressing the environmental health and safety implications of nanotechnology.

As NIOSH moves forward with research in this area, we would like to hear what you think are the critical needs in exposure assessment for nanomaterials in the workplace. Additionally, we would welcome comment on the exposure assessment part of the NNI Strategy for Nanotechnology-Related Environmental, Health, and Safety Research. We are also seeking volunteers for exposure assessment studies at work sites where nanomaterials currently are being produced or used and volunteers for NIOSH nanotech field team visits.

Disclaimer: this blog is not intended to be an official workshop update, but simply represents NIOSH’s informal reflections.

Dr. Murashov is a Special Assistant for Nanotechnology to the NIOSH Director. He was Chair of the Human and Environmental Exposure Assessment of Nanomaterials workshop committee and is a member of the U.S. Nanoscale Science, Engineering, and Technology subcommittee. Dr. Murashov also leads projects for the ISO Technical Committee 229 (Nanotechnologies) and the Organization for Economic Cooperation and Development’s Working Party on Manufactured Nanomaterials.

Posted 03/30/09 at 9:36 am