Research to Support Comprehensive Environmental Assessments of Nanomaterials

Issue:

The U.S. Environmental Protection Agency's mission and mandates call for an understanding of the health and ecological implications of engineered nanomaterials. To do this, a comprehensive environmental assessment is needed.

The unique properties of nanomaterials, along with their diversity and seemingly limitless uses, pose special challenges in assessing their potential risks. For example, nanomaterials are so small they may have multiple or unique ways to come in contact with people or ecosystems. And because of their complex physical and chemical properties, it is also a challenge to determine the amount of exposure or dose that will cause an adverse effect. Does the dose of a nanomaterial depend on the weight (mass), size, number of particles, shape, surface area, electrical charge, or perhaps some combination of these or other characteristics?

To evaluate the broad environmental implications of nanomaterials, it is important to consider how these materials are produced, shipped, stored, used, and disposed of or recycled across the entire life cycle of a product. A holistic view also includes how nanomaterials and waste by-products might move and change properties in air, water, and soil before coming into contact with humans and other organisms.

Ultimately, the ecological and human health effects related to exposure to nanomaterials and their by-products are the focus of a comprehensive environmental assessment.

Scientific Objective:

Two initial case studies focus on nanoscale titanium dioxide (nanoTiO2). One examines the nanomaterial's use for water treatment in the removal of arsenic and the other looks at its use as an ingredient in topical sunscreens. The studies will examine the life cycle of nanomaterials, how they are transported in the environment, how exposure occurs and potential health and ecological effects.

Application and Impact:

Many nanomaterials are currently in use and new ones keep coming on the market. EPA needs scientific tools and information to make informed risk assessments about this emerging technology, both in the near term and longer range. The case studies will serve as a foundation for creating a long-term research strategy to provide the information needed for comprehensive environmental assessments of nanomaterials. Decision analytic approaches will figure importantly in the development of a comprehensive research strategy, and they are also expected to be useful in assessing and managing potential risks of nanomaterials in the near future.

These efforts will help in protecting public health and the environment as the field of nanotechnology continues to emerge.

References

Davis, J. M. How to assess the risks of nanotechnology: learning from past experience. J. Nanoscience and Nanotechnology, 7: 402-409, 2007

Contact

Christina Powers (powers.christina@epa.gov), National Center for Environmental Assessment, EPA's Office of Research and Development, 919-541-5504.