skip navigation
Environmental Factor, May 2012

Whole Issue PDF
This issue's PDF is still being created and should be available 3-5 business days after the first of the month. Please check back in a few days.

Science writers learn about NIEHS nano program

By Heather King

Sri Nadadur, Ph.D.

Nadadur was animated as he talked about the variables in host susceptibility, material characteristics, and analysis that have made it difficult to reach definitive conclusions about the health effects of exposure to ENMs. (Photo courtesy of Steve McCaw)

NIEHS Health Scientist Administrator Sri Nadadur, Ph.D., delivered the American Scientist’s lunchtime seminar March 27 at Sigma Xi headquarters in Research Triangle Park (RTP), N.C. This monthly seminar series brings research scientists together with an audience of science writers and other scientific communications professionals. 

Download Media Player:


In this forum, scientists have an opportunity to consider the broader implications of their work, while science writers and communicators have a chance to hear firsthand about current research efforts and new findings. In his presentation, Nadadur spoke about the potential health risks associated with environmental exposure to some engineered nanomaterials (ENMs), as well as the role of NIEHS in establishing a program to investigate those risks and their public health implications.

Focus on health concerns

Nadadur began his talk, “Nanotechnology Environmental Health and Safety Research at NIEHS,” by describing the increasing use of ENMs in such consumer products as sunscreen, cosmetics, food, and pharmaceuticals. “There may be potential health concerns related to ENMs, substances used in abundance in many new products, but not yet well characterized in terms of their bioactivity,” he explained.

A coalition of government agencies is currently studying ENMs as part of the National Nanotechnology Initiative. NIEHS is playing a key role in this initiative by supporting research to gain fundamental understanding of ENM interactions with biology and ultimately their potential health effects. One of the initial activities in this direction is identifying reliable and reproducible test systems.

Nadadur emphasized the challenges of relating specific ENM biophysical characteristics to adverse effects on human health. Response to ENM exposure can be highly variable, and the toxicity of a particular ENM often varies, based on the individual, tissue, or cell type exposed. Additionally, the manufacturing process can lead to subtle differences in surface area, contaminants, or other ENM qualities, further complicating the dose-response relationship.

To illustrate, Nadadur pointed to several conflicting studies of the association between carbon nanotube exposure and lung damage similar to that observed in asbestos-related injuries. Carbon nanotubes are prized for their strength and used in a range of products from electronics to automotive components. Though some carbon nanotubes are harmful, others are not, and understanding why, based on key physical properties, is the major goal of the NIEHS program.

In addition to concerns about carbon nanotubes, Nadadur said there are issues arising from the increasing use of cerium oxide (CeO2) nanoparticles as a diesel additive to increase engine efficiency. Exposure to macroscale CeO2 is associated with liver damage, but it also reduces combustion-related pollution and possesses antioxidant properties. However, little is known regarding the health and safety of nanoscale CeO2 particles found in exhaust emissions. According to Nadadur, more research into the costs, benefits, and human health effects of CeO2 ENMs is clearly needed, as these and other unregulated nanomaterials come into wider use.

ENM research programs funded by NIEHS

After outlining problems unique to ENM research, such as developing reliable assays to test ENM toxicity and addressing the numerous types of ENMs in use, Nadadur described the NIEHS ENM research program. NIEHS has established a range of goals and funding opportunities for laboratories to investigate ENMs.

One arm of the Nano Grand Opportunity grant program focused on assay development and exposure models (see story), while the NIEHS Centers for Nanotechnology Health Implications Research Consortium has aimed to bring together ENM researchers funded through various grants programs, including research project grants and Challenge Grants (see story).  

The talk concluded with a number of questions from the audience. One audience member expressed surprise at the prolific use of ENMs, considering their unknown effects on human health. Nadadur’s talk clearly made an impression on the writers and communicators in attendance that potential adverse health risk posed by ENM exposure, though not currently as hot a topic in the media as the new technology’s potential, merits a much closer look.

(Heather King, Ph.D., is an Intramural Research Training Award fellow in the NIEHS Laboratory of Structural Biology Protein Expression Core.)

Sri Nadadur, Ph.D., delivering the American Scientist’s lunchtime seminar

Held in an intimate venue at Sigma Xi, the monthly lecture series attracts science communicators from nearby federal agencies, such as NIEHS, area universities and museums, and non-profit organizations concerned with health and scientific research. (Photo courtesy of Steve McCaw)

Fenella Saunders

Host Fenella Saunders, above, is senior editor of American Scientist. With support from the North Carolina Biotechnology Center, the journal hosts presentations each month from RTP area scientists working in a range of fields. (Photo courtesy of Steve McCaw)

"NIEHS scientist wins top ..." - previous story Previous story Next story next story - "New studies offer insight ..."
May 2012 Cover Page

Back to top Back to top