January 11, 2011

Shes Sussing Nano-Safety From The Inside

By: by Gwyneth K. Shaw, New Haven Independent


ALBANY, N.Y.-Sara Brenner loves nanotechnology.

At the University at Albany's College of Nanoscale Science and Engineering, she's a key ambassador, doing workshops with schoolchildren aimed at igniting an early passion for science and technology. In the burgeoning field of "nanobio," which seeks to capitalize on the promise of nanomaterials in innovative medical applications, Brenner is guiding undergraduate and graduate students as an assistant professor of nanobioscience.

As assistant head of the nanobioscience "constellation" at CNSE, she's also trying to foster collaborations among researchers who might never think of crossing disciplines. (Read about the development of CNSE here.)

Yet Brenner, who trained as a physician, remains a doctor-and one focused on public health-at heart. So even as her enthusiasm for the exploding science of the very small overflows, she remains focused on nano safety, trying to make sense of what risks these innovative materials pose and how to protect workers, people and the environment from any dangers.

Nanotechnology, which capitalizes on the often amazingly useful properties of super-small particles, is already in used in manufacturing items like bike frames, skin creams and cancer treatments. It's also heavily used in the electronics industry, as computer chips and components get smaller and smaller.

As Albany, part of the State University of New York system, and CNSE continue to grow as key players in nano world, especially the semiconductor industry, it's Brenner's job to push the crucial area of safety.

"We can do it at the R&D level, and that's about as proactive as it gets," Brenner said.

That means working with the companies with a presence at CNSE, such as IBM, Advanced Micro Devices, and Tokyo Electron Ltd. Through in-house research involving Albany faculty, as well as industrial partners and academics outside the university, Brenner said, she and others are trying to get a handle on what's dangerous, what's not, and how to protect workers, consumers and the world around us.

One of the selling points to students of CNSE is the chance to get hands-on experience, not just in the lab but at the commercial level, too. Brenner is already working with students who are interested in the health and safety aspects of nanotechnology. She hopes over time to build a nanotoxicology program that integrates medical training and nano know-how.

Nanotechnology safety is an international concern. Both governments and industry around the world are at different stages of knowledge, control and regulation. Every day, new research is released, some of it outlining serious worries about various nanomaterials.

The warnings cover everything from carbon nanotubes-which studies show could be dangerous if inhaled-to the wide variety of metals, such as gold, silver and titanium dioxide, that behave differently when shrunk to the nanoscale. (A nanometer is a billionth of a meter.)

What's difficult, Brenner said, is sorting through the trees to see the forest. Many safety studies, for example, examine the effects of nanomaterials on animals, or on cells in the lab. Often, she said, those studies involve large quantities of nanomaterials, levels unlikely to occur in everyday exposures.

"There's a sea of information, and we've got to wade through it to find out what's potentially relevant," Brenner said.

So, she said, it's important for scientists working in the safety field to understand how the lab work relates to real life. A critical component of that, Brenner said, is developing ways to measure exposure, as well as monitor human and environmental health.

"As nano becomes more ubiquitous," she said, "developing the tools to do the measurements is very important."

One example is carbon nanotubes, which have become the poster child for nanotechnology and safety. Because the tiny carbon cylinders behave like fibers-think about the tiny slivers of graphite you get when you break the point of a pencil-CNTs are of particular concern because studies show they can lodge in the lungs of rats and cause problems.

The tubes are often likened to asbestos, which can cause serious lung disease. That has led experts to recommend treating them very carefully. Last month, the National Institute for Occupational Safety and Health released draft exposure guidelines for carbon nanotubes that set the bar at what's essentially the minimum amount that can be measured by existing analytical tools.

But there are plenty of other nano-sized materials out there, many of which haven't been studied as much as carbon nanotubes. Brenner's work at CNSE includes looking at what's being manufactured there, even in the earliest research stages, and figuring out which materials are in use, and how the building process might expose workers.

The point, she said, is to "tailor their processes, and even the products themselves, to make them as benign as possible." Getting in at the development level, she said, is helpful, because if a product can't be made safer, it helps manufacturers to know early on, so that they can decide whether to continue.

Take a key part of semiconductor manufacturing, which involves polishing and flattening the silicon wafers that are the basis of the finished chip. Most of the nanomaterials used for semiconductors are metal oxides, such as aluminum, copper and titanium. Brenner said the nanoparticles are present in several of the steps used to process the wafers, including a liquid, the polishing pads, and an abrasive material.

Analyzing that process in terms of safety issues, she said, requires looking at all of the nanomaterials, and thinking about how workers are exposed to them-both separately and together. Since chips are being developed and built inside the ascetic clean rooms that dot the CNSE complex, there are lots of people, and processes, that are affected.

Among the questions she and others ask: do the properties of the particles change during the process, or when they're used together? What are the exposure levels like, and how risky are the materials themselves? And, pulling back to look at the broader perspective, what happens to the materials, and the workers, over the life span of each?

"It's important that we don't just characterize how they start, but how they end," Brenner said.