Grappling With The “Gray Zone,” Feds Focus on Nano Workers’ Health

NIOSH PhotoLOWELL, Mass.—How do you protect someone from something they can’t see?

That’s the trick for researchers trying to ensure that workers in the growing business of nanotechnology aren’t threatened by their livelihood.

But while U.S. regulators and scientists are mindful of past disasters—from lead to asbestos—they also know super-small nanoparticles present a huge challenge.

Charles Geraci, coordinator of the Nanotechnology Research Center for the National Institute of Occupational Safety and Health (NIOSH), calls it “working in the gray zone.” For him, it means using the newest toxicology research to educate and advise nano manufacturers about safeguarding workers, even as novel applications keep emerging for the minuscule particles with often amazing capabilities.

The good news, he said, is that many nanomaterials are simply smaller versions of substances that already are well-known, such as silver and titanium dioxide. The bad news is that the old rules for dealing with those materials might not apply to the nano versions. Geraci said manufacturers must take that into consideration.

Geraci spoke at the “Destination Nano” conference at the University of Massachusetts Lowell last week. His agency announced a partnership with the university on workplace safety issues, and Geraci spent some of his time in New England doing the kind of site visits he described in his discussion.

NIOSH has 52 active projects involving the safety of nanotechnology, Geraci said, as the agency works to concurrently study elements of a risk-management process that is traditionally done sequentially. First, scientists have to identify hazards associated with various nanoparticles, then figure out how those hazards behave. Next is determining whether workers could be exposed to the problem, how and at what level.

Only then can researchers map out a way to manage the risks, Geraci said.

He offered the example of carbon nanotubes: scientists know that exposing the lungs of mice to the fibrous particles can cause fibrosis. Certain types of the multi-walled tubes can reach the same spaces in the lungs where mesothelioma, a type of cancer associated with asbestos exposure, shows up.

“That’s exciting news for our pathologists and our toxicologists, because it says more research needs to be done,” Geraci said. “It doesn’t say this substance will cause cancer the way that asbestos causes cancer.”

It does mean, however, that it’s prudent to shield workers who are manufacturing nanotubes as much as possible, he said. That’s where the site visits come in.

NIOSH PhotoThose visits involve looking at how and where workers are interacting with nanoparticles, as well as taking samples of the air they’re breathing. Geraci showed off several images that show the presence of carbon nanotubes in some of those samples—sometimes in places where workers weren’t wearing protective suits or respirators to shield them from the small particles.

Geraci showed a before-and-after sequence of one such example. In the “after” photo, the worker resembled an extra from “The Hot Zone” but, Geraci said, was much safer from long-term problems.

“Some good risk management practices have eliminated the exposure for this particular technician,” he said.

Some fixes are easy, like convincing companies to work with nanoparticles mixed into a liquid—known as a slurry—instead of in a dry powder form, which is much harder to control. Many aren’t particularly expensive, and use readily available equipment. Others are harder to tackle.

Still others remain unknown. And it’s a struggle to keep up, Geraci said. Citing Nanowerk, an online news site about nanotechnology, he said there are now more than 2,500 nanomaterials on the market, coming from more than 150 suppliers.

“We really have a very small picture of what’s going on out there,” he said.

NIOSH is trying to reach a broader range of manufacturers through its own publications, and by drafting exposure limits for workers. The agency also is partnering with other academics and organizations that are putting out information on safety, such as the .(JavaScript must be enabled to view this email address) web site published by the International Council on Nanotechnology at Rice University. NIOSH also has an upcoming publication on carbon nanotubes that should be published soon.

Some manufacturers have already issued their own safety recommendations, Geraci said. He said that in his experience, industry has made a good partner, because nanotechnology pioneers are highly aware of the mistakes made in prior decades, when substance considered safe turned out to be harmful—or lethal—to people, the environment, or both.

“We’re all at the table, out front of this,” Geraci said.

The answer to living with nanotechnology, at least for now, is more research, he said. Now that scientists have shown that some nanoparticles can cause health problems, at least in theory, there is cause for concern, but not panic, he said. Although NIOSH is not a regulatory agency, Geraci said everyone at his organization is aware that they have a chance to shape the rules and laws that will govern nanotechnology in the future—for better or for worse.

“We want to do good science and the right science, the relevant science,” Geraci said. “From that will come good policy.”


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