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. Last Updated: 07/27/2016

Nanotechnology a Health Risk?

NEW YORK -- It's supposed to make computers small enough to implant into a wrist and supply materials that strengthen and lighten bridges and airplanes. It might even cure cancer.

But some environmentalists fear that nanotechnology, the fast-advancing science of manipulating materials at the molecular scale, may create contaminants whose tiny size makes them ultra-hazardous.

"If they get in the bloodstream or into ground water, even if the nanoparticles themselves aren't dangerous, they could react with other things that are harmful," said Kathy Jo Wetter, a researcher with the ETC Group, an environmental organization that also opposes genetically modified crops.

Scientists say such fears consist mainly of speculation.

Nanotechnology, they say, involves well-known materials such as carbon, zinc and gold -- both toxic and benign. New tools simply let researchers alter those materials at the atomic level, where the particles are measured in nanometers, or billionths of a meter.

"It may have some unexpected consequences. Some could be toxic," said Mihail Roco, the National Science Foundation's senior adviser on nanotechnology. "But this happens with larger particles and in other industries. The risks are very small in comparison with the benefits."

Nanotechnology research is one of the U.S. government's top science initiatives, fed by $604 million in federal funds this year. ETC estimates worldwide research funding at $4 billion, including government initiatives in Japan, Taiwan, South Korea and Australia.

Wetter, whose Canada-based group organized discussions at the World Summit on Sustainable Development last week in South Africa, believes the coming industrial production of nanoparticles has not been properly scrutinized for environmental or health risks.

What if the tiny, manmade particles accumulate in the liver or lungs? she asks.

Carbon nanotube molecules currently touted as a substitute for silicon in ever tinier transistors closely resemble spiky asbestos fibers, she said.

Although a pair of studies on mice and guinea pigs indicated that the carbon fibers probably posed little risk to humans, Wetter and others speculate they could damage humans' lungs.

In a move that researchers believe is too dramatic, ETC is asking governments to halt the development of nanotechnology until environmental and health concerns are researched and assuaged.

"Commercial applications are getting closer," Wetter said. "This is a new material and it needs to be looked at."

In the United States, the federal Environmental Protection Agency hopes to hatch a pair of such studies this year, although research grants to fund them have yet to be awarded, said Peter Preuss, director of EPA's National Center for Environmental Research.

The ETC Group poses other scary potential scenarios. It says nanoparticles being tested as bloodstream carriers for medicines that attack cancer and other diseases might as easily deliver toxins.

Since nanoparticles have been able to evade the brain's defenses against blood impurities, a toxin-toting piece of nanomatter could take hold in the brain, Wetter said. Scientists have called this a speculative long shot.

The ETC Group also worries that future nanotech-enabled foods such as so-called "interactive beverages," which could change color or flavor at the guzzler's behest, would require ingesting millions or billions of nanoparticles.

Rick Smalley, the Nobel Prize-winning nanotechnology researcher at Houston's Rice University, labeled the idea of such foods a futuristic scenario that would first need to pass muster with the FDA.

Nanoparticles are so small that they pass through most filters, and can't be seen. Some, like carbon nanotubes, aren't believed to exist in nature.

If there were a problem and nanoparticles needed to be removed from a normal environment, it might be too late. There remains no detector or sensor that can find some types of nanoparticles outside the laboratory.

Still, several companies are already producing nanoparticles, mainly those used in paints and sunscreen, along with the carbon nanotubes touted for electronics.

Smalley said an as-yet unreleased National Aeronautics and Space Administration study showed little cause for alarm, though one mouse tested died after receiving "vast amounts" of nanotubes in its lungs.

Besides, most potential uses of nanoparticles find them sealed inside a polymer used in a cellphone case, perhaps, or a car door or computer chip, Smalley said.

"Just because you have some nanothing in a product doesn't mean it is floating around and getting into your food," he said. Some nanoparticles, like those of gallium arsenide, which contain arsenic, are known to be toxic -- as is regular gallium arsenide, a substance used in computer chip manufacture.

"Are there going to be classes of nanomaterials that are going to pose health problems? Sure," said Kevin Ausman, director of the Rice University Center for Biological and Environmental Nanotechnology. "But those are things we'll know beforehand. We can plan around them."