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How safe are nanoparticles?

Boom in nanotechnology points up need to evaluate health risks; latest study suggests asbestoslike effect.

By Staff writer of The Christian Science Monitor / May 20, 2008

Carbon nanotubes: The tubes (magnified here 40,000 times) are made by rolling sheets of carbon atoms into tiny cylinders.



Small is beautiful when it leads to new products that do great things, like speed up computers or cleanse the environment. But the nanoscale-sized particles (a nanometer is one-billionth of a meter) behind some of these advances are also raising questions about their safety, questions that are not yet thoroughly understood or researched.

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In a study published May 20 in the journal Nature Nanotechnology, researchers found that one form of carbon nanotubes – long, thin multiwalled ones, whose shape bears a resemblance to asbestos fibers – appears to act like asbestos, causing damage to the lungs and potential serious illness. The nanotubes were injected into mice, not breathed in, leaving open the question of whether humans breathing in the nanotubes would be exposed to a health risk.

“If the fiber looks like asbestos, it may act like asbestos,” says Kristen Kulinowski, director of the International Council on Nanotechnology at Rice University in Houston, who has seen the paper. “Studies like this point to the need to understand the impacts of nanomaterials on human health and on the environment.”

According to one forecast, nanotube sales are expected to reach $1 billion to $2 billion annually within four to seven years. They are expected to be used in electronics, automobiles, drugs, and energy-efficient batteries.

Early this month, a House science committee approved a bill that would pump billions of dollars in US government funding into research on new applications for nanoparticles. The National Nanotechnology Initiative Amendments Act of 2008 includes a provision for a position within the White House Office of Science and Technology Pol­icy called the Coordinator for societal dimensions of nano­technology, which is expected to urge researchers to consider health, safety, and environmental effects in their research.

But many close observers say that’s not enough, and that the bill ought to include funds earmarked specifically for health and safety research. Outside experts unsuccessfully urged the committee to set aside 10 percent of the funds specifically for environmental, health, and safety research.

“There is a yawning knowledge gap between nanomaterials entering commerce now and what we know about their safety,” said Andrew Maynard, chief science adviser to the nonprofit Project on Emerging Nanotechnologies (PEN) at the Woodrow Wilson Center in Washington, in testimony before the committee in April. “This uncertainty over how to develop nanotechnologies safely is hamstringing regulators, im­­peding nano businesses, and confusing consumers. In short, moving toward the nanotechnology future without a clear understanding of the possible risks, and how to manage them, is like driving blindfolded.”

Dr. Maynard is a coauthor on the carbon-nanotubes study.

Meanwhile, three or four new products containing nanotechnology enter the market every week, according to a study released by the PEN last month. Well over 600 products already advertise their nano-content, viewing it as a marketing plus. But companies aren’t required to label their use of nanomaterials, so that number represents a “significant undercount” of what’s on the market, says David Rejeski, PEN director. Some of the nanomaterials products now on the market include socks, bandages, washing machines, lithium-ion batteries, refrigerators, camera lenses, sunscreens, toothbrushes, baby bottles, plush toys, the Xbox 360, pants, cosmetics, toothpaste, sheets, towels, pillows, and chopsticks.