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Monday, February 28, 2005; Page A06

Nanotech Gains, Risks Weighed

The fledgling science of nanotechnology, which deals with particles a millionth the size of the head of a pin, promises many benefits for medicine, materials science and computing, according to a highly anticipated report from the British government. But some nano products also pose risks to human health and the environment sufficiently worrisome to warrant new safety regulations, the report concludes.

Nanotechnology involves the manipulation of atoms and molecules to create materials and devices with novel electrical, optical and biological properties. It takes advantage of the fact that many ordinary substances behave in extraordinary ways at smaller dimensions.


Kent Hatch uses his breathalyzer, which shows what a bird has been eating. (Brigham Young University)

Some of those property changes are useful -- carbon nanofibers conduct electricity, for example, while larger pieces of carbon do not. But some materials that are normally benign are toxic or environmentally disruptive on the nano scale, in part because they can react with living cells.

The government report, which responds to an earlier report from two British science academies, concludes that "unbound" nanoparticles (as opposed to those embedded in solid materials) should be kept out of people's bodies and the environment as much as possible until their risks are better understood; new safety regulations should be created for nanoparticles; and the government should consider requiring labeling of consumer products containing unbound nanoparticles -- including some cosmetics already on the market -- so consumers can decide whether to use them.

Ann Dowling, who chaired the science academies group that wrote the earlier report, welcomed the government's call for new studies and regulations. "However, we are disappointed that there is no new money for the research that will be needed to underpin appropriate regulations," she said.

"Properly funded research is essential if we are going to ensure that these exciting technologies develop in a responsible way."

The report can be viewed at www.ost.gov.uk/policy/issues/nanotech_final.pdf

-- Rick Weiss

Birds Breathalyzed to Check Diet

Migrating songbirds stop periodically to eat and store energy for the next leg of their journeys. Now, thanks to a tiny, three-valve "bird breathalyzer," scientists can figure out what they're eating, and it's not always what seems obvious.

Working on Block Island off the Rhode Island coast, Brigham Young University ecologist Kent A. Hatch led a team that sampled the breath of migrating white-throated sparrows and yellow-rumped warblers that stopped, ostensibly to feed on bayberries, before continuing south to the Caribbean. The research was reported in the current issue of the journal Oecologia.

One breathalyzer valve stem had an oxygen-filled party balloon on it, the second had a tiny mask made from a party balloon, and the third was attached to a syringe: "It all fits in the palm of your hand," Hatch said in a telephone interview.

The team caught the birds with fine-mesh nets, put the mask on and let them breathe and re-breathe the oxygen before releasing them. They drew off the breath sample with the syringe and analyzed it for isotope content in a mass spectrometer.

Hatch said the warblers ate bayberries exclusively for the previous 12 hours, the period covered by the breathalyzer. But the sparrows' diet also included corn, millet or sorghum -- probably from bird feeders, he said, because Block lsland is not known for agriculture.

"Birds can burn fat, protein or carbohydrate, and it shows up in your breath," Hatch said. "The advantage of the breathalyzer is you don't hurt the bird, and you can take multiple samples without any harm at all."


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