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Wednesday, May 21, 2008

Nano particles may cause negative health impact

The matter of harm from nanotechnology was raised many years ago, yet industry seems to be pursuing the science with gusto.

Nano-fibres lead to pre-cancer symptoms in mice: study
Tue May 20, 2008

Scientists delivered a warning Tuesday about nanotechnology after tests on lab rodents found that microscopic, needle-like fibres that are already in commercial use led to lesions similar to those caused by asbestos.

In experiments, researchers led by Ken Donaldson of the University of Edinburgh, Scotland, exposed the mesothelium lining that swathes the lungs, the abdomen and the heart to fibres measuring billionths of a metre.

The fibres resulted in the same kind of inflammation and scarring, called granulomas, that are caused by exposure to asbestos, their study said.

"The granulomas and the inflammation are extremely strong indicators of mesothelioma," the cancer that attacks the body cavity's lining, said co-author Andrew Maynard.

If the mice had been allowed to carry on living, cancer would most probably have developed where the fibres were present, he told AFP.

A large body of research already exists about the potential of nanoscale fibres to attack the lungs.

But this is the first study to show that a form of nano-technology called carbon nanotubes can have the same damaging impact on the mesothelium.

Nanotubes -- structures engineered from single atoms and molecules -- hold great promise for applications in medicine, electronics and especially new materials.

"We are at the very, very beginning of using these materials commercially," said Maynard, who predicted that within half a dozen years the market for carbon nanotubes would be worth billions of dollars.

"Great caution must be exercised before introducing such products into the market if long-term harm is to be avoided," he said.

Investigation is urgently needed to see whether these tiny particles can be breathed in from air, and if they can migrate to within the lungs to cause cancer, he added.

The biggest potential danger is probably in the work place, but nanotubes might also escape into the environment once the products containing them wind up in landfills as refuse, he said.

"We don't have enough evidence to call for a moratorium, but there is very urgent need to for action to ensure safety, by government and by industry," Maynard said.

The research, published online in the British journal Nature Nanotechnology, showed that only so-called long carbon nanotubes, and not short ones, caused the pre-cancerous symptoms.

Further experiments are needed, however, to determine if short nanotubes are entirely safe.

Copyright © 2008 Agence France Presse.

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