http://www.nytimes.com/2003/04/14/technology/14NANO.html

Research Shows Hazards in Tiny Particles

By BARNABY J. FEDER

A new review of research on nanoscale materials suggests that tiny particles are often toxic because of their size and are likely to pose health hazards, especially to workers making them.

Dr. Vyvyan Howard, a pathology specialist at the University of Liverpool who examined results from 27 studies published since 1984, said that the type of material a particle is made of appears to be much less related to how hazardous it is than its size at such small scales.

Dr. Howard said that nanoscale particles, which are made up of tens to thousands of molecules and are far smaller than human cells, are easily ingested, inhaled or absorbed through the skin.

"I suppose that's something those working in the field would rather not hear but that's no reason not to say it," Dr. Howard said.

Dr. Howard's conclusions are to be released today by the ETC Group, an opponent of rapid nanotechnology development that asked him to perform the research review. ETC has been advocating, among other things, that production of nanotechnology products be put on hold until more data is available on potential health impacts. The report is available at www.etcgroup.org.

Nanoscale materials are already used in products as diverse as sun-blocking lotions, tennis balls, computer displays and paneling on cars. The range of potential applications has been expanding rapidly as researchers discover valuable and sometimes unexpected results by shrinking common materials, including extra strength and flexibility, new electrical properties and transparency.

Nanotechnology backers and researchers in the United States and Europe have repeatedly disagreed with the kinds of conclusions reached by Dr. Howard and there is no public support in the business community for any sort of moratorium.

"People who worry excessively underestimate the number of natural materials that size that have surrounded us for years," said Greg Blonder, a partner in the Morgenthaler venture capital firm. "It requires the usual good care but I don't see any new or unique threat."

Nanotechnology companies said that the havoc that asbestos claims have created in industry has made businesses extremely sensitive to the health impact of new materials. Halting development to perform health studies would simply send nanotechnology development offshore, they said.