In fact the new research, which was conducted on mice and whose results were published in the journal Toxicology, even suggests that the longer nanofibers are even more dangerous than asbestos, the BBC reported, though some are similar in shape to the asbestos fibers which are known to cause lung cancers such as mesothelioma.
While lungs in mice and humans are different, of course, researchers hope their study will lead to the design of safer nanofibers which are contained in a range of items, from aircraft wings to tennis rackets.
"Concern has been expressed that new kinds of nanofibers being made by nanotechnology industries might pose a risk because they have a similar shape to asbestos," said Ken Donaldson, a professor of respiratory toxicology at the University of Edinburgh in Great Britain.
Documenting the dangers
To conduct their research, Donaldson and his team injected silver nanofibers of varying lengths into the lungs of mice. Those larger than five micrometers, or five-thousandths of a millimeter, often became lodged in the lungs and caused inflammation. Smaller nanofibers were cleared by the lungs.
"We knew that long fibers, compared with shorter fibers, could cause tumors, but until now we did not know the cut-off length at which this happened," Donaldson told the BBC.
"Knowing the length beyond which the tiny fibers can cause disease is important in ensuring that safe fibers are made in the future as well as helping to understand the current risk from asbestos and other fibers," he added.
Prof. Stephen Spiro, of the British Lung Foundation, said asbestos-caused mesothelioma cases have nearly quadrupled in the past three decades.
"This research is particularly interesting as it gives us an indication of the size of fiber that might lead to mesothelioma if inhaled," he said. "If confirmed by subsequent studies, this minimum fiber length can be cited in industry guidelines to help ensure people are not exposed to the sorts of fiber that may lead to such deadly diseases."
Asbestos, once widely used as a fire retardant, has long been known to cause health problems.
"Asbestos is the name given to a number of naturally occurring fibrous minerals with high tensile strength, the ability to be woven, and resistance to heat and most chemicals," says a description on the website of the Environmental Protection Agency. "Because of these properties, asbestos fibers have been used in a wide range of manufactured goods, including roofing shingles, ceiling and floor tiles, paper and cement products, textiles, coatings, and friction products such as automobile clutch, brake and transmission parts."
Government health agencies say exposure to asbestos can cause asbestosis (a serious, long-term, non-cancer lung disease), as well as lung cancer and mesothelioma.
The U.S. Consumer Product Safety Commission says asbestos hazards in the home can come from a variety of sources - roofing and siding shingles, some vinyl floor tiles and coating of hot water and steam pipes - but those are contained mostly from houses built between 1920 and 1950.
However, nanofiber technology is making advances
Some nanofibers have been found to be potentially useful. For instance, a material developed by Northwestern University materials science professor Samuel Stupp could help prevent scars and encourage damaged nerve fibers to grow.
The engineered material "contains molecules that self-assemble into nanofibers, which act as a scaffold on which nerve fibers grow," said a report published in 2008, in the MIT-reviewed Technology Journal.
During trials, when injected directly into the spinal cords of paralyzed mice, the material restored some use of the animal's hind legs.
Learn more: http://www.naturalnews.com/037032_nanofibers_asbestos_health_hazards.html#ixzz3O3Rhj0Br