I am sure everyone has heard about the wonders of nanotechnology, but what about the other side?
In a continuing effort to find out if the tiniest airborne particles pose a health risk, University of Rochester Medical Center scientists showed that when rats breathe in nano-sized materials they follow a rapid and efficient pathway from the nasal cavity to several regions of the brain, according to a study in the August issue of Environmental Health Perspectives
There was a time when asbestos was the wonder material, malleable and fire resistant, capable of being woven into sheets, and being incorporated into buildings for fire retardation. Unfortunately, many cases of asbestosis and mesothelioma later, not so wonderful. Asbestos is a special case because the fibers started out big and would keep breaking down into smaller particles till they reached that magic size range between 0.1 and 1-2 um where they could stay suspended in the air for a long time, and also take advantage of the lungs’ inability to filter particles that size to any great degree of efficiency.
Nanoparticles are an order of magnitude smaller, and hence behave more like gases. They may also contain choice toxic heavy metals such as manganese which are not usually floating around in the air at these small sizes. So, this study is a little scary, especially for the folks in the manufacturing end of things, these miracle particles seem to be going straight to the brain. Traditional masks and air handling systems are not designed to filter such fine particles, so I am sure they’re floating around in the air waiting to be breathed in.
Update 9:00 AM, 8-3-2006
Well, I swear, I did not see this before I wrote this morning!
The question of the day, however, is are they safe for humans and other living things? Earlier this year, Andrew Seaton, A U.K. scientist who was the lead author of a 2004 report investigating the saftey of nanotechnological materials raised a bit of a ruckus by comparing carbon nanotubes to asbestos fibers. Asbestos once had its day in the sun as an all-purpose wonder material. But then we learned that tiny asbestos fibers, once ingested by the human body, could be extremely deadly. Carbon nanotubes: also easy to ingest, and exquisitely capable of penetrating cell structures. Could they be equally toxic?