Asbestos is a Mechanical carcinogen: (Score 1)

I'm surprised that nobody has mentioned this yet regading the nanotube/lung hazard. Yes, size and shape of particles influences many lung hazards effects. But Asbestos is particularly dangerous. The May 2007 Scientific American has an article "Chromosomal Chaos and Cancer", which I found disturbing in what has been known for a century, but nearly forgotten, and not is well known: ALL MALIGNANT CELLS HAVE BROKEN CHROMOSOMES! Cancer is not simply broken genes, or insructions. The whole computer file system is broken! Also, asbestos is particularly dangerous because of the specific shape and crystal structure. It has long, thin crystals, small enough to get inside the lung cells. But much worse than that, the crystal spacing is such that it very easily gets entangled in the microtubules that pull chromosomes apart during cell division. The end result is that during the most vulnerable part of cell division, chromosomes become mechanically sliced in half, and this is a starting point for all cancer! I'm sure that indiscriminate inhaling of nanotubes is a bad thing. But probably only very specifics forms can be remotely as dangerous as asbestos. Perhaps none of them.