21-01-2015 | By Paul Whytock
Do nanotubes represent an asbestos-like risk to people working with them? This is a challenging question to answer despite it having been asked for several years, and extracting a definitive conclusion from the plethora of research on the subject does, in itself, require copious research.
The scramble by industries to embrace nanotechnology advances is perfectly understandable. Among these is the electronics sector, where nanotube technology is rightly perceived as one of the next major steps forward in transistor technology. But in the enthusiastic rush to capitalise on this technology industry has, by and large, adopted a Nelsonesque approach and turned a blind eye to the possibility that certain nanotube technology may constitute a similar and serious health risk to those generated by asbestos fibres.
Fortunately, some clear facts are starting to emerge, but two fundamental questions remain unanswered. Can nanotube technology cause the killer lung disease mesothelioma to the same extent as asbestos, and are some nanotube structures more pernicious than others?
These questions must be fully answered not only from the moral standpoint of protecting humans working with nanotubes but also to prevent the enormous financial wave of healthcare costs and compensation claims that followed the onset of mesothelioma cases caused by asbestos. The cost of asbestos-related lawsuits in the USA exceeds $200 billion.
Well, nanotube research conducted at the University of Edinburgh examined and compared the health risks of long and short carbon nanotubes with long and short asbestos fibres. The material was injected into the abdominal cavity of mice, and within that area of tissue, the results showed that long, thin nanotubes caused the same effects as asbestos fibre.
Interestingly the shape of the nanotube may play a crucial part in just how dangerous it can be. The primary concern is that nanotube technology’s microscopic dimensions are easily airborne, and workers could be at risk of inhaling or ingesting nanotubes like asbestos fibres. Once embedded in the lungs, it’s doubtful that the body’s macrophages would be able to remove tissue damaged by them, especially when the invading nanotube had travelled beyond the lung surfactant. However, not all nanotubes behave the same. Those of a shorter length and those that are twisted may not act like asbestos. It is at least becoming clearer what type of nanotubes require greater diligence in industrial safety procedures.
The desire by the electronics industry to fully exploit nanotubes both technically and financially is well appreciated. Some time ago, Dutch scientists created a nanotube-activated transistor that could switch on and off using a single electron. The point here is that conventional transistor design needs millions of electrons to move, which creates heat dissipation challenges. Such a single electron-activated transistor could also result in substantially smaller designs.
However, the rush to implement the widespread use of nanotube technology must be tempered with great employee care. Otherwise, companies could find that the significant contribution it makes to their corporate bank accounts will soon evaporate in a cloud of compensation claims akin to those created by the asbestosis debacle.