Nano no-no? You cannot be serious…

“Nanotechnology” – technology on a microscopic scale – has been one of the scientific buzzwords bandied about most often in recent years.

Its potential applications cut across the whole of science and engineering – from making stronger, lighter tennis rackets to delivering cancer drugs – and scientists and engineers around the world are rushing to bring new products to market that exploit nano-scale substances and devices.

But the field has always had a whiff of controversy about it, notably with Prince Charles predicting, in a 2004 speech, that the world could be overrun by self-replicating ‘grey goo’ nanomachines.

Essentially, the situation is a rehash of the classic dilemma that has faced all new technologies down the years. Proving something’s absolutely completely 100 per cent safe, in advance of its widespread use, is exceedingly difficult… if not impossible.

This is because science finds it very hard to prove a negative: it’s relatively straightforward to prove that, under certain test conditions, something will or won’t happen. But going from there to say that it will never happen ever, under any circumstances, is nigh-on impossible.

So we were interested to read yesterday about a paper in Nature Nanotechnology showing that relatively long, thin carbon nanofibres – tubes of carbon atoms a few millionths of a millimetre long – were able to cause inflammation and scarring to a layer of tissue called the mesothelium in mice.

Moreover, the damage was extremely similar to the pre-cancerous damage caused by asbestos (which is also made of long, thin, microscopic fibres). And when shorter nanotubes were used, no such scarring occurred.

Since these longer fibres will likely be working their way into all sorts of everyday materials in the future, this is obviously something that merits further investigation. But are nanotubes ‘the new asbestos’? Might we see another epidemic of asbestosis and mesothelioma?

In short, should the general public be worried about this paper?

Not immediately. For a start, carbon nanotubes aren’t yet widely available – they’re only found in a few high-end sports products.

Also, although they raise some significant questions, these are the results of one study, under particular conditions, in animals other than humans. The researchers pointed out that when nanotubes are incorporated into commercially available products. they’re encased in a protective coating, so it’s almost impossible for people to come into contact with them, let alone breathe them in.

In fact, this study only answered the question of whether nanotubes could cause pre-cancerous irritation when injected straight into the abdominal cavity of laboratory animals. It didn’t look at whether these irritations developed into cancer, nor whether the nanotubes could travel naturally from the lungs to the abdominal cavity on inhalation, as asbestos does.

But clearly, we need more research to answer these questions, and to discover whether carbon nanotubes could pose a risk to human health.

And if (and it’s still a reasonably big ‘if’) this was shown to be the case, it would then be essential to take a good look at the way nanotube-containing products are manufactured and disposed of – those people most at-risk would be involved in these processes. And obviously products containing nanotubes would have to be clearly marked, which is not the case at the moment.

But for now, there’s no cause for concern amongst consumers. Even if you ‘accidentally’ smash your shiny new carbon-fibre tennis racket on the floor after a particularly dubious line call…

Henry