When it rains nanotechnology, it pours. Moments after publishing Tuesday morning's nanotechnology-and-globalization post, this week's edition of Semiconductor International Weekly arrived in my in box, with a slew of articles about nanotechnology and semiconductor manufacturing. I started ploughing through them, hoping to educate myself further, but the going got a little rough. I appreciate the poetry of words like "polyhedral oligiomeric silsesquioxane cage structure," but I'm not sure if anyone's interest is served in my trying to actually understand them.
But I wasn't going to be allowed to get off the nanotech beat that easily. Moments later in comes an alert from the Purdue University News Service announcing that "Engineers at Purdue University have developed a technique to grow individual carbon nanotubes vertically on top of a silicon wafer, a step toward making advanced electronics, wireless devices and sensors using nanotubes by stacking circuits and components in layers."
Carbon nanotubes are all the rage in contemporary nanoscience. These artificially constructed chicken-wire cylinders of carbon atoms are super-light and super-strong, and can boast all kinds of cool properties, like superconductivity. And they're real -- they're not science fiction. They are being manufactured now.
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?
Right now, we don't know much for sure, though a survey of the literature indicates that there has been a recent surge of academic interest in investigating the question. The journal Carbon devoted its entire June issue to the topic. Early in July, another journal, Nano Letters, reported on three separate studies of carbon nanotube toxicity, with widely varying results. A new newsletter, NanoRisk, which started publishing in June, does a decent job of summing up the current state of knowledge in layman-accessible form.
That inaugural NanoRisk newsletter observed that in 1898, a U.K. factory inspector named Lucy Deane warned of the harmful and "evil" effects of asbestos dust. According to Wikipedia, by 1906 "a British Parliamentary Commission confirmed the first cases of asbestos deaths in factories in Britain" and in 1918 "a U.S. insurance company produced a study showing premature deaths in the asbestos industry." And yet, it still took many decades before rigorous controls on asbestos production were put into place.
One would like to think we could do better today, 100 years later, when introducing new chemical entities into the world. But even though NanoRisk quotes Agnes Kane, one of the co-editors of the Carbon special issue, as saying, "These issues are being discussed openly. This is one of the few areas in toxiology that I've been involved in, where there has been discussion at the very beginning," the sobering truth is that the pace of modern technological innovation is so great that we are constantly experimenting with new substances without a clue as to what the long-term environmental or health consequences of their industrial deployment will be.
Maybe it will be different with nanotechnology. Maybe the botched introduction of genetically modified organisms, in which the private sector raced ahead before a regulatory structure was in place, will be a lesson for the nanotechnology industry. But it's hard to take much reassurance from history.
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