Archive for November, 2008

A shadow biosphere?

Wednesday, November 19th, 2008

Where are we most likely to find truly alien life? The obvious (though difficult) place to look is on another planet or moon, whether that’s under the icy crust of Europa, near the poles of Mars, or, perhaps, on one of the planets we’re starting to discover orbiting distant stars. Alternatively, we might be able to make alien life for ourselves, through the emerging discipline of bottom-up synthetic biology. But what if alien life is to be found right under our noses, right here on earth, forming a kind of shadow biosphere? This provocative and fascinating hypothesis has been suggested by philosopher Carol Cleland and biologist Shelley Copley, both from the University of Colorado, Boulder, in their article “The possibility of alternative microbial life on Earth” (PDF, International Journal of Astrobiology 4, pp. 165-173, 2005).

The obvious objection to this suggestion is that if such alien life existed, we’d have noticed it by now. But, if it did exist, how would we know? We’d be hard pressed to find it simply by looking under a microscope – alien microbial life, if its basic units were structured on the micro- or nano- scale, would be impossible to distinguish just by appearance from the many forms of normal microbial life, or for that matter from all sorts of structures formed by inorganic processes. One of the surprises of modern biology is the huge number of new kinds of microbes that are discovered when, instead on relying on culturing microbes to identify them, one directly amplifies and sequences their nucleic acids. But suppose there exists a class of life-forms whose biochemistry fundamentally differs from the system based on nucleic acids and proteins that all “normal” life depends on – life-forms whose genetic information is coded in a fundamentally different way. There’s a strong assumption that early in the ancestry of our current form of biology, before the evolution of the current DNA based genetic code, a simpler form of life must have existed. So if descendants of this earlier form of life still exist on the earth, or if life on earth emerged more than once and some of the alternative versions still exist, detection methods that assume that life must involve nucleic acids will not help us at all. Just as, until the development of the polymerase chain reaction as a tool for detecting unculturable microbes, we have been able to detect only a tiny fraction of the microbes that surround us, it’s all too plausible that if alien life did exist around us we would not currently be able to detect it.

To find such alien life would be the scientific discovery of the century. We’d like to be able to make general statements about life in general – how it is to be defined, what are the general laws, not of biology but of all possible biologies, and, perhaps, how can one design and build new types of life. But we find it difficult to do this at the moment, as we only know about one type of life and it’s hard to generalise from a single example. Even if it didn’t succeed, the effort of seriously looking for alien life on earth would be hugely rewarding in forcing us to broaden our notions of the various, very different, manifestations that life might take.

Deja vu all over again?

Wednesday, November 12th, 2008

Today the UK’s Royal Commission on Environmental Pollution released a new report on the potential risks of new nanomaterials and the implications of this for regulation and the governance of innovation. The report – Novel Materials in the Environment: The case of nanotechnology is well-written and thoughtful, and will undoubtedly have considerable impact. Nonetheless, four years after the Royal Society report on nanotechnology, nearly two years after the Council of Science and Technology’s critical verdict on the government’s response to that report, some of the messages are depressingly familiar. There are real uncertainties about the potential impact of nanoparticles on human health and the environment; to reduce these uncertainties some targeted research is required; this research isn’t going to appear by itself and some co-ordinated programs are needed. So what’s new this time around?

Andrew Maynard picks out some key messages. The Commission is very insistent on the need to move beyond considering nanomaterials as a single class; attempts to regulate solely on the basis of size are misguided and instead one needs to ask what the materials do and how they behave. In terms of the regulatory framework, the Commission was surprisingly (to some observers, I suspect) sanguine about the suitability and adaptability of the EU’s regulatory framework for chemicals, REACH, which, it believes, can readily be modified to meet the special challenges of nanomaterials, as long as the research needed to fill the knowledge gaps gets done.

Where the report does depart from some previous reports is in a rather subtle and wide-ranging discussion of the conceptual basis of regulation for fast-moving new technologies. It identifies three contrasting positions, none of which it finds satisfactory. The “pro-innovation” position calls for regulators to step back and let the technology develop unhindered, pausing only when positive evidence of harm emerges. “Risk-based” approaches allow for controls to be imposed, but only when clear scientific grounds for concern can be stated, and with a balance between the cost of regulating and the probability and severity of the danger. The “precautionary” approach puts the burden of proof on the promoters of new technology to show that it is, beyond any reasonable doubt, safe, before it is permitted. The long history of unanticipated consequences of new technology warn us against the first stance, while the second position assumes that the state of knowledge is sufficient to do these risk/benefit analyses with confidence, which isn’t likely to be the case for most fast moving new technologies. But the precautionary approach falls down, too, if, as the Commission accepts, the new technologies have the potential to yield significant benefits that would be lost if they were to be rejected on the grounds of inevitably incomplete information. To resolve this dilemma, the Commission seeks an adaptive system of regulation that seeks, above all, to avoid technological inflexibility. The key, in their view, is to innovate in a way that doesn’t lead society down paths from which it is difficult to reverse, if new information should arise about unanticipated threats to health or the environment.

The report has generated a substantial degree of interest in the press, and, needless to say, the coverage doesn’t generally reflect these subtle discussions. At one end, the coverage is relatively sober, for example Action urged over nanomaterials, from the BBC, and Tight regulation urged on nanotechnology, from the Financial Times. In the Daily Mail, on the other hand, we have Tiny but toxic: Nanoparticles with asbestos-like properties found in everyday goods. Notwithstanding Tim Harper’s suggestion that some will welcome this sort of coverage if it injects some urgency into the government’s response, this is not a good place for nanotechnology to be finding itself.

Nanocosmetics in the news

Thursday, November 6th, 2008

Uncertainties surrounding the use of nanoparticles in cosmetics made the news in the UK yesterday; this followed a press release from the consumer group Which? – Beauty must face up to nano. This is related to a forthcoming report in their magazine, in which a variety of cosmetic companies were asked about their use of nanotechnologies (I was one of the experts consulted for commentary on the results of these inquiries).

The two issues that concern Which? are some continuing uncertainties about nanoparticle safety and the fact that it hasn’t generally been made clear to consumers that nanoparticles are being used. Their head of policy, Sue Davies, emphasizes that their position isn’t blanket opposition: “We’re not saying the use of nanotechnology in cosmetics is a bad thing, far from it. Many of its applications could lead to exciting and revolutionary developments in a wide range of products, but until all the necessary safety tests are carried out, the simple fact is we just don’t know enough.” Of 67 companies approached for information about their use of nanotechnologies, only 8 replied with useful information, prompting Sue to comment: “It was concerning that so few companies came forward to be involved in our report and we are grateful for those that were responsible enough to do so. The cosmetics industry needs to stop burying its head in the sand and come clean about how it is using nanotechnology.”

On the other hand, the companies that did supply information include many of the biggest names – L’Oreal, Unilever, Nivea, Avon, Boots, Body Shop, Korres and Green People – all of whom use nanoparticulate titanium dioxide (and, in some cases, nanoparticulate zinc oxide). This makes clear just how widespread the use of these materials is (and goes someway to explaining where the estimated 130 tonnes of nanoscale titanium dioxide being consumed annually in the UK is going).

The story is surprisingly widely covered by the media (considering that yesterday was not exactly a slow news day). Many focus on the angle of lack of consumer information, including the BBC, which reports that “consumers cannot tell which products use nanomaterials as many fail to mention it”, and the Guardian, which highlights the poor response rate. The story is also covered in the Daily Telegraph, while the Daily Mail, predictably, takes a less nuanced view. Under the headline The beauty creams with nanoparticles that could poison your body, the Mail explains that “the size of the particles may allow them to permeate protective barriers in the body, such as those surrounding the brain or a developing baby in the womb.”

What are the issues here? There is, if I can put it this way, a cosmetic problem, in that there are some products on the market making claims that seem at best unwise – I’m thinking here of the claimed use of fullerenes as antioxidants in face creams. It may well be that these ingredients are present in such small quantities that there is no possibility of danger, but given the uncertainties surrounding fullerene toxicology putting products like this on the market doesn’t seem very smart, and is likely to cause reputational damage to the whole industry. There is a lot more data about nanoscale titanium dioxide, and the evidence that these particular nanoparticles aren’t able to penetrate healthy skin looks reasonably convincing. They deliver an unquestionable consumer benefit, in terms of screening out harmful UV rays, and the alternatives – organic small molecule sunscreens – are far from being above suspicion. But, as pointed out by the EU’s Scientific Committee on Consumer Products, there does remain uncertainty about the effect of titanium dioxide nanoparticles on damaged and sun-burned skin. Another issue recently highlighted by Andrew Maynard is the issue of the degree to which the action of light on TiO2 nanoparticles causes reactive and potentially damaging free radicals to be generated. This photocatalytic activity can be suppressed by the choice of crystalline structure (the rutile form of titanium dioxide should be used, rather than anatase), the introduction of dopants, and coating the surface of the nanoparticles. The research cited by Maynard makes it clear that not all sunscreens use grades of titanium dioxide that do completely suppress photocatalytic activity.

This poses a problem. Consumers don’t at present have ready access to information as to whether nanoscale titanium dioxide is used at all, let alone whether the nanoparticles in question are in the rutile or anatase form. Here, surely, is a case where if the companies following best practise provided more information, they might avoid their reputation being damaged by less careful operators.