Chris -  Airlines pressurise their airliners to about 7,000 feet worth of altitude, so slightly higher than ground level, and therefore, there will be a slight augmentation in haemoglobin, but not a huge one.  Probably not a physiologically (in other words, bodily) significant effect.

If those planes weren’t pressurised and they were flying at the kind of altitude they did, everyone onboard will be dead,  of course.  Most airliners are flying at more than 30,000 feet.  That’s the equivalent of the top of Mt. Everest where if you don't have supplemental oxygen there and you're not acclimatised, then you’d be dead very, very quickly.

So the answer is, when you go to high altitudes, you get a little bit more haemoglobin to compensate for the reduction in oxygen in the bloodstream, but it is proportional to how long you spend at altitude, and how high you go.  And because those planes are not flying very high – equivalently speaking because of the pressure in the cabin - and the exposure is limited, there won't be a very dramatic effect, but there might be a small one.

We put this question to Dr Jim Haseloff, from Cambridge University:

Jim -  Well I think, like with many technologies, there are different applications and certainly, as one can see with existing concerns about terrorist activity and other potential dangers, people are very concerned about the misuse of technologies.  For example, recently the field has highlighted the fact that these synthetic biology technologies can produce different types of, and more extreme, risks which need to be guarded against,

Chris -   I remember about seven years ago, someone decided to reassemble the genome of a polio virus using bits of genetic material they bought on the internet to prove that this was a genuine possibility that could be done.  I suppose, taking that a step further, you could do some fairly nasty things, given how easy it is to do some of this stuff these days.

Jim -   Yes.  In fact, DNA synthesis has been identified as one of the main potential dangers - that people can reconstruct elements which might be pathogenic for example.  Recently, there’s been an agreement, an international agreement among the major DNA synthesis companies.  So every sequence that are submitted for synthesis is now vetted.  So it would be – I wouldn’t say impossible, but probably very difficult to deliberately engineer a new DNA sequence for pathogen at this point.

Chris -   But if you made those sequences really short, they're not going to know, are they? If you ordered them from lots of different companies and got lots of little bits to stitch them altogether.  It would take you a long time but these people are dedicated.  They want to do what they want to do and if they want to bypass the system, they're going to find a way of doing it.

Jim -   Well I think the size of DNA elements that is unique is very small and it would be essentially impractical to make any large scale, even the smallest virus would be extremely difficult to construct that way.

We put this question to Dr Jim Haseloff, from Cambridge University:

Jim - Organic farmers actually use bacteria – the Bacillus thuringiensis bacterium which has a protein which affects the gut of specific insects and that protein, of course, is encoded in the gene and that gene can be then transferred to plants using genetic engineering techniques.  So it’s essentially a surgical procedure of isolating the particular gene using a natural bacterium to transfer that into a plant and then once it’s in there, it’s used as a gene that’s for breeding.

Chris -   So presumably, with synthetic biology, what one would do is to say "rather than take that toxin from a bacterium, what would be better would be to study the organisms that we want to make the plant resistant to, and then find our own way of making the plant resistant" and put some kind of specific thing into the plant that will be even better than what a bacterium toxin could do for us.

Jim -   That’s certainly feasible in the longer term.  I think most of the emphasis at this point is on better engineering using existing systems, existing parts from what we know in the biological world and rearranging their delivery inside say, for example a crop system, where you might get around some of the issues we’re talked about earlier in the program where you’ve got some insects which are immune to these very specific toxins and can escape.  So you can imagine a second element that would deal with that for example.

We put this question to Dr Jim Haseloff, from Cambridge University:

Jim -   I think it’s safe to say no.  The process of transfer – horizontal transfer from plants to humans requires some kind of vector, some kind of way of transferring it and I'm certainly not aware of any way of doing it,

We put this question to Dr Jim Haseloff, from Cambridge University:

Jim -  I think it’s an extremely interesting question and with synthetic biology, a lot of us are struggling with this idea that are shifting towards modified biological systems that are based on parts, and that those parts might be open-source and the technology is very cheap, so there’s certainly a potential for allowing access in developing countries to technology which can dial straight into important sustainable technologies.  The current model for biotechnology involves protecting elements and preventing other people from using them except under license.  So, this idea of protecting or removing fertility in seeds can have a bio-safety aspect, but it also can have an aspect of limiting use.  So, I think this is a question not for scientists but for society.

We put this question to Dr Jim Haseloff, from Cambridge University:

Chris -  A very pertinent question with what's going on in the Gulf of Mexico of course.

Jim -   Yes and one of the first patented organisms (and that’s another controversial issue, whether you can patent things) was a microbe that had improved oil degradation properties and so, clearly, the appeal of synthetic biology approaches is that you can take some of the diversity that you find in the natural world and transfer that into organisms for more specific purposes.

Chris -   In other words, to turn bacteria into things that can eat oil and therefore help with their clean up.