December
Chemistry World Podcast - December 2006
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Brought to you by the Royal Society of Chemistry: the Chemistry World Podcast.
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Interviewer - Chris Smith
Hello and welcome to episode 3 of the Chemistry World podcast with me Chris Smith, with Chemistry World's Editor Mark Peplow...
Interviewee - Mark Peplow
Hello!
Interviewer - Chris Smith
And science correspondents, Richard Van Noorden...
Interviewee - Richard Van Noorden
Hello!
Interviewer - Chris Smith
And Victoria Gill...
Interviewee - Victoria Gill
Hello!
Interviewer - Chris Smith
In this edition: The surprise departure of Lord Sainsbury as minister for science, but what was his legacy.
Interviewee - Peter Cotgreave
He presided over a huge increase in the amount of investment that the government put into British science. When he took over, the public spending on research and development was almost as low as it has ever been.
Interviewer - Chris Smith
Also how can chemistry make a difference to life in Africa?
Interviewee - Hareg Tadesse
Chemistry can be applicable everywhere, in the water we drink, to the environment, to produce things, to use things in an eco-friendly way.
Interviewer - Chris Smith
And death by polonium 210, but where did someone get hold of such a rare radioactive material?
Interviewee - Mark Peplow
This got to have come from a working nuclear facility, the question now that people have to address is where that facility might be and I suspect, like Litvinenko himself was doing, they're looking to the East.
Interviewer - Chris Smith
More on that story coming up shortly. But first listeners to last month's show will probably recall Victoria's question.
Interviewee - Victoria
I was just wanting to know why is that leaves change colour in autumn before they fall off the tree?
Interviewer - Chris Smith
Any ideas, well the answer may well surprise you and it's coming up later. But first, scientists are investigating antiprotons as a potential cancer buster of future, Richard.
Interviewee - Richard Van Noorden
Yeah, that's right, Chris. You might think that using antiprotons to treat cancer sounds a bit ridiculous, but in fact scientists working at CERN have just released the first report into the biological effects of antiprotons on living cells.
Interviewer - Chris Smith
Obviously this isn't using patients yet.
Interviewee - Richard Van Noorden
No not using patients. They've actually suspended hamster cells 2 centimetres deep in gelatine, which is a bit like when you would irradiate tissue in the body.
Interviewer - Chris Smith
So why do you think that the antiprotons are so much more effective because as far I know we already use proton beams in chemotherapy or radiotherapy type approaches to treat cancers now.
Interviewee - Richard Van Noorden
Yeah! So, the approach was to compare the antiproton beam to the proton beam and in fact they found that the antiproton beam when it gets to the end of the tumour, the antimatter collides with matter and releases a sort of shower of high energy particles, very short lived and that does even more damage at the focus end of the tumour.
Interviewer - Chris Smith
The problem with cancers is that they don't tend to be just a blob of tissue; they spread out in all directions, so how easy is it going to be to focus the energy just on the tumour, so you don't do lots of damage to the other healthy parts of the body?
Interviewee - Richard Van Noorden
Well that's exactly why proton beams are being used in the first place. X-ray beams do tend to damage the healthy tissue. Before you get to the tumours, the beams passes through the body and already we know that proton beams and also antiproton beams actually do less damage to the tissue surrounding a tumour, they tend to deposit all their energy at a focussed endpoint.
Interviewer - Chris Smith
Now CERN is a pretty big facility. So is it going to be possible to miniaturize this sufficiently, so that we could deploy in a hospital setting to use it like this?
Interviewee - Richard Van Noorden
Well yeah, a good question. A proton beam, or also known another type is a carbon ion beam, it's the same idea. One of those clinics, some of them are in operation and they cost around 150 to 200 million Euros, but an antiproton clinic could cost up to half a billion Euros, so it's really just a question of whether in the future someone is going to be able to invest that type of money.
Interviewer - Chris Smith
Or money that some would argue could be better spent on investigating other therapies perhaps.
Interviewee - Richard Van Noorden
Well absolutely. But an American far-sighted company called Nano Life Sciences doesn't think so, because they've already got the intellectual property rights to this type of treatment, so someone is already looking into the future.
Interviewer - Chris Smith
We're talking about repairing tissue; there's now research, Victoria, showing that you can spin cells in to webs to repair things.
Interviewee - Victoria Gill
Yeah, that's right. A team at University College, London have used a sort of nanotechnological method, it's called electrospinning. Basically you force a polymer, a viscous polymer through a needle, a charged needle, to an earth collector below and the electric field forces the polymer through the needle and it creates a thread and it has been used to create threads to make materials before, but what's new about this is that these materials are bioactive. So, what they've put into these polymers, they've generated a viscous polymer that's cell friendly and they've put living cells into this polymer to make a thread that's made out of living cells, but because it's within this polymer, it can make a supporting thread, so these threads can sort of shape into swigles that are like connective tissue.
Interviewer - Chris Smith
So, it looks a bit like beads along a string then?
Interviewee - Victoria Gill
Yeah, that's right, but then the polymer thread can shape itself into random patterns, which is much like how connective tissue is shaped, so you sort of get a very natural bioactive scaffold that will support the healing process.
Interviewer - Chris Smith
And how would you see it being used in the body?
Interviewee - Victoria Gill
Well I spoke with Suwan Jayasinghe who is the leader of this research and he gave the example of wound on a hand. So, if you had a very very deep cut that would normally need some kind of plastic surgery or some kind of reconstructive surgery to heal, you could put these polymers with these living cells into this cut and you could actually take the living cells to put in these polymers from the other hand, so it would be completely compatible.
Interviewer - Chris Smith
And why does that actually help the wound to heal out?
Interviewee - Victoria Gill
Because you have these living cells that can interact with the cells within the tissue, so you can take cells that would have been damaged by the wound, you can take living cells from the other healthy hand and put them in, they will interact with the rest of the tissue.
Interviewer - Chris Smith
And how easy is it to deploy this? Is this something that's going to be realistically usable in hospital in the near future?
Interviewee - Victoria Gill
So he says, but I did speak to Thomas Boland from Clemson University in the US. He does similar work and he threw a note of caution in. Because it would be more useful to have these polymers degrading at different levels because if you can imagine, if you have a sheet of these polymers that could be used to treat burn victims you would need them to degrade quicker on the inside, where this sheet is making contact with the skin, than on the outside so that you can get this gradual healing process that's compatible with the skin.
Interviewer - Chris Smith
Thanks Victoria. Well to politics now and the surprised resignation of one of our longest serving Government ministers who is Lord Sainsbury and he unexpectedly handed in his notice on November the 10th. To find out more about Sainsbury's scientific legacy, I spoke with Dr. Peter Cotgreave from CaSE, which is the UK's Campaign for Science and Engineering.
Interviewee - Peter Cotgreave
David Sainsbury was the first science minister for a long time who actually wanted to be science minister. He didn't see this relatively junior ministerial position as a stepping stone to a job in the cabinet or something like that. He wanted to be science minister because he was really interested in British science and he presided over a huge increase in the amount of investment that the government put into British science. When he took over, public spending on research and development was almost as low as it has ever been and now just as he retired, it is higher than it has ever been in real terms.
Interviewer - Chris Smith
Some could argue that if things were really bad, then it was really only one direction they could go in, which was a big increase upwards.
Interviewee - Peter Cotgreave
That's certainly true and science of course is not the only thing that has seen increases in public spending over that period, all sorts of other things like the health services have as well, but in fact the proportional increase in the science budget is even bigger than the proportional increase in those other areas of public spending and that is at least in part a recognition by the government that unless we invest more in chemistry and physics and biology and all sorts of science and engineering, then the economy of the country wouldn't be secured in the future.
Interviewer - Chris Smith
The evidence is that we're not actually doing that well. Are we? Because, if you look at universities around this country, they are going broke, there are departments closing and despite this massive increase we've got record levels of people not going into science.
Interviewee - Peter Cotgreave
That's a very good point. It's not true that Britain isn't doing well at science. If you look at all the measures of how many citations we get, how many papers about research and those sorts of things, we're doing very well at research. There is a problem that universities are closing departments, particularly in physics and chemistry at the moment and there is still clearly a very big job to do on sorting out how to fund, particularly teaching in the universities and how to deal with the shortage of teachers in physics and chemistry in schools as well as in universities where it has been another big problem.
Interviewer - Chris Smith
Well now let's talk about David's successor who is Malcolm Wicks, he is from, previously from the Department for Energy. Is he going to inject energy into science though, we hope?
Interviewee - Peter Cotgreave
Well, Malcolm Wicks comes to the job with no background in science at all, but Malcolm Wicks did this thing called the Energy Review, that the Energy Review had every potential to become a political nightmare and somehow Malcolm Wicks managed to steer that to a result that wasn't a huge embarrassment for the government, came up with some suggestions and these are the things for the future and I think that demonstrates that he is a serious person who can take a big challenge and deal with it in a effective way within the political sphere. So I'm prepared to say, well, let's see what he does, because he has got that background that isn't in science but does prove that he can take a difficult brief and deal with it effectively.
Interviewer - Chris Smith
So if you had five minutes of his ear, what would be the top five things you would say, Malcolm Wicks, this is what the scientific community would really need to see happen?
Interviewee - Peter Cotgreave
Well, number one is, don't imagine that just because a lot of new money has gone in we've done enough, we're still behind the competition. Number two, on research, is stop the government interfering in research priorities, stop the government from producing lists of questions and ring-fencing parts of money for this or that or the other. Thirdly, the government needs to get much more scientific expertise in the departments so that they can commission and use and interpret scientific advise better, but the two most important ones are on education and one of those is in the universities, he needs to stop this business of physics and chemistry departments being under such financial pressures that they are forced to close and lastly, it is to deal with the place of science in the education systems, in schools and in colleges. We have to make teaching a much more attractive job for good physics graduates, good chemistry graduates, good biology graduates, so we can reverse this horrific decline in the number of well qualified science teachers.
Interviewer - Chris Smith
Peter Cotgreave from the Campaign for Science and Engineering in the UK, discussing Lord Sainsbury's legacy to UK science following his resignation in early November. And now from stormy political waters to climate change and has the debate entered melt down Richard?
Interviewee - Richard Van Noorden
Well that's right Chris, has November been the month where political talk about climate change has really reached some kind of tipping point and we might start saying political action, has already kicked off with Stern report just before November started and that was written by an economist, not a scientist, which some scientists were slightly annoyed about, as they've been really giving out the same message for some years.
Interviewer - Chris Smith
But now everyone is paying attention.
Interviewee - Richard Van Noorden
But now everyone is paying attention because it is being in monetary terms, Stern says "Act Now or Pay Later."
Interviewer - Chris Smith
And how much we'll have to pay?
Interviewee - Richard Van Noorden
Well Stern estimates that we only have to contribute 1% of the world's GDP, a trivial amount and that will save around up to 20% of the world's GDP in the worst case scenario.
Interviewer - Chris Smith
So what are they actually proposing we do, because it is all very worse we are going to spend some money, but what are we supposed to spend it on?
Interviewee - Richard Van Noorden
Yeah, well one thing we can do is try and cut carbon emissions and there are lots of ways we can try and do that. Some include, for example, the Kyoto Protocol and the dress rehearsal for that which is the European emission's trading scheme, which has not been going entirely smoothly, but in November again received its first assessment and that suggested it had done quite well and they are hoping to extend the scheme not just to talk about trading carbon but also trading methane and other green house gas and extending it to the aviation sector.
Interviewer - Chris Smith
Now you say that this is really focussing attention and making everyone take climate change very very seriously, but all the evidence I have seen suggests that president Bush takes it slightly less seriously than he takes going out for a walk.
Interviewee - Richard Van Noorden
That's true! President Bush is still in charge and if he is still in charge of America's climate policies, then he might argue that it is not going to make any difference what Britain or any other small country does; however, the recent midterm elections this November suggests that things might change there. The Democrats have got a bit more power and for example Barbara Boxer, the new head of the Senate's Environmental Committee has said that she wants to introduce some environmental policies on climate change.
Interviewer - Chris Smith
Finally, politicians are getting hot under the collar about the subject of climate change and what we might be able to do about it, thank you Richard. And now to science in Africa, here is Helen Carmichael, who is a science writer and Hareg Tadesse who is a chemistry Ph.D. student at the University of Nottingham.
Interviewee - Helen Carmichael
Quite a lot of changes are happening in Africa at the moment to do with chemistry, there's a big brain drain of talented scientists leaving especially sub-Saharan Africa, there is plenty of jobs going elsewhere and it is not necessarily such a great place from a job point of view to stick around in certain countries, although some governments are doing something to change that now.
Interviewer - Chris Smith
And what sort of things are they doing?
Interviewee - Helen Carmichael
Well, there's a number of different schemes some are having more success than others. One of the most effective schemes is in Rwanda where the Governor is giving people a quick phone call and offering them some really good job with some great pay to try and tempt them back when he hears they have gone overseas. So that seems to have been having some success there.
Interviewer - Chris Smith
But surely the kind of conditions that you can offer in Africa, Research Laboratories, the amount of funding can't be a fraction of what some people, if they are really world leaders, are going to be able to obtain overseas and receiving the same thing with people in Britain going to the US?
Interviewee - Helen Carmichael
Yeah, I think that is exactly the case and that is probably why those who are sticking around in Africa to do chemistry are trying to bond together, perhaps collaborate a bit more between countries as well as within countries and really work to promote chemistry and explain to people how important it is and how important it is to not only to some indeed, but to actually educate scientists in future as well so that they can take the battle on further.
Interviewer - Chris Smith
But you could do all the explaining you like, but that can't compete with good hard cash, which is what people are after.
Interviewee - Helen Carmichael
Well, I think people do appreciate that and I mean one person in particular called Calestous Juma, who is a UN task force coordinator who specializes in science and technology, has actually said in the past that the scientific collaboration with British Universities would do more for Africa than distributing food aid, so think what he is saying now; if people in other countries will put some money and time and effort in to help training people there, that would make all the difference, compared to them trying to do it all by themselves.
Interviewer - Chris Smith
Well, this seems like a very good opportunity to bring in someone who is in the UK studying science, but I do know, perhaps Hareg Tadesse, you're going to return to Ethiopia when you finish your training, what are your plans?
Interviewee - Hareg Tadesse
Yeah, that's my plan. After getting my Ph.D. and after finishing my research, my plan is to go back to Ethiopia and to help other students from the experiences what I am getting from UK.
Interviewer - Chris Smith
Are you pretty unusual in having that outlook of wanting to return? I would think, most people, if they felt they could stay and have better research environments to do their work in, would want to stay, wouldn't they?
Interviewee - Hareg Tadesse
Yeah, that's true, but my research area, what I want to do is just directly related to the resource we have in the county back home, with the natural products, it's with plants. So it is very good to be there in the country and you know how to use the resource there and at the same time share the experiences.
Interviewer - Chris Smith
What do you think science can do for Africa?
Interviewee - Hareg Tadesse
You know, the application of sciences is wide in everything. For example, in the area, what I am studying chemistry can be applicable everywhere, in the water we drink, to the environment, to produce things, to use things in an eco-friendly way, so I believe science is important.
Interviewer - Chris Smith
And returning back to you Helen, would you echo those sentiments and is this typical of what people in Africa say when you talk to them?
Interviewee - Helen Carmichael
Yeah, I think so, I mean to start of with, there is a big emphasis on talk and choke kind of teaching and a much less emphasis partly because of practical reasons, when actually carrying out practical experiments, I think this is really holding people back. Another sort of resource that's missing or has been missing up until recently is access to other people's research using journals. Whether you're part of a university or an research organization costs money and lot of universities or individuals can't actually afford to pay the subscriptions for these journals to get hold of them. I think that's one thing that the Royal Society of Chemistry have done well, is that it has actually recently opened up all of its archives and offered them for free to many African nations and some other developing nations in other parts of the world as well. So I think that has been very well received by researchers there and I said it will make a big difference and I think they're really hoping that some other journal publishers will follow suit.
Interviewer - Chris Smith
Science writer, Helen Carmichael and chemistry Ph.D. student Hareg Tadesse describing how chemistry can be reactive to Africa's needs. Now in just a second, a way to pinpoint people who have risk of schizophrenia, but first it's worrying news that industrial chemicals could be harming the developing brain, what is this all about Richard?
Interviewee - Richard Van Noorden
Well, according to a review article in The Lancet published in November, industrial chemicals worldwide could be "damaging millions of children's brains". The authors say that just as lead was eventually found to cause damage to developing foetuses and children's brains at lower concentration than regulated, so why not many other currently known to be neurotoxic chemicals, they might also cause damage to developing foetuses' brains at much lower unmonitored levels.
Interviewer - Chris Smith
There is a lot of possibilities and might in there Richard, have we got any hard facts?
Interviewee - Richard Van Noorden
Well absolutely, as Chemistry World was told by one toxicologist "pandemics need proof" he said and we don't have any proof. It's all just precautions, it's all just arguing from historic cases of lead and PCBs, but nonetheless toxicologists have said that this issue is worth talking about.
Interviewer - Chris Smith
How do they propose to take this forward and work out whether there is real case to be made?
Interviewee - Richard Van Noorden
Well, the author Philippe Grandjean told us that he suggested that we would need some kind of formula of testing to be set up and he suggested for the moment that reducing the levels of these chemicals by around 10 times would be a suitable precautionary measure.
Interviewer - Chris Smith
Because the EU have recently changed their rules on this kind of thing, will that get the grips with the problem?
Interviewee - Richard Van Noorden
That's right, well the EU's regulation which is shortened as REACH, the EU system of Registration, Evaluation, and Authorization of Chemicals which has recently been slowing down but it may actually happen quite soon, that's being cited as a way of being very stringent about chemicals, but Grandjean told Chemistry World that he thinks that it really doesn't focus on neurotoxicity damage to the brain, it just focuses on carcinogenicity and your everyday toxicity.
Interviewer - Chris Smith
Certainly worrying news, we hope that there is no basis to it in the long-term future, well from one kind of neurotoxicity to a neurodegenerative problem and that's schizophrenia that has now scientists think they might be able to pinpoint who is at risk and who may be developing the disease, Victoria.
Interviewee - Victoria Gill
This is actually looking towards developing a diagnostic test for schizophrenia, so this is the way it has come out of the University of Cambridge and what they've done is they've taken samples from the cerebrospinal fluid of schizophrenia patients. So a cerebrospinal fluid is the nourishing, sort of, protective fluid that surrounds the spinal cord and brain and it is about as close as you can get to a sample from the brain without biopsying brain which is really a dangerous procedure. So the team from Cambridge have, they've taken patients with schizophrenia, but crucially patients that haven't had any treatment for schizophrenia, so none of the chemicals that are showing up in their cerebrospinal fluid are going to be from drug treatment, they're all going to be from the disease or from any proteins they would normally find in that fluid.
Interviewer - Chris Smith
But these are diagnosed patients they have schizophrenia. It is confirmed.
Interviewee - Victoria Gill
Yeah, that's right. So, this is an initial result that should hopefully help lead to a diagnostic test in the future.
Interviewer - Chris Smith
And what they're looking for proteins or what sorts of chemicals are they finding in the CSF that gives you a clue to the fact these people have schizophrenia?
Interviewee - Victoria Gill
Well they found a protein; proteins that are biomarkers that are specific biomarkers for schizophrenia as far as they can tell.
Interviewer - Chris Smith
And what they go up / down or they're just not present in a normal person but only in someone with schizophrenia?
Interviewee - Victoria Gill
Their levels are much higher, significantly higher, in patients with schizophrenia. So what they're thinking is that they'll be able to take this and make into a diagnostic test by looking for these specific proteins, because at the moment what they're doing is just using mass spectrometry to look for the levels of different proteins, but if they actually have a marker to look for, then you'll be able to take it to the next level and make it diagnostic.
Interviewer - Chris Smith
What about other Neuropsychiatric disorders, depression and so on. Do they give any clues as to whether someone has got one of those?
Interviewee - Victoria Gill
Well the main bulk of the study was with patients with schizophrenia, but they have taken a few patients with other central nervous system disorders, other psychiatric disorders, the main one being depression. They had quite a few patients with depression that also underwent these tests and they seemed to have found biomarkers that delineate between schizophrenia and depression. So they're hoping that another stage of this is going to be to try and delineate between lots of psychiatric disorders.
Interviewer - Chris Smith
Thanks Victoria and now some really great news for University science departments Mark.
Interviewee - Mark Peplow
Yes Chris, at the start of November the Higher Education Funding Council for England announced that it was providing an extra 75 million pounds over 3 years for courses in Chemistry and Physics and certain types of engineering like Chemical Engineering. And this is really a response to many years of lobbying, pointing out that the amount of money that they were providing for student courses in these subjects simply wasn't reflecting the true cost of teaching lab-based subjects like these. The extra money they HEFC has promised should mean about an extra thousand pounds a year for each science undergraduate.
Interviewer - Chris Smith
So how does this sit with the fact that the University of Sussex have recently almost had to close their chemistry department, because they argued it wasn't that because they were hard out, it was because they were struggling to recruit students that were good enough to go into those courses.
Interviewee - Mark Peplow
Well this is the trouble. It's a common example of how education policies isn't terribly joined up at the moment despite the fact that universities are getting this extra money for students. At secondary school, science education is still in a pretty powerless state, for example, The Royal Society of Chemistry says that you need about 2 billion pounds to upgrade school science laboratories to a decent state. And in fact earlier this month, The House of Lords Science and Technology Committee said that the chemistry departments and science departments in certain secondary schools were understaffed and poorly equipped and the students got very very little practical experience. So this means that effectively you've got a real absence of keen A level students that are wanting to go ahead and take advantage now of this extra money that's provided for University education.
Interviewer - Chris Smith
Do you think this is not just a case of bit too little, a bit too late, I mean the University of Reading have recently announced that they're shutting their physics department.
Interviewee - Mark Peplow
Yeah, I mean Tony Blair would as he said earlier this month, he said that 'he was born again on the subject of science and he was a real believer now and how important science was for the economy'. But you're right, a lot of scientists would say that this was definitely too little, too late, as the education in science has really been neglected at different levels and a little bit of fixing from the Higher Education Funding Council at this stage really isn't going to redress a far bigger deficit that has been growing for many years within science education.
Interviewer - Chris Smith
That's Chemistry World's Editor Mark Peplow and now Victoria, big pharma companies look like they could be in trouble, it seems.
Interviewee - Victoria Gill
I'm not sure they're in big trouble exactly, but there do seem to be a few problematic results in phase III clinical trials for quite a few of the major big pharma companies. We saw some reports this month and that were particularly concentrating on British big pharmas. There are reports from AstraZeneca and GlaxoSmithKline and they announced good results for their third financial quarter, but at the same time they announced that they're withdrawing or delaying some big blockbuster drugs. And probing a little deeper, it seems that they're not the only ones with the problem and Merck have also had a very disappointing clinical trial of an obesity drug and Pfizer have had to delay their potential cholesterol blockbuster because the FDA are demanding more tests.
Interviewer - Chris Smith
Any clues as to why this rash of problems seems to have cropped up right now?
Interviewee - Victoria Gill
Well that's what we're wondering, so we're wondering whether may be the FDA have changed their rules, have tightened up on the amount of safety testing they want in phase III, or whether there are more new drugs being tested. So we went to the FDA and spoke to Robert Temple, who is the Director of the Centre for Drug Evaluation. He said that in actual fact, drug companies have been coming to the FDA and complaining that they are having this problem with what they call translation, so the FDA themselves are investigating what might be going wrong in phase II that's just not translating to phase III, because apparently these companies have actually said that half or more than half of the drugs that go into phase III don't actually make it out of phase III, so this could be a problem.
Interviewer - Chris Smith
I just wonder whether the fact that Merck is now facing what could amount to a billion dollar law suit for its problems with the drug Vioxx that was subsequently found to trigger heart attacks, whether this has focussed the mind to the drug companies and cause them to do a bit of belt tightening.
Interviewee - Victoria Gill
Well possibly, but one of the things that Robert Temple mentioned to us was purely the fact that more of the drug companies seem to be investigating novel molecules, rather than follow-on molecules, so rather than looking into new and improved versions of all drugs, a lot of companies, a lot of the big pharma are looking into new drugs for things like obesity and cholesterol and when you are making something from scratch, there seems to be a lot more potential problems with it.
Interviewer - Chris Smith
Well from a big pharma to a big political scandal now. And Mark the story of polonium 210.
Interviewee - Mark Peplow
Yeah, that's right. A former Russian spy, Alexander Litvinenko died on the 23rd of November in London and he'd been ill for several weeks. People had been following his condition and there'd been a lot of speculation about what was actually wrong with him. It appeared when he first turned up to the hospital that he had been poisoned, his hair had fallen out. The idea came up that he had been poisoned with thallium. Thallium poisoning classically reveals itself as causing the hair to fall out, but after he died, very quickly doctors managed to ascertain that he had actually been poisoned with polonium 210.
Interviewer - Chris Smith
Well Mark, how much polonium 210 would you need to actually kill someone?
Interviewee - Mark Peplow
Very very little. It's trillions of a gram quantities. Essentially polonium 210 is a very very radioactive element. It emits alpha particles, which have two neutrons and two protons bundled together like the nucleus of the helium atom. Although the radiation, that is the alpha particles can be stopped by skin or paper or something like that, if you actually ingest this substance, the alpha particles can do untold damage to you cells, to DNA, things like that. Really, the amazing thing about the fact that this has been used to poison someone is that it is such a rare element. It is naturally occurring but in minute quantities.
Interviewer - Chris Smith
Wasn't it actually first described by the Curies'?
Interviewee - Mark Peplow
Yeah that's right, 1897, Marie and Pierre Curie discovered it and indeed they did by trolling through huge quantities of uranium ore and it was a real task to actually separate it.
Interviewer - Chris Smith
So where did this sample, because this was present, I know it was only a small amount that was used, but where did this amount come from, that got into this guy's food?
Interviewee - Mark Peplow
Well, these days there are some commercial uses for polonium, so it is made on the scale of about 100 grams a year, but it is made in nuclear reactors or particle accelerators by bombarding Bismuth with neutrons. So, it's clearly not the sort of thing you can pick up easily, this has come from a serious facility, which in theory, should have serious high security around it.
Interviewer - Chris Smith
So that suggests big government or big bucks to be able to unleash this kind of crime, doesn't it?
Interviewee - Mark Peplow
It certainly means it's not amateur, yeah. I mean this has got to have come from a working nuclear facility. The question now that people have to address is where that facility might be and I suspect like Litvinenko himself was doing, they're looking to the east.
Interviewer - Chris Smith
A chilling thought about a very hot topic. Well on the subject on chilly things, autumn did finally arrive this year and it provoked Victoria to ask this.
Interviewee - Victoria
I was just wanting to know why is that leaves change colour in autumn, before they fall off the tree?
Interviewer - Chris Smith
And with the answer, that might just surprise you, here's David Wilkinson, from Liverpool John Moores University.
Interviewee - David Wilkinson
This is something we are so familiar with, but often people don't ask the question, you know, what are autumn clues there for? In fact we look in all biology text they say that they're really just an accident and the reds you see which are produced by anthocyanins and orangy-yellowy sorts of colour that is produced are carotenoids are really just there as an accidental by-product and they are being unveiled as the green of the forest that goes during the death of the leaves. And in fact that's not quite true and really no plant scientist quite believes that anymore. The carotenoids are unveiled like that, but anthocyanins are actually being produced in the leaf. In the autumn periods, the red colours are being produced for some reason and the question is why. The commonest explanation is that these colours are actually providing protection to the plants, because photosynthesis still has to happen during that time although the apparatus for photosynthesis is being broken down in the leaf, the leaf is too shrunk to get nutrients particularly ones with nitrogenous things out of the leaf, back into the tree for the next year and to continue the photosynthesis particularly in whole bright sunny weather is actually very difficult and also the chemical problems in these pigments are providing antioxidants that providing also sinks for too much energy that can be flooding into these things, so they are allowing photosynthesis to continue and these nutrients to be got out. But other ecologists and evolution biologists have been thinking about other possibilities and in particular an idea that has a lot of attention over the last few years was thought by the late Bill Hamilton of Oxford and he wondered whether these colours which sort of signal autumn to us are actually also signalling something to insects and saying, 'I got these bright colours, I'm a really healthy tree, don't mess with me; go somewhere else and that tree down there with the pale washed out colours. It is a bit sick tree it won't be able to fight back if you attack it and lay your eggs on it'.
Interviewer - Chris Smith
So you could say, 'there are no flies on tree', thank you David for that. And now in true Christmas spirit, here's Mary with this month's highly festive Chemical Conundrum.
Interviewee - Mary
When Christmas crackers were invented what made them go bang?
Interviewer - Chris Smith
So if you can help us out with that then please do drop us a line to chemistry world at rsc dot org and you can also use that address if you'd like to send us any feedback. That's it for this month's edition, which was produced and presented by me Chris Smith from the naked scientists dot come, by Chemistry World's editor, Mark Peplow and science correspondents, Richard Van Noorden and Victoria Gill. For more science in the meantime, do check out the Chemistry World web site at chemistry world dot org, but until next time, have a very Merry Christmas and Good Bye!
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