The Planet Earth podcast - 'Bees, nanomaterials, and methane on Mars'.
18 June 2012
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Sue Nelson:Hello, I'm Sue Nelson and this is the Planet Earth podcast from the equivalent of a bumble bee's camp site in Berkshire. You will find out why in a moment. Also on the podcast - studying the effects of nanotechnology on the environment and human health.
Helena Johnston:You might get exposure inhalation into the lung would be a target, be it ingestion, so we have the gut as an exposure, we have the skin. Once the nano particle is exposed to the different exposure site they can access the blood because of their small size.
Sue Nelson:The sound of just a few of the several hundred bees here at an experimental farm in Sonning not far from Reading. It belongs to the University of Reading and I'm with Simon Potts who is Professor of Biodiversity in Ecosystems Services there and also the deputy director of the Centre for Food Security.
Simon, I sort of mentioned that it was like a bee camp site - it's an unusual camp site in that you can effectively see through the canvas because it's like a see through gauze - what exactly are we looking at?
Simon Potts:Well, what we've got here is a set of experimental cages where we can actually manipulate the types of pollinators we have inside them and then we can actually expose different plants, they can be wild flowers or they can be crops and we can actually test what the impact of the different pollinators are on the pollination success.
Sue Nelson:What types or other types of pollinators, is it strictly bees?
Simon Potts:Well there's lot of different insects that pollinate but probably bees are THE most important, certainly in Europe. What we have here - we have honey bees which most people will know about but we also have managed bumble bees, which you sometimes also see in your garden, but we also have some solitary bees and one particular sort is called the mason bees, because they nest in small tubes, and we also have some hover flies as well.
Sue Nelson:You've got 40 or so of these flight cages and let's just walk over to one of them and see it in a bit more detail here, and Duncan Costan is with us, he's a research technician at the university. Duncan, your responsibility is to look after some of these flight cages, well all of them. Could you explain the sort of crops that we've got? I think I can vaguely recognise the flower of one of those, possibly broad bean.
Duncan Costan:Well, here it's a field bean.
Sue Nelson:That's why it's so much taller than a broad bean.
Duncan Costan:Yeah, and they're grown quite often for things like cattle feed but here we're using them because we can use them as quite a nice indicator with our various different pollinator species. So, we've got them here in individual plant pots so we can move individual plants to expose them to our various pollinator species and then we can keep them in another cage, keep them excluded from all pollinators so we know the only thing that has pollinated that is the species that we've exposed it to.
Sue Nelson:How big are they, about four metres or so long?
Duncan Costan:Each cage is constructed of blocks of roughly two metre cubed cages but we can then connect the blocks to make double or treble cages to create multiple sizes and various sizes for cages that we want. For our solitary bees and our bumble bees we keep them in double cages, so that we can keep the bumble bees in and they've got plenty of space, they're got forage space, and we can then put plants in to expose our treatments and we can also put forage in to keep them going when we're not running our experiments.
Sue Nelson:So, let's just wander across here, because you've got the field beans there which is, as I say, new for me because I've actually seen field beans and then in the one next to it there, that's very recognisable, the yellow flower.
Duncan Costan:Yep, in this cage and in a lot of our cages is full of oil seed rape, which is another one of the main crops we're using for the crops project.
Sue Nelson:Simon, last year you discovered that wild bumble bees play a much more important role in crop pollination than was previously thought.
Simon Potts:I would say a very widely held believe that honey bees basically did most of the pollination of crops in the UK and actually that was true back in the 70s and 80s, but since then we've had really like catastrophic declines in the number of hives and it turns out that know currently it's about only 10 or 15% of the work is actually done by honey bees, so the real heroes of our crop pollination turn out to be these wild bees and we have 267 species in the UK, including a number of bumbles bees, solitary bees and other small bees as well. So it's really important if we want to sustainably grow food and make sure we've got good pollination we need to know who does the work, and if it's the wild bees doing the work then we really need to think about how to manage the landscape to help them.
Sue Nelson:So do we know who does most of the work when it comes to crop pollination?
Simon Potts:We're getting there!
Sue Nelson:So we still don't know.
Simon Potts:Well it's amazing. I mean people have known about pollination for decades but actually that really fundamental question, who actually does the work, we don't know for all crops and we're just starting to pick it apart. So quite often it's a combination, it's really good to have a diversity of pollinators because that provides insurance. So, for instance, bumble bees are really good in cold weather and they can fly in those sorts of temperatures. But when it's really hot they don't like it so much and maybe the more solitary bees come in and do the pollination. So as we've got climate change and environment change one of the big questions is how can we manage the landscape to make sure we have the right set of pollinators, not just a single one but a whole set of them so we can always have good pollination.
Sue Nelson:So this is partly why you've got these very carefully controlled conditions in our little bee flight cage camp site here so you know what crops you've got, as Duncan was saying, you know what pollinators you've got and then you're looking at the mix to see which one works best.
Simon Potts:Yeah, so, the first question is on their own how well do they do and the second question is if we add them together do we actually get a greater benefit of having a different combination of pollinators, and actually what we do finally is then we cross check this by actually going out into the fields, into real farms, and actually looking at what's actually visiting the flowers. Not every flower is a pollinator, so there are some very crafty bumble bees and they go to the flowers but if you watch very carefully they go to the base and they pinch a hole and in fact they are nectar robbers and they do nothing for the field beans at all, they just take the nectar away. So we've got to know a lot about their individual behaviour as well as which species are out there.
Sue Nelson:Now, I noticed you had some strawberry plants around the corner and are they apple trees over there?
Simon Potts:Yeah, so we've got potted apple trees as well. I mean they're a very important crop in the UK and some of the apple growers have problems getting honey bees to go on the apples, I mean if there's anything else around the honey bees will almost always go to them, so if oil seed is flowering it's a real job to get your honey bees in there. We found that, actually, the small mason bees are absolutely brilliant on apples and actually farmers could make a small change to the way they manage their orchards just to get these mason bees in by providing very small nest tubes and they work really hard. In fact some statistics suggest they may be several hundred times more efficient on an individual basis than honey bees.
Sue Nelson:Are there any benefits to having crops pollinated via insects than other techniques?
Simon Potts:Well definitely. So one of the questions we're asked is why should we worry about pollinators. Can we just not breed plants that just rely on, say, wind pollination and actually that's not really technically possible. So some plants definitely need that actual transfer of pollen by insects and the quality and the quantity of actual fruit and seeds you get is much better with pollinators. So there are other ways of doing it and we also looked at the economics of it and we said, well if we lost all the pollinators in the UK and we had to, say, resort to pollinating by hand, so you can imagine someone with a paint brush picking up pollen from a flower and taking it across, how much would that cost to pay people at a minimum wage and it's £1.8 billion a year, which is crazy, because the actual value given by bees and other pollinating insects is about half a billion. So, economically it doesn't make sense to try and replace what wild bees and managed bees can do.
Sue Nelson:This field we're in, I mean it's perfect for bees really isn't it because it's like a meadow. I mean where we're standing you can hear the rustle of the tall grass here, it is, it's perfect meadow conditions with wild flowers and daisies and buttercups and clovers.
Duncan Costan:Yes, it's quite good for us because we can then go out and we can collect forage for our bees from very close to where we're working and we have one bumble bee colony that we actually keep outside so in case we have any issues we can move it back inside, so they can just forage on any of the wild plants, but the only problem we actually have with all these flowers around here is because we're all very interested in bees it keeps distracting us. We keep wandering around and something interesting will fly past and there will be an entire crew of people trying to figure out what this bee is, we're all just getting excited about what's just flying past.
Sue Nelson:It's nice to be able to see them under safe conditions because we're always a bit wary of bees - or well I am anyway, and thinking well I like looking at them but don't want to get too close in case you get stung, but at least I can go up close here and look through and see them through the gauze of the flight cage of more field beans and just watch them hovering and buzzing around the plants, it's quite therapeutic isn't it.
Duncan Costan:Yes, it's very good and we've got the advantage that working with bumble bees and the solitary bee that Simon was saying about, the red mason bee, they're very, very passive creatures. So you can quite happily go inside to these cages with the bumble bees and the solitary bees and get quite close to them and watch them pollinating the flowers in quite good detail, it's very interesting.
Sue Nelson:Oh, you've got a bee on your head.
Duncan Costan:Have I?
Sue Nelson:Oh, now it's on your...what type of bee is that, that's got two yellow stripes and it looks like a white bottom.
Duncan Costan:This to me looks like a Bombous Vestalis worker and it is possibly from our colony that we have outside. So they fly around quite often and as you can see here this one has quite happily landed on my head and on my jumper and it's absolutely no threat to me whatsoever.
Sue Nelson:Gosh, I've not seen them so passive actually just standing there on your sweatshirt.
Simon Potts:Yes it's a common misconception that bees are aggressive. Now, honey bees if you were to go and shake the hive or annoy them then of course they're going to be defensive but actually bumble bees and solitary bees are fairly passive. They're much more into the business of going out and foraging and producing young and, okay, if you do really press them and annoy them they may sting you but in general they are very passive and docile animals.
Sue Nelson:What about the research that has come out recently. There were two papers that cited neo-nicotinoid insecticides and the extremely negative impact that they have had on wild bees.
Simon Potts:Well I think these [unintelligible 0:10:07.5] are really important because we're just starting to see now and not just the direct lethal effects of pesticides but there is also the sub-lethal effects where maybe changes how reproductive they can be or it may changes honey bees the way they forage and their homing behaviour, and I think it's just a really clear warning that we don't know enough and actually as we look more and more we are finding these negative impacts and we should think more carefully about the types of pesticides we use and how we use them.
Sue Nelson:There have been calls in Europe by some scientists, particularly those who are involved in the study, to actually consider banning this type of insecticide. Do you agree?
Simon Potts:Well I think on a precautionary principle we may want to consider it but the evidence isn't strong enough, so we know a little bit about some pesticides on some species but there is a very wide range of pesticides and a very wide range of species so we actually need to know the combinations that are really having a negative impact and we also have to be realistic, so farmers have to grow food and without pesticides they're going to lose something like 30% of their yield. So, given food security issues on the one hand and environmental conflict on the other hand, we need to find a common solution and there are pesticides out there that aren't so bad for bees and the ways of applying them aren't so bad for bees. So we need to be smart, we need to grow food but we also need to look after our pollinators and there is a way forward, we just need to get that research done to be able to help farmers select the right pesticides.
Sue Nelson:Simon Potts and Duncan Costan, thank you both very much indeed.
This is the Planet Earth podcast and you can see pictures of Simon and Duncan by our bee shanty town or camp site on our Facebook page. Nanotechnology which involves particles up to one billionth of a metre promises to revolutionise the drugs industry and make smelly socks a thing of the past. Now, you can already find nanomaterials in clothing, cosmetics and cleaning products, but what are the environmental dangers of these tiny particles to health or the environment? Well a joint research project between the UK and the United States has been set up to analyse the potential risk of nanomaterials. One of the studies is being led by Teresa Fernandes at the Heriott-Watt University in Edinburgh. So, Richard Hollingham visited her lab and began by asking her to describe what a nano material is?
Teresa Fernandes:A nanomaterial is by convention a particular matter that is really, really small. If you think about a metre everybody knows and understands what a metre is like, you have to go nine zeros below to get to the range we are talking about.
Richard Hollingham:You've got a cupboard full of them. Can we have a look?
Teresa Fernandes:Yes, sure, let's have a look.
Richard Hollingham:There's a series of pots, almost like small paint pots, the sort you do a model kit, something like that with.
Teresa Fernandes:Yes, we have here a few metals, for example, oxides. We have titanium dioxide, we have zinc oxide, some of them are produced as powder, so a very, very fine powder and of course you have to be very careful when handling them because they can go in the air and you can breathe them in because of being so fine. Some of them are actually suspended in some kind of medium disbursent.
Richard Hollingham:Where are they found in the real world when they are not in this cupboard because they are now all over the place?
Teresa Fernandes:They are found everywhere and you have natural nanomaterials, they have been around for many, many years. You have what is called incidental, they come out from combustion and then of course we have what we call manufactured or engineered nanomaterials which are used in many applications now. Some are fantastic applications, for medical, for example, new ways of detecting cancer or targeting cancer or other conditions but others are things like impregnating garments like socks, everybody knows about.
Richard Hollingham:The ones in socks, these are silver particles that are supposed to deal with the smell, to make your socks less smelly.
Teresa Fernandes:Yeah, the way that works is supposed to be antibacterial/antimicrobial, so of course it prevents microbes to grow in your materials, whatever they are; your socks and you prevent the odour.
Richard Hollingham:Let's close the cupboard up. What are you working on in the lab here then?
Teresa Fernandes:We have here a range of projects looking at hazards, so we keep some organisms, very, very small organisms. We keep some [unintelligible 0:14:15.7] producers, some algae and microalgae and single cell organisms and we keep the water flea, for example, and some worms, some aquatic worms.
Richard Hollingham:Can we have a look at some?
Richard Hollingham:Pass the lab bench and to...well these just look like large freezers really, food freezers, fridge freezers.
Teresa Fernandes:You could nearly walk into these ones.
Richard Hollingham:So let's have a look; let's get down and a bit closer to here. So you've got these beakers, I don't know how big are these, a couple of litres beakers with slightly greenish water and these little water fleas skimming around. And then in there you've put some nano particles and nanomaterials to see what happens.
Teresa Fernandes:So if they indicate that there are reasons to be concerned, for example, there's mortality or reduced reproduction or other end points I am looking at, then there's a concern and if effects happen at low concentration, there's a concern that there might be a reason to prevent, I don't know, control in use of these chemicals.
Richard Hollingham:Teresa, now while you're looking at the environmental impact of these nanomaterials, I'm also with Helena Johnston and you're looking at the impact on human health.
Helena Johnston:Yep. In order to do that we can either look at the effect on cells cultured in vitro or we can look at the effect within animals in vivo.
Richard Hollingham:So when you say in vitro you mean in the test tube?
Helena Johnston:Yes, so in a cultured condition in a test tube. So, what we generally do is we take cells isolated from different parts of the body, so you might get exposure inhalations to the lung would be a target, digestion, so we have the gut as an exposure via the skin. Once the nano particle is exposed to these different exposure sites they can access the blood because of their small size and then travel throughout the body, so the liver is a primary target. We also look at the kidneys, cardiovascular system, the list is endless.
Richard Hollingham:Teresa has chambers full of water fleas and the like, you have some human cells.
Helena Johnston:Yep. So the cells need to be cultured at 37 degrees celsius because that's what-
Richard Hollingham:Our body temperature.
Helena Johnston:Yep, exactly, the body temperature. They need a supply of carbon dioxide and oxygen and they need a medium which gives them all the nutrients they need to grow in these artificial conditions.
Richard Hollingham:Can we have a look at some?
Helena Johnston:Of course. So we've got a variety of different cell types in here so, for example, this is an epithelial cell, so it's found within the lining of the lung.
Richard Hollingham:It just looks like a clear liquid or a slightly opaque liquid.
Helena Johnston:If you look at the back of the dish you can see the cell growing, so all these little islands, if you like, are the cells-
Richard Hollingham:So they're the same cells that we would have in our lungs?
Helena Johnston:Yes, so these have been isolated, I think, from a tumour so these cells will grow indefinitely in culture. If you take them from a human they will only divide a certain number of times and it limits the amount of times you can use these cells.
Richard Hollingham:You've got some darker ones in here as well.
Helena Johnston:This will be a different medium, I think. So these are macrophage cells, it is a mean cell within the body, so they are responsible for clearing foreign materials. Again, you can see them growing on the back of the dish and whereas these epithelial cells will all grow together, these ones are isolated; they are not attached to any other cells.
Richard Hollingham:And when you're looking at these, again you're looking for the impact of nano materials on them?
Helena Johnston:Yes, so the types of toxicity tests we do will administer the nano particles and see the cells die, so they have a cytotoxic effect, they elicit information, oxidated stress, so these are all common mechanisms that we know nano particles can act, and it allows us to compare the toxicity of different types of nano particles and see if they elicit a similar toxicity and some are more potent than others.
Richard Hollingham:And Teresa, doesn't this come to the nub of this that these things are already out there, shouldn't maybe this work have been done ten years ago when these kinds of products were being developed before nano particles were released.
Teresa Fernandes:That's certainly correct, but unfortunately it's not the first time and the only industry where this has happened. Industry can develop very fast and the research and evidence needs to take its time because you don't want to necessarily to prevent an area of industry and if indeed there's no mechanism to do so it's a great promise to society, so it is a question of getting the pace right, you know, speed up the research, speed up the ability to translate results from researching to the regulatory process.
Sue Nelson:Teresa Fernandes and Helena Johnston from Heriott-Watt University studying the effects of nano materials on the environment and human health. They were talking to Richard Hollingham.
And before we go you may be interested to hear about a couple of news stories on the Planet Earth Online website. The first is about a study that has highlighted places that are food risk hot spots due to climate change. The team including Dr Evan Frazer from the University of Leeds used climate models to identify areas at risk from drought induced famines. Now, countries are often most vulnerable in the early stages of development before the benefits from modernisation and so while the very poorest and the richest societies may be okay the study found that it was that vulnerable group in the middle that may fare worse, possibly because assistance from other nations or NGOs may dry up when a country or region is no longer classified among the poorest.
And finally for those of us who welcome the prospect of extra terrestrial life slightly disappointing news that the small amounts of methane discovered in Mars' atmosphere might not be signs of life after all. After discovering that methane is released from living and dead vegetation when it is radiated by ultraviolet radiation an international team of scientists decided to expose extra terrestrial matter to UV light as well. The team showed that samples from a meteorite also released methane and so the number of meteorites that bombard the red planet could have generated the methane detected in the Martian atmosphere. Fortunately, though, for those of us who do want ET to phone home there's still hope as meteorites may not be the only source.
This has been the Planet Earth podcast for the Natural Environment Research Council. Don't forget to check out our Facebook page and Twitter feed. I'm Sue Nelson, thanks for listening.