Ben - Nanotechnology promises to make smelly socks a thing of the past and we've already heard today how it could revolutionise medicine and the drugs industry. But what are the environmental dangers of these tiny particles. They're a fraction the size of a human hair, so could they have an impact on health or on the environment? A joint research project between the UK and the United States has been setup to analyse the potential risks of nano materials. One of the studies is being led by Teresa Fernandes at Heriott-Watt University in Edinburgh. Planet Earth podcast presenter Richard Hollingham went to visit her in her lab.

Teresa - We have here a range of projects looking at hazards, so we keep some organisms, very, very small organisms. We keep some primary producers, some algae and microalgae and single cell organisms, and we keep the water flea, for example, and some worms, some aquatic worms.

Richard - Can we have a look at some?

Teresa - Sure.

Richard - Well these look like just large freezers really, food freezers, fridge freezers.

Teresa - We could merely walk in to these ones.

Richard - So you've got these beakers, a couple of litres of beakers with slightly greenish water and these little water fleas skimming around. And then in there, you've also put some nano particles, nanomaterials to see what happens.

Teresa - If they indicate that there are reasons to be concerned, for example, there's mortality or reduced reproduction, or other end points I'm looking at, then there's a concern and if these effects happen at low concentration, there's a concern that there might be a reason to prevent, or have controls in use of these chemicals.

Richard - Teresa, 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 - So, in order to do that, we can either look at the effect on cells cultured in vitro or we can look at the effects within animals in vivo.

Richard - So when you say in vitro, you mean in the test tube?

Helena - 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 exposed via inhalation - so the lung would be a target; via digestion - so we have the gut, or through 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, the cardiovascular system. The list is endless.

Richard - Teresa has chambers full of water fleas and the like. You have some human cells.

Helena - Yeah. So the cells need to be cultured at 37 ° C because that's what you would have.

Richard - Our body temperature.

Helena - Yeah, exactly, 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 - So, open the cabinet up.

Helena - 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 - It just looks like a clear liquid or a slightly opaque liquid.

Helena - If you look at the back of the dish, you can see the cells growing, so all these little islands, if you like, are the cells...

Richard - So they're the same cells that we have in our lungs?

Helena - 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 - You've got some darker ones in here as well.

Helena - So these are macrophage cells. So an immune 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.

Richard - And when you're looking at these, again, you're looking for the impact of nano materials on them?

Helena - Yes, so the types of toxicity tests we do, we'll administer nano particles and see if the cells die, so they're having a cytotoxic effect. Do they elicit an inflammation, oxidative 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, or some are more potent than others.

Richard - 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?

Teresa - Industry can develop very fast and the research and evidence needs to take its time because you don't want necessarily to prevent an area of industry that has great promise for society. So, it's a question of getting the pace right, you know, speed up the research, speed up the ability to translate results from research to the regulatory process.