Horizon (1964) s55e10 Episode Script
E-Cigarettes...Miracle or Menace?
1 I think they have a great potential to save millions of lives over the next 20, 30 years.
There are so many unknowns here and frankly, I think, right now, we have It's a human experiment that's going on right now.
They could turn out to be one of the greatest, perhaps the greatest even, public health innovations of our generation.
We really don't know what the long-term effects will be.
I think they are a game changer and I'm very excited by that possibility.
Electronic cigarettes.
This bit of technology has absolutely exploded into our lives.
Ten years ago, they barely existed.
Now, they're everywhere.
Science is scrabbling to keep up and the experts are bitterly divided.
So we're going to carry out our own unique experiment to test the effects of e-cigarettes.
I think I'll be able to do it with e-cigarettes.
I've got access to one of the more controversial companies which produce them.
So how do I know you haven't got some other lovely piece of research which actually shows that it is harmful and you're just not showing it? And I'll seek out cutting-edge research to discover exactly what they do to people who use them Oh, wow! This is really surprising.
We killed 95% of the cells.
.
.
and to people who don't.
This, I think, is about as high as we've seen it.
Through the roof, really.
Are we on the brink of a health revolution or gambling our way into a catastrophe? Now, I'm about to do something that, many years ago, I swore I would never do.
It's dangerous, it's addictive, it's disgusting and there's a good chance that I'm going to be sick, which is why I've got a bucket down there.
For me, this will be a first, but it's something more than a billion people do every day.
I'm being wired up to monitor what happens.
HE COUGHS LOUDLY Aargh! God! And people do this for pleasure? That was That was really horrible.
That was really rank.
It's, um, really sort of burning.
It's way down my throat at the moment.
You might find it hard to believe but I have never, ever smoked before, not even a drag.
HE COUGHS LOUDLY This is not, I think, what happens in the movies.
As soon as you draw that smoke into your lungs, your heart rate and blood pressure goes soaring up and toxic chemicals enter your blood.
I'd like to say it's really vile but it isn't.
I mean, the coughing is vile, the smell is vile, but the effects are actually quite pleasant.
I don't feel remotely nauseous.
I just feel quite buzzy at the moment.
So I get it.
I think I finally get why people smoke.
What I've just experienced is an extremely efficient drug delivery system, sending nicotine to my brain in just ten seconds.
I put a spell on you In the 1950s, it was advertised by sports stars, glamorised by Hollywood and even endorsed by doctors.
These days, we're fully aware of the dangers yet there are still ten million smokers in the UK and about half of them will die from smoking-related diseases.
But in the last few years, a new device has appeared that could finally blow away this deadly habit.
You're mine, you're mine.
Now we've got the electronic or e-cigarette.
It's been marketed as a much less harmful way of getting your nicotine hit but is it the greatest public health measure ever invented, as some people claim, or simply another way of keeping us addicted to nicotine with dangerous unforeseen consequences? For these people, using e-cigarettes or vaping, as it's known, is part of their daily lives.
So, how long have you been vaping for? Just over two years.
I'll be on my vape-versary for three years.
Three years? When you took up vaping, did you intend to give up smoking? Yes.
OK.
That was my goal.
I never tried to give up smoking.
It's just the curiosity of the products and then, just slowly, over time, used them more and more.
E-cigarettes are fast becoming a socially acceptable way to consume nicotine but are we gambling with technology we don't yet understand, simply replacing one danger with another? These new devices are the subject of scientific studies all over the world but there are still significant gaps in our knowledge.
So we decided to carry out our own test.
To help us, we've recruited 26 smokers, all with one thing in common.
I think it's time to quit.
First of all, health reasons.
Secondly, it's not a good example for my kids.
And also, financial reasons.
My mum died of lung cancer about four years ago so I saw what that had done to her, and if it cuts my chances of getting that, then that's good enough for me.
I was diagnosed with throat cancer - that's why my voice is a bit croaky - last July and, even though I've been advised by all of my consultants and health care professionals, I'm still smoking.
These smokers are about to embark on what should be a fascinating experiment - to uncover what e-cigarettes really do to us.
It's being run by behavioural scientist Paul Aveyard from Oxford University and Peter Hajek from Queen Mary University of London.
We're going to test the effects of e-cigarettes against smoking tobacco and compare them with other, more traditional ways to quit.
To do this, we're dividing our volunteers into four groups.
One group is going to stick to regular cigarettes.
And that means you've got four more weeks of smoking.
My wife's not going to believe I've got this group but thanks anyway! Another will try to quit smoking the hard way.
You're going to be quitting cold turkey.
It's not what you wanted? No! Have you tried cold turkey before? Yes.
Yeah.
Didn't work.
No.
This group will try quitting with the help of nicotine patches.
You're going to be quitting with nicotine replacement therapy.
All right.
That's good.
Is that all right? Yeah.
Yeah.
And this is the group who we're really interested in.
You're going to be quitting with e-cigarettes.
Yay! Why yay? I think I'll be able to do it with e-cigarettes.
I've never tried it but I think it's possibly the easiest way.
Everybody here currently smokes at least 20 cigarettes a day, and it's a notoriously hard habit to break.
Research shows that when people try without help, the success rate is just 4%.
So this is a pretty hard-core group of people, smokers.
They've really tried and tried again, is that right? They certainly are.
I mean, we selected them for being hard-core and, of course, you don't volunteer for this kind of study unless, really, you've struggled to just quit smoking on your own.
Our volunteers are all undergoing a range of health tests.
We're measuring the levels of some toxic substances in their bodies, like carbon monoxide in their lungs.
Most of the people, possibly all the people, here on the programme are heavy smokers.
You will see the flashing red lights showing you that that level of carbon monoxide they have is rather alarming.
And we're using cutting-edge technology to probe deep inside their airways.
We're measuring airways resistance.
It's a measure of how well the lungs are functioning.
This will give us baseline measurements before our experiment starts, while our volunteers are still heavy smokers.
The major cause of health problems for people who smoke is, of course, heart attack and stroke.
So we've got a couple of tests here that are looking at the heart function itself.
Mm-hm.
And over here, we're looking at the way that the arteries respond when they're called on to do so by a physiological stress.
In four weeks' time, the volunteers will undergo exactly the same tests to find out if anything's changed.
Remember that today, for most of you, is the last day of your smoking and tomorrow is the first day of your non-smoking lives.
And I can see it's going to be really tough but I'm really crossing my fingers for you because you know it's important and I know it's important and I really look forward to seeing you again in four weeks' time and we shall see what we shall see.
We're feeling good, though, aren't we? Yeah! APPLAUSE I'm hoping that, in a month's time, our results will begin to answer some of the fundamental questions about vaping.
There are still so many unknowns because the habit has become popular so suddenly.
E-cigarettes are one of those bits of technology, like mobile phones, that have absolutely exploded into our culture.
From nowhere, they have become a multibillion pound industry.
In the UK alone, there are over 2.
5 million users.
Their extraordinary rise has polarised opinion around the world.
So when electronic cigarettes came on the market, many countries prohibited their use.
They include countries like Canada, Brazil, Uruguay, Australia.
When you look at some of those governments that are doing practically nothing about tobacco control and yet they're banning e-cigarettes, you think, why? The UK took a different approach.
So in 2010, we took the view, in the Behavioural Insights Team, that we should make these widely available because of their potential to be a very effective route out of smoking, and so we argued for a deliberately light touch regulation in order to make them widely available.
On this advice, the UK government took a relatively liberal stance and allowed the sale and advertising of e-cigarettes.
You know that feeling you get when something's great? But not everybody agreed with this decision.
There was widespread concern that e-cigarettes would have a broader appeal than just as a tool to help smokers quit.
Well, now you can taste it.
Now, some people are worried that e-cigarettes will encourage non-smokers to take up vaping.
Even if that's true, would it be such a bad thing? Well, surprisingly enough, no-one has really studied the effects of vaping on healthy volunteers.
So I thought I'd give it a go.
Current research tends to look at the effects of e-cigarettes only on smokers.
To discover what they do to a healthy non-smoker, I'm going to test them on myself.
I guess this is how addiction begins - you start with a single cigarette, and the next thing you know, you've committed yourself to a month full of vaping.
I must admit, I'm feeling a little apprehensive.
So, for some advice on how to get started, I've come to one of the many e-cigarette shops that have sprung up all over the country.
Ah! Hi there.
Afternoon.
How are you? I'm expecting something a little bit smoky, but actually, it's quite sort of pleasantly fruity, isn't it? I'm expecting also sort of fungus yellow wallpaper with stuff dripping down it.
So assume I'm a vaping virgin, which I am.
Yep.
Er What have you got? Lovely.
So what I've got - some of our bestselling starter kits for someone who's never used an electronic cigarette before.
Do you think that's a bit girlie for me? Not necessarily.
I would say this one here is one of our most basic.
OK.
And what about this? This is kind of cooler and more geeky? Yeah, definitely.
E-cigarettes come in many shapes and sizes but they all work on the same principle.
There is a battery, which powers a heating element known as a coil.
A fluid called an e-liquid is put in here.
The heat from the coil turns it into a vapour which the user inhales through the mouthpiece.
The e-liquid usually contains nicotine and flavourings, and there are hundreds of flavours to choose from.
Blimey! So you've got fruity flavours, sweet and dessert flavours, tobacco-based flavours to replicate a real cigarette, which is really good for someone who's about to quit, in my opinion, then we've got another category called Fresh, which is menthol-based flavours or neutral flavours, so not too much taste.
I suspect I'm not going to go for the tobacco.
Fruity sounds Fruity sounds lovely.
Fruity sounds kind of healthy and Fresh sounds healthy.
I'm going to go for Fresh, and I like mint.
Spot on.
So give me a mint.
So all I want you to do is to hold this button down for 2-3 seconds, take an inhale of the device as you would a normal cigarette.
HE COUGHS AND SPLUTTERS OK.
It's not as aggressive as a cigarette, is it? No, not at all.
And I got a nice sort of minty flavour to it rather than tobacco flavour.
And how often would you kind of do a little puff? I use the device when I'm kind of getting the shakes or when I feel I want a drag.
So, for me, it might be a puff or two puffs every 15-20 minutes, but there's no right or wrong way to use these devices.
It's however you feel like you'd want to take a drag and when you feel you need one.
Right.
But as a non-smoker, I don't yet have nicotine needs.
So I've asked psychologist and addiction expert Dr Lynne Dawkins to create a vaping schedule for me to follow.
If you want to reflect what a regular vaper would do, you're looking at fairly continuous puffing throughout the day.
So you don't want to have a big three-hour gap.
Yeah.
You want to maybe have a few short bouts of 5-10 puffs every half an hour to an hour.
And then it gradually increases, the nicotine strength increases, and, as you say, either I will tolerate it or there will come a point where it just makes me feel so awful that I have to stop.
What are the possible side effects from that experience? You might experience nausea, headache, you might feel a little bit sick or feel a little bit dizzy, but if you feel that you can't withstand those effects, then please, please do stop.
Throughout the day Don't know what my wife is going to make of this! I warned her My wife is a GP and, I have to say, she's not ecstatically happy about this.
I'm not surprised.
As we say, it's not recommended for non-smokers.
No.
Of course, it's not advisable for anyone who doesn't smoke to start using e-cigarettes.
I'm a bit worried I might end up getting hooked on nicotine.
# Alabama, Arkansas I do love my ma and pa Just four days into my experiment and I'm already finding it difficult to stick to my vaping schedule.
I'm behind in my exercise.
I'm supposed to have puffed, I think, 60 today and I've only done about ten, maybe.
I'm still not kind of feeling it.
When Mike first said to me that he was going to start vaping, I was horrified and said, absolutely, you know, don't go there.
Um Not terribly well-informed but that was my initial instinct, partly because, you know, I don't want him to become a poster boy for vaping.
He doesn't look like he's going to be doing that because he's kind of coughing and spluttering at the moment.
Now I've started on e-cigarettes, I want to dig deeper into exactly what these things are doing to us.
But first, I'm going right back to the beginning of the story.
Remarkably, it all begins with one man - Chinese pharmacist Hon Lik.
TRANSLATION: I started smoking when I was 18 and I smoked between one to two packs each day.
Am I right in thinking your father used to be a heavy smoker? TRANSLATION: My father smoked for a long time and, in his old age, he got lung cancer.
Hon Lik had tried to quit smoking six times.
It occurred to him he might find it easier if he used a device that resembled a cigarette.
So he decided to invent one.
TRANSLATION: This is the first generation product.
It is very similar to this prototype.
So this is the prototype and this is your first model, and you had to kind of cram all of that into that? In 2004, Hon Lik launched his new product - the e-cigarette.
He had no idea that, within a decade, it would be a global success.
So how do you feel when you come to somewhere like the UK and you see people on the street using your product? TRANSLATION: I think that British consumers are very health-conscious and I'm so pleased that my invention has been recognised.
From these modest beginnings in China, e-cigarettes were first imported into the West by small independent companies.
But as their popularity soared, large corporations jumped on the bandwagon, and that was controversial.
When e-cigarettes became popular, what we call the big companies, transnational tobacco companies, coming in and buying up these manufacturers.
has misled populations about the impacts of cigarette smoking on people's health, what's in cigarettes.
There's a long history of, you know, pretty bad behaviour by some tobacco companies.
It must be correct to look at it with a degree of wariness that those companies are getting involved.
The big tobacco companies are now major players in the business of making e-cigarettes.
David O'Reilly is the director of research and development at one of the largest.
And I've come here for a rare opportunity - to quiz a scientist who's been working in the tobacco industry for many years.
I've never seen a tobacco plant before.
I must admit, it's rather beautiful.
And it's hard to imagine the scale of sort of death and destruction that this plant has wrought, if you like.
So what is it in the plant that is so destructive to human beings? When you take tobacco, that's in any plant.
So if you took lettuce and you dried it and you rolled it up into a rod like this, you set fire to it and you inhaled it, you would inhale very similar toxicants that you would get from tobacco.
So there's nothing particularly damaging about this plant per se.
It's actually mainly the process of combustion.
Is that right? Correct.
So if you set fire to something, you're going to create round about 100 toxicants or so that are known to be harmful, potentially harmful, to humans.
So really, the idea is to get rid of combustion altogether, to give consumers the nicotine which they're seeking along with the flavours that they want in a way that they would find acceptable.
And that's what takes you to e-cigarettes, presumably because you don't get combustion - you simply get heating? In 2013, British American Tobacco started selling e-cigarettes.
Now they make a range of products, including e-liquids.
What's actually in this e-liquid that I'm eagerly puffing? E-liquids are fairly simple.
You have nicotine, you'd have water and flavourings, and also two simple compounds called propylene glycol and glycerol which bulk out the vapour and give that cloud that you see when people use e-cigarettes.
What's the difference between what you inhale if you smoke a real cigarette and what you inhale if you smoke an e-cigarette? This is a scan of toxicants produced by the combustible cigarette.
There are around about 6,000 chemicals on this chart.
Each of these peaks represents a different chemical? Each of these peaks represent a different chemical and around about 100 of those are known to be harmful, or potentially harmful to humans.
When you look at an e-cigarette, you can see in the same scan, there are fewer peaks, much fewer peaks.
And most of the toxicants that you see in cigarettes, combustible cigarettes, are absent.
Those that are there tend to be at levels way below the levels that we would be concerned on.
Nobody says that e-cigarettes are totally safe.
The evidence to date suggests they are about 95% safer than cigarette smoking and this is part of the supporting evidence, that the chemistry of the vapour of the e-cigarettes is completely different from combustible cigarettes.
Lab analysis shows the chemistry of the vapour is vastly different from cigarette smoke.
But what really matters is what it does to us, and that's something that David's team are investigating in their biology lab.
This is what would happen in a normal, healthy individual.
Yeah.
Seen through a microscope, these are cells that line our blood vessel.
The gap in the middle is a tiny tear.
The kind of minor damage that is happening all the time as we go about our daily lives.
In a healthy person, these minute wounds heal very easily, as we see in this time-lapse film.
The cells move back together to close the gap.
And that's healthy.
So that's healthy, that's the normal system.
To test the effects of smoking, David's team have carried out what is called a scratch test.
They make a tiny scratch in healthy blood vessel cells to mimic the natural tears that happen every day.
Then they pass tobacco smoke in a liquid solution over the cells and see what happens.
You can see the wound in the middle.
It looks completely different.
Yeah.
It's looking very cruddy, isn't it? You've got a lot of sort of black bits.
The black bits you can see are dead and dying cells.
They're just not closing.
They're not closing.
The cells are moving around, they don't which direction to go and the tear is not being repaired, even after 21 hours.
Right, it's very striking, isn't it? The tobacco smoke disrupts the way the cells behave.
We can see the wound just isn't healing.
I do find something ironic about the fact that here I am in a cigarette company looking at footage and being told just how bad cigarettes are for me.
Not something I ever imagined would happen.
We've been doing this research for years and of course it's well known that cigarette smoking causes diseases, including heart disease and this is a model of heart disease.
Now, the big question is, what will happen with vaping? The team here have repeated the scratch test with e-cigarette vapour.
You can see now it's repairing normally, even though it has been exposed to e-cigarette vapour and again, after 12, 13 hours, it is closing the gap and by 21 hours, it should have closed the gap completely.
That is good evidence that e-cigarettes, the vapour of e-cigarettes, doesn't impair the ability of blood vessels to repair themselves when they are naturally injured, as they are on a day-to-day basis.
It's certainly compelling, yes.
The blood vessel cells on top were exposed to nothing more than fresh air.
The middle ones, e-cigarette vapour and the bottom ones, cigarette smoke.
The difference is clear.
So what that shows us is that the ability of the cells to repair themselves with fresh air or with e-cigarette vapour are very similar, virtually indistinguishable, but with cigarette smoke, it impedes the ability of the blood vessel to repair itself.
This single test doesn't mean the vapour from e-cigarettes is harmless.
But it does suggest that vaping doesn't impair our body's ability to heal in the same way that tobacco smoke does.
So, how do I know you haven't got some other lovely piece of research which actually shows that it is harmful and you're just not showing me that? All of the research that we do in British American Tobacco we publish in international peer review journals.
That's a policy, regardless of the result.
OK.
And we do operate to good research practice in all of our R facilities around the group.
It does feel odd, having someone from a tobacco company telling me how much healthier vaping is than smoking.
But the real point is to quit.
So how effective are e-cigarettes at helping people do that? In our big experiment, it's been a week since our volunteers tried to stop smoking.
So, how are they getting on? It's just been really hard to not think about smoking, to be honest.
I was so chuffed with the amount of money I'd saved, I decided to go out and treat myself because I had been such a good girl and bought myself a new duvet.
I haven't killed the missus yet or kicked the dogs out, or vice versa! The cold turkey group are struggling.
Several of them have gone back to smoking.
But the e-cigarette and nicotine patch groups are doing much better.
Probably because they both have a replacement source of nicotine to help them get through the cravings.
By midday I was really, really, really, wanting to smoke a cigarette so I put on my patch, I didn't smoke a single cigarette.
I've still got my e-cigarette so that's helping with the cravings a bit.
The only thing is, I am finding that I am smoking this a lot more that I would a normal cigarette.
I found the e-cigarette to be most helpful.
It really does help with satisfying the urges and cravings to smoke.
I'm having a very different experience.
As a non-smoker who has taken up vaping for a month to see how it affects me, I'm struggling to stick to my schedule.
I'm not experiencing cravings but I am experiencing inconvenience.
Vaping several times an hour is tricky when you work on the seventh floor of a building that doesn't allow it.
My colleagues are amused and slightly alarmed by my new habit.
It kind of reminds me of the naughty boys at school.
OK.
I've always wanted to be Never having been one.
SHE LAUGHS You weren't in that crowd? I wasn't, I was a science nerd.
Is it making me look cool? No.
Sophisticated? No.
A man of the world? A bit dirty maybe.
THEY LAUGH So, you don't approve? No.
You do what you like, Mike.
I wouldn't do it.
OK.
Crazy.
COUGHING It's not surprising my colleagues feel uneasy about seeing me using e-cigarettes.
Every few days, there are new headlines warning of their dangers.
There have been recent reports claiming that some of the chemicals used to give e-liquids their flavours are potentially toxic.
I've got a rhubarb and custard.
This is pear drops.
Peach yoghurt in there.
Cheesecake.
Black honey tobacco and cream.
Ginger, vanilla, wild hops and mild tobacco.
They all sound rather benign, but very few have been properly tested.
So, should vapers be worried? It's a question that concerns this toxicologist.
After many years researching tobacco, he has begun to investigate how the flavours used in e-liquids affect our bodies.
Many flavourings are in the cosmetics and in the food and they were tested.
We know that they are safe when we eat them, when we apply them on the skin.
However, now we need to make sure that they are also safe when we inhale them.
To find out if flavourings which are safe to eat are also safe when inhaled, he has devised an experiment using living cells grown from a human airway.
First, he puts a sample of healthy cells into a Petri dish.
This is connected to a tube.
At the end, he attaches an e-cigarette which contains menthol flavoured e-liquid.
The e-cigarette is connected to a machine that mimics someone puffing and creates vapour.
That vapour travels down the tube and over the living cells.
After 55 puffs, he puts the cells into a machine to count how many are still alive.
He then repeats the experiment with fresh cells, but this time, there will be one crucial difference.
We will use the same device, the same type of electronic cigarette, we will use the e-liquid with exactly the same nicotine concentration and the same composition of the solvent for nicotine.
The only difference will be the flavouring in the product.
This time, the e-cigarette is filled with pina colada flavoured e-liquid.
He then compares the number of cells that survive being exposed to the two different flavours, menthol and pina colada.
After exposure to pina colada flavour, 53% of cells survived.
Comparing to menthol, there was 25% that survived.
So it's twice as many cells survived after being exposed to pina colada electronic cigarette compared to menthol electronic cigarette.
Surprisingly enough, in this experiment, the fresh menthol flavouring killed many more cells than the sweet pina colada.
I think that people will be surprised about the effect of the menthol.
We have menthol in many products like toothpaste and cosmetics and chewing gums, but this is very important that we are looking at the toxicity of menthol when it is inhaled with electronic cigarettes.
His research certainly suggests that flavourings which are safe to eat can be harmful to inhale.
He is working through different flavours one by one.
We need to get this data as soon as possible to inform users and regulators about different flavourings and the effect on our lungs.
It's worrying that after being exposed to menthol, only a quarter of the cells survived.
But how does that compare to tobacco smoke? He repeats the experiment with fresh cells but this time he connects the machines to a normal cigarette.
Oh, this is really, really toxic.
Only 6% of the cells survived exposure to tobacco smoke.
Remember the pina colada, we had 53% cells survived and here, only 5%.
There is a huge difference between electronic cigarettes and tobacco cigarettes.
So, not as bad as cigarette smoke but hardly a clean bill of health for e-liquids.
Now, I chose mint because I like the flavour and because it's widely used in foods but the toxicologist's research has shown that just because something is safe to eat doesn't necessarily mean it is safe to inhale.
He and his team are currently working their way through different flavours but in the meantime, if you are a vaper, the best advice seems to be to try a range of flavours so you don't get too much of any one.
HE COUGHS E-cigarettes can harm the airways of people who use them, but what about passive vaping? You're not going to vape in front of the stall, are you? This is an electronic one.
It's as bad.
Almost as bad.
But are these reactions prejudiced, unreasonable or could the vapour from my e-cigarette really be harming people around me? Dr Mark Travers of the Roswell Park Cancer Institute believes very strongly that air in public places should be clean and uncontaminated.
His research played a big part in helping get smoking banned in restaurants and pubs.
We've made tremendous progress with smoke-free air policies, especially globally.
We have whole countries, dozens of countries around the world, that are completely smoke-free.
And then electronic cigarettes appeared.
Is this something to be concerned about? How is this product going to fit into our existing policies? Do clean air laws apply to this product? Do we need to worry about it? For years, Mark has been studying the effects of passive smoking.
He has set up a special chamber.
It is fitted with sensitive air monitoring equipment .
.
to measure exactly what is released into the air when volunteers smoke inside the chamber.
You put a non-smoker in there and it's a very hazardous environment for them.
We know that being exposed to that over time leads to a wide variety of health effects, so heart disease, respiratory disease, lung cancer.
Things that are going to kill you.
But what about e-cigarettes? Is there any such thing as passive vaping? Mark is now using his chamber for a new set of experiments.
You guys are both e-cigarette users, or vapers What we're going to ask you to do is come into our chamber and essentially you're just going to hang out and vape while you're doing that.
As the vapers vape inside the chamber, Mark measures the aerosol, the number of particles suspended in the air.
Oh, wow.
In a matter of seconds, we saw a huge increase in the aerosol in the room.
They started vaping and immediately the levels went through the roof really.
This is unusual.
We usually don't see levels this high and sustained during electronic cigarette experiments.
Mark is a surprised because in previous experiments, the levels of particles released by vapers were far lower.
What this tells me is that there is huge potential variability in exposures when using an electronic smoking device, depending on the device itself and how the user chooses to use it.
But the key question is, what are these particles? Mark has been looking for carbon monoxide and other toxic chemicals that are present in cigarette smoke.
What we found with electronic cigarettes is no exposure to carbon monoxide, so compared to traditional cigarettes, electronic cigarettes have at least 99% less toxins in them.
So, dramatically different in terms of exposure profile.
E-cigarettes release far fewer toxins than cigarettes because there's no combustion.
But there's one thing they have in common with cigarettes, nicotine.
We found nicotine in the air but at a much lower level than with tobacco smoke.
The levels were about 20 times higher from tobacco smoke, compared to the e-cig vapour.
There's a lot more nicotine in the air from tobacco smoking compared to electronic cigarettes, vaping.
Mark's experiments have shown that e-cigarette vapour contains far lower levels of toxins and nicotine than tobacco smoke, so what is in the vapour? We know most of it is the carrier liquids, so propylene glycol or glycerin.
That is getting vaporised and getting put in the air.
That is the bulk of what we're seeing.
But frankly, we don't know what the potential health effects are of that.
Propylene glycol and glycerin aren't usually present in the air we breathe.
They could be harmless, they might not be.
And it's the fact that we don't know that worries Mark.
We find that there is a massive amount of aerosol emitted from electronic cigarettes into the air.
What we don't know is what the ultimate health effect of that exposure might be.
So we need more research to look at that and see what's going to happen over time.
We just do not know at this point.
'The evidence we do have at the moment suggests that passive vaping 'is nothing like as bad for you as passive smoking.
' Nonetheless, if you are using an e-cigarette, you will be breathing out a small amount of nicotine on your nearest and dearest.
And that is, presumably, a bad thing.
Or is it? 'When it comes to nicotine, experts are divided.
' Nicotine in your system is not necessarily particularly harmful to your health.
It doesn't seem to be carcinogenic, that means it doesn't cause cancer.
If there is an excess risk of heart disease, it is small.
Mothers that are exposed to nicotine, whether it's through tobacco or just through pharmaceutical nicotine, have potential harmful effects on a developing foetus.
There have been studies done and there seems to be negligible risks of nicotine, when used outside of smoking.
So my own feeling is that it's probably equivalent to caffeine.
Nicotine has been associated with cells behaving in abnormal manners and leading to premature cell death.
When most people think of nicotine, they obviously think of cigarettes.
And this is certainly nicotine in a purer form.
I'd never sampled nicotine before I started this little self experiment.
And yet I've been puffing away conscientiously for four weeks.
So what has it been doing to me? 'To find out, I am catching up with Dr Lynne Dawkins.
' So how have you been getting on, Michael? I've actually been OK.
So, have you managed to stick to the schedule? Broadly.
I haven't managed to fit in as many vapes as you wanted me to.
Cos I can only fit in about five vapes in one go, before I start feeling a bit light-headed and ever so slightly nauseous.
'But although I am not enjoying nicotine, 'it may be giving me an edge.
'Some studies have shown that nicotine quickens reaction times.
'But most of the research into nicotine has been done in smokers.
'Less is known about its effect on non-smokers.
'And so I am a rare and, I like to think, valuable test subject.
' In this task, an arrow will appear on the screen and the arrow will point either to the left or to the right.
Before each problem, you will see the instruction, "Which direction"? 'Lynne is putting me through a variety of cognitive tests.
BEEPING 'She tested me before I started vaping.
'Now, we will see if nicotine has made any difference to my brain.
' Your reaction time today, after using your e-cigarette, was fairly consistently slower than when we tested you at baseline.
OK.
We did find some improvement.
For example, on the fine motor task, we found that your accuracy had improved.
And when might I want to use a skill like that? We're talking about sewing or writing or I could be better at sewing.
'I've improved in a couple of tests, but in others I've got worse.
BEEPING 'My results aren't consistent with what Lynne has found in smokers.
' Well, in smokers, there's very clear evidence that, if you test somebody after they've taken nicotine, compared to their performance when they haven't had nicotine for several hours, there's a clear cognitive enhancing effect.
So it may be, in smokers, that nicotine is just reversing an effect associated with not having nicotine for a period of time.
So it's like, basically, coffee drinking.
If you are a heavy coffee drinker, you feel terrible.
And if you have coffee, you then feel better.
But you don't necessarily feel better than you would have if you'd never drunk coffee.
Yes, of course.
'A few weeks of inhaling nicotine hasn't made me any smarter' Whoa! '.
.
or quicker.
'But, surprisingly enough, there is research which suggests 'taking nicotine in a pure form 'can benefit people with certain brain diseases, 'whether they have smoked before or not.
' There is some emerging evidence that, in certain conditions, such as Alzheimer's disease, Parkinson's disease, the nicotine may have a cognitive enhancing effect.
'So there are potential health benefits.
'But what about the obvious downside?' Nicotine is an addictive substance.
Once you're hooked, it is very, very difficult to quit.
'When I set out to vape for a month, 'I was worried I'd get hooked on nicotine.
'But I haven't begun to crave it at all.
'Research in animals suggests that nicotine is more addictive 'when it is delivered in combination with other chemicals 'found in regular cigarettes.
'So it may be that vaping is simply less addictive than smoking.
' We are seeing an increase in experimentation with electronic cigarettes amongst young people, say 11 to 18.
What we are not seeing is regular use among young people who are never smokers.
And that might be because, actually, when young people use these products, they might be appealing, but they are not as addictive as a tobacco cigarette.
I think they are quite different.
In Britain, the proportion of young people who don't smoke, who are using an e-cigarette, it's so small that it's barely measurable.
It's something in the region of 0.
02%.
So, most regular e-cigarettes users are ex-smokers, just like our volunteers.
It's now four weeks since Quit Day.
And I'm going to find out how they are getting on.
I'm still kind of irritable.
The first week, I nearly broke up with my partner.
The e-cigarette has been a great help.
It's really sort of curbed the urges for smoking.
And I'vebeen using it like a trooper.
I have not managed to stop smoking.
I was on cold turkey.
It's proving to be very, very difficult.
I have decreased the amount I smoke phenomenally.
'I'm keen to discover just how the results 'from the e-cigarette group compare with others.
'Which ones were most successful at quitting smoking? 'First, the group that went cold turkey.
' Out of the seven of you in this group, two of you have managed to make it.
'Not a brilliant result.
'Has the nicotine replacement group done any better?' We've got seven out of eight of you who succeeded in the NRT group.
So well done for you.
APPLAUSE AND CHEERING 'And what about the e-cigarette group?' And you have done exactly the same as the NRT group, in that seven out of eight of you have made it through being perfectly abstinent.
Well done.
Brilliant.
APPLAUSE 'So, when it comes to helping smokers quit, 'e-cigarettes, like nicotine replacement therapy, 'are far more effective than going cold turkey.
'Everyone is repeating the test they did four weeks ago.
' BEEPING Nice, steady blow.
'First, carbon monoxide.
'The people who have quit smoking all have far lower levels 'of this toxic gas in their lungs than four weeks ago, 'regardless of which method they used.
' So that's a non-smoker's reading.
It's really good.
Whey, well done.
Someone who has never smoked would have the same reading.
Thank you.
Well done.
Yeah.
'We've also been testing for acrolein, 'a toxic chemical known to increase the risk of cancer.
'Here again, everyone who's quit smoking 'has dramatically reduced their levels.
'Next, nicotine.
'The people in the e-cigarette and the nicotine replacement groups 'are still taking in nicotine, but the levels in the body 'are just half of what they were when they were smoking.
'And the levels of nicotine in the two volunteers who managed to quit 'cold turkey are less than a quarter of what they were.
'In some of our volunteers, 'there has already been measurable improvement in heart function.
' So what we can see now, from this scan, is that your heart's actually made a great improvement and is far more elastic than it was before.
So we can see that you're well within the healthy spectrum now, whereas you were on the borderline before.
I'm surprised, actually, that there is such a change in just a month.
I feel really pleased, cos it's nice to see it in black and white, that, you know, that there are good side effects from not smoking and your heart is so important.
'Most of the tests showed no real difference between the people 'who used e-cigarettes and the other groups.
'But one test has revealed something that has not been seen before.
'They've been testing what's called airway resistance.
'That's how easily air goes in and out of our volunteers' lungs.
' How's it been going then? Not too bad.
We have some interesting results.
After they stopped smoking, they showed an improvement in airway resistance, indicating that air goes in and out of the lungs more easily.
Even in four weeks, you saw changes? That's right, yes.
'What is particularly intriguing our scientists 'is our nicotine replacement group showed a greater improvement 'than the people who used e-cigarettes.
'But our study is quite small, 'so this result could just be down to chance.
'But it is possible that e-cigarettes are slowing down 'the improvement in airway resistance.
'The scientists are planning more research.
'Our experiment has produced some really interesting findings.
'For me, the most impressive has been the clear demonstration 'that giving up smoking, however you do it, 'produces such big health benefits in just four weeks.
' What the experiment tells us about e-cigarettes is that they are probably on par with nicotine replacement and they may have a slight edge, in that they give people a little bit of enjoyment as well.
So, in other words, it's just like NRT in fancy clothes.
But the thing is, those are clothes that a lot of people who smoke want to wear.
Most people on the e-cigarettes were not keen to keep using them for ever and ever.
I was going to say, all of them, when I spoke to them, their goal was essentially to give it up entirely.
Yep.
They didn't see it as a sort of bridge, or an alternative, or a way to just keep on inhaling nicotine.
The plan was eradication.
Now, it's absolutely fantastic that almost all the heavy smokers who took up e-cigarettes have managed to stop smoking.
I was, however, in a completely different situation, because I was a non-smoker to begin with.
So what, if anything, has vaping done to me? I'm going to a specialist airway lab at the Royal Brompton Hospital in London.
I came here before I started vaping and now I'm going to repeat the same tests I did then to find out if vaping has affected my lungs.
OK.
So make sure your mouth is well sealed around this.
OK.
Blow! Keep on going.
Keep on going.
As long as you can.
As long as you can.
Go on.
'The nurse tests for the amount of nitric oxide I'm exhaling - 'an indicator of inflammation of the airways.
' That's good.
Take your nose clip off.
'The scientists also want to analyse samples of my sputum - 'mucus from deep inside my airways.
'I will need to cough it up 'and, to help, she gives me salty air to inhale.
' OK.
A bit like fresh sea air.
Yep.
Down by the seaside.
Yeah.
Are you OK? You don't feel sick or anything? No.
'It is incredibly unpleasant.
' HE RETCHES 'Will the tests find any damage in my airways?' OK.
That's it.
I'm afraid that's your lot.
Yep.
'The results of these tests will be analysed 'by respiratory specialist Dr Omar Usmani.
'First, he measures my airway resistance, 'one of the tests our volunteers did.
'In them, there was a suggestion 'that e-cigarettes increased resistance.
' We didn't really see much difference over the 28 days, with this specialised long blowing test.
This is unsurprising to me, because you are a healthy person.
It was a very short period of time.
And what I'd be interested in seeing is the long-term effects of e-cigarettes on these measures.
So you'd like me to go on vaping for another six months? I'd like you to go on vaping for six to nine months to a year and then my hunch is we may see something.
'That's not going to happen.
'But, even after just four weeks, 'Omar discovered a difference in other tests.
' So what did change, interestingly, is a marker of airway inflammation, called nitric oxide.
And what happened to you was that your baseline level, before you had your e-cigarettes, was well within the normal range.
And then, after five minutes of vaping, we found that it had slightly increased.
Does it mean anything? Yeah, every time you puff, there is an insult to your airway cells.
By an insult, you mean a mild injury? An injury that increased your airway inflammation to nearly four times the level that it should do, into abnormal areas.
So, if you are taking - and I asked you earlier - 100 puffs a day, that's happening to you 100 times a day.
'And there's more.
'When Omar analysed my sputum sample, 'he discovered an increase in the number of macrophages in my lungs.
' Macrophages are defence cells that line the airways of our lungs to protect them from foreign bodies.
Too many can be detrimental.
They produce enzymes, which can, ultimately, damage the airways.
'From these test results, 'it's clear that vaping has done some subtle damage.
' Do you think that e-cigarettes are safer than cigarettes? The concern I have with e-cigarettes is they are being used as a substitute for smoking in environments where you can't smoke.
And that's the real concern I have.
So there really needs to be a concerted approach to actually quit to zero cigarettes.
And, in that scenario, if e-cigarettes are able to achieve that aim, then they can only be a good thing.
But there are concerns about their safety and there are concerns that, actually, they are used as a substitute.
And, in those two scenarios, they can be a real detriment, I think.
'My month-long experiment has shown 'that vaping can affect healthy lungs.
'But Omar assures me they should return to normal once I stop.
' It seems to me that whether e-cigarettes are good news or not really depends on how they are used.
The evidence suggests that vaping is far safer than smoking and is also an effective way to help you quit.
Vaping does seem to cause some harm to our bodies, but in the short term the risks appear to be low.
The one thing that science can't yet answer is what are the long-term effects? On this, there is no consensus.
'Medicine has been littered with examples' where there's been a revolutionary new drug and then it's had to be withdrawn several years later, because of side-effects or complications.
Cigarettes are so uniquely dangerous.
Every cigarette reduces somebody's life by 11 minutes.
If everybody in the population took up electronic cigarettes, we'd still be better off.
I do worry that, in 10, 20, 30 years from now, we are going to discover health effects from e-cigarette use that we don't know about now.
Books and PhDs and movies will be made about how was it possible that people from within public health vigorously opposed something which provides such a huge public health benefit? When I started, I was quite sceptical about the benefits of e-cigarettes.
But I've changed my mind.
Clearly, if you are not a smoker, then taking up vaping is a stupid thing to do.
'But, if I was a smoker, then, despite the uncertainties 'and potential downsides, I would certainly give it a go.
' 'Worldwide, there are currently around one billion smokers 'and about half of them will be killed by their habit.
'If e-cigarettes can win a significant share 'of the trillion dollar tobacco market, 'this could transform the world's health.
' Why has the weekly recommended limit changed so much for men? The Truth About series continues:
There are so many unknowns here and frankly, I think, right now, we have It's a human experiment that's going on right now.
They could turn out to be one of the greatest, perhaps the greatest even, public health innovations of our generation.
We really don't know what the long-term effects will be.
I think they are a game changer and I'm very excited by that possibility.
Electronic cigarettes.
This bit of technology has absolutely exploded into our lives.
Ten years ago, they barely existed.
Now, they're everywhere.
Science is scrabbling to keep up and the experts are bitterly divided.
So we're going to carry out our own unique experiment to test the effects of e-cigarettes.
I think I'll be able to do it with e-cigarettes.
I've got access to one of the more controversial companies which produce them.
So how do I know you haven't got some other lovely piece of research which actually shows that it is harmful and you're just not showing it? And I'll seek out cutting-edge research to discover exactly what they do to people who use them Oh, wow! This is really surprising.
We killed 95% of the cells.
.
.
and to people who don't.
This, I think, is about as high as we've seen it.
Through the roof, really.
Are we on the brink of a health revolution or gambling our way into a catastrophe? Now, I'm about to do something that, many years ago, I swore I would never do.
It's dangerous, it's addictive, it's disgusting and there's a good chance that I'm going to be sick, which is why I've got a bucket down there.
For me, this will be a first, but it's something more than a billion people do every day.
I'm being wired up to monitor what happens.
HE COUGHS LOUDLY Aargh! God! And people do this for pleasure? That was That was really horrible.
That was really rank.
It's, um, really sort of burning.
It's way down my throat at the moment.
You might find it hard to believe but I have never, ever smoked before, not even a drag.
HE COUGHS LOUDLY This is not, I think, what happens in the movies.
As soon as you draw that smoke into your lungs, your heart rate and blood pressure goes soaring up and toxic chemicals enter your blood.
I'd like to say it's really vile but it isn't.
I mean, the coughing is vile, the smell is vile, but the effects are actually quite pleasant.
I don't feel remotely nauseous.
I just feel quite buzzy at the moment.
So I get it.
I think I finally get why people smoke.
What I've just experienced is an extremely efficient drug delivery system, sending nicotine to my brain in just ten seconds.
I put a spell on you In the 1950s, it was advertised by sports stars, glamorised by Hollywood and even endorsed by doctors.
These days, we're fully aware of the dangers yet there are still ten million smokers in the UK and about half of them will die from smoking-related diseases.
But in the last few years, a new device has appeared that could finally blow away this deadly habit.
You're mine, you're mine.
Now we've got the electronic or e-cigarette.
It's been marketed as a much less harmful way of getting your nicotine hit but is it the greatest public health measure ever invented, as some people claim, or simply another way of keeping us addicted to nicotine with dangerous unforeseen consequences? For these people, using e-cigarettes or vaping, as it's known, is part of their daily lives.
So, how long have you been vaping for? Just over two years.
I'll be on my vape-versary for three years.
Three years? When you took up vaping, did you intend to give up smoking? Yes.
OK.
That was my goal.
I never tried to give up smoking.
It's just the curiosity of the products and then, just slowly, over time, used them more and more.
E-cigarettes are fast becoming a socially acceptable way to consume nicotine but are we gambling with technology we don't yet understand, simply replacing one danger with another? These new devices are the subject of scientific studies all over the world but there are still significant gaps in our knowledge.
So we decided to carry out our own test.
To help us, we've recruited 26 smokers, all with one thing in common.
I think it's time to quit.
First of all, health reasons.
Secondly, it's not a good example for my kids.
And also, financial reasons.
My mum died of lung cancer about four years ago so I saw what that had done to her, and if it cuts my chances of getting that, then that's good enough for me.
I was diagnosed with throat cancer - that's why my voice is a bit croaky - last July and, even though I've been advised by all of my consultants and health care professionals, I'm still smoking.
These smokers are about to embark on what should be a fascinating experiment - to uncover what e-cigarettes really do to us.
It's being run by behavioural scientist Paul Aveyard from Oxford University and Peter Hajek from Queen Mary University of London.
We're going to test the effects of e-cigarettes against smoking tobacco and compare them with other, more traditional ways to quit.
To do this, we're dividing our volunteers into four groups.
One group is going to stick to regular cigarettes.
And that means you've got four more weeks of smoking.
My wife's not going to believe I've got this group but thanks anyway! Another will try to quit smoking the hard way.
You're going to be quitting cold turkey.
It's not what you wanted? No! Have you tried cold turkey before? Yes.
Yeah.
Didn't work.
No.
This group will try quitting with the help of nicotine patches.
You're going to be quitting with nicotine replacement therapy.
All right.
That's good.
Is that all right? Yeah.
Yeah.
And this is the group who we're really interested in.
You're going to be quitting with e-cigarettes.
Yay! Why yay? I think I'll be able to do it with e-cigarettes.
I've never tried it but I think it's possibly the easiest way.
Everybody here currently smokes at least 20 cigarettes a day, and it's a notoriously hard habit to break.
Research shows that when people try without help, the success rate is just 4%.
So this is a pretty hard-core group of people, smokers.
They've really tried and tried again, is that right? They certainly are.
I mean, we selected them for being hard-core and, of course, you don't volunteer for this kind of study unless, really, you've struggled to just quit smoking on your own.
Our volunteers are all undergoing a range of health tests.
We're measuring the levels of some toxic substances in their bodies, like carbon monoxide in their lungs.
Most of the people, possibly all the people, here on the programme are heavy smokers.
You will see the flashing red lights showing you that that level of carbon monoxide they have is rather alarming.
And we're using cutting-edge technology to probe deep inside their airways.
We're measuring airways resistance.
It's a measure of how well the lungs are functioning.
This will give us baseline measurements before our experiment starts, while our volunteers are still heavy smokers.
The major cause of health problems for people who smoke is, of course, heart attack and stroke.
So we've got a couple of tests here that are looking at the heart function itself.
Mm-hm.
And over here, we're looking at the way that the arteries respond when they're called on to do so by a physiological stress.
In four weeks' time, the volunteers will undergo exactly the same tests to find out if anything's changed.
Remember that today, for most of you, is the last day of your smoking and tomorrow is the first day of your non-smoking lives.
And I can see it's going to be really tough but I'm really crossing my fingers for you because you know it's important and I know it's important and I really look forward to seeing you again in four weeks' time and we shall see what we shall see.
We're feeling good, though, aren't we? Yeah! APPLAUSE I'm hoping that, in a month's time, our results will begin to answer some of the fundamental questions about vaping.
There are still so many unknowns because the habit has become popular so suddenly.
E-cigarettes are one of those bits of technology, like mobile phones, that have absolutely exploded into our culture.
From nowhere, they have become a multibillion pound industry.
In the UK alone, there are over 2.
5 million users.
Their extraordinary rise has polarised opinion around the world.
So when electronic cigarettes came on the market, many countries prohibited their use.
They include countries like Canada, Brazil, Uruguay, Australia.
When you look at some of those governments that are doing practically nothing about tobacco control and yet they're banning e-cigarettes, you think, why? The UK took a different approach.
So in 2010, we took the view, in the Behavioural Insights Team, that we should make these widely available because of their potential to be a very effective route out of smoking, and so we argued for a deliberately light touch regulation in order to make them widely available.
On this advice, the UK government took a relatively liberal stance and allowed the sale and advertising of e-cigarettes.
You know that feeling you get when something's great? But not everybody agreed with this decision.
There was widespread concern that e-cigarettes would have a broader appeal than just as a tool to help smokers quit.
Well, now you can taste it.
Now, some people are worried that e-cigarettes will encourage non-smokers to take up vaping.
Even if that's true, would it be such a bad thing? Well, surprisingly enough, no-one has really studied the effects of vaping on healthy volunteers.
So I thought I'd give it a go.
Current research tends to look at the effects of e-cigarettes only on smokers.
To discover what they do to a healthy non-smoker, I'm going to test them on myself.
I guess this is how addiction begins - you start with a single cigarette, and the next thing you know, you've committed yourself to a month full of vaping.
I must admit, I'm feeling a little apprehensive.
So, for some advice on how to get started, I've come to one of the many e-cigarette shops that have sprung up all over the country.
Ah! Hi there.
Afternoon.
How are you? I'm expecting something a little bit smoky, but actually, it's quite sort of pleasantly fruity, isn't it? I'm expecting also sort of fungus yellow wallpaper with stuff dripping down it.
So assume I'm a vaping virgin, which I am.
Yep.
Er What have you got? Lovely.
So what I've got - some of our bestselling starter kits for someone who's never used an electronic cigarette before.
Do you think that's a bit girlie for me? Not necessarily.
I would say this one here is one of our most basic.
OK.
And what about this? This is kind of cooler and more geeky? Yeah, definitely.
E-cigarettes come in many shapes and sizes but they all work on the same principle.
There is a battery, which powers a heating element known as a coil.
A fluid called an e-liquid is put in here.
The heat from the coil turns it into a vapour which the user inhales through the mouthpiece.
The e-liquid usually contains nicotine and flavourings, and there are hundreds of flavours to choose from.
Blimey! So you've got fruity flavours, sweet and dessert flavours, tobacco-based flavours to replicate a real cigarette, which is really good for someone who's about to quit, in my opinion, then we've got another category called Fresh, which is menthol-based flavours or neutral flavours, so not too much taste.
I suspect I'm not going to go for the tobacco.
Fruity sounds Fruity sounds lovely.
Fruity sounds kind of healthy and Fresh sounds healthy.
I'm going to go for Fresh, and I like mint.
Spot on.
So give me a mint.
So all I want you to do is to hold this button down for 2-3 seconds, take an inhale of the device as you would a normal cigarette.
HE COUGHS AND SPLUTTERS OK.
It's not as aggressive as a cigarette, is it? No, not at all.
And I got a nice sort of minty flavour to it rather than tobacco flavour.
And how often would you kind of do a little puff? I use the device when I'm kind of getting the shakes or when I feel I want a drag.
So, for me, it might be a puff or two puffs every 15-20 minutes, but there's no right or wrong way to use these devices.
It's however you feel like you'd want to take a drag and when you feel you need one.
Right.
But as a non-smoker, I don't yet have nicotine needs.
So I've asked psychologist and addiction expert Dr Lynne Dawkins to create a vaping schedule for me to follow.
If you want to reflect what a regular vaper would do, you're looking at fairly continuous puffing throughout the day.
So you don't want to have a big three-hour gap.
Yeah.
You want to maybe have a few short bouts of 5-10 puffs every half an hour to an hour.
And then it gradually increases, the nicotine strength increases, and, as you say, either I will tolerate it or there will come a point where it just makes me feel so awful that I have to stop.
What are the possible side effects from that experience? You might experience nausea, headache, you might feel a little bit sick or feel a little bit dizzy, but if you feel that you can't withstand those effects, then please, please do stop.
Throughout the day Don't know what my wife is going to make of this! I warned her My wife is a GP and, I have to say, she's not ecstatically happy about this.
I'm not surprised.
As we say, it's not recommended for non-smokers.
No.
Of course, it's not advisable for anyone who doesn't smoke to start using e-cigarettes.
I'm a bit worried I might end up getting hooked on nicotine.
# Alabama, Arkansas I do love my ma and pa Just four days into my experiment and I'm already finding it difficult to stick to my vaping schedule.
I'm behind in my exercise.
I'm supposed to have puffed, I think, 60 today and I've only done about ten, maybe.
I'm still not kind of feeling it.
When Mike first said to me that he was going to start vaping, I was horrified and said, absolutely, you know, don't go there.
Um Not terribly well-informed but that was my initial instinct, partly because, you know, I don't want him to become a poster boy for vaping.
He doesn't look like he's going to be doing that because he's kind of coughing and spluttering at the moment.
Now I've started on e-cigarettes, I want to dig deeper into exactly what these things are doing to us.
But first, I'm going right back to the beginning of the story.
Remarkably, it all begins with one man - Chinese pharmacist Hon Lik.
TRANSLATION: I started smoking when I was 18 and I smoked between one to two packs each day.
Am I right in thinking your father used to be a heavy smoker? TRANSLATION: My father smoked for a long time and, in his old age, he got lung cancer.
Hon Lik had tried to quit smoking six times.
It occurred to him he might find it easier if he used a device that resembled a cigarette.
So he decided to invent one.
TRANSLATION: This is the first generation product.
It is very similar to this prototype.
So this is the prototype and this is your first model, and you had to kind of cram all of that into that? In 2004, Hon Lik launched his new product - the e-cigarette.
He had no idea that, within a decade, it would be a global success.
So how do you feel when you come to somewhere like the UK and you see people on the street using your product? TRANSLATION: I think that British consumers are very health-conscious and I'm so pleased that my invention has been recognised.
From these modest beginnings in China, e-cigarettes were first imported into the West by small independent companies.
But as their popularity soared, large corporations jumped on the bandwagon, and that was controversial.
When e-cigarettes became popular, what we call the big companies, transnational tobacco companies, coming in and buying up these manufacturers.
has misled populations about the impacts of cigarette smoking on people's health, what's in cigarettes.
There's a long history of, you know, pretty bad behaviour by some tobacco companies.
It must be correct to look at it with a degree of wariness that those companies are getting involved.
The big tobacco companies are now major players in the business of making e-cigarettes.
David O'Reilly is the director of research and development at one of the largest.
And I've come here for a rare opportunity - to quiz a scientist who's been working in the tobacco industry for many years.
I've never seen a tobacco plant before.
I must admit, it's rather beautiful.
And it's hard to imagine the scale of sort of death and destruction that this plant has wrought, if you like.
So what is it in the plant that is so destructive to human beings? When you take tobacco, that's in any plant.
So if you took lettuce and you dried it and you rolled it up into a rod like this, you set fire to it and you inhaled it, you would inhale very similar toxicants that you would get from tobacco.
So there's nothing particularly damaging about this plant per se.
It's actually mainly the process of combustion.
Is that right? Correct.
So if you set fire to something, you're going to create round about 100 toxicants or so that are known to be harmful, potentially harmful, to humans.
So really, the idea is to get rid of combustion altogether, to give consumers the nicotine which they're seeking along with the flavours that they want in a way that they would find acceptable.
And that's what takes you to e-cigarettes, presumably because you don't get combustion - you simply get heating? In 2013, British American Tobacco started selling e-cigarettes.
Now they make a range of products, including e-liquids.
What's actually in this e-liquid that I'm eagerly puffing? E-liquids are fairly simple.
You have nicotine, you'd have water and flavourings, and also two simple compounds called propylene glycol and glycerol which bulk out the vapour and give that cloud that you see when people use e-cigarettes.
What's the difference between what you inhale if you smoke a real cigarette and what you inhale if you smoke an e-cigarette? This is a scan of toxicants produced by the combustible cigarette.
There are around about 6,000 chemicals on this chart.
Each of these peaks represents a different chemical? Each of these peaks represent a different chemical and around about 100 of those are known to be harmful, or potentially harmful to humans.
When you look at an e-cigarette, you can see in the same scan, there are fewer peaks, much fewer peaks.
And most of the toxicants that you see in cigarettes, combustible cigarettes, are absent.
Those that are there tend to be at levels way below the levels that we would be concerned on.
Nobody says that e-cigarettes are totally safe.
The evidence to date suggests they are about 95% safer than cigarette smoking and this is part of the supporting evidence, that the chemistry of the vapour of the e-cigarettes is completely different from combustible cigarettes.
Lab analysis shows the chemistry of the vapour is vastly different from cigarette smoke.
But what really matters is what it does to us, and that's something that David's team are investigating in their biology lab.
This is what would happen in a normal, healthy individual.
Yeah.
Seen through a microscope, these are cells that line our blood vessel.
The gap in the middle is a tiny tear.
The kind of minor damage that is happening all the time as we go about our daily lives.
In a healthy person, these minute wounds heal very easily, as we see in this time-lapse film.
The cells move back together to close the gap.
And that's healthy.
So that's healthy, that's the normal system.
To test the effects of smoking, David's team have carried out what is called a scratch test.
They make a tiny scratch in healthy blood vessel cells to mimic the natural tears that happen every day.
Then they pass tobacco smoke in a liquid solution over the cells and see what happens.
You can see the wound in the middle.
It looks completely different.
Yeah.
It's looking very cruddy, isn't it? You've got a lot of sort of black bits.
The black bits you can see are dead and dying cells.
They're just not closing.
They're not closing.
The cells are moving around, they don't which direction to go and the tear is not being repaired, even after 21 hours.
Right, it's very striking, isn't it? The tobacco smoke disrupts the way the cells behave.
We can see the wound just isn't healing.
I do find something ironic about the fact that here I am in a cigarette company looking at footage and being told just how bad cigarettes are for me.
Not something I ever imagined would happen.
We've been doing this research for years and of course it's well known that cigarette smoking causes diseases, including heart disease and this is a model of heart disease.
Now, the big question is, what will happen with vaping? The team here have repeated the scratch test with e-cigarette vapour.
You can see now it's repairing normally, even though it has been exposed to e-cigarette vapour and again, after 12, 13 hours, it is closing the gap and by 21 hours, it should have closed the gap completely.
That is good evidence that e-cigarettes, the vapour of e-cigarettes, doesn't impair the ability of blood vessels to repair themselves when they are naturally injured, as they are on a day-to-day basis.
It's certainly compelling, yes.
The blood vessel cells on top were exposed to nothing more than fresh air.
The middle ones, e-cigarette vapour and the bottom ones, cigarette smoke.
The difference is clear.
So what that shows us is that the ability of the cells to repair themselves with fresh air or with e-cigarette vapour are very similar, virtually indistinguishable, but with cigarette smoke, it impedes the ability of the blood vessel to repair itself.
This single test doesn't mean the vapour from e-cigarettes is harmless.
But it does suggest that vaping doesn't impair our body's ability to heal in the same way that tobacco smoke does.
So, how do I know you haven't got some other lovely piece of research which actually shows that it is harmful and you're just not showing me that? All of the research that we do in British American Tobacco we publish in international peer review journals.
That's a policy, regardless of the result.
OK.
And we do operate to good research practice in all of our R facilities around the group.
It does feel odd, having someone from a tobacco company telling me how much healthier vaping is than smoking.
But the real point is to quit.
So how effective are e-cigarettes at helping people do that? In our big experiment, it's been a week since our volunteers tried to stop smoking.
So, how are they getting on? It's just been really hard to not think about smoking, to be honest.
I was so chuffed with the amount of money I'd saved, I decided to go out and treat myself because I had been such a good girl and bought myself a new duvet.
I haven't killed the missus yet or kicked the dogs out, or vice versa! The cold turkey group are struggling.
Several of them have gone back to smoking.
But the e-cigarette and nicotine patch groups are doing much better.
Probably because they both have a replacement source of nicotine to help them get through the cravings.
By midday I was really, really, really, wanting to smoke a cigarette so I put on my patch, I didn't smoke a single cigarette.
I've still got my e-cigarette so that's helping with the cravings a bit.
The only thing is, I am finding that I am smoking this a lot more that I would a normal cigarette.
I found the e-cigarette to be most helpful.
It really does help with satisfying the urges and cravings to smoke.
I'm having a very different experience.
As a non-smoker who has taken up vaping for a month to see how it affects me, I'm struggling to stick to my schedule.
I'm not experiencing cravings but I am experiencing inconvenience.
Vaping several times an hour is tricky when you work on the seventh floor of a building that doesn't allow it.
My colleagues are amused and slightly alarmed by my new habit.
It kind of reminds me of the naughty boys at school.
OK.
I've always wanted to be Never having been one.
SHE LAUGHS You weren't in that crowd? I wasn't, I was a science nerd.
Is it making me look cool? No.
Sophisticated? No.
A man of the world? A bit dirty maybe.
THEY LAUGH So, you don't approve? No.
You do what you like, Mike.
I wouldn't do it.
OK.
Crazy.
COUGHING It's not surprising my colleagues feel uneasy about seeing me using e-cigarettes.
Every few days, there are new headlines warning of their dangers.
There have been recent reports claiming that some of the chemicals used to give e-liquids their flavours are potentially toxic.
I've got a rhubarb and custard.
This is pear drops.
Peach yoghurt in there.
Cheesecake.
Black honey tobacco and cream.
Ginger, vanilla, wild hops and mild tobacco.
They all sound rather benign, but very few have been properly tested.
So, should vapers be worried? It's a question that concerns this toxicologist.
After many years researching tobacco, he has begun to investigate how the flavours used in e-liquids affect our bodies.
Many flavourings are in the cosmetics and in the food and they were tested.
We know that they are safe when we eat them, when we apply them on the skin.
However, now we need to make sure that they are also safe when we inhale them.
To find out if flavourings which are safe to eat are also safe when inhaled, he has devised an experiment using living cells grown from a human airway.
First, he puts a sample of healthy cells into a Petri dish.
This is connected to a tube.
At the end, he attaches an e-cigarette which contains menthol flavoured e-liquid.
The e-cigarette is connected to a machine that mimics someone puffing and creates vapour.
That vapour travels down the tube and over the living cells.
After 55 puffs, he puts the cells into a machine to count how many are still alive.
He then repeats the experiment with fresh cells, but this time, there will be one crucial difference.
We will use the same device, the same type of electronic cigarette, we will use the e-liquid with exactly the same nicotine concentration and the same composition of the solvent for nicotine.
The only difference will be the flavouring in the product.
This time, the e-cigarette is filled with pina colada flavoured e-liquid.
He then compares the number of cells that survive being exposed to the two different flavours, menthol and pina colada.
After exposure to pina colada flavour, 53% of cells survived.
Comparing to menthol, there was 25% that survived.
So it's twice as many cells survived after being exposed to pina colada electronic cigarette compared to menthol electronic cigarette.
Surprisingly enough, in this experiment, the fresh menthol flavouring killed many more cells than the sweet pina colada.
I think that people will be surprised about the effect of the menthol.
We have menthol in many products like toothpaste and cosmetics and chewing gums, but this is very important that we are looking at the toxicity of menthol when it is inhaled with electronic cigarettes.
His research certainly suggests that flavourings which are safe to eat can be harmful to inhale.
He is working through different flavours one by one.
We need to get this data as soon as possible to inform users and regulators about different flavourings and the effect on our lungs.
It's worrying that after being exposed to menthol, only a quarter of the cells survived.
But how does that compare to tobacco smoke? He repeats the experiment with fresh cells but this time he connects the machines to a normal cigarette.
Oh, this is really, really toxic.
Only 6% of the cells survived exposure to tobacco smoke.
Remember the pina colada, we had 53% cells survived and here, only 5%.
There is a huge difference between electronic cigarettes and tobacco cigarettes.
So, not as bad as cigarette smoke but hardly a clean bill of health for e-liquids.
Now, I chose mint because I like the flavour and because it's widely used in foods but the toxicologist's research has shown that just because something is safe to eat doesn't necessarily mean it is safe to inhale.
He and his team are currently working their way through different flavours but in the meantime, if you are a vaper, the best advice seems to be to try a range of flavours so you don't get too much of any one.
HE COUGHS E-cigarettes can harm the airways of people who use them, but what about passive vaping? You're not going to vape in front of the stall, are you? This is an electronic one.
It's as bad.
Almost as bad.
But are these reactions prejudiced, unreasonable or could the vapour from my e-cigarette really be harming people around me? Dr Mark Travers of the Roswell Park Cancer Institute believes very strongly that air in public places should be clean and uncontaminated.
His research played a big part in helping get smoking banned in restaurants and pubs.
We've made tremendous progress with smoke-free air policies, especially globally.
We have whole countries, dozens of countries around the world, that are completely smoke-free.
And then electronic cigarettes appeared.
Is this something to be concerned about? How is this product going to fit into our existing policies? Do clean air laws apply to this product? Do we need to worry about it? For years, Mark has been studying the effects of passive smoking.
He has set up a special chamber.
It is fitted with sensitive air monitoring equipment .
.
to measure exactly what is released into the air when volunteers smoke inside the chamber.
You put a non-smoker in there and it's a very hazardous environment for them.
We know that being exposed to that over time leads to a wide variety of health effects, so heart disease, respiratory disease, lung cancer.
Things that are going to kill you.
But what about e-cigarettes? Is there any such thing as passive vaping? Mark is now using his chamber for a new set of experiments.
You guys are both e-cigarette users, or vapers What we're going to ask you to do is come into our chamber and essentially you're just going to hang out and vape while you're doing that.
As the vapers vape inside the chamber, Mark measures the aerosol, the number of particles suspended in the air.
Oh, wow.
In a matter of seconds, we saw a huge increase in the aerosol in the room.
They started vaping and immediately the levels went through the roof really.
This is unusual.
We usually don't see levels this high and sustained during electronic cigarette experiments.
Mark is a surprised because in previous experiments, the levels of particles released by vapers were far lower.
What this tells me is that there is huge potential variability in exposures when using an electronic smoking device, depending on the device itself and how the user chooses to use it.
But the key question is, what are these particles? Mark has been looking for carbon monoxide and other toxic chemicals that are present in cigarette smoke.
What we found with electronic cigarettes is no exposure to carbon monoxide, so compared to traditional cigarettes, electronic cigarettes have at least 99% less toxins in them.
So, dramatically different in terms of exposure profile.
E-cigarettes release far fewer toxins than cigarettes because there's no combustion.
But there's one thing they have in common with cigarettes, nicotine.
We found nicotine in the air but at a much lower level than with tobacco smoke.
The levels were about 20 times higher from tobacco smoke, compared to the e-cig vapour.
There's a lot more nicotine in the air from tobacco smoking compared to electronic cigarettes, vaping.
Mark's experiments have shown that e-cigarette vapour contains far lower levels of toxins and nicotine than tobacco smoke, so what is in the vapour? We know most of it is the carrier liquids, so propylene glycol or glycerin.
That is getting vaporised and getting put in the air.
That is the bulk of what we're seeing.
But frankly, we don't know what the potential health effects are of that.
Propylene glycol and glycerin aren't usually present in the air we breathe.
They could be harmless, they might not be.
And it's the fact that we don't know that worries Mark.
We find that there is a massive amount of aerosol emitted from electronic cigarettes into the air.
What we don't know is what the ultimate health effect of that exposure might be.
So we need more research to look at that and see what's going to happen over time.
We just do not know at this point.
'The evidence we do have at the moment suggests that passive vaping 'is nothing like as bad for you as passive smoking.
' Nonetheless, if you are using an e-cigarette, you will be breathing out a small amount of nicotine on your nearest and dearest.
And that is, presumably, a bad thing.
Or is it? 'When it comes to nicotine, experts are divided.
' Nicotine in your system is not necessarily particularly harmful to your health.
It doesn't seem to be carcinogenic, that means it doesn't cause cancer.
If there is an excess risk of heart disease, it is small.
Mothers that are exposed to nicotine, whether it's through tobacco or just through pharmaceutical nicotine, have potential harmful effects on a developing foetus.
There have been studies done and there seems to be negligible risks of nicotine, when used outside of smoking.
So my own feeling is that it's probably equivalent to caffeine.
Nicotine has been associated with cells behaving in abnormal manners and leading to premature cell death.
When most people think of nicotine, they obviously think of cigarettes.
And this is certainly nicotine in a purer form.
I'd never sampled nicotine before I started this little self experiment.
And yet I've been puffing away conscientiously for four weeks.
So what has it been doing to me? 'To find out, I am catching up with Dr Lynne Dawkins.
' So how have you been getting on, Michael? I've actually been OK.
So, have you managed to stick to the schedule? Broadly.
I haven't managed to fit in as many vapes as you wanted me to.
Cos I can only fit in about five vapes in one go, before I start feeling a bit light-headed and ever so slightly nauseous.
'But although I am not enjoying nicotine, 'it may be giving me an edge.
'Some studies have shown that nicotine quickens reaction times.
'But most of the research into nicotine has been done in smokers.
'Less is known about its effect on non-smokers.
'And so I am a rare and, I like to think, valuable test subject.
' In this task, an arrow will appear on the screen and the arrow will point either to the left or to the right.
Before each problem, you will see the instruction, "Which direction"? 'Lynne is putting me through a variety of cognitive tests.
BEEPING 'She tested me before I started vaping.
'Now, we will see if nicotine has made any difference to my brain.
' Your reaction time today, after using your e-cigarette, was fairly consistently slower than when we tested you at baseline.
OK.
We did find some improvement.
For example, on the fine motor task, we found that your accuracy had improved.
And when might I want to use a skill like that? We're talking about sewing or writing or I could be better at sewing.
'I've improved in a couple of tests, but in others I've got worse.
BEEPING 'My results aren't consistent with what Lynne has found in smokers.
' Well, in smokers, there's very clear evidence that, if you test somebody after they've taken nicotine, compared to their performance when they haven't had nicotine for several hours, there's a clear cognitive enhancing effect.
So it may be, in smokers, that nicotine is just reversing an effect associated with not having nicotine for a period of time.
So it's like, basically, coffee drinking.
If you are a heavy coffee drinker, you feel terrible.
And if you have coffee, you then feel better.
But you don't necessarily feel better than you would have if you'd never drunk coffee.
Yes, of course.
'A few weeks of inhaling nicotine hasn't made me any smarter' Whoa! '.
.
or quicker.
'But, surprisingly enough, there is research which suggests 'taking nicotine in a pure form 'can benefit people with certain brain diseases, 'whether they have smoked before or not.
' There is some emerging evidence that, in certain conditions, such as Alzheimer's disease, Parkinson's disease, the nicotine may have a cognitive enhancing effect.
'So there are potential health benefits.
'But what about the obvious downside?' Nicotine is an addictive substance.
Once you're hooked, it is very, very difficult to quit.
'When I set out to vape for a month, 'I was worried I'd get hooked on nicotine.
'But I haven't begun to crave it at all.
'Research in animals suggests that nicotine is more addictive 'when it is delivered in combination with other chemicals 'found in regular cigarettes.
'So it may be that vaping is simply less addictive than smoking.
' We are seeing an increase in experimentation with electronic cigarettes amongst young people, say 11 to 18.
What we are not seeing is regular use among young people who are never smokers.
And that might be because, actually, when young people use these products, they might be appealing, but they are not as addictive as a tobacco cigarette.
I think they are quite different.
In Britain, the proportion of young people who don't smoke, who are using an e-cigarette, it's so small that it's barely measurable.
It's something in the region of 0.
02%.
So, most regular e-cigarettes users are ex-smokers, just like our volunteers.
It's now four weeks since Quit Day.
And I'm going to find out how they are getting on.
I'm still kind of irritable.
The first week, I nearly broke up with my partner.
The e-cigarette has been a great help.
It's really sort of curbed the urges for smoking.
And I'vebeen using it like a trooper.
I have not managed to stop smoking.
I was on cold turkey.
It's proving to be very, very difficult.
I have decreased the amount I smoke phenomenally.
'I'm keen to discover just how the results 'from the e-cigarette group compare with others.
'Which ones were most successful at quitting smoking? 'First, the group that went cold turkey.
' Out of the seven of you in this group, two of you have managed to make it.
'Not a brilliant result.
'Has the nicotine replacement group done any better?' We've got seven out of eight of you who succeeded in the NRT group.
So well done for you.
APPLAUSE AND CHEERING 'And what about the e-cigarette group?' And you have done exactly the same as the NRT group, in that seven out of eight of you have made it through being perfectly abstinent.
Well done.
Brilliant.
APPLAUSE 'So, when it comes to helping smokers quit, 'e-cigarettes, like nicotine replacement therapy, 'are far more effective than going cold turkey.
'Everyone is repeating the test they did four weeks ago.
' BEEPING Nice, steady blow.
'First, carbon monoxide.
'The people who have quit smoking all have far lower levels 'of this toxic gas in their lungs than four weeks ago, 'regardless of which method they used.
' So that's a non-smoker's reading.
It's really good.
Whey, well done.
Someone who has never smoked would have the same reading.
Thank you.
Well done.
Yeah.
'We've also been testing for acrolein, 'a toxic chemical known to increase the risk of cancer.
'Here again, everyone who's quit smoking 'has dramatically reduced their levels.
'Next, nicotine.
'The people in the e-cigarette and the nicotine replacement groups 'are still taking in nicotine, but the levels in the body 'are just half of what they were when they were smoking.
'And the levels of nicotine in the two volunteers who managed to quit 'cold turkey are less than a quarter of what they were.
'In some of our volunteers, 'there has already been measurable improvement in heart function.
' So what we can see now, from this scan, is that your heart's actually made a great improvement and is far more elastic than it was before.
So we can see that you're well within the healthy spectrum now, whereas you were on the borderline before.
I'm surprised, actually, that there is such a change in just a month.
I feel really pleased, cos it's nice to see it in black and white, that, you know, that there are good side effects from not smoking and your heart is so important.
'Most of the tests showed no real difference between the people 'who used e-cigarettes and the other groups.
'But one test has revealed something that has not been seen before.
'They've been testing what's called airway resistance.
'That's how easily air goes in and out of our volunteers' lungs.
' How's it been going then? Not too bad.
We have some interesting results.
After they stopped smoking, they showed an improvement in airway resistance, indicating that air goes in and out of the lungs more easily.
Even in four weeks, you saw changes? That's right, yes.
'What is particularly intriguing our scientists 'is our nicotine replacement group showed a greater improvement 'than the people who used e-cigarettes.
'But our study is quite small, 'so this result could just be down to chance.
'But it is possible that e-cigarettes are slowing down 'the improvement in airway resistance.
'The scientists are planning more research.
'Our experiment has produced some really interesting findings.
'For me, the most impressive has been the clear demonstration 'that giving up smoking, however you do it, 'produces such big health benefits in just four weeks.
' What the experiment tells us about e-cigarettes is that they are probably on par with nicotine replacement and they may have a slight edge, in that they give people a little bit of enjoyment as well.
So, in other words, it's just like NRT in fancy clothes.
But the thing is, those are clothes that a lot of people who smoke want to wear.
Most people on the e-cigarettes were not keen to keep using them for ever and ever.
I was going to say, all of them, when I spoke to them, their goal was essentially to give it up entirely.
Yep.
They didn't see it as a sort of bridge, or an alternative, or a way to just keep on inhaling nicotine.
The plan was eradication.
Now, it's absolutely fantastic that almost all the heavy smokers who took up e-cigarettes have managed to stop smoking.
I was, however, in a completely different situation, because I was a non-smoker to begin with.
So what, if anything, has vaping done to me? I'm going to a specialist airway lab at the Royal Brompton Hospital in London.
I came here before I started vaping and now I'm going to repeat the same tests I did then to find out if vaping has affected my lungs.
OK.
So make sure your mouth is well sealed around this.
OK.
Blow! Keep on going.
Keep on going.
As long as you can.
As long as you can.
Go on.
'The nurse tests for the amount of nitric oxide I'm exhaling - 'an indicator of inflammation of the airways.
' That's good.
Take your nose clip off.
'The scientists also want to analyse samples of my sputum - 'mucus from deep inside my airways.
'I will need to cough it up 'and, to help, she gives me salty air to inhale.
' OK.
A bit like fresh sea air.
Yep.
Down by the seaside.
Yeah.
Are you OK? You don't feel sick or anything? No.
'It is incredibly unpleasant.
' HE RETCHES 'Will the tests find any damage in my airways?' OK.
That's it.
I'm afraid that's your lot.
Yep.
'The results of these tests will be analysed 'by respiratory specialist Dr Omar Usmani.
'First, he measures my airway resistance, 'one of the tests our volunteers did.
'In them, there was a suggestion 'that e-cigarettes increased resistance.
' We didn't really see much difference over the 28 days, with this specialised long blowing test.
This is unsurprising to me, because you are a healthy person.
It was a very short period of time.
And what I'd be interested in seeing is the long-term effects of e-cigarettes on these measures.
So you'd like me to go on vaping for another six months? I'd like you to go on vaping for six to nine months to a year and then my hunch is we may see something.
'That's not going to happen.
'But, even after just four weeks, 'Omar discovered a difference in other tests.
' So what did change, interestingly, is a marker of airway inflammation, called nitric oxide.
And what happened to you was that your baseline level, before you had your e-cigarettes, was well within the normal range.
And then, after five minutes of vaping, we found that it had slightly increased.
Does it mean anything? Yeah, every time you puff, there is an insult to your airway cells.
By an insult, you mean a mild injury? An injury that increased your airway inflammation to nearly four times the level that it should do, into abnormal areas.
So, if you are taking - and I asked you earlier - 100 puffs a day, that's happening to you 100 times a day.
'And there's more.
'When Omar analysed my sputum sample, 'he discovered an increase in the number of macrophages in my lungs.
' Macrophages are defence cells that line the airways of our lungs to protect them from foreign bodies.
Too many can be detrimental.
They produce enzymes, which can, ultimately, damage the airways.
'From these test results, 'it's clear that vaping has done some subtle damage.
' Do you think that e-cigarettes are safer than cigarettes? The concern I have with e-cigarettes is they are being used as a substitute for smoking in environments where you can't smoke.
And that's the real concern I have.
So there really needs to be a concerted approach to actually quit to zero cigarettes.
And, in that scenario, if e-cigarettes are able to achieve that aim, then they can only be a good thing.
But there are concerns about their safety and there are concerns that, actually, they are used as a substitute.
And, in those two scenarios, they can be a real detriment, I think.
'My month-long experiment has shown 'that vaping can affect healthy lungs.
'But Omar assures me they should return to normal once I stop.
' It seems to me that whether e-cigarettes are good news or not really depends on how they are used.
The evidence suggests that vaping is far safer than smoking and is also an effective way to help you quit.
Vaping does seem to cause some harm to our bodies, but in the short term the risks appear to be low.
The one thing that science can't yet answer is what are the long-term effects? On this, there is no consensus.
'Medicine has been littered with examples' where there's been a revolutionary new drug and then it's had to be withdrawn several years later, because of side-effects or complications.
Cigarettes are so uniquely dangerous.
Every cigarette reduces somebody's life by 11 minutes.
If everybody in the population took up electronic cigarettes, we'd still be better off.
I do worry that, in 10, 20, 30 years from now, we are going to discover health effects from e-cigarette use that we don't know about now.
Books and PhDs and movies will be made about how was it possible that people from within public health vigorously opposed something which provides such a huge public health benefit? When I started, I was quite sceptical about the benefits of e-cigarettes.
But I've changed my mind.
Clearly, if you are not a smoker, then taking up vaping is a stupid thing to do.
'But, if I was a smoker, then, despite the uncertainties 'and potential downsides, I would certainly give it a go.
' 'Worldwide, there are currently around one billion smokers 'and about half of them will be killed by their habit.
'If e-cigarettes can win a significant share 'of the trillion dollar tobacco market, 'this could transform the world's health.
' Why has the weekly recommended limit changed so much for men? The Truth About series continues: