There was recently a study conducted among high school students in Hawaii, and it seemed to conclude that vaping leads to smoking. But are the results reliable?

Let's take a look!

Longitudinal study of e-cigarette use and onset of cigarette smoking among high school students in Hawaii

Wills et al, 2015

This study was a longitudinal study, which is where they take data from a set group of subjects at set time intervals.

In this case, they surveyed 2,338 students aged between 14-15 at one point in time then followed them up one year later. They examined whether they vaped and/or smoked cigarettes, along with whether their parents influenced their behaviour, how rebellious they were and how disposed towards cheap thrills they were (psychosocial covariates for short).

The method

The researchers busted out a questionnaire designed to answer the following questions:

1. What their family support structure was like (single parent, step-parent, biological parents, extended family).

2. How educated their parents were

3. Have they ever heard of e-cigarettes

4. Do they think e-cigs are healthier than tobacco

5. How often they vape

6. How often they smoke

They also hit them with the old "how true is this statement on a scale" type of questions, with answers ranging from "not at all true for me" to "very true for me" on either a five- or seven-point scale. The statements included:

1. "When I feel bad about something, my parent will listen"

2. "My parent knows where I am after school"

3. "I like to do dangerous things for fun"

4. "I like to break the rules"

The surveys were completed once, then again one year later.

The results

Both cigarette and e-cigarette use increased over the space of the year.

The conclusion

The authors of the paper determined that (to paraphrase) for whatever reason, e-cigarette use seemed to act as a gateway to cigarette use.

Are these results reliable?

It may come as no surprise to you that I have a few bones to pick with this study.

The survey says...?

The study did not publish the full results of the survey, which is fair enough. You can't cram all of that paperwork into a six-page PDF.

But they also didn't publish all of the questions they asked. The questions I wrote above were a sample of the kinds of questions they asked. So we can't know if all the questions were appropriate for collecting the data they required. We also can't know if any of the questions were liable to skew the results at all.

OK, fair enough, I am nitpicking here, but still...

The gateway hypothesis...?

Is the gateway hypothesis based on fact? Is it such an established theory that it can be taken as a given that it exists?

No, don't panic, I'm not muddying my boots in these particular waters. What I am concerned about, though, is that this paper seems to use the gateway hypothesis to make the results seem self-evident.

For example:

"The reasons for the effect of e-cigarette use on transition to smoking remain to be clarified, but plausible hypotheses have been suggested" (Wills et al, 2015).

So... your data shows that both e-cigarette use and tobacco use increased, but doesn't explain how or why? OK, so your data basically shows... nothing.

We all know that teenagers are rebellious and thrill-seeking. We all know that a number of them experiment with tobacco and other drugs at young ages. There's a lot of noise in there; did throwing e-cigs into the mix really have an effect?

Correlation equals causation...?

I must admit I had a little chuckle when I was reading the results. To paraphrase (heavily), it went a little something like this:

"OK, so, kids who used e-cigs also started smoking. We don't know why, but here are some really good ideas..."

Essentially, all this paper did was show a correlation between kids who started using e-cigs and kids who started smoking. And for those playing at home...

Correlation does NOT imply causation.

To make this easier to understand, here are some shocking correlations:

Thanks to tylervigen.com for these. You can also make your own spurious correlations here.

You get the idea.

The takeaway

This is all very well and good, Lloyd, but what's the takeaway here? How is the knowledge of this one particular study supposed to help me?

I'm glad you asked!

First and most importantly, you may have recently heard that there is movement in the SA legislature to regulate e-cigs and the like under the same laws as tobacco. One of the common cries of adherents to this movement is that e-cigarette use is linked to increased tobacco use amongst minors. You may even hear this study cited at you because of its recency. Well, now you can say "actually, NO, that study did not show a causative link, and failed to take into account the tendency of teenagers to try whatever is going around at the time, and wasn't transparent in publishing its conclusions, so NER!"

Secondly, being the skeptic that I am, I am always keen to encourage anyone who will listen to me to take a skeptical look at things. And with such a politically charged issue such as the usage of e-cigarettes, you need to be on your guard and take every bit of evidence, both for and against your position, with a grain of salt. This study, as is the case with a lot that I've seen, seemed biased from the outset with statements such as:

"...it is important to have evidence from different settings on the relation between ecigarette [sic] use and smoking" (Wills et al, 2015).

This is a case of begging the question - "we know that e-cig use leads to smoking, we just need some more evidence that shows it". Sorry, but this study fails to represent evidence. You may as well just submit it to tylervigen.com for a laugh.

There is a great article on Forbes that basically says the same thing as I just have, but in far fewer and more professional-sounding words. Check it out here.

Photo credit: Jonny Williams  www.ecigclick.co.uk

According to a recent report by Public Health England (a neutral government body in the U.K. with no ties to Big Tobacco) vaping is 95% less harmful than smoking, and they encouraged the use of e-cigarettes as a way to help smokers quit.

For those not game enough to read all 111 pages of the full report (like me), the abridged version is here.

For those of you who would much rather read a blog post than an abridged U.K. government health body report, let's break down the main points:

1. Vaping rates increase, smoking rates decrease

The report found that over the four-year period between April 2011 and March 2015, e-cigarette use in England increased from almost 0% to over 5%.

Over the same period, cigarette use in England declined from 21% to just over 18%. This decline was in both adult and youth usage.

Correlation or causation?

The report doesn't go as far as to claim that the two are directly related, which would be fallacious. It's still interesting though, and worth noting along with the other data points in the report.

2. Most vapers are almost exclusively ex-smokers

The report found that the overwhelming majority of e-cig users are those who either used or are using e-cigs to quit tobacco: ~60% still smoke, ~40% have stopped smoking, with the estimated e-cig use of never-smokers around 0.2%. This flies in the face of some experts who claim e-cigs are a gateway to tobacco use for young people who have never smoked.

The 0.2 percent?

So it would appear some young people are using e-cigarettes, then switching to conventional tobacco, because all of the adult e-cig users are current or ex-smokers.

This has been one of the catch cries of the anti-e-cig movement - that e-cig use will "re-normalise" tobacco use, and encourage young people who would not have smoked otherwise to smoke. I have two fairly big problems with this line of thought:

1. Correlation does not equal causation.

There is no evidence at all to support the claim that these young people would never have tried cigarettes if it weren't for e-cigs. Furthermore, how would you even go about getting such evidence?

2. Horses for courses

If you think about it for - oh, I don't know - five seconds, the type of young people who are likely to be attracted to e-cigarettes are exactly the type of young people who are also likely to be attracted to tobacco cigarettes, and goodness knows what else besides.

3. E-cigarettes have become England's most popular - and most successful - quit smoking aid

E-cigs, e-liquids and advanced personal vaporizers (APVs) are unregulated devices intended for personal use. They are not quit-smoking aids, and are not advertised or sold with these claims. In spite of this, many people who buy e-cigarettes and related products take it upon themselves to use them for this purpose, and as this report suggests, have found great success doing so.

One self-reported study found that 35% of all smokers trying to quit use e-cigs, with the next most popular method of over-the-counter aids such as patches, oral sprays and gums coming in at just over 20%.

In another self-reported study, smokers using only unlicensed nicotine-containing products (i.e. e-cigs) enjoyed a 66% quit rate after four weeks. This was a better outcome than all other forms of therapy, including prescription medication.

Crossing the legislative line?

In Australia, e-cigarettes are not approved as smoking cessation devices by the Therapeutic Goods Association, and anyone caught marketing e-cigs as such will find themselves in hot water.

But there are plenty of ways to quit smoking; only a handful are regulated, and not all of them are legal. So however you do it, quitting smoking is the best thing you will ever do, short of inventing time travel and convincing yourself never to start in the first place.

4. The current "best estimate" is that e-cigarettes are 95% less harmful than tobacco cigarettes

This makes for a catchy headline, but be aware this is a "best estimate" based on the current literature on the safety of e-cigs. If you've ever had a look through this, you'll see there is a lot of variation in the outcomes.

Worth noting is that PHE has been gathering this data since early 2014, so as far as "best estimates" go, this one has some decent weight behind it.

Mostly harmless?

• most of the chemicals that cause smoking-related illness are absent from e-cigarettes
• the chemicals that are present pose little to no danger
• e-cigs release negligible amounts of nicotine into ambient air and pose no health risks to bystanders

Let's put this into context. You're playing Russian Roulette and can choose between two guns. One has 95% less chance of firing a bullet than the other one. Which one will you pick? Yeah, thought so. The obvious flaw in my little analogy being why are you playing Russian Roulette in the first place, but - you catch my drift.

What this means for vaping in Australia

Initially, not a great deal. But PHE prepared this report to inform the government about legislation they are preparing to pass on e-cigarettes. The report made several recommendations, namely:

• e-cigarettes represent a real and effective way to quit smoking and carry a fraction of the risks of smoking;
• appropriate legislation will ensure e-cigarettes realise their full potential to help stop smoking without providing a path into smoking for children and never-smokers;
• e-cigarettes should be considered as a wide-reach, low-cost quit smoking aid;
• legislation should consider the potential of e-cigarettes to curb smoking rates in disadvantaged societal groups;
• legislation should consider the potential of e-cigarettes to tackle the high smoking rates among people with mental health problems, and accordingly the opportunity to create smoke-free mental health units;
• smoking cessation services should not discourage people who want to quit from using e-cigarettes;
• health and social care workers need to be educated about the risks and benefits of e-cigarette use;
• the general public need to be educated about the risks and benefits of e-cigarette use.

Whilst Australia generally follows American legislative lead over Europe, if major changes take place in England that see real and dramatic results (which we all know they will if they are sensible about it), we may see many more people saved from smoking in the same way we all have.

E-liquid, e-juice, juice, nicotine liquid, "nic liq" - whatever it's called, let's talk about one of the main components of any e-cig setup that tends to confuse new vapers.

What is e-liquid?

"E-liquid" is the liquid solution that is vaporised and inhaled with the e-cigarette. It is a suspension of solvents, flavouring and often nicotine.

The e-liquid is either:

1. Absorbed into the filler material in cartomisers at the time of manufacture,
2. Decanted into the tank of a clearomizer or rebuildable tank atomizer, or
3. Dripped directly onto the coil of a rebuildable dripping atomizer.

E-cigarettes work by heating the coil of your atomizer and atomizing the e-liquid, which is what you inhale. This is what allows you to get a nicotine fix without inhaling tobacco leaf combustion products.

What are the ingredients of e-liquid?

There are generally only four main ingredients:

1. Propylene Glycol and
2. Vegetable Glycerin (mixture of PG and VG making up >95%),
3. Food flavourings (~5%), and
4. Therapeutic nicotine (<1%).

Propylene Glycol (PG)

Scary name, but it's not scary stuff!

Propylene Glycol is a colourless and odourless liquid at room temperature. It is hygroscopic, meaning it has the ability to attract and trap water molecules. It is also used as a non-toxic and environmentally-friendly antifreeze.

Apart from in e-cigarettes, Propylene Glycol is used in the manufacturing of polyester by mixing with chemicals it reacts with. It is also used as a food additive - number E1520 - as a humectant, solvent and preservative. Propylene Glycol is also used in tobacco cigarettes to help them retain moisture. Lastly it is used in medical applications for medicines that are either inhaled, ingested or injected intravenously.

Long term studies show no irritant potential to humans, however some people may be sensitive to Propylene Glycol and experience an irritation of the eyes or airways which typically goes away as soon as exposure is stopped.

In e-cigarettes, it is used primarily to imitate the "throat hit" of tobacco cigarettes.

Vegetable Glycerin (VG)

Better known just as "Glycerine" in Australia, Vegetable Glycerin is widely used in food and pharmaceutical applications.

It is also a colourless and odourless hygroscopic liquid that has a chemical structure similar to fat. It is non-toxic, very sweet tasting and very viscous (thick and sticky).

Apart from in e-cigarettes, Vegetable Glycerin is used in most of the stuff you consume on a daily basis - it is food additive E422 and is used in low-fat snack foods, cake icing, liqueurs, as a sweetener, as a preservative and as a humectant. It is also used in moisturising skin care products, sensitive skin care products, cough syrup, toothpaste, mouthwash, shaving cream, shampoo and personal lubricants. It's basically everywhere in the supermarket - you can even buy bottles of pure VG itself.

It is completely non-toxic and naturally occurs in soybeans, palm trees and animal fats.

In e-cigarettes, it is used primarily to produce the "clouds" reminiscent of tobacco smoke.

Food flavourings

E-liquids get their flavour from commercially available food flavourings, which is why there are literally thousands of different e-liquid flavours. Manufacturers of e-liquid will generally experiment for great lengths of time in order to get the perfect flavouring mix.

Therapeutic nicotine

The nicotine in e-liquid is derived from tobacco and refined to remove pollutants, including the cancer-causing tobacco-specific nitrosamines. It is the same as is used in nicotine replacement therapy products such as patches, gum and inhalers. Nicotine in and of itself has not been proven to cause cancer.

Other known additives

There have been instances of e-liquid containing water, vodka or pure-grain alcohol, but these are not necessary and reputable e-liquid manufacturers don't use them. It's easy to avoid these additives and it's always a good idea to.

What PG/VG ratio should I choose?

The ratio you choose will generally come down to a few factors:

1. What kind of device you are using,
2. How "strong" you want it to be (eg. lots of "throat hit" or "lung hit" or little to none),
3. How big you want your clouds, and
4. How sweet you want it to taste.

PG is responsible for the "throat hit" and "lung hit", but can cause dryness of the mouth and airways in excessive amounts. PG does not produce a lot of vapour.

VG is responsible for the clouds and the sweeter flavouring, but can clog certain tanks and clearomizers. VG does not produce any "throat hit" or "lung hit".

Rule 1 - if in doubt, 50/50 it

If it's your first time buying, or you're using a clearomizer, or you just aren't sure how to choose, go 50/50. You will get the best of both worlds with the strength, sweetness and cloud production, and won't clog your gear up. Once you're in the swing of vaping you can begin to experiment with different ratios.

Rule 2 - not strong enough? Up the PG.

If you have decreased your dose of nicotine but are not getting the same amount of satisfaction from vaping, upping the PG to 60% can be a good way to deal with it.

Rule 3 - not cloudy enough? Up the VG.

VG is responsible for the cloud production, which can be quite impressive with the right mixture and right equipment. If you're switching to using a rebuildable dripping atomizer, it's also a good idea to up the VG, as the simple logistics of how RDAs work will change the flavour of the vape and make it harsher than out of a clearo or tank.

Is e-liquid safe?

It's very important to only get your e-liquid from reputable manufacturers. In Australia, we are very lucky to have an abundance of exceptional quality e-juice producers - in fact, you're reading the blog of one of the best right now! ;-)

When buying from overseas, only buy from vendors who have a good reputation and who have been in the game for a while. You should exercise extra caution when buying from anywhere other than the US, Australia or New Zealand, the countries with the highest quality standards.

It is also vitally important to treat liquid nicotine with respect. Nicotine is a toxic substance which can kill you in the right dose. There's no need to buy "pure" nicotine or 100mg/L solution unless you are an expert mixer, highly experienced and knowledgeable in toxic chemical handling and safety. You're far better off buying nicotine solution at a set strength and mixing it with Aussie-made doublers. You can check out this blog post for more information on doublers.

Hopefully we've been able to shed some light on the issue of PG/VG ratios and which one you should pick. If you're still not sure, hit up your local vendor for some more advice and information. 

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Batteries are an irrevocable part of vaping life. Whether it's a little cig-a-like or a massive monster mechanical mod, they all rely on a battery (or batteries) to give you those sweet clouds of craving-killer goodness.

When you start vaping you start with devices that have built-in batteries, such as the aforementioned cig-a-likes or an Ego twist. But sooner or later, you will begin to experiment with mods.

Whether a stick or box mod, these devices generally involve advanced battery technology, and by extension, owning one pays to have advanced battery knowledge. You don't need to go get a degree in electro-chemical engineering or anything, but you do need to know the basics.

So bear with me here - I'm going to assume zero knowledge of batteries, and work my way up to advanced aspects that every vaper should know, whether you plan on getting the Snow Wolf or not.

What is a battery?

A battery is a self-contained cell that stores electricity for the purpose of powering electrical devices. I'm pretty sure you know the rest.

How do batteries work?

When you boil it down, all batteries work via chemical reactions.

All batteries have an anode (or negative pole), cathode (or positive pole) and an electrolyte (no, not Gatorade, a fluid or other chemical medium to act as a barrier between the anode and cathode).

The anode and cathode are made up of two different types of chemical compounds. Due to the chemical reactions within the cells, electrons build up at the anode causing a voltage difference (you may remember how voltage works from our earlier blog post about vaping and electricity).

Now electrons are fussy little beasts - they don't like being all bunched up, and would much rather spread themselves out evenly; therefore, all they want to do is go back to the cathode. But they can't, because the electrolyte is in the way. So they sit at the anode, elbowing each other for room and generally being rather keen to get moving.

When you close the circuit between the anode and cathode with a wire or other kind of conductive material, the electrons are free to go back to the cathode and finally get some personal space. As they flow along the material connecting the anode and cathode - voila - you get an electrical current.

This is how all electrically powered devices work. They draw current from one end, pass it through anything that needs electricity, then whatever is left over goes back into the battery.

Then why do batteries run out?

Remember that all batteries work via chemical reactions. As the electrons flow, it causes chemical reactions in the anode and cathode mediums that eventually cause them to stop producing electrons. This is why the voltage of a battery drops as you use it - the potential to produce a current drops as the chemical reactions progress.

So how do rechargeable batteries work?

All you are doing in a rechargeable battery is reversing the flow of electrons, sending them back to the anode like trillions of microscopic four-year-olds being sent back to their rooms. The chemical reactions reverse, and the process is ready to start again.

So, those are the basics of batteries. Now on to some more interesting stuff...

Chemical makeup

Different kinds of batteries will have different chemical mediums by which they produce electrons.

Your typical car battery is a lead-acid battery. Whilst they have a low energy density (that is, capacity to store electrons), they are capable of producing massive bursts of high current - perfect for quick zaps to power your starter motor. They consist of two lead plates and sulfuric acid dissolved in the electrolyte, which is typically water.

The average battery you buy from Bunnings to power your wall clock is an alkaline battery. They actually contain manganese dioxide and powdered zinc; they get their name from the alkaline electrolyte. These are your perfect batteries for prolonged, low-current usage. For longer lasting power you can pick up a nickel cadmium battery, which were the first kind of alkaline battery.

If you owned a mobile phone in the 90s you would be familiar with the nickel-hydrogen and nickel-metal-hydride batteries. These are more energy-dense and last longer than alkaline batteries and therefore can be made to be much smaller.

Lithium-ion batteries

Now we're back in the present day in the world of the lithium-ion battery.

Lithium is the third element on the periodic table. It's a very small atom; likewise the least dense of all the metals with the highest electrochemical potential and energy-to-weight ratio, making it perfect for batteries. However it's also very unstable, which is why, although lithium batteries were invented back in 1912, they were not used until the development of the lithium-ion battery in the mid 80s.

Things you need to know about LiON batteries

1. They are a slightly different animal to normal batteries. Lithium ions actually pass through the electrolyte to either the anode or cathode, depending on whether the battery is charging or discharging. The anode, cathode and electrolyte are actually sheets, not solid terminals in a liquid solution, so lithium-ion cells consist of the anode, cathode and electrolyte sheet wound around each other in a spiral.
2. Lithium is highly reactive. The last thing you want to do is get lithium wet. Remember back to high school chemistry, when the teacher put sodium in water? Think that, but like ten times more powerful. Which is partially why...
3. Lithium cells are contained under pressure. This is to keep any air or water reacting with the lithium. Therefore it is never a good idea to throw a lithium battery onto concrete as hard as you can. I mean it. Never.

So your lithium-ion battery is literally a metal canister jam-packed with a highly explosive chemical that is not unknown to occasionally catch fire! Kind of makes you think twice about having your next vape.

Fortunately for us, good LiON batteries have inbuilt safety features, which are:

1. A voltage sensor. If the sensor detects that too much current is being drawn, it will restrict the flow of electrons.
2. A temperature sensor. If the sensor detects that the cell is getting too hot, it will isolate the overheated part to prevent a runaway thermal reaction.

Note that I said a "good" LiON battery will have these...

Why you should be fussy about your batteries

A LiON battery will fail if you over-charge or over-discharge it.

You will over-charge it if you leave it in a charger that does not have a full charge cut off feature. Keep pumping those electrons into the battery when it's already full and the battery will let you know about it. If you're lucky it will just be ruined. If you're unlucky...

You will over-discharge it if you try to draw too much current through it. Drag 30 amps out of a 20amp-rated battery and you will degrade the electrolyte, causing the cell to overheat, and - again, if you're lucky, only ruin the battery. This is why a sound understanding of battery technology is non-negotiable for mechanical mod users - even with the battery's built-in safety features, the lack thereof in the mechanical mod can still mean you push them too hard and get yourself in trouble.

So...

What to make sure when buying high-current lithium ion batteries for your mod

1. Check the ampere rating. Back in the old days this would be represented as the "C" rating, however in these more enlightened times they just write it on the side of the battery. In order to determine if the particular batteries are right for what you are going to put them through, you need to understand Ohm's law and how to calculate the amps your setup will draw. Again, because we're such legends here at Vapoureyes, we have a blog post about this.
2. DON'T BUY REWRAPS! A rewrap is a battery that is not in its original skin, meaning that you can't trust the amp rating written on it. Past experience has told us that some unscrupulous characters have re-wrapped batteries with skins over-stating their amp rating, which means they can charge original price for a cheap knock-off, and you might have to suffer the consequences.
3. Make sure they are protected. Make sure they have the built-in safety features mentioned above. It's as simple as making sure your vendor tells you whether they are "protected" or "unprotected". If you're highly experienced and full of expert battery knowledge (or an electro-chemical engineer), you might be able to get away with using an unprotected battery if you're very very careful with your resistances. For the rest of us - buy protected.
4. Buy a decent charger. Make sure the charger you get has the full charge cut-off feature, meaning it will cut off the current as soon as it senses the batteries are fully charged.

A few other pro-tips:

• Learn Ohm's law.
• If you're using a mechanical mod, buy an ohms meter whatever you do.
• Don't leave them charging unattended - especially not overnight. You don't want to wake up with half your face blown off. You'll probably frighten yourself when you look in the mirror.
• Don't discharge them all the way. If a LiON battery gets fully discharged, it is ruined. Charge them up as soon as they dip below 20% or so.
• If you're using multiple batteries, get smart about whether to use them in series or in parallel.
• Don't drop them in water.
• Don't freeze them.
• Don't leave them in the sun.
• Don't throw them at people. It's not nice.

There's absolutely no reason to be scared of batteries. If you treat them right you will have no problems at all. But before you venture into the world of high-powered or mechanical mods, make sure you know enough to keep yourself and your loved ones safe. Batteries don't take abuse lying down!

For more information on battery and battery safety, please check out these awesome websites:

http://www.mpoweruk.com/safety.htm

http://www.livescience.com/50657-how-batteries-work.html

http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm

A little while ago, some studies were floating around in the news about there being dangerous levels of toxic heavy metals in e-cig vapour, most notably chromium and cadmium.

There was also the fuss over formaldehyde in e-cig vapour, and the backlash when it was discovered that they achieved this result by melting the coil.

With this in mind, I thought I'd have a look to see if anyone had done some actual science on this. Lucky for me, they had!

Are Metals Emitted from Electronic Cigarettes a Reason for Health Concern? A Risk-Assessment Analysis of Currently Available Literature

(Farsalinos, Voudris & Poulas, 2015)

This type of study was a systematic review of other studies, in which the results were collated. Also worth noting (unlike last week): none of the authors work for tobacco companies. (To learn the difference between different types of scientific study, click here).

Purpose of the study

This interested me somewhat. They basically said "OK, so there might be toxic metals in e-cig vapour. BUT - are they at dangerous levels?"

So they didn't argue on whether there was or wasn't toxic metal in e-cig vapour. Instead they assessed, if toxic metals were detected, were they at levels likely to cause any real harm?

Methods

The authors conducted a literature search and found nine studies analysing the toxic metal components of e-cig vapour. They discounted the ones assessing environmental impacts as the levels of metals were much lower, leaving them with two studies that examined the levels in the vapour itself.

Let's call the two studies Goniewicz et al. and Williams et al. (mainly because that's what the authors of this study called them).

Goniewicz et al.

This crew took twelve e-cigs and measured their metal by-products with a mass spectrometer. They compared their results to pharmaceutical nicotine inhalers.

They specifically measured for arsenic, barium, cadmium, chromium, cobalt, copper, lead, manganese, nickel, rubidium, strontium and zinc. Of all these metals, they only found evidence of cadmium, lead and nickel.

They also took blank sample measurements, i.e. they measured the air in the room in the mass spectrometer as a control. They then subtracted the levels detected in the blank samples from the e-cig samples to give a true indication of what was present in the e-cig vapour.

Williams et al.

This mob took the grand total of one e-cig and measured the vapour products (it is not stated how they did this).

They reported the results in amount per ten puffs. They happened to find aluminum, barium, chromium, copper, iron, lead, manganese, nickel, strontium, tin, titanium, zinc and zirconium.

They said they took room samples, but didn't report on the levels they found and didn't subtract the values from their one e-cig sample.

So, in short, it was a pretty average study.

Measurements

Farsalinos, Voudris & Poulas measured the levels found against two metrics - the United States Pharmacopia (USP) Permissible Daily Exposure (PDE) levels, and for the metals that weren't referenced in the USP list, they used the Minimal Risk Level (MRL) as dictated by the Agency for Toxic Substances and Disease Registry (ATSDR). They also used the stricter of the two measures where there was any doubt.

The thinking behind this was to measure the worst-case scenario of toxic metal existence against levels generally recognised as safe for medicinal inhalers and other nicotine replacement therapies.

Next they had to estimate how many puffs per day the average vaper takes, and what the levels of these metals would be extrapolated to the average daily exposure in order to properly measure against the USP PDE and the ATSDR MRL. Based on a previous study (Farsalinos et al. 2013) which determined an average consumption of 5mg of vapour per puff, and based on another previous study (Farsalinos et al. 2014) which determined the average daily consumption to be 3g, they assumed a level of 600 puffs per day to be the average. Then (just to be safe) they gave it an uncertainty factor of 2 and worked off a baseline of 1200 puffs per day.

Multiplying the results according to numbers of puffs, then averaging it across the amount of air typically inhaled in a daily period, carry the two and divide by the number you first thought of, and you'll have the daily exposure levels you get from these metals from e-cigs.

Results

Although the Williams et al. study was a bit average, the authors included the results anyway. Below are the metals and their amounts compared to the daily safe limits across the various measures:

So... if I'm reading this correctly, even using the strictest measures, and even using terrible data, and even at twice the average vape rate, the levels of toxic metals are still way below the maximum safe daily threshold, even based on the standards for inhaled medicines... in fact, you'd probably get the same kind of dose just walking down Rundle Mall.

Conclusion

The authors of the study say it best:

"In conclusion, the levels of metals emitted to the [e-cigarette] aerosol, as found in currently available literature, are unlikely to generate significant adverse health effects for smokers switching to [e-cigarette] use" (Farsalinos, Voudris & Poulas, 2015, pg. 5228).

What this means for you

If you were worried about the possibility of inhaling toxic metals when you vape, you probably don't have to - even if you are, they are nowhere near the kind of levels needed to do you any damage.

The main message is still what it has always been - vaping is about harm reduction. We vape because we want a safer alternative to smoking tobacco - both for us and the people close to us.

No responsible vaper I have ever met is in favour of the idea of giving e-cigs to kids, or getting non-smokers hooked. We just want to be able to vape ourselves, save money and save our health.

What's your opinion on all this? I'd love to hear your feedback. Jump onto Facebook and let me know!

References:

Farsalinos, K., Voudris, V., & Poulas, K. (2015). Are Metals Emitted from Electronic Cigarettes a Reason for Health Concern? A Risk-Assessment Analysis of Currently Available Literature. International Journal Of Environmental Research And Public Health, 12(5), 5215-5232. doi:10.3390/ijerph120505215

Farsalinos, K., Romagna, G., Tsiapras, D., Kyrzopoulos, S., & Voudris, V. (2013). Evaluation of Electronic Cigarette Use (Vaping) Topography and Estimation of Liquid Consumption: Implications for Research Protocol Standards Definition and for Public Health Authorities’ Regulation. International Journal Of Environmental Research And Public Health, 10(6), 2500-2514. doi:10.3390/ijerph10062500

Farsalinos, K., Romagna, G., Tsiapras, D., Kyrzopoulos, S., & Voudris, V. (2014). Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers. International Journal Of Environmental Research And Public Health, 11(4), 4356-4373. doi:10.3390/ijerph110404356