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===Addiction===
===Addiction===
It is not clear whether using e-cigarettes will decrease or increase overall nicotine addiction.<ref>{{cite journal|last1=Palazzolo|first1=DL|title=Electronic Cigarettes and Vaping: A New Challenge in Clinical Medicine and Public Health. A Literature Review.|journal=Frontiers in public health|year=2013|volume=1|pages=56|pmid=24350225|doi=10.3389/fpubh.2013.00056|pmc=3859972}}</ref> A number of organizations have concerns that e-cigarettes might increase addiction to and use of nicotine and tobacco products in children.<ref name=DrugFacts>{{cite web|title=DrugFacts: Electronic Cigarettes (e-Cigarettes)|url=http://www.drugabuse.gov/publications/drugfacts/electronic-cigarettes-e-cigarettes|work=National Institute on Drug Abuse|accessdate=24 May 2014|date=Nov 2013|quote=There is also the possibility that they could perpetuate the nicotine addiction and thus interfere with quitting.}}</ref><ref>{{cite web|title=Citing Health Concerns the American Cancer Society Calls for Action|url=http://www.cancer.org/myacs/eastern/areahighlights/cancernynj-news-ny-ecig-health-vote|work=American Cancer Society|accessdate=12 November 2013|quote=Government agencies and medical organizations, such as the FDA, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics have also expressed concern that electronic cigarettes could increase nicotine addiction and tobacco use in young people.}}</ref><ref>{{cite journal|last=Centers for Disease Control and Prevention|first=(CDC)|title=Notes from the field: electronic cigarette use among middle and high school students – United States, 2011–2012|url=http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6235a6.htm |journal=MMWR. Morbidity and mortality weekly report|date=6 September 2013|volume=62|issue=35|pages=729–30|pmid=24005229}}</ref> This including: the Centers for Disease Control and Prevention,<ref name = "CDC Q&A">{{cite web |author=Edgar, Julie |title=E-Cigarettes: Expert Q&A With the CDC |url=http://www.webmd.com/smoking-cessation/news/20131112/e-cigarettes-cdc |publisher=WebMD |accessdate=17 November 2013}}</ref> the [[International Union Against Tuberculosis and Lung Disease]],<ref name=IUATLD>{{cite web |title=Position Statement on Electronic Cigarettes [ECs] or Electronic Nicotine Delivery Systems [ENDS] |url=http://www.theunion.org/what-we-do/publications/official/body/E-cigarette_statement_FULL.pdf |format=PDF |date=October 2013 |publisher=The International Union against Tuberculosis and Lung Disease}}</ref> the [[American Academy of Pediatrics]]<ref>{{cite web|last=Korioth|first=Trisha|title=E-cigarettes easy to buy, can hook kids on nicotine|url=http://aapnews.aappublications.org/content/early/2013/10/04/aapnews.20131004-4|work=The American Academy of Pediatrics|accessdate=17 November 2013}}</ref> and the Food and Drug Administration.<ref name=FDAConsumer2009>{{cite web|title=FDA Warns of Health Risks Posed by E-Cigarettes|url=http://www.fda.gov/forconsumers/consumerupdates/ucm173401.htm|work=FDA|accessdate=17 November 2013|date=23 July 2009|postscript=—Reviewed 17 September 2013}}</ref> The World Health Organization raised concern of addiction for nonsmokers from their use in July 2013.<ref name=WHOJuly2013/> A review had found no evidence that they are used regularly by those who have never smoked<ref name=Haj2014>{{cite journal|last1=Hajek|first1=P|last2=Etter|first2=JF|last3=Benowitz|first3=N|last4=Eissenberg|first4=T|last5=McRobbie|first5=H|title=Electronic cigarettes: review of use, content, safety, effects on smokers and potential for harm and benefit.|journal=Addiction (Abingdon, England)|date=31 July 2014|pmid=25078252}}</ref> while another review had found that up to a third of young people using electronic cigarettes have never smoked traditional cigarettes.<ref name=Grana2014/>
It is not clear whether using e-cigarettes will decrease or increase overall nicotine addiction.<ref>{{cite journal|last1=Palazzolo|first1=DL|title=Electronic Cigarettes and Vaping: A New Challenge in Clinical Medicine and Public Health. A Literature Review.|journal=Frontiers in public health|year=2013|volume=1|pages=56|pmid=24350225|doi=10.3389/fpubh.2013.00056|pmc=3859972}}</ref> A number of organizations have concerns that e-cigarettes might increase addiction to and use of nicotine and tobacco products in children.<ref name=DrugFacts>{{cite web|title=DrugFacts: Electronic Cigarettes (e-Cigarettes)|url=http://www.drugabuse.gov/publications/drugfacts/electronic-cigarettes-e-cigarettes|work=National Institute on Drug Abuse|accessdate=24 May 2014|date=Nov 2013|quote=There is also the possibility that they could perpetuate the nicotine addiction and thus interfere with quitting.}}</ref><ref>{{cite web|title=Citing Health Concerns the American Cancer Society Calls for Action|url=http://www.cancer.org/myacs/eastern/areahighlights/cancernynj-news-ny-ecig-health-vote|work=American Cancer Society|accessdate=12 November 2013|quote=Government agencies and medical organizations, such as the FDA, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics have also expressed concern that electronic cigarettes could increase nicotine addiction and tobacco use in young people.}}</ref><ref>{{cite journal|last=Centers for Disease Control and Prevention|first=(CDC)|title=Notes from the field: electronic cigarette use among middle and high school students – United States, 2011–2012|url=http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6235a6.htm |journal=MMWR. Morbidity and mortality weekly report|date=6 September 2013|volume=62|issue=35|pages=729–30|pmid=24005229}}</ref> This including: the Centers for Disease Control and Prevention,<ref name = "CDC Q&A">{{cite web |author=Edgar, Julie |title=E-Cigarettes: Expert Q&A With the CDC |url=http://www.webmd.com/smoking-cessation/news/20131112/e-cigarettes-cdc |publisher=WebMD |accessdate=17 November 2013}}</ref> the [[International Union Against Tuberculosis and Lung Disease]],<ref name=IUATLD>{{cite web |title=Position Statement on Electronic Cigarettes [ECs] or Electronic Nicotine Delivery Systems [ENDS] |url=http://www.theunion.org/what-we-do/publications/official/body/E-cigarette_statement_FULL.pdf |format=PDF |date=October 2013 |publisher=The International Union against Tuberculosis and Lung Disease}}</ref> the [[American Academy of Pediatrics]]<ref>{{cite web|last=Korioth|first=Trisha|title=E-cigarettes easy to buy, can hook kids on nicotine|url=http://aapnews.aappublications.org/content/early/2013/10/04/aapnews.20131004-4|work=The American Academy of Pediatrics|accessdate=17 November 2013}}</ref> and the Food and Drug Administration.<ref name=FDAConsumer2009>{{cite web|title=FDA Warns of Health Risks Posed by E-Cigarettes|url=http://www.fda.gov/forconsumers/consumerupdates/ucm173401.htm|work=FDA|accessdate=17 November 2013|date=23 July 2009|postscript=—Reviewed 17 September 2013}}</ref> The World Health Organization raised concern of addiction for nonsmokers from their use in July 2013.<ref name=WHOJuly2013/> A review had found no evidence that they are used regularly by those who have never smoked<ref name=Haj2014>{{cite journal|last1=Hajek|first1=P|last2=Etter|first2=JF|last3=Benowitz|first3=N|last4=Eissenberg|first4=T|last5=McRobbie|first5=H|title=Electronic cigarettes: review of use, content, safety, effects on smokers and potential for harm and benefit.|journal=Addiction (Abingdon, England)|date=31 July 2014|pmid=25078252}}</ref>


== Construction ==
== Construction ==

Revision as of 18:34, 13 October 2014

First generation electronic cigarette resembling a tobacco cigarette
Second generation types of electronic cigarettes

An electronic cigarette (e-cig or e-cigarette), personal vaporizer (PV) or electronic nicotine delivery system (ENDS) is a battery-powered vaporizer which simulates tobacco smoking by producing an aerosol[1] that resembles smoke. It generally uses a heating element known as an atomizer, that vaporizes a liquid solution known as e-liquid. E-liquids usually contain a mixture of propylene glycol, vegetable glycerin, nicotine, and flavorings,[2] while others release a flavored vapor without nicotine.[3] In surveys of regular users the most liked e-liquids had a nicotine content of 18 mg/ml.[4]

The benefits and risks of electronic cigarette use are uncertain.[5][6] Evidence suggests e-cigarettes may be safer than smoking tobacco products, and possibly as safe as other nicotine replacement products, but there is insufficient data to draw conclusions.[7][8] While they may carry a risk of addiction in those who do not already smoke,[9] there is no evidence of ongoing use among those who have never smoked.[4] They may promote continuation of addiction in those who already smoke.[10] With the spread of e-cigarette use, calls to poison control centers related to possible ingestion or skin exposure to e-cigarette liquids have increased.[11] E-cigarette aerosol emissions contains flavors, aroma transporters, glycerol, propylene glycol, nicotine, known carcinogens, heavy metals, ultrafine particles, and other chemicals.[4][2] E-cigarettes do not smolder like traditional cigarettes, they do not emit smoke, but bystanders are exposed to any exhaled e-cigarette aerosol.[2] E-cigarette aerosol has notably fewer toxicants than cigarette smoke (other than particulates) and is likely to pose less harm to users or by-standers.[2][4] Complaints of less serious adverse effects of throat and mouth inflammation, vomiting, nausea, and cough have resulted from e-cigarette use,[2] but causal relationships were not established.[4]

The frequency of use has increased with up to 10% of American high school students having ever used them as of 2012 and around 3.4% of American adults as of 2011.[12] In the UK the number of e-cigarette users has increased from 700,000 in 2012 to 2.1 million in 2013. About 60% are smokers and most of the rest are ex-smokers.[13] E-cigarette users most commonly continue to smoke traditional cigarettes.[2] Currently marketed e-cigarette devices arose from an invention made in China in 2003[14] and devices are predominantly manufactured in China.[2] E-cigarette brands have been increasing advertising at a fast rate, the aggressive marketing used is similar to that used to sell cigarettes in the 1950s and 1960s.[2]

Because of the possible relationship to tobacco laws and medical drug policies, electronic cigarette legislation and public health investigations are currently pending and are being debated in many countries.[3][15] The European Parliament passed regulations in February 2014 requiring standardization of liquids and personal vaporizers, disclosure of ingredients, and child- and tamper-proofing of liquid containers; the United States Food and Drug Administration published proposed regulations in April 2014 including some similar measures.[16]

Health effects

Smoking cessation

In July 2014, a report developed by the World Health Organization (WHO) for consideration by the signatories of its Framework Convention on Tobacco Control found insufficient evidence to determine an effect of electronic cigarettes on the ability to quit smoking. This report found electronic cigarettes have not been approved for smoking cessation by any government, and current smokers should be encouraged to use approved methods for smoking cessation.[17]

The WHO report also discussed expert opinion in the scientific literature suggesting that electronic cigarette may have a role for those who have not had success quitting smoking with other methods.[17] A statement previously published by the WHO in July 2013 stated that the effectiveness of electronic cigarettes in aiding smoking cessation had not been demonstrated and recommended that "consumers should be strongly advised not to use" electronic cigarettes unless a reputable national regulatory body has found them safe and effective.[9] The US Government smoking cessation site, smokefree.gov, stated that the efficacy of electronic cigarettes in aiding smoking cessation has not been demonstrated and did not recommend them.[18]

The concept of harm reduction has largely been controversial in the public health approach of tobacco control.[19] A 2011 review article states how electronic cigarettes may aid in smoking cessation and may likely be more effective than traditional pharmacotherapy, as the physical stimuli of holding and puffing on the electronic cigarette may better reduce short-term cravings.[19] The review found no studies that directly measured the effectiveness of electronic cigarettes in smoking cessation, and examined two published studies that indirectly consider the issue by measuring the effect of the product on cravings and other short-term indicators.[19] A 2014 review asserted how electronic cigarettes may be a reasonable substitute for cigarette smoking.[3] The review also states that even individuals that did not intend to quit smoking before being introduced to e-cigarettes may subsequently do so.[3] Another 2014 review concluded that the benefit with respect to helping people quit smoking was uncertain.[6]

The American Association of Public Health Physicians (AAPHP) suggests those who are unwilling to quit tobacco smoking or unable to quit with medical advice and pharmaceutical methods should consider other nicotine containing products such as electronic cigarettes and chewing tobacco for long term use instead of smoking.[20] The British Medical Association (BMA) reported in 2013 that there was a possibility for smoking cessation benefits, but had concerns that e-cigarettes are less regulated than nicotine replacement therapy (NRT), and that there was no peer reviewed evidence concerning their safety or efficacy. Recommendations point to a "strong regulatory framework" for e-cigarette distribution in order to ensure the safety, quality, and that marketing and sales are restricted to adults. The BMA encourages health professionals to recommend conventional nicotine replacement therapies, but for patients unwilling to use or continue using such methods, health professionals may present e-cigarettes as a lower-risk option than tobacco smoking.[21] A report commissioned by Public Health England concluded that there is large potential for health benefits when switching from tobacco use to other nicotine delivery devices such as electronic cigarettes, but realizing the full potential requires regulation and monitoring to minimize possible risks.[7]

A 2012 review found electronic systems appear to generally deliver less nicotine than smoking, raising the question of whether they can effectively substitute for tobacco smoking over a long-term period.[22] A 2013 randomized controlled trial found no difference in smoking cessation rates between e-cigarettes with nicotine, e-cigarettes without nicotine and traditional NRT patches.[23] There are some non-controlled studies which have reported possible benefit.[8]

Electronic cigarettes were not regularly associated with trying to quit tobacco among young people.[12] Adults most often used electronic cigarettes as a replacement for tobacco, although not invariably to quit.[12] The majority of youth using e-cigarettes are dual users, though some youth who used an e-cigarette have never tried a traditional cigarette, indicating that some youth are initiating use of the addictive drug nicotine through e-cigarettes.[2] There is a high levels of use of both e-cigarettes and traditional cigarettes, no proven help with stopping smoking, and increasing numbers of young people using e-cigarettes.[2] Although some people have a desire to quit smoking by using e-cigarettes, other common explanations for the use of these products are to evade smoke-free laws,[2] to reduce harm from smoking[24] and to cut back on traditional cigarettes, which may reinforce delaying or deterring to quit smoking.[2]

Safety

The risks of electronic cigarette use are uncertain.[5][6] This is due to there being little data regarding their health effects[25] and to the variability of vaporizers and variability in liquid ingredients and in their concentration and quality, and thus variability of the contents of aerosol delivered to the user.[2][5][22][25][26][27] However, some evidence suggests e-cigarettes may be safer than smoking tobacco products, and possibly as safe as other nicotine replacement products but there is insufficient data to draw conclusions.[2][22] Switching from smoking tobacco to using e-cigarettes may result in reduced exposure to nicotine and reduced potential risk of disease from smoking.[21][26][28]

Chart showing various toxicants as measured in cigarette and e-cigarette smoke.[29]

A preliminary analysis of e-cigarette cartridges by the US Food and Drug Administration (FDA) in 2009 identified that some contain tobacco-specific nitrosamines (TSNAs), known cancer-causing agents.[30] The amounts of TSNAs present were on par with existing NRT products like nicotine gum and inhalers. The FDA's analysis also detected diethylene glycol, a poisonous and hygroscopic liquid, in a single cartridge manufactured by Smoking Everywhere and nicotine in one cartridge claimed to be nicotine-free.[31][30][32] While diethylene glycol was found in a cartridge tested in 2009 by the FDA, in 2011 researchers reviewed the data and noted that 15 other studies had failed to find any evidence of this chemical in e-cigarettes.[33] Further concerns were raised over inconsistent amounts of nicotine delivered when drawing on the device.[31] In some e-cigarettes, "Tobacco-specific impurities suspected of being harmful to humans – anabasine, myosmine, and β-nicotyrine – were detected in a majority of the samples tested."[34] The UK National Health Service noted that the toxic chemicals found by the FDA were at levels one-thousandth that of cigarette smoke, and that while there is no certainty that these small traces are harmless, initial test results are reassuring.[35] While propylene glycol and other chemicals commonly used as solvents or carrier compounds in e-cigarettes liquids are generally recognized as safe, they have not been used before in vaporized form over long periods of time. The risks, especially to the lungs, are not fully understood and are of concern to public health authorities and some reviewers.[7][25][36][37] Some reviewers have noted that while there is variability in the ingredients and concentrations of ingredients in e-cigarette liquids, tobacco smoke contains thousands of chemicals, most of which are not understood and many of which are known to be harmful.[3][25] A 2014 review found e-cigarettes emissions contain known ultrafine particles and heavy metals.[2] Heavy metal nanoparticles have been found in the aerosol, which can deposit in the lung's alveolar sacs, potentially leading to local respiratory toxicity and entering the bloodstream.[2] A 2014 review found it can be assumed that there is no evidence of contamination of the aerosol with metals that justifies a health concern.[38]

A July 2014 WHO report cautioned about potential risks of using electronic cigarettes. Passive exposure was also mentioned as a concern with the report, indicating that current evidence is insufficient to determine whether the levels of exhaled aerosol are safe to involuntarily exposed bystanders.[17] Rare major injuries have occurred from battery malfunctions such as explosions and fires.[2] Complaints of less serious adverse effects of throat and mouth inflammation, vomiting, nausea, cough have resulted from e-cigarette use.[2] The US Food and Drug Administration Center for Tobacco Products reported between 2008 and the beginning of 2012, 47 cases of adverse effects associated with e-cigarettes, and eight was considered serious.[4] A causal relationship between e-cigarettes and the reported adverse effects was not established with the exception of two severe outcomes in the United States: a deaths when an infant chocked on the cartridges and burns when one blew up.[4] Liquids used with e-cigarettes also pose a risk if they are ingested or if the skin is exposed to them, especially for children.[39] In the US, the number of calls to poison control centers associated with e-cigarette liquid rose from one per month in September 2010 to 215 per month in February 2014; the proportion related to e-cigarettes jumped from 0.3 percent in September 2010 to 41.7 percent in February 2014.[39] More than half (51.1 percent) of the calls to poison centers due to e-cigarettes involved children under 5 years old.[39]

Second-hand aerosol

E-cigarettes deliver nicotine by forming an aerosol of ultrafine particles, which are variable and chemically intricate.[2] The general particle size and various particles resulting from e-cigarettes are akin to those in traditional cigarettes, with the majority of particles being ultrafine.[2] Some of these particles are exhaled, which exposes nonsmokers to "passive vaping."[2] Like cigarettes, small e-cigarette particles are able to enter far into the lungs and enter the systemic circulation.[2] At the very least, this limited research demonstrates it is transparent that e-cigarette emissions are not simply "harmless water vapor," as is commonly claimed, and can be a cause of indoor air pollution.[2] E-cigarettes do not smolder like traditional cigarettes do, they do not emit smoke, but bystanders are exposed to any exhaled e-cigarette aerosol.[2] Only what is exhaled by electronic cigarettes users enters the surrounding air.[4] This includes nicotine and some other particles, primarily consisting of flavors, aroma transporters, glycerol and propylene glycol.[4] Generally e-cigarette aerosol has notably fewer toxicants than cigarette smoke (other than particulates) and is likely to pose less harm to others.[2][3][25][40] Other studies concluded that the current evidence indicates that the levels of contaminants are not of significant health concern for human exposures by the standards used in workplaces to ensure safety.[38] Nonsmokers exposed to e-cigarette aerosol produced by a machine and pumped into a room were found to have detectable levels of the nicotine metabolite cotinine in their blood.[2] The same study pointed out that 80% of nicotine is normally absorbed by the vaper, so the results may be higher than in actual second hand exposure. There are concerns about pregnant women using e-cigarettes or are subjected to second hand e-cigarette aerosol.[2]

Addiction

It is not clear whether using e-cigarettes will decrease or increase overall nicotine addiction.[41] A number of organizations have concerns that e-cigarettes might increase addiction to and use of nicotine and tobacco products in children.[10][42][43] This including: the Centers for Disease Control and Prevention,[26] the International Union Against Tuberculosis and Lung Disease,[37] the American Academy of Pediatrics[44] and the Food and Drug Administration.[45] The World Health Organization raised concern of addiction for nonsmokers from their use in July 2013.[9] A review had found no evidence that they are used regularly by those who have never smoked[4]

Construction

Disassembled cigarette-styled electronic cigarette.
A. LED light cover
B. battery (also houses circuitry)
C. atomizer (heating element)
D. cartridge (mouthpiece)

Most electronic cigarettes take an overall cylindrical shape although a wide array of shapes can be found: box, pipe styles etc. First generation electronic cigarettes were usually designed to simulate smoking implements, such as cigarettes or cigars, in their use and appearance.[46] New generation electronic cigarettes often called mods, PVs (personal vaporizer) or APVs (advanced personal vaporizer) have an increased nicotine-dispersal performance,[46] housing higher capacity batteries,[47] and come in various form factors, including metal tubes and boxes.[47][48][49] Many electronic cigarettes are composed of standardized replaceable parts that are interchangeable from one brand to the other,[50] while disposable devices combine all components into a single part that is discarded when its liquid is depleted.[51] Common components include a liquid delivery and container system like tanks or cartomizers, an atomizer, and a power source.[52]

Atomizer

An e-cigarette atomizer with the coil (heating element) in view.

An atomizer generally consists of a small heating element responsible for vaporizing e-liquid, as well as a wicking material that draws liquid in. Along with a battery, the atomizer is the central component of every personal vaporizer. Differences between atomizers cause differences in the ingredients and their concentrations delivered to users, even when the same liquid is used.[2]

A small length of resistance wire is coiled around the wicking material and then connected to the positive and negative poles of the device. When activated the resistance wire (or coil) quickly heats up thus turning the liquid into a vapor, which is then inhaled by the user.[53]

The electrical resistance of the coil, the voltage output of the device, the airflow of the atomizer and the efficiency of the wick play important roles in the perceived quality of the aerosol that is produced by an atomizer. They also greatly affect the quantity or volume of aerosol that will be produced by the atomizer.

Atomizer resistances usually vary from 1.5Ω (ohms) to 3.0Ω from one atomizer to the next but can go as low as 0.1Ω in the most extreme cases of DIY coil building which produce large amounts of vapor but could present a fire hazard and other dangerous battery failures if the user is not knowledgeable enough about basic electrical principles and how they relate to battery safety.[54]

Wicking materials vary greatly from one atomizer to another but silica fibers are the most commonly used in manufactured atomizers. "Rebuildable" or "do it yourself" atomizers can use silica, cotton, rayon, porous ceramic, hemp, bamboo yarn, oxidized stainless steel mesh and even wire rope cables as wicking materials.[55]

A wide array of atomizers and e-liquid container combinations are available:[56]

Cartomizers

A 45mm length, extra-long cartomizer

A "cartomizer" (a portmanteau of cartridge and atomizer) or "carto" consists of an atomizer surrounded by a liquid-soaked poly-foam that acts as an e-liquid holder. It is usually disposed of once the e-liquid acquires a burnt taste, which is usually due to an activation when the coil is dry or when the cartomizer gets consistently flooded (gurgling) because of sedimentation of the wick. Most cartomizers are refillable even if not advertised as such.[57]

Cartomizers can be used on their own or in conjunction with a tank that allows more e-liquid capacity. In this case the portmanteau word of "cartotank" has been coined. When used in a tank, the cartomizer is inserted in a plastic, glass or metal tube and holes or slots have to be punched on the sides of the cartomizer to allow liquid to reach the coil.

Clearomizers

eGo style e-cigarette with a top-coil clearomizer. Silica fibers are hanging down freely inside of the tank, drawing e-liquid by capillary action to the coil that is located directly under the mouthpiece.

Clearomizers or "clearos", not unlike cartotanks, use a clear tank in which an atomizer is inserted.[58] Unlike cartotanks, however, no poly-foam material can be found in them. There are a lot of different wicking systems employed inside of clearomizers to ensure good moistening of the wick without flooding the coil. Some rely on gravity to bring the e-liquid to the wick and coil assembly (bottom coil clearomizers for example) whereas others rely on capillary action and to some degree the user agitating the e-liquid while handling the clearomizer (top coil clearomizers).[59]

Rebuildable atomizers

A rebuildable atomizer or an RBA is an atomizer that allows the user to assemble or "build" the wick and coil themselves instead of replacing them by an off-the-shelf atomizer "head". They also allow the user to build atomizers at any desired electrical resistance. The materials needed to "rebuild" the atomizers are usually much cheaper than the usual prefabricated replaceable wick and coil assemblies destined to clearomizers.

These atomizers are divided into three main categories; rebuildable tank atomizers (RTAs), rebuildable dripping atomizers (RDAs), and rebuildable dripping tank atomizers (RDATs).

Rebuildable tank atomizers (RTAs) are similar to clearomizers in that they use a tank or container to hold and bring liquid to the coil. They usually hold significantly more e-liquid than their RDA counterparts.

Rebuildable dripping atomizers (RDAs) on the other hand lack the container section and hold very little liquid compared to RTAs, but are usually a lot smaller. They typically consist only of an atomizer "building deck" which can accept one or more coils and a "top cap" to cover the coils where a mouth piece can be attached. The user needs to manually keep the atomizer wet by dripping liquid on the bare wick and coil assembly, hence their name.

Rebuildable dripping tank atomizers (RDATs) combine features of both RTAs and RDAs. They usually consist of a RDA build deck with a tank over the deck held up by a spring. The user pushes down on the mouth piece and liquid is then dripped onto the coils.This is unlike a RTA that continuously feeds liquid to the wicks.

Power

Most portable devices contain a rechargeable battery, which tends to be the largest component of an electronic cigarette. The battery may contain an electronic airflow sensor whereby activation is triggered simply by drawing breath through the device, while other models employ a power button that must be held during operation. An LED to indicate activation may also be employed. Some manufacturers also offer a cigarette pack-shaped portable charging case (PCC), which contains a larger battery capable of charging e-cigarettes. Devices aimed at more experienced users may sport additional features, such as variable power output and support of a wide range of internal batteries and atomizer configurations and tend to stray away from the cigarette form factor. Some cheaper devices use an microphone to activate.[60] Other batteries, like Ego type batteries, can use a custom IC to indicate battery status on the included LCD and a button to activate.[61]

Variable power and voltage devices

PV with variable and regulated power offering battery protection

Variable voltage or power personal vaporizers are devices that contain a built in electronic chip that allows the user to adjust the power that goes through the heating element. They usually incorporate a LED screen to display various information. Variable PVs eliminate the need to replace an atomizer with another one of lower or higher electrical resistance to change the intensity of the vapor.[62] They also feature voltage regulation and some battery protection.[63][64]

Some of these devices offer additional features through their menu system such as: atomizer resistance checker, remaining battery voltage, puff counter, activation cut-off etc.[65]

On 9/2/2014 Evolv vapor received a patent on variable wattage. Evolve was the company that introduced variable wattage to the industry. The technology goes all the way back to the Darwin, the companies first variable wattage device.[66]

Mechanical personal vaporizers

Mechanical PV with a rebuildable atomizer

Mechanical PVs or mechanical "mods", often called "mechs" are devices without electronic components and battery protection (apart from vent holes drilled in some mechanical devices) or voltage regulation. Because there is neither protection nor regulation, they will work either way the battery is inserted. They are activated by spring loaded or opposing magnetic mechanical switches, hence their name. They rely on the natural voltage output of a battery and the material that the mod is made of.[67]

They are commonly used with "low resistance" (1.0Ω ~ 0.2Ω) rebuildable atomizers. Seeing that most e-cigarettes containing electronic battery protection will interpret sub ohm resistance coils as a short circuit, thus prohibiting the device from being activated, mechanical mods are among the only devices that will accept such atomizer resistances although more recent (2013) electronic devices offers this possibility as well[citation needed]

Since mechanical PVs are unregulated and unprotected, they require special attention on the user's part that other regulated and protected PVs do not need. Making sure that the battery does not over-discharge and that the atomizer will not require more amperage than what the battery can safely allow are the user's responsibilities.[67]

E-liquid

E-liquid, e-juice or simply "juice", refers to a liquid solution that produces an aerosol when heated by an atomizer. The main ingredients of e-liquids are usually a mix of propylene glycol (PG), vegetable glycerin (VG), and/or polyethylene glycol 400 (PEG400), sometimes with differing levels of alcohol mixed with concentrated or extracted flavorings; and optionally, a variable concentration of tobacco-derived nicotine.[8][68] Most e-cigarette liquids contain nicotine, but the level of nicotine is chosen by the consumer.[38] The consumer can even purchase e-liquid that has no nicotine.[38] There is variability in the purity, kinds and concentrations of chemicals used in liquids, and significant variability between labeled content and concentration and actual content and concentration.[22][25][37][69]

The solution is often sold in bottles or pre-filled disposable cartridges, or as a kit for consumers to make their own eJuices. Components are also available individually and consumers may choose to modify or boost their flavor, nicotine strength, or concentration with various offerings. Pre-made e-liquids are manufactured with various tobacco, fruit, and other flavors,[2] as well as variable nicotine concentrations (including nicotine-free versions). The standard notation "mg/ml" is often used in labeling for denoting nicotine concentration, and is sometimes shortened to a simple "mg".[70] In surveys of regular e-cigarette users the most liked e-liquids had a nicotine content of 18 mg/ml, and largely the favorite flavors were tobacco, mint and fruit.[4]

Usage

File:Bangor bilingual station no smoking sign.jpg
Common reasons people use the e-cigarette is a desire to quit smoking cigarettes, cut down on their smoking habit or to circumvent smoke-free laws.[2]

Electronic cigarette sales increased from 50,000 in 2008 to 3.5 million in 2012.[68] Most people who use electronic cigarettes have a history of smoking cigarettes while some young people who have never smoked cigarettes have tried electronic cigarettes at least once.[12] E-cigarette users most commonly continue to smoke traditional cigarettes.[2] Many users report that electronic cigarettes help them either quit smoking or reduce the number of cigarettes smoked.[4]

In the United States, as of 2011, one in five adults who smoke have tried electronic cigarettes and 3.3% are currently using them.[12][71] Among grade 6 to 12 students in the United States, those who have at least once used the product increased from 3.3% in 2011 to 6.8% in 2012.[12][72] and those currently using electronic cigarettes increased from 0.6% to 1.1%. Over the same period the percentage of grade 6 to 12 students who regularly smoke tobacco cigarettes fell from 7.5% to 6.7%.[73] The frequency of use has increased with up to 10% of American high school students having ever used them as of 2012.[12][72] In 2013 the CDC found a three fold increase from 2011 in the number of youth who have used electronic cigarettes who have never smoked.[74]

In the UK in 2014, 18% of regular smokers identified themselves as using electronic cigarettes and 51% stated that they had used them in the past.[75] Among those who had never smoked, 1.1% said they had tried them and 0.2% continue to use them.[75] In 2013, among those under 18, 7% have used e-cigarettes at least once.[75] Among non-smokers children, 1% reported having tried e-cigarettes "once or twice," and there was no evidence of continued use.[75] Sustained was mostly confined to children who smoke or have smoked.[75] In 2014 child regular users was at 1.8%, children who have ever used e-cigarettes was at 10%, and occasional or greater use among never smoking children was at 0.18%.[76]

A February 2014 survey estimated that between 7.7 and 9.2 million individuals have experimented with using electronic cigarettes, with between 1.1 and 1.9 million using on a daily basis. 67% of tobacco smokers in the survey used electronic cigarettes to reduce or quit tobacco smoking. 9% of those who experimented with electronic cigarettes had never smoked tobacco. Of the 1.2% that had recently stopped tobacco smoking at the time of the survey, 84% (or 1% of the population surveyed) credited electronic cigarettes for stopping tobacco use.[77]

History

The earliest electronic cigarette can be traced to Herbert A. Gilbert, who in 1963 patented a device described as "a smokeless non-tobacco cigarette" that involved "replacing burning tobacco and paper with heated, moist, flavored air". This device heated the nicotine solution and produced steam. It was never commercialized.[78][79]

Hon Lik, a Chinese pharmacist, is credited with the invention of the electronic cigarette.[14][80] In 2003,[81] he came up with the idea of using a piezoelectric ultrasound-emitting element to vaporise a pressurized jet of liquid containing nicotine diluted in a propylene glycol solution.[82] This design produces a smoke-like vapour that can be inhaled and provides a vehicle for nicotine delivery into the bloodstream via the lungs. He also proposed using propylene glycol to dilute nicotine and placing it in a disposable plastic cartridge which serves as a liquid reservoir and mouthpiece.

Electronic cigarettes using a different design were first introduced to the Chinese domestic market in May 2004 as an aid for smoking cessation and replacement. The company that Hon Lik worked for, Golden Dragon Holdings, changed its name to Ruyan (如烟, literally "Resembling smoking"), and started exporting its products in 2005–2006[14] before receiving its first international patent in 2007.[83] E-cigarette devices are predominately manufactured in China.[2] E-cigarette brands have been increasing advertising at a fast rate, the aggressive markiting used is similir to that used to sell cigarettes in the 1950s and 1960s.[2] While advertising of tobacco products was ended long ago, television and radio e-cigarette advertising in a number of countries may be indirectly creating a desire for traditional cigarette smoking.[2]

The electronic cigarette continued to evolve from the first generation three-part device. In 2006 the "cartomizer" was invented by British entrepreneurs Umer and Tariq Sheikh of XL Distributors.[84] This is a mechanism which integrates the heating coil into the liquid chamber. The new device was launched in the UK in 2007 in their Gamucci brand and is now widely adopted by the majority of 'cigalike' brands. The grant of the UK patent for the "cartomizer" was made to XL Distributors in February 2013 and published by the UK Intellectual Property Office.[85]

The international tobacco companies, recognising the development of a potential new market sector that could render traditional tobacco products obsolete,[86] are increasingly involved in the production and marketing of their own brands of e-cigarettes and in acquiring existing e-cigarette companies.[87] Blu, a prominent US e-cigarette producer, was acquired by Lorillard Inc. in 2012.[88] British American Tobacco launched Vype in 2013, while Imperial Tobacco's Fontem Ventures acquired the intellectual property owned by Hon Lik through Dragonite for $US 75 million in 2013 and launched Puritane in partnership with Boots UK.[89][90] On October 1, 2013 Lorillard Inc. acquired another e-cigarette company, this time a UK based company SKYCIG.[91] On 3 February 2014, Altria Group, Inc. acquired popular electronic cigarette brand Green Smoke for $110 million. The deal was finalized in April 2014 for $110 million and $20 million in incentive payments.[92] Altria also markets its own e-cigarette, the MarkTen, while Reynolds American has entered the sector with its Vuse product.[87]

Society and culture

Consumers of electronic cigarettes or "vapers" as some call them have shown evident and passionate support for the product that other nicotine replacement therapy did not receive.[56][24] This suggests that electronic cigarettes have the potential mass appeal that could challenge the preeminence of combustible tobacco as the object of choice for nicotine users.[24]

As the electronic cigarette industry grows, a subculture has emerged which calls itself "the vaping community".[56][93][94] Members of this emerging subculture often view electronic cigarettes as a safer alternative to smoking[4] and some even view it as a hobby. They tend to use highly customized devices that do not resemble what are known, by some, as "cig-a-likes," or electronic cigarettes that resemble real cigarettes.[95]

Large gatherings of vapers, called vape meets, are happening around the United States which focus around e-cig devices, accessories, and the life style that accompanies them.[56] People attending these meetings are usually enthusiasts that use specialized, community-made products that are not found in typical places like convenience stores or gas stations.[56] These products are mostly available online or in dedicated "vape" storefronts where mainstream e-cigarettes brands from the tobacco industry and larger e-cig manufacturers are not available.[96]

A growing subclass of vapers called "cloud-chasers" assemble their atomizers in such a way that can produce extremely large amounts of vapor by using heating coils of less than 1 ohm.[97] This practice is known as "cloud-chasing". By using a coil at less that 1 ohm the batteries of PVs are stressed considerably more than what could be considered regular use and could represent a risk of dangerous battery failures.[98] As vaping comes under more and more scrutiny, some members of the vaping community have voiced their concerns about cloud-chasing claiming the practice gives vapers a bad reputation when doing it in public.[99]

Main article: Legal status of electronic cigarettes

The emerging phenomenon of electronic cigarettes has raised concerns among the health community, pharmaceutical industry, health regulators and state governments.[3] Some jurisdictions are now prohibiting or regulating the use of e-cigarettes in public spaces.

Because of the relative novelty of the technology and the possible relationship to tobacco laws and medical drug policies, electronic cigarette legislation and public health investigations are currently pending in many countries.[15] Current regulations vary widely, from regions with no regulations to others banning the devices entirely.[15]

In February 2014 the European Parliament passed regulations requiring standardization and quality control for liquids and vaporizers, disclosure of ingredients in liquids, and child-proofing and tamper-proofing for liquid packaging.[100][101] In April 2014 the US FDA published proposed regulations for e-cigarettes along similar lines.[69][102]

In March 2014 Western Australia banned sale of electronics cigarettes.[103]

Economics

According to Nielsen Holdings, convenience store e-cigarette sales went down for the first time during the four-week period ending on 10 May 2014. This decline is attributed by Wells Fargo analyst Bonnie Herzog to a shift in consumers behavior, buying more specialized devices or what she refers to as "vapor/tank/mods (VTMs)" that are not tracked by Neilsen.[104] According to Herzog these products, produced and sold by stand alone makers are now (2014) growing 2 times faster than traditional electronic cigarettes marketed by the major players (Lorillard, Logic Technology, NJOY etc...) and account for a third of the 2.2 billion dollar market for vapor products.[105] There is no evidence that the cigarette brands are selling e-cigarettes as part of a plan to phase out traditional cigarettes, despite some claiming to want to cooperate in "harm reduction."[2]

There are other technologies currently under development that seek to deliver nicotine for oral inhalation in an effort to mimic both the ritualistic and behavioural aspects of traditional cigarettes.

  • British American Tobacco, through their subsidiary Nicoventures Limited, licensed a nicotine delivery system based on existing asthma inhaler technology from UK-based healthcare company Kind Consumer Limited.[106][107] In September 2014 a product based on this - named Voke - obtained approval from the United Kingdom's Medicines and Healthcare Products Regulatory Agency.[108]
  • Philip Morris International bought the rights to a nicotine pyruvate technology developed by Jed Rose at Duke University.[109] The technology is based on the chemical reaction between nicotine acid and a base, which produces an inhalable nicotine pyruvate vapour.[110]
  • Heatsticks which heats tobacco.

References

  1. ^ Bertholon, JF; et al. (November 2013). "Comparison of the aerosol produced by electronic cigarettes with conventional cigarettes and the shisha". Rev Mal Respir. 30 (30(9)): 752–757. doi:10.1016/j.rmr.2013.03.003. PMID 24267765.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Grana, R; Benowitz, N; Glantz, SA (13 May 2014). "E-cigarettes: a scientific review". Circulation. 129 (19): 1972–86. doi:10.1161/circulationaha.114.007667. PMID 24821826.
  3. ^ a b c d e f g Saitta, D; Ferro, GA; Polosa, R (March 2014). "Achieving appropriate regulations for electronic cigarettes". Therapeutic advances in chronic disease. 5 (2): 50–61. doi:10.1177/2040622314521271. PMID 24587890.
  4. ^ a b c d e f g h i j k l m Hajek, P; Etter, JF; Benowitz, N; Eissenberg, T; McRobbie, H (31 July 2014). "Electronic cigarettes: review of use, content, safety, effects on smokers and potential for harm and benefit". Addiction (Abingdon, England). PMID 25078252.
  5. ^ a b c Odum, L. E.; O'Dell, K. A.; Schepers, J. S. (December 2012). "Electronic cigarettes: do they have a role in smoking cessation?". Journal of pharmacy practice. 25 (6): 611–4. doi:10.1177/0897190012451909. PMID 22797832.
  6. ^ a b c Harrell, PT; Simmons, VN; Correa, JB; Padhya, TA; Brandon, TH (4 June 2014). "Electronic Nicotine Delivery Systems ("E-cigarettes"): Review of Safety and Smoking Cessation Efficacy". Otolaryngology—head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. doi:10.1177/0194599814536847. PMID 24898072. These devices are unregulated, of unknown safety, and of uncertain benefit in quitting smoking.
  7. ^ a b c Britton, John; Bogdanovica, Ilze (15 May 2014), Electronic cigarettes – A report commissioned by Public Health England (PDF), Public Health England
  8. ^ a b c Caponnetto P; Russo C; Bruno CM; Alamo A; Amaradio MD; Polosa R. (March 2013), "Electronic cigarette: a possible substitute for cigarette dependence." (PDF), Monaldi archives for chest disease, 79 (1): 12–19, PMID 23741941
  9. ^ a b c "Tobacco Free Initiative (TFI)". World Health Organization. 9 July 2013.
  10. ^ a b "DrugFacts: Electronic Cigarettes (e-Cigarettes)". National Institute on Drug Abuse. November 2013. Retrieved 24 May 2014. There is also the possibility that they could perpetuate the nicotine addiction and thus interfere with quitting.
  11. ^ "New CDC study finds dramatic increase in e-cigarette-related calls to poison centers". CDC. 3 April 2014. Retrieved 6 June 2014. The most recent National Youth Tobacco Survey showed e-cigarette use is growing fast, and now this report shows e-cigarette related poisonings are also increasing rapidly
  12. ^ a b c d e f g Carroll Chapman, SL; Wu, LT (18 March 2014). "E-cigarette prevalence and correlates of use among adolescents versus adults: A review and comparison". Journal of Psychiatric Research. 54: 43–54. doi:10.1016/j.jpsychires.2014.03.005. PMID 24680203.
  13. ^ ASH UK (28 April 2014). "Over 2 million Britons now regularly use electronic cigarettes". Retrieved 30 May 2014.
  14. ^ a b c A high-tech approach to getting a nicotine fix, Los Angeles Times
  15. ^ a b c Etter, J. F.; Bullen, C.; Flouris, A. D.; Laugesen, M.; Eissenberg, T. (May 2011). "Electronic nicotine delivery systems: a research agenda". Tobacco control. 20 (3): 243–8. doi:10.1136/tc.2010.042168. PMC 3215262. PMID 21415064.
  16. ^ http://www.fda.gov/NewsEvents/PublicHealthFocus/ucm172906.htm
  17. ^ a b c WHO. "Electronic nicotine delivery systems" (PDF). Retrieved 28 August 2014.
  18. ^ Tobacco Control Research Branch of the National Cancer Institute. Smokefree.gov: E-cigarettes
  19. ^ a b c M., Z.; Siegel, M (February 2011). "Electronic cigarettes as a harm reduction strategy for tobacco control: a step forward or a repeat of past mistakes?". Journal of public health policy. 32 (1): 16–31. doi:10.1057/jphp.2010.41. PMID 21150942.
  20. ^ "Principles to Guide AAPHP Tobacco Policy". American Association of Public Health Physicians. Retrieved 31 July 2013.
  21. ^ a b "BMA calls for stronger regulation of e-cigarettes" (PDF). British Medical Association. Retrieved 18 November 2013.
  22. ^ a b c d O'Connor, RJ (March 2012). "Non-cigarette tobacco products: what have we learnt and where are we headed?". Tobacco control. 21 (2): 181–90. doi:10.1136/tobaccocontrol-2011-050281. PMC 3716250. PMID 22345243.
  23. ^ Polosa, Riccardo; Rodu, Brad; Caponnetto, Pasquale; Maglia, Marilena; Raciti, Cirino (2013), "A fresh look at tobacco harm reduction: the case for the electronic cigarette" (PDF), Harm Reduction Journal, 10 (10), doi:10.1186/1477-7517-10-19, PMID 24090432{{citation}}: CS1 maint: unflagged free DOI (link)
  24. ^ a b c Britton, J. & Bogdanovica, I. (May 2014). "Electronic Cigarettes" (PDF). Public Health England. Retrieved 21 May 2014.{{cite web}}: CS1 maint: multiple names: authors list (link)
  25. ^ a b c d e f Palazzolo, Dominic L. (November 2013), "Electronic cigarettes and vaping: a new challenge in clinical medicine and public health. A literature review.", Frontiers in Public Health, 1 (56), doi:10.3389/fpubh.2013.00056, PMC 3859972, PMID 24350225{{citation}}: CS1 maint: unflagged free DOI (link)
  26. ^ a b c Edgar, Julie. "E-Cigarettes: Expert Q&A With the CDC". WebMD. Retrieved 17 November 2013.
  27. ^ "Public Health Focus: Electronic Cigarettes (e-Cigarettes)". FDA. 24 April 2014.
  28. ^ Kufe, Donald W. (2009). Holland-Frei cancer medicine (8th ed.). New York: McGraw-Hill Medical. p. 395. ISBN 9781607950141.
  29. ^ Arnold, Carrie (2014). "Vaping and Health: What Do We Know about E-Cigarettes?". Environmental Health Perspectives. 122 (9): A244–A249. doi:10.1289/ehp.122-A244. PMC 4154203. PMID 25181730.
  30. ^ a b "Safety Watch: Electronic Cigarettes". FDA.
  31. ^ a b FDA (4 May 2009). "FDA 2009 Study Data: Evaluation of e-cigarettes" (PDF). Food and Drug Administration (US) -center for drug evaluation and research. Retrieved 4 May 2009.
  32. ^ Zezima, K. (22 July 2009). "Analysis Finds Toxic Substances in Electronic Cigarettes". The New York Times. Retrieved 26 April 2010.
  33. ^ Palmer, Roxanne (8 September 2013). "E-Cigarettes As Effective As Nicotine Patches in Helping Smokers Quit: Study". International Business Times. Retrieved 15 December 2013.
  34. ^ FDA (22 July 2009). "Summary of Results: Laboratory Analysis of Electronic Cigarettes Conducted By FDA". Retrieved 22 July 2009.
  35. ^ "E-cigarettes to be regulated as medicines". National Health Service. 12 June 2013. Retrieved August 2013. {{cite web}}: Check date values in: |accessdate= (help)
  36. ^ "Electronic cigarettes (e-cigarettes) or electronic nicotine delivery systems". World Health Organization. 3 June 2014.
  37. ^ a b c "Position Statement on Electronic Cigarettes [ECs] or Electronic Nicotine Delivery Systems [ENDS]" (PDF). The International Union against Tuberculosis and Lung Disease. October 2013.
  38. ^ a b c d Burstyn, I (9 January 2014). "Peering through the mist: systematic review of what the chemistry of contaminants in electronic cigarettes tells us about health risks". BMC Public Health. 14: 18. doi:10.1186/1471-2458-14-18. PMC 3937158. PMID 24406205.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  39. ^ a b c "New CDC study finds dramatic increase in e-cigarette-related calls to poison centers". CDC Newsroom (Press release). Centers for Disease Control and Prevention. 3 April 2014.
  40. ^ Hayden McRobbie, National Centre for Smoking Cessation and Training, 2014. Electronic cigarettes
  41. ^ Palazzolo, DL (2013). "Electronic Cigarettes and Vaping: A New Challenge in Clinical Medicine and Public Health. A Literature Review". Frontiers in public health. 1: 56. doi:10.3389/fpubh.2013.00056. PMC 3859972. PMID 24350225.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  42. ^ "Citing Health Concerns the American Cancer Society Calls for Action". American Cancer Society. Retrieved 12 November 2013. Government agencies and medical organizations, such as the FDA, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics have also expressed concern that electronic cigarettes could increase nicotine addiction and tobacco use in young people.
  43. ^ Centers for Disease Control and Prevention, (CDC) (6 September 2013). "Notes from the field: electronic cigarette use among middle and high school students – United States, 2011–2012". MMWR. Morbidity and mortality weekly report. 62 (35): 729–30. PMID 24005229.
  44. ^ Korioth, Trisha. "E-cigarettes easy to buy, can hook kids on nicotine". The American Academy of Pediatrics. Retrieved 17 November 2013.
  45. ^ "FDA Warns of Health Risks Posed by E-Cigarettes". FDA. 23 July 2009. Retrieved 17 November 2013—Reviewed 17 September 2013{{cite web}}: CS1 maint: postscript (link)
  46. ^ a b Farsalinos KE, Spyrou A, Tsimopoulou K, Stefopoulos C, Romagna G, Voudris V (2014). "Nicotine absorption from electronic cigarette use: Comparison between first and new-generation devices". Scientific Reports. 4: 4133. doi:10.1038/srep04133. PMC 3935206. PMID 24569565.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  47. ^ a b McQueen, Amy; Tower, Stephanie; Sumner, Walton (2011). "Interviews with "vapers": implications for future research with electronic cigarettes" (PDF). Nicotine & Tobacco Research. 13 (9): 860–7. doi:10.1093/ntr/ntr088. PMID 21571692.
  48. ^ "FAQs about electronic cigarettes – Las Vegas Sun News". Las Vegas Sun. Retrieved 20 November 2013.
  49. ^ "Vaping; nicotine gadget craze reaches Southern Utah". St George News. Retrieved 20 November 2013.
  50. ^ http://www.clubic.com/materiel-informatique/article-704447-1-cigarette-electronique.html%7C
  51. ^ "Disposable eCig Features". Blu cigs. Retrieved 19 November 2013.
  52. ^ Cassidy, Susan (26 October 2011). "HowStuffWorks "How Electronic Cigarettes Work"". Science.howstuffworks.com. Retrieved 27 August 2013.
  53. ^ EP application 2614731, Yonghai Li, Zhongli Xu, "An atomizer for electronic cigarette", published 17 July 2013 
  54. ^ http://www.hardingenergy.com/pdfs/5%20Lithium%20Ion.pdf
  55. ^ Ngonngo, Nancy. "As e-cigarette stores pop up in Twin Cities, so do the questions". Pioneer Press. Retrieved 20 November 2013.
  56. ^ a b c d e Couts, Andrew (13 May 2013). "Inside the world of vapers, the subculture that might save smokers' lives". Digital Trends. Retrieved 20 November 2013.
  57. ^ "E-Cig Basics: What Is a Cartomizer?". VapeRanks. Retrieved 19 November 2013.
  58. ^ Greg Olson (29 January 2014). "Smoking going electronic". Thetelegraph.com. Retrieved 6 February 2014.
  59. ^ "WHAT'S THE CHOICE BETWEEN A CLEAROMIZER VS ATOMIZER?". Retrieved 6 February 2014.
  60. ^ "How does the battery work?". Retrieved 3 October 2014.
  61. ^ "eGo VV Battery". Retrieved 3 October 2014.
  62. ^ "A Solution For Leading A Tobacco Free Healthy Life". Retrieved 6 February 2014.
  63. ^ "Vapor Corp. Launches New Store-in-Store VaporX(R) Retail Concept at Tobacco Plus Convenience Expo in Las Vegas". The Wall Street Journal. 29 January 2014. Retrieved 6 February 2014.
  64. ^ "E-cigarettes to be regulated as medicines". NHS, Gov.uk. 12 June 2013. Retrieved 6 February 2014.
  65. ^ "JoyeTech eVic Review". Real Electric Cigarettes Reviews.
  66. ^ "Evolv Seals The Deal – Gets Patent on Wattage, Plus More". Retrieved 11 October 2014.
  67. ^ a b "Battery Safety and Ohm's Law". http://onvaping.com. 10 February 2014. Retrieved 1 October 2014. {{cite web}}: External link in |publisher= (help)
  68. ^ a b "E-cigarettes: No smoke, but fiery debate over safety". USA Today. Retrieved 20 July 2013.
  69. ^ a b US FDA. Federal Register. Deeming Tobacco Products To Be Subject to the Federal Food, Drug, and Cosmetic Act, as Amended by the Family Smoking Prevention and Tobacco Control Act; Regulations on the Sale and Distribution of Tobacco Products and Required Warning Statements for Tobacco Products: A Proposed Rule by the Food and Drug Administration on 04/25/2014
  70. ^ Murray Laugesen (17 October 2007). "The Ruyan e-cigarette; Technical Information Sheet". Health New Zealand. Retrieved 31 March 2008.
  71. ^ "CDC Electronic Cigarette Statistics". CDC Newsroom. 28 February 2013. Retrieved 4 March 2013.
  72. ^ a b Centers for Disease Control and Prevention (CDC) (September 2013). "Notes from the field: electronic cigarette use among middle and high school students – United States, 2011–2012". MMWR Morb. Mortal. Wkly. Rep. 62 (35): 729–30. PMID 24005229.
  73. ^ Centers for Disease Control and Prevention, MMWR, 15 November 2013 Tobacco Product Use Among Middle and High School Students — United States, 2011 and 2012, retrieved 20 November 2013.
  74. ^ "More than a quarter-million youth have used e-cigarettes who have never smoked". 25 August 2014. Retrieved 30 August 2014.
  75. ^ a b c d e "Use of electronic cigarettes in Great Britain" (PDF). ASH. ASH. July 2014. Retrieved 18 September 2014.
  76. ^ "New survey finds regular use by children still rare". ASH-UK. Retrieved 17 September 2014.
  77. ^ Observatoire Français des Drogues et des Toxicomanies, Prévalence, comportements d’achat et d’usage, motivations des utilisateurs de la cigarette électronique, retrieved 28 March 2014.
  78. ^ James Dunworth for the Ashtray Blog. 3 May 2012 The History of the Electronic Cigarette
  79. ^ "US Patent 3200819. Smokeless non-tobacco cigarette". Retrieved 29 February 2012.
  80. ^ E-Cigarettes: The New Frontier In War On Smoking, NPR
  81. ^ "Who Invented Electronic Cigarettes?". Inventors.about.com. Retrieved 20 November 2013.
  82. ^ "CA Patent 2518174 – A Non-Smokable Electronic Spray Cigarette". WikiPatents. Retrieved 15 August 2012.
  83. ^ "Electronic Atomizer Cigarette European patent". Worldwide.espacenet.com. 22 November 2007. Retrieved 29 February 2012.
  84. ^ "Brothers who took a punt on a new market". CityAM. Retrieved 4 April 2014.
  85. ^ "Patent document and information service (Ipsum)". Intellectual Property Office. Retrieved 20 November 2013.
  86. ^ The Economist, 28 Sep 2013, Kodak Moment, retrieved 11 March 2014
  87. ^ a b "Altria Expands in E-Cigarettes With Green Smoke". Wall Street Journal. 3 February 2014. Retrieved 7 March 2014.
  88. ^ CBS News, 11 June 1023, Tobacco companies bet on electronic cigarettes, retrieved 16 August 2013.
  89. ^ Gustafsson, Katarina (2 September 2013). "Imperial Tobacco Agrees to Acquire Dragonite's E-Cigarette Unit". Bloomberg. Retrieved 20 November 2013.
  90. ^ "Our Story Puritane". Retrieved 4 April 2014.
  91. ^ "Lorillard, Inc. Acquires British-based SKYCIG, Expanding its Electronic Cigarette Business". Retrieved 1 October 2013.
  92. ^ "Altria Acquires Green Smoke, Inc". Green Smoke. 3 February 2014. Retrieved 23 February 2014.
  93. ^ Park, Andy (26 August 2013). "The Feed: The subculture around e-cigarettes". SBS World News. Retrieved 20 November 2013.
  94. ^ "Electric Cigarette Builds a Bizarre Latest Sub Culture in Town Says Deltascan.org". Sbwire.com. 4 June 2013. Retrieved 20 November 2013.
  95. ^ "Crutch or cure: issues surround use of e-cigarettes". Fremont Tribune. 9 November 2013.
  96. ^ Mike Esterl for the Wall Street Journal. 29 May 2014 'Vaporizers' Are the New Draw in E-Cigarettes
  97. ^ "The Cloud Chasers". 29 January 2014.
  98. ^ http://www.engadget.com/2014/05/23/vaporizers-explainer/
  99. ^ http://www.newsweek.com/veteran-e-cigarette-users-fret-cloud-chasers-give-them-bad-name-238978
  100. ^ European Commission. 26 February 2014 Memo/14/134: Questions & Answers: New rules for tobacco products
  101. ^ Eliza Gray for Time Magazine. 27 Feb. 2014 Europe Sets New Rules for E-Cigs While the U.S. Drags Its Feet
  102. ^ Sabrina Tavernise for the New York Times. 24 April 2014 F.D.A. Will Propose New Regulations for E-Cigarettes
  103. ^ "E-cigarette message goes up in smoke".
  104. ^ http://www.cspnet.com/category-news/tobacco/articles/nielsen-electronic-cigarette-dollar-sales-decline
  105. ^ http://blogs.wsj.com/corporate-intelligence/2014/04/14/are-e-cigarettes-losing-ground-in-the-vapor-market/
  106. ^ Nioventures. Nicoventures: "About Us" Accessed 2 June 2014
  107. ^ Tobacco Journal International (2011) BAT unit to market nicotine inhaler
  108. ^ Financial Times. "British American Tobacco nicotine inhaler wins regulatory approval". Retrieved 18 September 2014.
  109. ^ "News Release: Philip Morris International (PMI) Enters into a Patent Purchase Agreement of New Technology with the Potential to Reduce the Harm of Smoking". Philip Morris International. 26 May 2011. Retrieved 27 August 2013.
  110. ^ "New smoking cessation therapy proves promising". Esciencenews.com. 27 February 2010. Retrieved 27 August 2013.
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