E-cigarettes have become increasingly popular as an alternative to conventional tobacco cigarettes. But little is still known about their long-term health effects.

The U.S. Centers for Disease Control and Prevention says e-cigarettes may potentially help adult smokers if they completely substitute the devices for tobacco products. But the CDC cautions that it is still unclear whether e-cigarettes can help smokers kick the habit. And it warns that the products are not safe for teens, young adults, pregnant women or non-smokers.

Most e-cigarettes deliver nicotine to their user, creating the potential for addiction.

The United States Surgeon General has called e-cigarette use among teens an epidemic, citing a 900 percent increase in vaping among teens between 2011 and 2015. The industry faces e-cigarette lawsuits over teens becoming addicted to nicotine and over manufacturers’ marketing practices that downplayed addiction risks.

How E-Cigarettes Work

E-cigarettes, or e-cigs, come in a variety of shapes and sizes. Some may look like tobacco cigarettes, pens USB drives or other objects. But most consist of a battery, heating element and a tank or compartment to hold a liquid. Liquids may come in the form of a replaceable cartridge and come in a wide variety of flavors. Using an e-cigarette is sometimes called vaping.

Illustration of how an e-cigarette works
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Illustration breaking down how an e-cigarette works

When the user inhales, it activates the device. The battery-powered heating element heats the liquid in the e-cig, turning it into an aerosol vapor. Users inhale this vapor into their lungs. Bystanders may also inhale it as the user exhales.

The vapor usually contains nicotine, the addictive chemical in tobacco, along with other chemicals. E-cigarettes may also be used to deliver marijuana or other illicit drugs.

E-Cigarette Myths

E-cigarettes are often marketed as smoking cessation tools or as a safe alternative to tobacco. But these and other myths about e-cigs create a smokescreen of false security about the devices.

5 Myths About E-Cigarettes
E-Cig vapor is safe or pure
E-cigarette vapor usually contains nicotine as well as other potentially toxic chemicals that can lead to nicotine addiction or other serious health conditions.
E-Cigarettes are a safe alternative to tobacco
Neither e-cigs nor the e-liquids they use are regulated for purity or safety by federal regulators. Toxins in e-liquids may not be included on labels.
E-Cig nicotine is addictive but not dangerous
Nicotine does not cause cancer, but it plays a key role in promoting tumor growth. It also contributes to cardiovascular and respiratory conditions.
There is no gateway effect
A 2017 study in the Journal of the American Medical Association Pediatrics found that young people who started with e-cigarettes were at a greater risk for moving on to tobacco use.
E-cigs don't produce secondhand smoke
Breathing in secondhand vapor, also called passive vaping, can expose non-users to toxic chemicals. A 2017 study in the Bulletin of the World Health Organization found that levels of some metals in secondhand vapor were higher than in secondhand smoke.

Can E-Cigarettes Help You Stop Smoking?

Manufacturers have marketed e-cigarettes as a tool to help people stop smoking. But there is no conclusive scientific evidence that e-cigs are effective at helping people quit smoking long-term, according to the National Institute on Drug Abuse.

The U.S. Food and Drug Administration has not approved e-cigarettes as a smoking cessation aid. The FDA has approved seven other quit-smoking aids that have been shown to be safe and effective. These include over-the-counter nicotine gum, lozenges and patches. It also includes two prescription drugs that do not contain nicotine, Chantix and Zyban.

The National Academies of Science, Engineering and Medicine concluded in 2018 that there is limited evidence that e-cigarettes can be effectively used to stop smoking. The academies also found insufficient evidence on whether e-cigarettes are an effective smoking cessation aid when compared to no treatment or to other FDA approved smoking cessation methods.

E-Cigarette Risks

Since e-cigarettes are a relatively new invention, little is known about their long-term health effects. But a 2018 study presented at the Society for Research on Nicotine and Tobacco was the first to find evidence of long-term health risks of e-cigs. Researchers from the University of California San Francisco studied 70,000 people and found daily e-cigarette use doubled the risk of a heart attack.

Scientists already know a lot about nicotine and other chemicals the devices deliver to users. Nicotine increases a user’s heart rate and raises blood pressure and is highly addictive.

Nicotine addiction can increase the risk of cardiovascular, respiratory and digestive tract diseases. It also weakens the immune system, disturbs reproductive health and affects the health of cells in the human body, which can lead to cancer. Nicotine may also lead to Type 2 diabetes and insulin resistance.

“The more chemicals contained in an e-liquid, the more toxic it was likely to be.”

Other chemicals in e-cigarette liquids also pose serious health risks. There are more than 7,700 e-liquid flavors on the market in the United States. But the two most common chemicals are propylene glycol and vegetable glycerin. A 2018 study in PLOS Biology found that inhaling even small doses of these chemicals exposes users to high levels of toxins.

The researchers developed a system to quickly analyze the toxicity of different e-liquids. They found that flavors with more chemicals also posed greater risks to the user.

“The more chemicals contained in an e-liquid, the more toxic it was likely to be,” the authors wrote.

The researchers also set up an online database of e-liquid chemicals. E-cigarette users can search by flavor or individual chemical to find out how toxic their e-liquid is.

Fire and Explosion Risks

Unlike tobacco cigarettes, e-cigs pose an explosion risk due to their lithium ion batteries. The batteries are generally safe and are used in a multitude of electronic devices, including cell phones and computers. But the batteries can catch fire or explode when they are damaged or defective.

While explosions are rare, the Federal Emergency Management Administration highlighted the unique risk of e-cigarettes in a 2017 report.

“The combination of an electronic cigarette and a lithium-ion battery is a new and unique hazard,” the report said. “There is no analogy among consumer products to the risk of a severe, acute injury presented by an e-cigarette.”

The agency’s U.S. Fire Administration documented 195 fires and explosions associated with e-cigarettes between January 2009 and the end of 2016. These resulted in 133 injuries, including 38 that the agency classified as severe.

“The combination of an electronic cigarette and a lithium-ion battery is a new and unique hazard. There is no analogy among consumer products to the risk of a severe, acute injury presented by an e-cigarette.”

The agency found that 62 percent of the reported fires or explosions involving an e-cigarette or its battery happened when the device was in a pocket or in use.

The report said the design of e-cigarettes can make them “behave like ‘flaming rockets’ when a battery fails.”

Teen Vaping Risks

In addition to potential long-term health effects of e-cigarettes, teens and young adults who take up vaping are at risk of quickly developing nicotine addiction, experiencing seizures and suffering upper respiratory problems.

E-cigarettes have been the most commonly used tobacco product among young people since 2014, according to an advisory from the United States Surgeon General. And research by the National Academies of Science, Engineering and Medicine found evidence that vaping may lead teens to take up other tobacco products in the future.

A December 2018 advisory from the Surgeon General’s office labeled teen e-cig use an epidemic and noted that more than 3.6 million young Americans use the devices. The Surgeon General estimated 1 in every 5 high school students and 1 in 20 middle school students used e-cigarettes in 2018.

High school and middle school e-cigarette use statistic
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Source: Surgeon General’s Advisory on E-cigarette Use Among Youth

“The recent surge in e-cigarette use among youth, which has been fueled by new types of e-cigarettes that have recently entered the market, is a cause for great concern,” Surgeon General Jerome Adams said in the advisory.

“The recent surge in e-cigarette use among youth, which has been fueled by new types of e-cigarettes that have recently entered the market, is a cause for great concern.”
Surgeon General’s Advisory on E-cigarette Use Among Youth Source: Surgeon General

The National Academies determined that if teens or young adults take up vaping, there is “substantial evidence” they are more likely to use conventional cigarettes.

The report’s authors reviewed more than 800 different studies. They also found moderate evidence that e-cig use put young people at a higher risk for coughing and wheezing as well as asthma-related incidents.

A 2019 study in the journal Pediatrics surveyed teens and young adults and found they are unaware that they inhale nicotine when using e-cigarettes. The researchers looked at 517 adolescents who were between 12 years old and 21 years old. They found that 40 percent of the adolescents thought they had been using nicotine-free products but were actually inhaling the addictive chemical.

“This is one of the first studies showing the amount of nicotine kids are getting from e-cigarettes,” study author Dr. Rachel Boykan told NBC News. “They’re getting a lot — as much or more than they would with traditional cigarettes.”

Young people may also be at risk for developing seizures linked to e-cigarette use. The FDA launched an investigation into the possible connection after it received 35 reports of e-cig users experiencing seizures since 2010. The agency said most cases involved teens and young adults.

Teen Brain Risks

Nicotine in e-cigarettes can also affect brain development in teens. The human brain continues to develop into the mid-20s.

Brain cells build stronger connections, called synapses, each time a person learns a new skill or creates a new memory. Young people build these connections faster than older people. But nicotine changes the way a brain forms synapses.

Nicotine exposure during adolescence can affect memory, learning, mood, impulse control and attention. And it can increase addictive behavior, leading to abuse of other addictive substances.

Is Big Tobacco Behind E-Cigarettes?

JUUL, the top-selling e-cigarette brand in the United States, marketed itself as independent of “Big Tobacco.” On June 22, 2018, the company even posted, “JUUL Labs is not big tobacco” on its now-deleted Instagram account. But in December 2018, JUUL sold 35 percent of the company’s ownership to tobacco company Altria.

Altria is the parent company of Philip Morris, the maker of Marlboro cigarettes. It controls more than half the tobacco cigarette market in the United States. As part of the deal, Altria promised to give up top-shelf display space in retail stores so that JUUL e-cigs could be displayed next to Marlboro cigarettes.

Large tobacco companies have moved quickly into the e-cig business. CNBC reported that big tobacco brands had already controlled more than 20 percent of the e-cigarette market in the United States before the deal between Altria and JUUL.

Big Tobacco E-cig and Combustible Cigarette Brands

British American Tobacco
E-Cig Brands
Vuse, Vype, Chic, VIP
Tobacco Brands
Camel, Newport, American Spirit, Lucky Strike
Altria – Philip Morris
E-Cig Brands
JUUL (35% ownership), MarkTen (discontinued), Green Smoke (discontinued)
Tobacco Brands
Marlboro, Virginia Slims, Parliament, Basic
Imperial Brands
E-Cig Brands
Blu
Tobacco Brands
Winston, Kool, Salem, Maverick

E-cigarettes are big business, worth more than $10 billion in 2017. Sales of e-cigarettes have been increasing even as sales of conventional cigarettes have plummeted.

Some big tobacco companies prominently display their e-cigarette products on their websites and promote them to investors as products that will drive future profits.

Last Modified: July 16, 2019

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