What Are E-Cigarettes?

E-cigarettes, also known as vapes or electronic nicotine delivery systems (ENDS), are battery-powered devices that heat a liquid solution (usually containing nicotine) to create an aerosol that the user inhales. They were first introduced in the mid-2000s as a less harmful alternative to traditional combustible cigarettes. The main ingredients in e-cigarette liquid are:

• Propylene glycol and vegetable glycerin (base liquids)
• Nicotine
• Flavorings

E-cigarettes come in many different designs, but most fall into one of four main categories:

Type	Description
Cig-a-likes	Small devices designed to look like traditional cigarettes. Often disposable.
Vape pens	Pen-shaped rechargeable devices with replaceable e-liquid cartridges.
Mods	Larger, customizable devices with more powerful batteries and adjustable settings. For experienced users.
Pods	Compact rechargeable devices that use pre-filled e-liquid pods. Popular with youth.

Prevalence of E-Cigarette Use

E-cigarette use has rapidly increased over the past decade, especially among youth and young adults. According to the 2021 National Youth Tobacco Survey:

• 11.3% of high school students and 2.8% of middle school students reported using e-cigarettes in the past 30 days
• For high schoolers, this was a significant decline from 27.5% in 2019, likely due to increased regulations and the COVID-19 pandemic
• Disposable e-cigarettes like Puff Bar have become increasingly popular among youth

In adults, e-cigarette use is most common among:

• Young adults aged 18-24
• Current and former smokers using e-cigarettes to quit traditional cigarettes
• Men compared to women

Health Effects of E-Cigarettes

Toxicology

While e-cigarette aerosol generally contains fewer toxic chemicals than the smoke from burned tobacco products, it is not harmless. E-cigarette liquid and aerosol have been found to contain substances that can be dangerous to human health, including:

• Ultrafine particles that can be inhaled deep into the lungs
• Flavorings like diacetyl, a chemical linked to a serious lung disease
• Volatile organic compounds
• Cancer-causing chemicals
• Heavy metals such as nickel, tin, and lead

The long-term health effects of inhaling these substances are not yet fully known. More research is needed.

Nicotine Exposure

Most e-cigarettes contain nicotine, a highly addictive substance that can harm brain development in youth and young adults. Nicotine exposure from e-cigarettes is a serious concern for several reasons:

• Youth who use e-cigarettes are more likely to become addicted to nicotine and transition to smoking regular cigarettes
• E-cigarettes can deliver high levels of nicotine, especially in products like Juul which uses nicotine salts
• The developing brain is more vulnerable to addiction

Comparison of nicotine levels in popular e-cigarette products:

Product	Nicotine Concentration	Nicotine Per Pod/Cartridge
Juul	59 mg/mL (5%)	40-50 mg
Vuse Alto	18-50 mg/mL	17-47 mg
NJOY Ace	35-50 mg/mL	17-25 mg
blu	9-36 mg/mL	7-25 mg

Other Health Risks

Studies suggest that e-cigarette use may be associated with several other health risks:

• Respiratory problems like cough, wheezing, and shortness of breath
• Cardiovascular issues like increased blood pressure and heart rate
• Increased risk of smoking-related illnesses for e-cigarette users who also smoke regular cigarettes (dual users)
• Increased risk of e-cigarette or vaping use-associated lung injury (EVALI), a severe lung illness linked to vitamin E acetate in THC vaping products

More long-term research is needed to fully understand the risks of e-cigarette use. However, the evidence so far indicates that e-cigarettes are not without harm and their long-term use is likely to have negative effects on health.

E-Cigarettes and Smoking Cessation

One of the main arguments in favor of e-cigarettes is their potential to help people quit smoking traditional cigarettes. Some evidence supports this idea:

• A 2021 Cochrane review found that nicotine e-cigarettes probably help more people to stop smoking than traditional nicotine replacement therapies like patches and gum
• Randomized control trials in the UK have shown higher quit rates for smokers given e-cigarettes compared to those given nicotine replacement therapy

However, there are also concerns about using e-cigarettes for smoking cessation:

• Most smokers who attempt to quit using e-cigarettes do not fully switch and end up using both products (dual use)
• There is a risk that smokers may simply switch to long-term e-cigarette use rather than quitting nicotine products altogether
• The effectiveness of e-cigarettes for quitting may depend on the type of device and frequency of use

Major health organizations currently have differing recommendations on e-cigarettes for smoking cessation:

Organization	Recommendation
CDC	“If you are an adult who used e-cigarettes containing nicotine to quit cigarette smoking, do not return to smoking cigarettes.”
American Heart Association	“E-cigarettes should not be promoted or prescribed as a first-line tobacco cessation aid.”
American Cancer Society	“Using e-cigarettes may be helpful for some people who are trying to quit smoking.”
US Preventive Services Task Force	“The current evidence is insufficient to recommend e-cigarettes for smoking cessation in adults, including pregnant women.”

More research is needed to determine the long-term effectiveness of e-cigarettes for smoking cessation and to understand which usage patterns are most likely to result in successful quitting.

Regulation of E-Cigarettes

E-cigarette regulations vary widely between countries and are constantly evolving as new evidence emerges. In the United States, the Food and Drug Administration (FDA) has regulatory authority over e-cigarettes under the Family Smoking Prevention and Tobacco Control Act.

Key US regulations include:

• As of 2016, e-cigarettes are regulated as tobacco products
• Nationwide minimum age of 18 for e-cigarette sales (21 in some states)
• Required health warnings on e-cigarette packaging and advertising
• Ban on misleading marketing terms like “light” or “mild”
• Premarket application requirements for new e-cigarette products

In response to the youth vaping epidemic, several additional regulations have been implemented or proposed:

• 2020 FDA enforcement priorities on cartridge-based flavored e-cigarettes
• State and local restrictions on e-cigarette flavors and sales
• Increased taxes on e-cigarettes products
• Further limits on e-cigarette marketing and advertising

As the long-term health impact of e-cigarettes becomes clearer, it is likely that regulations will continue to evolve.

Conclusions

The latest evidence suggests that while e-cigarettes are likely less harmful than traditional cigarettes, they are not without health risks. The long-term effects of e-cigarette use are not yet fully known, but studies have identified several potential harms, including exposure to toxic chemicals, nicotine addiction, and negative impacts on respiratory and cardiovascular health.

E-cigarettes may have a role to play in helping some smokers quit, but their effectiveness for smoking cessation is still uncertain. Youth use of e-cigarettes is a major concern, as nicotine exposure during adolescence can harm brain development and lead to lifelong addiction.

Regulators face the challenge of balancing the potential benefits of e-cigarettes for adult smokers against the clear risks they pose to youth. As more evidence emerges, e-cigarette regulations are likely to continue evolving to protect public health.

FAQs

Are e-cigarettes safe?

E-cigarettes are likely less harmful than traditional cigarettes, but they are not safe. E-cigarette aerosol contains toxic chemicals and high levels of nicotine that can harm health. The long-term effects of e-cigarette use are not yet fully known.

Can e-cigarettes help me quit smoking?

Some studies suggest that e-cigarettes may help smokers quit, but the evidence is mixed. E-cigarettes are not approved by the FDA as a smoking cessation aid. If you are trying to quit smoking, talk to your doctor about evidence-based methods like nicotine replacement therapy, prescription medications, and counseling.

Why is there an epidemic of youth e-cigarette use?

Several factors have contributed to high rates of e-cigarette use among youth:
– Flavors and design features that appeal to youth
– Misleading marketing suggesting e-cigarettes are safe
– High nicotine levels that can lead to addiction
– Easy access through online sales and social sources

Comprehensive regulations are needed to address this serious public health problem.

What are the signs of EVALI?

Symptoms of e-cigarette or vaping use-associated lung injury (EVALI) include:
– Cough, shortness of breath, or chest pain
– Nausea, vomiting, abdominal pain, or diarrhea
– Fever, chills, or weight loss

See a healthcare provider right away if you have symptoms of EVALI. Be sure to mention any history of vaping or e-cigarette use.

Where can I find more information about e-cigarettes?

For more information about e-cigarettes and their health effects, check out these trusted resources:

• CDC: About Electronic Cigarettes
• FDA: Vaporizers, E-Cigarettes, and other ENDS
• Truth Initiative: E-cigarettes: Facts, stats and regulations
• American Lung Association: E-Cigarettes and Lung Health

Talk to your healthcare provider if you have specific questions or concerns about your e-cigarette use.