E-cigarettes (or electronic nicotine delivery systems, or ENDS) are devices that heat a liquid to produce aerosols that the user inhales. The vapor is typically composed of nicotine and flavourings, but can also contain propylene glycol and vegetable glycerin. Some e-cigarettes look like conventional combusted cigarettes or cigars, while others resemble pens or USB flash drives. ENDS are usually sold pre-filled with a liquid containing nicotine and other ingredients (e-liquid), although refillable models are available.
Nicotine is an addictive substance that can cause serious harms to the body, especially in smokers. In addition to the well-known risks of tobacco smoking, e-cigarettes are associated with various adverse health effects, including inflammation and oxidative stress. However, it is not yet possible to determine their long-term effects on human health, as they have only been around for about a decade.
Research on e-cigarettes is ongoing and some of the negative consequences that have been observed so far include platelet activation, altered vascular endothelial function and atherogenesis, as well as changes in blood pressure regulation. There are also reports that e-cigarettes can increase inflammatory markers in the blood, such as leukocyte activation index and C-reactive protein.
Despite these health concerns, e-cigarettes are very popular and widely used worldwide. Many governments have banned or restricted their sale, while some promote the use of e-cigarettes as a smoking cessation tool. Despite the widespread belief that e-cigarettes are safer than conventional cigarette smoking, a growing number of studies have shown that they are not. In particular, a recent study has shown that even short-term exposure to e-cigarette aerosols can cause serious lung inflammation and can damage the lungs.
The toxicity of e-cigarettes is due to the combustion of a flammable liquid called e-liquid, which typically contains nicotine (and often other additives, flavourings and chemicals) and is heated in an atomizer. This process generates a vapour that the user inhales. The liquid is usually stored in a container such as a cartridge or tank and can be recharged or replaced.
Several different models of ENDS are currently available, ranging from large devices that look like conventional combusted cigarettes to small “pod” systems that are pre-filled with e-liquids. The most popular model is JUUL, a reusable device that has gained popularity since it was first introduced in 2015 and currently accounts for over half of the reusable e-cigarette market share. Other popular e-cigarettes are the Suorin Drop, myblu and Vuse Alto. They all follow the JUUL blueprint of high nicotine delivery via nicotine salt e-liquids sold in pre-filled disposable pods.
Regardless of their design, all e-cigarettes should be considered dangerous and should be avoided by children, adolescents, pregnant women and adults who have a history of smoking or are at risk for developing one. If you are currently using a cigarette substitute, such as an e-cigarette, talk to your doctor or nurse about the best way to quit. Decide why you want to quit and make a plan, including getting help from your doctor or a support group. Pick a day to quit and write it down or put it on your calendar. Tell supportive friends and family about your plans to quit, as they can help you stay motivated. 電子煙