Many view e-cigarettes as a safer alternative to tobacco containing products because they do not contain the carcinogens known to be present in tobacco. However, a review article published in the May 1 edition of Scientific American contained evidence that e-cigarettes might pose a risk of lung cancer. It also pointed to marketing campaigns to attract teens and non-smokers to e-cigarettes.
E-cigs use a small, heated coil to vaporize a solution into an aerosol mist. They first appeared in China in 2003 and are currently undergoing a significant increase in popularity. Both the US Food and Drug Administration (FDA) and the European Union are pondering how to regulate the products as well as defining the risk of “vaping” or exposure of others to the vapor. Thus, users of e-cigarettes are able to inhale their vapors in non-smoking areas.
E-cigarettes contain three main ingredients: nicotine, a flavoring agent, and propylene glycol, which is a syrupy synthetic liquid that is added to food, cosmetics, and certain medicines to absorb water and preserve moisture. A proven negative of e-cigarettes is the nicotine, which is a highly addictive stimulant. Nicotine causes constriction of the arteries, which can increase the risk of cardiovascular disease. It also has resulted in amputation of limbs in susceptible individuals. Some studies have suggested that nicotine may impact the immune system. The FDA has designated the substances as “generally recognized as safe,” (GRAS); however this designation has been applied to ingestion rather than inhaling its vapor.
The flavoring agent contained in e-cigarettes also poses a public health risk because it attracts teens to the product. According to recent data from the Centers for Disease Control and Prevention's National Youth Tobacco Survey, e-cigarette use among US high school students more than doubled from 4.7% in 2011 to 10% in 2012. Furthermore, approximately 160,000 students who had never tried conventional cigarettes have vaped. E-cigarettes come in kid-friendly flavors, such as bubble gum, chocolate, gummy bear. The can be purchased online and in malls; thus, minors can readily acquire the products.
In addition to the three main ingredients of e-cigarettes, small amounts of other substances are present, which are by-products from heating the devices and the solution inside them. A number of studies have reported that the vapors from e-cigarettes contain several carcinogens, as well as extremely tiny particles of tin, chromium, nickel, and other heavy metals; in a high enough concentration, these minerals can cause lung damage. The researchers believe that tiny particles (nanoparticles) probably break off the solder joints or metal coil in the devices when heated. Because they are extremely tiny, they can travel deep into the lungs. Thus, they could aggravate asthma, bronchitis, and emphysema. To date, however, studies have not proven for certain whether e-cigarettes exacerbate these lung problems.
Another recent study assessed the cancer risk of e-cigarettes. It involved growing human lung cells, which had been modified to have mutations related to cancer risk, in two types of liquids. One had been exposed to e-cigarette vapor, and the other was exposed to tobacco smoke. Both sets of cells changed in ways associated with cancer. Limitations of the study were that it was an in vitro (conducted in a laboratory) study rather than an in vivo (conducted on human subjects). The study has not been published to date but was reported at a meeting of lung cancer researchers. It is likely that this pilot study may lead to further research on a link between e-cigarettes and lung cancer.
Take home message:
If a link between e-cigarettes and cancer is proven, it will most likely be a lower risk than that of tobacco products. However, even a small increase in risk (e.g., 1%) is 100% if it happens to you. The increasing popularity of e-cigarettes among teens is disturbing. Once addicted to nicotine, teens—and adults—may switch to more harmful tobacco products. One must keep in mind that nicotine is addictive and can, in itself, have serious health consequences. Some individuals switch to e-cigarettes in an attempt to quit smoking. This is unproven because some studies have supported this concept while others refute it. Another health hazard of e-cigarettes is that one teaspoon of liquid nicotine can kill a person—the user or even a child who swallows it.