Vapers, Beware of the Vapors

They were touted as safe tobacco alternatives. They would help smokers quit and discourage non-smokers—especially young people—from taking up the habit in the first place. Yet, e-cigarettes, also known as e-cigs, vapes, e-hookahs, vape pens or cigalikes, may in fact be more harmful than conventional cigarettes. What’s more, they are attracting an alarming and growing number of young customers, whose regular vaping exposes them to dangerous levels of nicotine and an array of toxic and potentially carcinogenic chemicals that could endanger their health. Because it is not known what harmful chemicals e-cigarettes contain, it has been virtually impossible to assess their long-term health impact—until now.

Dr. Ilias Kavouras, Professor of Environmental, Occupational, and Geospatial Health Sciences at CUNY SPH, and colleagues recently published a study assessing the toxicity of e-cigarette vapors. The study, which appeared in the March 2018 issue of Inhalation Toxicology, found that specific aspects of e-cigarette use, including device brands and types, flavorings, puffing patterns, and voltage/heat level, profoundly influence and often increase the toxicity of vapors that e-cigarettes emit and that users inhale.

“The younger you are when you use e-cigarettes, the more chemicals will enter your body and interact with still-developing vital organ functions, which is why young people are at higher risk than adults,” says Kavouras. “E-cigarettes are marketed as safer than tobacco smoking but youngsters who use them may be inhaling carcinogens. They may not produce tar like tobacco but they’re not safe.”

A Vaping Epidemic: What’s the draw?

Vaping has reached epidemic proportions among youth. A December advisory from the U.S. surgeon general estimated that e-cigarette use among high-school students increased by 900 percent between 2011 and 2015 and by 78 percent in 2018. The Centers for Disease Control and Prevention (CDC) reports that more high school students choose e-cigarettes over conventional cigarettes, and their use exceeds that of adults. Compared to 3.2 percent of U.S. adults who used e-cigarettes in 2016, more than two million U.S. middle and high school students had used e-cigarettes in the past 30 days, the CDC says. From 2011 to 2017, e-cigarette use among high school students rose from 1.5 percent to 11.7 percent, and from 0.6 percent to 3.3 percent among students in middle school.

Curiosity and the perception of e-cigarettes’ relative harmlessness entice children and teens, the surgeon general’s advisory notes. But the biggest draw is their extensive variety of flavors—more than 7,700—including fruit, candy, tobacco, mint, coffee, and alcoholic cocktails, like strawberry daiquiri.

“You step into a vaping store and it’s like stepping into a candy store,” Kavouras says. “The packaging and flavors are very attractive to kids.” Some stores make their own flavors, using unregulated ingredients of questionable quality, he adds.

In November, in an effort to make vaping less popular among young people, the U.S. Food and Drug Administration ruled that flavored e-cigarettes may only be sold in closed off-areas, inaccessible to teenagers. Earlier that month, a proposal to ban the products entirely was leaked, prompting Juul Labs to announce it would stop selling most of its flavored e-cigarettes in retail stores and promoting its products on social media.

At a January public hearing, FDA Commissioner Dr. Scott Gottlieb threatened to ban e-cigarettes altogether if companies, namely Juul, didn’t stop marketing their products to minors.

“I’ll tell you this,’ Gottleib said. “If the youth use continues to rise, and we see significant increases in use in 2019, on top of the dramatic rise in 2018, the entire category will face an existential threat.”

These are not the first attempts to clamp down on e-cigarettes. In August 2016, the FDA said that it would subject e-cigarettes to the regulations of the Family Smoking Prevention and Tobacco Control Act, requiring, among other things, that manufacturers provide the FDA with detailed information about the ingredients in their products. So far, however, the FDA has only required manufacturers to disclose the quantity of nicotine in their products—a requirement that many ignore, Kavouras says.

“It’s taken many years for the FDA to decide they have the authority to regulate e-cigarettes but they haven’t regulated anything yet,” he says.

Last spring, more than a half-dozen public health groups, joined by pediatricians, sued the FDA for delaying regulation of e-cigarettes. In the meantime, Kavouras notes, “the market is exploding.”

Customization Increases Risk

Little is known about the long-term health effects of e-cigarettes because little is known about their ingredients. Kavouras’ study found that, in addition to their specific ingredients, it is e-cigarettes’ customizability—users’ ability to enhance personal satisfaction by increasing operational voltage, incorporating different flavor additives or alternating puffing patterns—that makes them so dangerous. Individually or together, these variables compound the toxicity of the mist they produce, which settles deep into the lungs of vapers and bystanders alike.

Although e-cigarettes don’t produce a steady smoke stream, they do produce secondhand smoke in the form of exhaled vapors that linger in closed spaces. Moreover, because people believe e-cigarettes to be safe, they smoke in places where traditional smoking is forbidden, like commuter trains and restaurants, exposing others to secondhand vapors.

“There are harmful components in e-cigarette vapors that users are inhaling, and some of these are carcinogenic,” notes Kavouras, who has spent his career, including his post-doctoral years at the Harvard T.H. Chan School of Public Health, studying the health effects of environmental toxins, such as air toxics and ozone pollution, nanoparticles embedded in paints, and polynuclear aromatic hydrocarbons in residences. To conduct his research on e-cigarettes, he used sophisticated methods that his research team developed, as well as partnerships at Harvard.

In his analysis, Kavouras identified four groups of chemicals in the liquid that e-cigarettes contain: nicotine, solvents (mostly propylene glycol and glycerin), flavor additives, and preservatives. Nicotine comprises only five percent of e-cigarette liquid, far less than that of regular cigarettes, but it poses multiple risks, including addiction, (a 2010 Surgeon General’s report deemed it as addictive as cocaine and heroin) and at the very least, damage to cardiovascular, respiratory, renal, and reproductive health.

Because e-cigarettes have inefficient nicotine-delivery systems, young users tend to take more frequent, longer and harder puffs to get the desired dose, subjecting their developing brains to the risk of nicotine over-exposure, as well as chemicals and volatile organic compounds which, when heated and vaporized, become toxic.

“Once you heat the e-liquid, byproducts through the thermal breakup of the solvents, flavors and other chemical in the e-liquid are produced,” Kavouras explains.

Propylene glycol and glycerin (the most abundant ingredients in e-cig liquids) are deemed safe in food products but inhaling them may be harmful. Furthermore, when heated they produce benzene and formaldehyde, which can, among other things, cause damage to the liver, kidneys, and central nervous system.

“These byproducts are not in the original e-liquid but are formed through heating,” Kavouras says. “The more you use an e-cigarette, the more vapor and chemicals you are going to inhale. The fact that you have formaldehyde and benzene in there is alarming by itself because they are known human carcinogens.”

Increasing e-cigarettes’ voltage—and thus, heat—is another strategy that teens use to maximize their intake of nicotine and overall vaping satisfaction, and that also intensifies the concentration of chemical byproducts, Kavouras says.

“The higher temperatures you use to heat e-liquids, depending on their flavors, the more likely you are to generate greater quantities of these chemicals.”

For example, he found that raising an e-cigarette’s voltage from 2.2 to 5.7 volts generated 1500 times more particle mass, 2000 times more propylene glycol, 2700 times more glycerin, 2300 times more nicotine, 11 times more benzene, and two times more toluene. Higher voltages also generated more particles, a finding that he says is particularly important since most e-cigarette users use advanced devices that allow them to adjust voltage.

Flavor additives, which comprise only five percent of e-cigarette liquid, are also potentially dangerous because they often contain the chemical diacetyl, which is linked to serious lung disease. And, as Kavouras’ study revealed, additives such as aldehydes, ketones and esters cause different flavors, when heated, to produce different quantities of volatile organic compounds. The tobacco flavored liquid, for example, generated more than seven times greater particle mass than the menthol flavor, while the menthol flavor generated four times more benzene and two times more toluene than the tobacco flavor. E-cigarette type also affected emissions, Kavouras found. Disposable designs generated more small particles and the highest amount of benzene, compared to pre-filled and refillable designs.

A Changing Market

Despite the FDA’s attempts to regulate e-cigarettes, their market continues to grow. Understanding the health risks may dissuade potential smokers but manufacturers are still not disclosing their health information, Kavouras says.

“The whole risk assessment process needs to be done and that takes time and a huge amount of resources. Toxicological studies that do exist have large discrepancies largely because there are no standards regulating the generation and characterization of e-cigarette emissions.”

Complicating matters is the ever-changing makeup of e-cigarettes. “The technology is changing, e-liquids are changing, and markets are evolving,” Kavouras adds. Newer and more potent mixtures are rapidly coming onto the market, with some sellers custom-mixing e-liquids, combining more or less nicotine and a range of other ingredients, whose interaction is unknown.

“The market is only 15 years old and changing very rapidly, so it’s difficult for scientists to catch up and make conclusions because it takes time and money to do risk assessment evaluations.”

Kavouras hopes his ongoing research will close this critical information gap, even though he knows he has just begun to scratch the surface.

“The fact that these chemicals are there at the levels we’re finding is of great concern,” he says. “We’re trying to understand what else is in there, other than what we’ve already found.”