The hazy science around vaping safety

The ongoing epidemic, which is mostly but not entirely tied to black market vapes containing the marijuana component THC, has killed at least 27 people and sickened nearly 1,300 as of Friday. It caught the public by surprise but it wasn’t such a shock to the researchers who have been studying vaping for the last decade. They’ve gathered evidence of lots of potential damage, even the possibility of cancer.

“We see loads of changes in the lungs of vapers — some like smokers’ lungs, some different,” said Robert Tarran, a University of North Carolina biologist who has studied e-cigarette safety since 2013. “The [lung cells] look really unhappy is the best way to describe it.”

The surge in youth vaping also has caused alarm. The Trump administration last month moved to ban flavored vapes, as health officials grapple with regulation of the e-cig industry overall.

As vaping took off in recent years the industry — whose large companies are owned by tobacco interests — put forward an easy-to-inhale theory that their products were a clean and healthy alternative to smoking. Smokers, teenagers, pundits and even doctors were swayed by the argument, since tobacco contains 4,000 chemicals — including 70 known carcinogens. Standard vapes have only nicotine, solvents and flavorings.

Meanwhile, independent scientists toiling in their labs were finding other evidence, and several of them told POLITICO that the industry argument is a smokescreen. Just because vapes have fewer chemicals than regular cigarettes doesn’t mean they are safe.

“It’s apples and oranges,” says Tarran’s colleague Ilona Jaspers, an environmental scientist who runs a separate lab at the University of North Carolina. “We’re going to be finding things we’ve never seen with smoking cigarettes.”

This creates problems for FDA, which announced Sept. 20 it plans to regulate e-cigarettes under the standard that they must be proven “appropriate for the protection of the public health.” FDA clearly will demand that marketers keep vapes out of the hands of teenagers. Youth vaping has reversed decades of declining nicotine use among the young. Older smokers who decide to switch, meanwhile, would have to balance the known risks of tobacco against the growing, yet uncertain risks of vaping.

Policymakers need to learn the lessons of cigarette history, scientists say: it took decades for medicine to notice that the heavily marketed products caused lung cancer, decades more to prove they were addictive and caused a host of other diseases as well. The effects of e-cigarette use may not be apparent for decades. And they may look quite different from the harms of smoking.

Another lesson from tobacco: a survey of health literature on vapes last year found that 95 percent of research papers that had no conflict of interest found potentially harmful effects from e-cigarettes — compared to only 8 percent of tobacco industry-related studies.

Most of the illnesses in the lung disease epidemic that CDC began tracking in August have been attributed to black-market marijuana vapes thought to contain an inadvertent toxin, perhaps material added as a thickener. But 13 percent of patients reported only vaping nicotine products. And that’s just the acute cases of injury. No one has studied the impact of sucking these vapors deep into the lungs for years on end.

An NIH-funded study published Monday in the Proceedings of the National Academy of Sciences showed that standard e-cigarette vapor causes lung cancer and potentially bladder cancer in mice, leading researchers at New York University to conclude that vaping will probably cause some human cancers, as well as other diseases.

In a recent review of the health evidence around vaping published in the British Medical Journal, Tarran and other senior researchers propose that e-cigarettes be regulated like drugs, with FDA requiring well-documented safety studies in animals and people.

To be sure, except for some flavorings, the ingredients of standard vapes are not known to cause cancer. Some, like the propylene glycol and vegetable glycerine that are heated to form the vapor that e-cigarette users inhale, are known to be safe when eaten in small amounts. But there is little research into their impact when the ingredients are mixed, vaporized at high temperatures, and inhaled regularly over months or years. One study showed that people who work on live shows employing propylene glycol “fog machines” can develop lung irritation and asthma exacerbations.

“Honestly, these [chemicals] were never made to be inhaled to start with,” said Luca Cucullo, a Texas Tech University professor of pharmacy.

Even short-term studies provide ambivalent evidence of the relative safety of vaping, says Tarran. Cigarette smoke, puff per puff, kills more cells than vaping, “but we’re seeing more changes in vapers’ lungs than in smokers’ lungs,” he said.

“To date, no long-term vaping toxicological/safety studies have been done in humans,” Tarran and his colleagues summed up in their article. “Without these data, saying with certainty that e-cigarettes are safer than combustible cigarettes is impossible.”

Farrah Kheradmand, a Baylor Medical College physician who studied the impact of common vaping solvents on mice lungs, found changes in lung tissue “could put people in danger of not being able to breathe or defend their lungs from infectious organisms,” she said.

However FDA writes its final regulation, any action it takes must emphasize the risks of youth vaping, said Stanford University psychologist Bonnie Halpern-Felsher.

“These young people were not smoking cigarettes,” she said. “They are initiating tobacco products through e-cigarettes, and [teens who vape] are four times as likely to go on to smoke cigarettes.”

“We don’t have enough good evidence as to whether they are going to be less harmful than cigarettes — some evidence, but nothing conclusive. And we have a lot of evidence of new initiates.”

Vaping is a rapidly changing industry involving a variety of different basic chemicals, flavorants and heating elements that make it hard to generalize about e-cigarettes as a whole, scientists say.

A 2014 survey found more than 7,700 different flavors in vaping liquids, many of which have appeal to younger vapers. Many of these chemicals turn carcinogenic when heated to high temperatures. At the time of the 2014 survey, three quarters of the flavored vapes contained diacetyl, a chemical that causes the vividly disastrous disease “bronchiolitis obliterans” in workers who inhale a lot of it.

Scientists have noted that Juul, which entered the market in 2015 and seized control of two-thirds of it within a few years, employs a form of nicotine, created by cigarette makers, that renders the chemical less irritating, so more nicotine can be used, delivering a bigger kick and increasing the product’s addictiveness. Juul is partly owned by tobacco giant Altria.

An independent British study, published in the New England Journal of Medicine earlier this year, showed that e-cigarettes worked better than nicotine patches at smoking cessation; after a year, 18 percent of e-cig users had stopped using tobacco cigarettes, compared to 10 percent of patch users. But an accompanying editorial noted that a year into the study, 80 percent of the e-cigarette group was still vaping, with whatever risks that implies.

As for the current vaping disease epidemic, many scientists believe that it probably includes a level of background cases that were already occurring. During the flu season, especially, people frequently enter emergency rooms with pneumonia and doctors there haven’t asked about vaping until recently, scientists say.

In the view of several scientists, the paucity of evidence vindicating e-cigarettes provides grounds for strict regulation. Among other steps, FDA should require that vaping coils — which heat the vaping liquid into an aerosol — be set in a way to prevent high temperatures that allow dangerous compounds to form. FDA also should ban flavoring agents and allow each to be reintroduced only after careful study of their safety when inhaled, said Cucullo.

The vaping disease epidemic should serve as a wake-up call, Cucullo said. “What we’re seeing now are limited, short side effects,” he said. “Several years down the road you may start seeing other effects popping up.”

FDA will “have to make an administrative/scientific judgement based on the evidence we have, and how they draw the line in terms of safeguards,” said Matthew Myers, president of the Campaign for Tobacco-Free Kids.

“If I’m a pack-a-day Marlboro smoker and there’s solid evidence that this product appeals to adults, has solid data that it helps you quit, a rational decisionmaker would say, I’m prepared to accept the risks of whatever’s in the vapes,’’ Myers said. The public health standard is, ‘Will introducing this product on the market increase, decrease or have no impact on tobacco deaths?”