Yesterday, Massachusetts Gov. Charlie Baker (R) announced an "emergency" ban on the sale of all vaping products, including devices used to consume cannabis extracts, nicotine, or solutions with no psychoactive ingredients. Unlike the bans on flavored e-cigarettes in Michigan and New York or the similar ban planned by the Food and Drug Administration (FDA), which were presented as responses to underage consumption, the Massachusetts edict is based mainly on concerns about recent reports of severe respiratory illnesses associated with vaping. But the governor's explanation is highly misleading in light of what we know about the causes of those illnesses, and his sweeping ban is apt to undermine public health instead of protecting it.

"The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) are currently investigating a multi-state outbreak of lung disease that has been associated with the use of e-cigarettes or vaping products (devices, liquids, refill pods, and/or cartridges)," Baker's press release says. "To date, the CDC has confirmed 530 cases of lung injury across 38 states. While many of the patients reported recent use of Tetrahydrocannabinol (THC)-containing products, some reported using both THC and nicotine products. No single product has been linked to all cases of lung disease."

Baker is echoing the CDC's framing, which obscures the fact that the overwhelming majority of lung disease cases (not just "many") are associated with black-market cannabis products. In states where the products used have been reported, the share of patients who admitted vaping THC ranges from 83 percent to 100 percent. The actual rates in some of those states may be even higher, since patients might be reluctant to admit illegal drug use.

The most plausible explanation for the respiratory illnesses is that vaping oil-based THC solutions is leading to lipoid pneumonia, a rare condition caused by fat particles in the lungs, or eosinophilic chemical pneumonitis, a disease marked by elevated levels of white blood cells in the lungs. A leading suspect is vitamin E acetate, which was detected in most of the THC fluids tested by the FDA and New York's state lab. Legal nicotine e-cigarettes, by contrast, typically vaporize e-liquids containing propylene glycol and vegetable glycerin. Furthermore, such e-cigarettes have been used by millions of Americans for years, while the respiratory illnesses have been reported only in the last few months, which suggests that relatively new additives or contaminants are to blame.

"These excipients [propylene glycol and vegetable glycerin] have been used in e-liquids for the past 12 years without a problem," notes Boston University public health professor Michael Siegel, a physician and epidemiologist who supports e-cigarettes as a harm-reducing alternative to the conventional, combustible kind. "If PG/VG were the problem, then there would be a huge number of cases occurring among adults, much less of a differential by gender, and much less of an age gradient in the reported cases."

Siegel faults the CDC for its muddled message about vaping-related lung disease. "Given the fact that close to 90% of cases and 100% of the deaths for which products have been reported are associated with marijuana vaping, it is inexcusable that the CDC fails to distinguish between the products being vaped," he writes. "It is also inexcusable that CDC has failed to distinguish between the vaping of oil-based e-liquids (which are typically used in [THC cartridges]) and water/alcohol-based e-liquids (as are used in virtually all e-cigarettes)."

In this context, Baker's comprehensive ban on all vaping products makes little sense. He is relying on his authority to declare an emergency "which is detrimental to the public health." Based on Baker's declaration, the commissioner of the Massachusetts Department of Health, with the approval of the state Public Health Council, has imposed a four-month ban covering a wide range of products that, so far as we know, have not been implicated in respiratory illnesses.

Implicitly conceding the inadequacy of his main justification, Baker also cites recent increases in e-cigarette use by minors as a rationale for the ban. "Vaping products are marketed and sold in nearly 8,000 flavors that make them easier to use and more appealing to youth," says Lt. Gov. Karyn Polito. "Today's actions include a ban on flavored products, inclusive of mint and menthol, which we know are widely used by young people."

Baker's action highlights the alarmingly broad authority that some governors are claiming to ban products they don't like in the name of "public health." Since the statutes on which they are relying do not define "public health," they seemingly allow governors to declare any situation an "emergency" and impose bans without new legislation. Gregory Conley, president of the American Vaping Association, which seeks to preserve e-cigarettes as an option for smokers who want to quit, asks, "If a governor is permitted to just ban e-cigarettes for four months, what else could they ban?" That seems to be an open question, although litigation by vaping businesses may clarify the answer.

Baker's defense of his ban lumps together several distinct issues: the outbreak of respiratory illnesses related to THC vaping, the surge in underage e-cigarette use, and the relative hazards of vaping and smoking. His take on that last issue is decidedly unscientific. "To further inform the public about the dangers of vaping and e-cigarette use," his press release says, the Department of Public Health "is relaunching two public awareness campaigns aimed at educating parents and middle and high school-aged youth. 'Different Products, Same Danger,' originally launched in April 2019, links the dangers of vaping to cigarette smoking."

Legal e-cigarettes, which deliver nicotine without tobacco or combustion, emphatically do not pose the "same danger" as conventional cigarettes. As David Abrams, a professor of social and behavioral sciences at NYU, explained in a recent interview with CBS News, studies of biomarkers in smokers who have switched to vaping find that they are exposed to far fewer hazardous substances, at far lower levels, than people who continue to smoke. "E-cigarettes are way less harmful than cigarettes," he said, "and they can and do help smokers switch if they can't quit."

If every smoker in the United States switched to e-cigarettes, Abrams estimates, it would prevent as many as 7 million smoking-related deaths. Vaping "delivers nicotine in a very satisfying way without the major harms of burning tobacco," he said. "If we lose this opportunity, I think we will have blown the single biggest public health opportunity we've ever had in 120 years to get rid of cigarettes and replace them with a much safer form of nicotine."

The harm-reducing potential of e-cigarettes has been recognized by a wide range of public health agencies and organizations, including the FDA, the Royal College of Physicians, Public Health England, the American Cancer Society, and the National Academies of Sciences, Engineering, and Medicine. In 2015, Public Health England said "best estimates show e-cigarettes are 95% less harmful to your health than normal cigarettes." Yet the Massachusetts Department of Public Health is telling people that e-cigarettes pose the "same danger" as combustible cigarettes, a false premise that seems to be part of the logic underlying its ban.

If you ignore the enormous difference between the health risks posed by smoking and the health risks posed by vaping, it is easier to rationalize a policy that will deprive current and former smokers of an alternative that could save their lives. Massachusetts Health and Human Services Secretary Marylou Sudders implicitly acknowledges the impact the vaping ban will have on smokers who have switched to e-cigarettes or might be interested in doing so. "As a result of the public health emergency," she says, "the Commonwealth is implementing a statewide standing order for nicotine replacement products, like gum and patches, which will allow people to access these products as a covered benefit through their insurance without requiring an individual prescription."

As David Abrams noted in his CBS News interview, research indicates that e-cigarettes are nearly twice as effective in smoking cessation as those "nicotine replacement products." Many smokers who did not manage to quit with "gum and patches" were able to do so with e-cigarettes. By ignoring that reality, Massachusetts pretends that its vaping ban will improve public health when in fact it is apt to result in more smoking-related diseases and deaths as former smokers return to a much more hazardous habit and current smokers are deterred from quitting.

"Massachusetts has made significant progress over the past two decades in curbing youth and adult tobacco use," the governor's press release notes. "In 1996, the youth smoking rate was 36.7%. Today, the youth smoking rate is 6.4%. The adult smoking rate is also low, with just under 14% of adults using combustible tobacco products." These downward trends not only continued as vaping became more common; they accelerated, suggesting that e-cigarettes are replacing a far more dangerous source of nicotine. But that consideration does not seem to have figured at all in Baker's decision.

It should go without saying that the Massachusetts ban will not curtail vaping of mystery cartridges and e-liquids available on the black market, which pose the greatest risks. To the contrary, the ban will drive vapers toward those products. "Legal vapes while not safe are subject to regulation on manufacturing, sales, marketing, ingredients, warnings," former FDA chief Scott Gottlieb noted last month. "If we outlaw all vapes, and pull legal products off the market, problems with illegal and counterfeit products will get worse." Yet that's exactly what Massachusetts is doing.