"There is clearly an epidemic that begs for an urgent response," wrote Harvard's Dr. David Christiani in the New England Journal of Medicine. The epidemic to which he refers is vaping, which is on the verge of being seen as a public health crisis. At the time of that writing, officials were investigating 450 possible cases of severe lung disease linked to vaping with five reported deaths around the country. A sixth potentially vaping-related death was reported on Tuesday in Kansas.

"If you or a loved one is vaping, please stop," said Kansas State Health Officer Lee Norman. Both the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) are conducting a nationwide investigation into the health effects of vaping products but have not yet established a link between respiratory illnesses and any specific product. Nevertheless, in this official's estimation, it's time for drastic action. "I think that I'd like to see our federal officials and law enforcement step up and say we need to pull these things off the shelves until we know what's going on," Norman averred.

Even before a public-health concern arose, vaping had become a target of public-health reformers. In 2018, the FDA announced new measures "to address the epidemic of youth e-cigarette use." Former FDA Commissioner Scott Gottlieb insisted that his agency "won't allow the current trends in youth access and use to continue, even if it means putting limits in place that reduce adult uptake of these products." His agency has since accused the e-cigarette maker JUUL of illegally claiming that its product helps smokers "quit," even though JUUL never used that word. "I'm not going to sit here and allow this committee to be used," Rep. Rashida Tlaib told a JUUL representative, "to say that e-cigarettes, vaping, JUUL, is not killing our people; they are." For Tlaib, the threat posed by vaping is too urgent to wait for evidence that validates her claim. Nor, it seems, could Michigan Gov. Gretchen Whitmer wait; she unilaterally banned the sale of flavored e-cigarettes in her state pending an investigation into their effects.

The headlines are dire; young people are getting sick and dying. The art that graces the news reports of health defects and rising rates of addictions always features colorful images of candy-flavored products. Even the first lady is getting in on the action. "I am deeply concerned about the growing epidemic of e-cigarette use in our children," Melania Trump wrote. "We need to do all we can to protect the public," she added, bringing her demand to the attention of the Department of Health and Human Services.

You could be forgiven for believing that the nation is in the grip of a serious health crisis. But public officials who call vaping in America an "epidemic" are using clinical language without a clinician's caution.

Though it is not exclusively the case, most reported illnesses arising from vaping products are linked to marijuana-related products purchased on the streets โ€” not in licensed distribution centers. The CDC has warned of precisely this threat since the summer, and it has been circumspect about what products cause risk. Gottlieb, now a member of the board of directors of the drugmaker Pfizer, noted that the increased risk is likely the result of new products entering the illicit marketplace. "It's probably something new that has been introduced into the market by an illegal manufacturer," he told the New York Times, "either a new flavor or a new way to emulsify T.H.C. that is causing these injuries."

Indeed, the New England Journal of Medicine study found that 84 percent of those who were sickened by vaporized inhalants reported using unlicensed marijuana-related products. Those who have surrendered their counterfeit marijuana aerosols for testing confirm Gottlieb's suspicions. Vitamin E acetate, a thickening agent that facilitates the vaporization of THC (the primary psychoactive compound in marijuana), has been found in almost all of the products from patients who fell ill in New York state in recent weeks. Unregistered cannabis producers have been accused of lacing their products with pesticides, fungicides, and growth hormones, as well, in the effort to produce marijuana plants as quickly as possible, since the yield of cannabis oil derived from a marijuana plant is only about 20 percent.

Neither licensed marijuana distributors nor nicotine products, which use either vegetable glycerin or propylene glycol as a means of vaporization, should be seen as primarily responsible for this threat (though counterfeit THC cartridges have been found in otherwise reputable distribution centers). But the demand for THC products has outstripped the supply in many states where marijuana exists in legal limbo โ€” neither legal nor expressly prohibited. In places such as New York, for example, where recreational marijuana possession is decriminalized but not licensed for distribution, disreputable producers can and do sell unlicensed THC vaping products. It is incumbent on the consumer to know the risks. The FDA has and continues to conduct extensive oversight over vape shops and e-liquid manufacturers, but that oversight is not extended to those who make illicit marijuana products. And that, so far, is the exclusive source of potentially fatal health risks from vaping. You wouldn't know it from the press coverage of the issue.

And what about the belief that vaping nicotine products has reversed the rates at which young people are abandoning the use of tobacco products? That, too, isn't much better than a guess. "First evidence that e-cigarettes may be prompting UK teens to try the real thing," read the headline from the British Medical Journal. The evidence consists primarily of a study that found substantial overlap among teens who smoke and teens who had, at one point, tried vaporized nicotine products โ€” a correlation that does not establish causation. You have to read well into the story to learn the researchers themselves confess that "there is no direct evidence" to indicate that vaping "normalizes" tobacco use.

In the United States, the CDC presents reasonably credible evidence that the wild popularity of vaporized nicotine products among high-school-aged students is responsible for an uptick in cigarette smoking. But while e-cigarette smoking among young people rose from 11.8 percent in 2017 to 20.8 percent in 2018, the number of young cigarette smokers rose by only one half of a percentage point from 7.6 to 8.1 percent. "It's not a statistically significant rise," CNBC's report on the phenomenon read, "but it still has some concerned."

The crusade against vaping bears all the hallmarks of a moral panic. It involves irrational and illogical assumptions based on a perceived threat to public safety. It draws on stereotypes involving a marginalized group within society โ€” tobacco users, in this case โ€” exaggerates distinctions, and exacerbates social tensions. Just like prior moral panics โ€” from the 17th century witch trials to the supposed epidemic of satanic ritual abuse in the 1980s โ€” it is, at root, a theory of moral deviance. It begins with popular media overhyping a perceived threat, often involving new technology or a cultural fad. That hype creates the demand for a political response, and the cycle culminates in the assumption of new state powers to curb the supposed threat. And though the danger is eventually exposed as chimerical, the new governmental intrusion into public lives is very real and persists long after the panic has dissipated.

If the threat posed by vaping is limited to adulterated and unlicensed marijuana products, as the available evidence seems to suggest, a rational response to the problem would be two-fold. First, curb the distribution of those products through tailored legislation and policing โ€” not a blanket assault on the vaping industry. Second, reduce the incentives to engage in the black market by licensing and regulating safe products. Black markets arise as a result of consumer demand. Limiting the public's access to state or federally regulated vaping products in the name of public safety will not only fail to address the problem but will create more consumers willing to take their business underground. The patchwork of national marijuana laws contributes to this condition. Establishing one national standard for consumer safety would go a long way towards addressing it.

Sadly, these are not rational times. As rates of tobacco use have declined, anti-smoking organizations have transitioned into sowing fears about the unknown long-term effects of vaping products. That is mission creep based on conjecture. It's also arguably unethical if it leads to a social trend of curtailing the availability of nicotine-replacement therapies that are proven to help people quit smoking. The campaign against vaping is hysteria, and it should end.