How bad are e-cigarettes for you?

THE REGULATORS at America’s Food and Drug Administration could be forgiven for wanting a cigarette break. They rushed to meet a September 9th deadline to decide whether more than 6.5m e-cigarette products made by over 500 companies can remain on the market. When the deadline arrived, the agency had made determinations covering about 93% of the products submitted for review. It will block the sale of more than 946,000 flavoured products. But on the question of Juul—the largest player, with 40% of the market for e-cigarettes—regulators said they need more time. E-cigarettes have attracted keen government attention in recent years. In 2019 America’s surgeon-general called vaping an epidemic among young people, criticising in particular products with “kid-friendly” flavours, such as cinnamon and vanilla. Later that year more than 450 people in America suffered from a mysterious and severe lung illness that was linked to vaping, and was probably caused by black-market cartridges containing cannabis extracts and harmful substances such as vitamin E oil. Other countries, including Brazil, India and Singapore, have already banned e-cigarettes. So what goes into them, and how bad are they really?

The devices use an electric charge to vaporise a dose of nicotine (accompanied, often, by various flavouring chemicals). The composition of the vapour varies between brands. Its main ingredients—propylene glycol and glycerol—are thought to be mostly harmless when inhaled. But that is not certain. Nitrosamines, a carcinogenic family of chemicals, have been found in e-cigarette vapour, albeit at levels low enough to be deemed insignificant. Metallic particles from the device’s heating element, such as nickel and cadmium, are also a concern. High exposure to these can increase the risk of cancer. And some studies have found that the vapour can contain high levels of unambiguously nasty chemicals such as formaldehyde, acetaldehyde and acrolein, all derived from other ingredients that have been exposed to high temperatures. It also contains free radicals, highly oxidising substances that can damage tissue or DNA, and which are thought to come mostly from flavourings. Then there is nicotine. Besides being addictive, it is known to have an adverse affect all around the body. The main concern is its effects on children. Work in animals suggests that exposure to nicotine at an early age could make users more susceptible to other addictive substances later in life.

This sounds worrying, but e-cigarettes are nowhere near as nasty as their combustible cousins. Cigarette smoke contains about 70 carcinogens, as well as carbon monoxide (a poison), particulates, toxic heavy metals such as cadmium and arsenic, oxidising chemicals and assorted other organic compounds. Instead of the thousands of different compounds in cigarette smoke, e-cigarette vapour probably contains merely hundreds. And cigarettes may be more addictive than some e-cigarettes because they deliver other chemicals along with nicotine. For example tobacco smoke amplifies the addictive nature of nicotine by inhibiting monoamine oxidase, an enzyme that helps to break down the dopamine (a pleasure hormone) that nicotine releases in the brain.

Regulators and politicians are right to worry about the long-term effects of e-cigarettes, but widespread bans risk forgoing the potential health benefits of people turning to e-cigarettes as a substitute for the conventional sort. And the tide may be turning on the vaping epidemic among teenagers. The proportion of America’s high-school students vaping fell from 27.5% in 2019 to 19.6% last year, according to the National Youth Tobacco Survey. But smoking still kills 480,000 Americans every year, and 8m people worldwide. That means regulators must strike a fine balance: help smokers to quit while deterring a new generation of nicotine addicts.

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