Why vapers are much more likely to get Covid-19 and lung damage.
The latest signs are that vaping is helping some smokers give up cigarettes, and that it is more effective than other cessation methods, such as patches or gum. In fact, recent research from the University of Otago, Wellington, suggests the most common reason for using vaping devices is to quit or cut down on smoked tobacco.
However, that same study highlighted a concern. Aside from the quitters, the cohort that vaping most appeals to is youth. And in the era of Covid-19, as evidence emerges that vaping is a risk factor, this is especially problematic.
It is early days with this coronavirus, but we know it can trigger deadly levels of lung inflammation, and one new study from Stanford University School of Medicine has shown that young people who vape are five to seven times more likely to be infected with the virus than those who don't.
"Teens and young adults need to know that if you use e-cigarettes, you are likely at immediate risk of Covid-19, because you are damaging your lungs," says the study's senior author, Bonnie Halpern-Felsher.
About a third of Kiwi kids have tried vaping, according to the most recent research, and the number of regular young users is rising. That's no surprise to Tim O'Connor, who has seen it for himself. He is headmaster of Auckland Grammar School, where smoking was never too much of a problem until vaping became an epidemic.
"It's not like in my day with kids disappearing behind the bike sheds for a smoke," he says. "In fact, we were seeing more marijuana than cigarettes. But now we're dealing with vaping every week, and tens of students at a time. Some are going into the toilets to vape between classes and others are attempting to vape in class."
Auckland Grammar has taken a strong stand, banning pupils from a nearby fast-food restaurant where they were recruiting older kids to go to a nearby vape shop and make purchases for them. O'Connor issues warnings in school assemblies about vaping. And a senior staff member regularly devotes time to meeting with kids who have been caught, and their parents, most of whom are horrified because they had no idea what their kids were up to.
"With cigarettes, you knew your kids were smoking, because you'd smell it on their clothes, but vaping is an invisible habit – some of the products don't emit any vapour," says O'Connor.
Scientific consensus holds that vaping is far less harmful than traditional cigarettes, but it isn't risk free. And whether it is up to 95 per cent safer – a statistic that tends to be bandied about – is looking increasingly unlikely.
One US study found that users of the common vape flavours menthol and mint are exposed to high levels of the carcinogen pulegone, which is banned by the US Food and Drug Administration as a food additive. And when cinnamon flavour is heated, it creates a unique aldehyde – cinnamaldehyde – which can damage the respiratory system. There are thousands of other flavours containing ingredients that are potentially toxic.
Aaron Scott is a respiratory scientist at Birmingham University. He isn't anti-vape, believing that for cigarette addicts, particularly those suffering the progressive lung condition chronic obstructive pulmonary disease (COPD), it is a less harmful habit. But Scott is concerned about the new, younger generation of vapers.
His research focuses on the immune response within the lungs. He works with alveolar macrophages, sentinel cells that are exposed to everything we breathe. Scott has looked at the effect of vaped e-liquid on these cells and found that both those that contain nicotine and those that don't are toxic to the macrophages. Even in smaller doses, where it doesn't kill them, it is pro-inflammatory.
When e-liquids are vaped, humectants, such as propylene glycol and vegetable glycerine, heat up to make the vapour. As they break down, they generate other, more harmful components, including highly toxic formaldehyde. The alveolar macrophages react, bringing in other cells, such as neutrophils, whose main job is to ingest micro-organisms.
"Alveolar macrophages are fantastic and they'll deal with it," says Scott.
Continue vaping over and over, and sparking the same immune response, and in time it will create chronic lung inflammation. "You'll start to see that same early signal of harm you get with cigarette smoking," says Scott. "It's not as pronounced – cigarette smoking is the gold standard of harm you can do yourself – but eventually we're going to get to the same end result."
This month sees the first phase of the Smokefree Environments and Regulated Products (Vaping) Amendment Act take effect. Vaping will be banned in workplaces and sales to under-18s will be prohibited, as will advertising and sponsorship of products.
O'Connor is among those who believe the act doesn't go far enough.
"It's a start, but if the purpose of vaping is to help people addicted to cigarette smoking, then I think vapes should be prescription-only and with limited flavours," he says.