E-cigs popular with teens, but few are regular users

Of those who do use them regularly, most are also tobacco smokers, they added.

Just 1.5 percent of schoolchildren aged 11-16 said they used e-cigarettes regularly, a term defined as at least once a month, according to their study, published in the journal BMJ Open.

The probe touches on one of the most contested areas of e-cigarettes, whose rise has spurred a verbal battle between defenders and promoters.

E-cigarettes are battery-powered devices that heat up a liquid containing nicotine and artificial flavouring. The vapour is inhaled -- "vaped" -- much like a cigarette.

In the last few years, health watchdogs have been embroiled in debate as to whether the gadgets are safe or addictive.

The study did not focus on the safety issue, but pointed to evidence that, so far, addiction did not seem to be a problem.

Nor, according to the replies recorded in the survey, do e-cigarettes seem to be a gateway to smoking.

"E-cigarettes are unlikely to make a major direct contribution to adolescent nicotine addiction at present," the paper said.

The findings are based on two "nationally representative" surveys in Wales, in which two batches of children -- 1,601 aged 10 to 11 and 9,055 aged 11 to 16 -- were questioned about their use of e-cigarettes.

Use of e-cigarettes at least once was more common than having smoked an ordinary cigarette in every age group except the oldest category, the 15- to 16-year-olds.

Among the 10- to 11-year-olds, 5.8 percent said they had tried e-cigs, several times more than those (1.6 percent) who had tried tobacco.

Among the 11- to 16-year-olds, 12.3 percent said they had tried the device.

But among regular users, there was a strong association with smoking cigarettes -- which implies teens are not using the device as an aid to give up tobacco -- as well as cannabis.

The study admitted to some limitations, such as the accuracy of self-reported use of e-cigarettes, and differences in questionnaire wording for the two batches of children.

Independent commentators said the picture tallied with other research that suggests only a tiny portion of non-smoking youngsters go on to regularly use e-cigarettes after trying one.

"It shows what we might predict," David Nutt, a professor of neuropsychopharmacology at Imperial College London, told Britain's Science Media Centre.

"My personal view is that e-cigarettes are unlikely to be remotely as harmful as cigarettes. Even if everyone used e-cigarettes, the burden of harm would be less than that of current cigarette smoking."

Linda Bauld, a professor of health policy at the University of Stirling, Scotland, said that laws governing nicotine-dosed e-cigarettes were important.

"However it may be time to move on from the moral panic that e-cigarette experimentation in young people elicits among some," said Bauld.

Speaking at an anti-tobacco conference in Abu Dhabi last month, World Health Organization (WHO) chief Margaret Chan voiced support for governments that ban or regulate e-cigarettes.