More must be done to examine the impact of e-cigarettes on health, experts have said.
The call comes as new research showed that almost 30 million people around Europe have tried the battery operated products.
A new study published in the journal Tobacco Control examined data from 26,500 people across 27 European countries.
The authors of the study, from Imperial College London, the US and Greece, found that 20.3 per cent of current smokers, 4.7 per cent of ex-smokers and 1.2 per cent of never smokers had tried an e-cig at least once. This means that 29.3 million European adults have tried the products, they added.
But the researchers said that the scientific community is yet to provide information regarding the harm or efficacy of e-cigarettes.
Meanwhile a separate study, published in a special supplement of Tobacco Control, found that the market of e-cigarettes is growing rapidly.
Researchers from the US sought to identify the quantities of these products available online. They did two separate internet searches of English language websites, the first between May and August in 2012 and the second between December 2013 and January 2014.
In the period between searches there was a net increase of 10.5 new brands and 242 new flavours every month, they said.
By January 2014, they identified 466 brands with 7,764 unique flavours.
The research was published as health experts from around the globe called on the World Health Organisation (WHO) to put new controls on e-cigarettes.
In a letter to WHO director general Margaret Chan, they raised concerns about what the unregulated products actually contain.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article