Harvard researchers have found traces of potentially harmful substances in the vapour emitted by electronic cigarettes.

Electronic cigarettes - otherwise known as ‘e-cigs’, ‘vapourisers’ or just ‘vapes’ – are growing in popularity around the world, as millions of former smokers look for a less destructive alternative.

But little is known about the long-term health effects of the relatively new technology, so research is needed to let users know what they are inhaling.

Researchers at Harvard’s T.H. Chan School of Public Health say diacetyl, a flavouring chemical linked to cases of severe respiratory disease, has been found in more than 75 percent of flavoured electronic cigarettes and refill liquids.

Their study has been published in the journal Environmental Health Perspectives.

At least one of three chemicals - diacetyl, acetoin, or 2,3-pentanedione - was detected in 47 of the 51 flavours tested.

Diacetyl was detected in 39 of the flavours tested, while acetoin and 2,3-pentanedione were detected in 46 and 23 and of the flavours, respectively.

The liquid used in electronic nicotine delivery systems consists primarily of vegetable glycerine and propylene glycol – two incredibly common and long considered safe substances.

To this is added a small amount of nicotine and flavouring, and the presence of diacetyl in the flavouring concentrates and subsequently in ‘e-juice’ has been known for several years.

What the Harvard study fails to note is that the actual amounts of diacetyl in vapouriser juice are far less than the amount found in cigarette smoke.

Additionally, even cigarettes (with drastically higher levels of diacetyl) have not been shown to cause the debilitating respiratory disease bronchiolitis obliterans, colloquially known as “popcorn lung”.

The disease is so named because it first appeared in workers who inhaled artificial butter flavour in microwave popcorn processing facilities.

Given that the research misses major points of comparison and seeks to over-state the risk of such small amounts of diacetyl, some have leapt to conclude that the study is one of many designed on a shaky premise to come up with alarming results that diminish the benefits of electronic cigarettes.

Big tobacco firms are usually blamed for stimulating this sort of research, and it is a view that has been stoked in this case by the press release accompanying the Harvard study.

Some of the major arguments against the new style of nicotine delivery are about the flavours – specifically the idea that fruit and confectionary flavoured juices make e-cigarettes more appealing to children.

The Harvard press release, while apparently reporting on the risk of lung disease, finds several occasions to make the link between sweet flavours and childhood nicotine addiction.

“Two other related, potentially harmful compounds were also found in many of the tested flavours, which included varieties with potential appeal to young people such as cotton candy, ‘Fruit Squirts’, and cupcake,” the statement reads, despite the intended flavour used in the study being largely irrelevant.

“Diacetyl and other related flavouring chemicals are used in many other flavours beyond butter-flavoured popcorn, including fruit flavours, alcohol flavours, and, we learned in our study, candy-flavoured e-cigarettes,” lead researcher Joseph Allen is quoted as saying.

The argument ignores that fact that adults enjoy and are drawn to these flavours too.

It also ignores the existence of fruit-flavoured vodka and other alcoholic mixes, and even of watermelon-scented and printed rolling papers for cigarettes, which are less fervently used as arguments against those drugs.

Many e-cigarette users will see a study such as this and continue not claiming that ‘vaping’ is 100 per cent safe, just safer than cigarettes.

While personal safety and active research should be practiced whenever possible, this kind of paranoid and hyperbolic coverage of a study does nothing to help build a rational view of where and how addicts should get their nicotine.

The growing army of e-cigarettes suers and manufacturers has a research arm just like the big tobacco companies, with figures like Dr Konstantinos Farsalinos undertaking some of the most accurate research and fact-based advocacy on the subject.