The researchers "caution against the widely held opinion that e-cigarettes are safe".
With vaping becoming a style statement globally including in India, a small yet significant study has found that vaporisers may potentially disable key immune cells in the lung and boosts inflammation if used for long.
Earlier this year, an independent review concluded that e-cigarettes should be available on prescription due to the fact that there is "overwhelming evidence" that they are better for you than smoking.
The report was published online August 13 in the journal Thorax.
Martin Dockrell, tobacco control lead at Public Health England, said: "E-cigarettes are not 100% risk-free but they are clearly much less harmful than smoking".
Vaping should not be assumed to be totally safe, as the cigarette-substitute may actually cause inflammation of the lung cells and impair the organ's ability to get rid of dust and bacteria, finds a new study.
The study, conducted at the University of Birmingham, found that in some cases the vapour from e-cigarettes disabled important immune system cells within the lungs.
The study looked at eight non-smokers who vaped over a 24-hour period. Britain's public health authorities are pushing smokers to switch to it as a safer choice; experts in the U.S. have warned that electronic cigarettes increase the risk of nicotine addiction among young people, while the World Health Organization has said uneasily that warming up electronic cigarettes can lead to the formation of toxic substances.
Researchers devised a mechanical procedure to mimic vaping and produce condensate from the vapour.
Although vaping is increasing in popularity, most of the current body of research has focused only on the chemical composition of e-cigarette liquid before it is vaped. They noticed that the damage to the lung tissues caused by the vapours were same as those seen in regular smokers.
While e-cigarettes are safer in terms of cancer risk, there may be a greater risk of chronic obstructive pulmonary disease (COPD) after vaping for a number of years, said lead study author, Professor David Thickett.
"In terms of cancer causing molecules in cigarette smoke, as opposed to cigarette vapour, there are certainly reduced numbers of carcinogens", he said.
Initially public health experts were not that concerned about e-cigarettes because they were being marketed as a way to help smokers quit, Blaha said.
"We should have a cautious skepticism that [e-cigarettes] are as safe as we are being led to believe", Thickett said. The effects were worse when it contained nicotine.