Smoking e-cigarettes, or vaping, may be more harmful than we think, according to University of Birmingham scientists.
Vaping blocks alveolar macrophages from working – part of the lungs that get rid of dust, bacteria and other allergens, they claimed.
Twenty-four hours of vaping leads to cell death, and increases the number of free radicals being produced by 50 times, they warned.
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.
“There’s certainly an agenda to portray e-cigarettes as safe,” said Thickett.
While vaping is safer than traditional cigarettes, they may still be harmful in the long-term, he warned.
“In terms of cancer-causing molecules in cigarette smoke, as opposed to cigarette vapour, there are certainly reduced numbers of carcinogens.
“They are safer in terms of cancer risk, but if you vape for 20 or 30 years and this can cause COPD, then that’s something we need to know about.
“I don’t believe e-cigarettes are more harmful than ordinary cigarettes.
“But we should have a cautious scepticism that they are as safe as we are being led to believe.”
Most research on the safety of vaping is based on the e-cigarette liquid before it’s smoked.
But, the scientists wanted to explore how the chemical composition the liquid changes after being vaped.
They created a mechanism to mimic the effects of vaping, as well as to turn the smoke back into a liquid afterwards.
Testing the new fluid on lung tissue samples, the scientists revealed it was “significantly more harmful” than plain e-cigarette fluid.
The vaping process damaged the vital immune system cells, they concluded.
E-cigarettes don’t proceed tar or carbon monoxide; two of the main toxins in cigarette smoke, said the NHS.
E-cigarettes work by heating a liquid, and creating a vapour that usually contains nicotine.
Switching to e-cigarettes could help smokers to give up smoking, it added.
Around two out of three people who used e-cigarettes, while also using the NHS stop smoking service, successfully quit smoking.
Find your nearest NHS stop smoking service on the NHS Smokefree website, or call the Smokefree National Helpline to speak to a trained adviser on 0300 123 1044.