A new study suggests that vaping may not be as safe as some have thought – but Public Health England has warned that the news should not deter any smokers from switching to e-cigarettes, as they are “clearly much less harmful than smoking”.
The study, published in Thorax, compared the effects of unvaped e-cigarette liquid (ECL) to e-cigarette vapour condensate (ECVC) on the function of alveolar macrophage (AM), important immune cells in the lung.
The researchers took lung tissue samples from eight non-smokers and exposed them to ECL and ECVC via a mechanical process.
They found that ECVC is “significantly more toxic to AMs than non-vaped ECL”. They speculate: “Excessive production of reactive oxygen species (ROS), inflammatory cykotines and chemokines induced by e-cigarette vapour may induce an inflammatory state in AMs within the lung that is partly dependent on nicotine.”
“Inhibition of phagocytosis also suggests users may suffer from impaired bacterial clearance,” the authors add.
The authors acknowledge that the study has limitations, such as the fact that it monitored change over 48 hours, rather than showing the results of “a chronic exposure system”.
The study was led by professor David Thickett of the University of Birmingham, who commented: “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.”
Earlier this year, PHE suggested that pharmacy teams “communicate the large difference in relative risk [between smoking and vaping] unambiguously so that more smokers are encouraged to make the switch from smoking to vaping” and help tackle the UK’s leading cause of preventable illness and premature death.
Martin Dockrell, tobacco control lead at Public Health England, commented on the new study findings: “E-cigarettes are not 100% risk free but they are clearly much less harmful than smoking.”
“Any smoker considering e-cigarettes should switch completely without delay”, Mr Dockrell said.