VAPING may be worse for you than traditional smoking, a new study claims.
Greek researchers found that flavourings in e-cigarettes harm the lungs by causing inflammation.
Experiments conducted on mice showed that even in the short-term, the inflammation they caused was similar or worse than conventional cigarettes.
Dr Constantinos Glynos said: "The observed detrimental effects in the lung upon e-cigarette vapour exposure in animal models highlight the need for further investigation of safety and toxicity of these rapidly expanding devices worldwide."
They simulate smoking a traditional cigarette by dispensing a vapour derived from liquid chemicals in a refillable cartridge that typically contain propylene glycol, nicotine and often flavourings.
Propylene glycol - a colourless and odourless additive - is found in numerous processed food and beverages. It is also used as a solvent in a number of pharmaceuticals.
The findings, published in the American Journal Of Physiology-Lung Cellular, show e-cigs and refills are not well regulated and their long-term effects on health are unknown.
Researchers compared several groups of mice that received whole-body exposure to varying chemical combinations four times each day, with every session separated by 30-minute smoke-free intervals.
Dr Glynos from the University of Athens, said: "Electronic cigarettes are advertised as a less harmful nicotine delivery system or as a new smoking cessation tool. Our findings suggest that exposure to e-cig vapour can trigger inflammatory responses and adversely affect respiratory system mechanics."
"We conclude that both e-cig vaping and conventional cigarette smoking negatively impact lung biology."