A scientific study has found that e-cigarette vapours carry no toxin threat to human lungs, strengthening the case for widespread e-cigarette use.

British American Tobacco funded the research which showed the vapours omitted from e-cigarettes could be as innocuous as fresh air.

Scientists constructed a “smoking robot” which carried lung cell replicas which were ruthlessly tested by tobacco smoke, e-cig vapours and fresh air.

The fake lung cells were quickly dismantled by the tobacco smoke, but were untroubled by vapours, and the damage was similar to the effect of air.

“Despite the limitations of the research, it adds additional evidence to support the contention that vaping is a lot safer than smoking,” said Dr Michael Siegel, professor in the department of community health sciences at Boston University’s school of public health.

Siegel also called for public health bodies and anti-tobacco movements to help and encourage smokers to start vaping.