Key points from article :
Laboratory study looked into the effects of e-cigarette liquid on human alveolar macrophage cells.
Researchers created a device to generate puffs of vapour to mimic the action of using e-cigarettes.
Alveolar macrophage cell samples were taken from 8 people who'd never smoked.
Around 38 % of cells exposed to vapour that contained nicotine died.
The study was done by researchers from the University of Birmingham, Swansea University in the UK and SUNY Downstate Medical Center in the US.
