What are e-cigarettes and are they safe?

E-cigarettes are set to be prescribed on the NHS under plans announced by the government to tackle smoking. How do these devices work, how safe are they and what is the debate around them?What are e-cigarettes?E-cigarettes are now a common sight. According to the charity Action on Smoking and Health (ASH), 7.1% of adults in Great Britain use e-cigarettes, equating to about 3.6 million people....