Dr. Helen McAvoy:

They can be for some people. The challenge is that in the studies that compared the use of e-cigarettes with other forms of nicotine replacement therapy, NRT, many people were still vaping at the end by comparison with those who used oral NRT and moved off it. If you are still addicted to nicotine, you are still vulnerable to returning to tobacco. That is really the concern we have. People who use e-cigarettes may even be dual-using at the end, so they are not even effectively reducing the risk of all the tobacco-related diseases because-----