I suggest you follow up on the links provided by malyden.
E-cigs are fairly new, so there is no definitive answer as to the long term effects of
vaping. However, logic dictates that it is safer than cigarettes due to the fact that you are inhaling fewer chemicals. There have been no indications that
vaping is dangerous.
From my own personal experience, I can tell you that I feel much healthier now. My biggest health issue with smoking was with sinus problems. Since I quit smoking my sinuses have cleared up. I no longer have the issues I had previously. I breathe better, I sleep better, no more sore throat, no more hacking up phlegm, no more nausea caused by sinus drainage. You get the point.
In the long run, I know
vaping instead of smoking may prolong my life. COPD runs in my family. I've seen several family members suffer from this devastating disease. If I continue to smoke I will undoubtedly have to endure the effects of COPD.
Although we can't be absolutely sure that vaping for several decades is perfectly safe, I am more than willing to take my chances. If I were to continue smoking cigarettes I would have no chance.