Just my opinion, but if you don't smoke then please don't start
vaping! Nicotine is more addictive than crack, and anything that takes you one step closer to the possibility of smoking tobacco is something to avoid like the plague.
But even if vaping doesn't lead to smoking or cancer, consider that twice as many people die from chronic lung disease (COPD) than from lung cancer. It's the fourth leading cause of death in the world, right up there with heart attack and stroke. COPD (chronic bronchitis, emphysema, etc.) can seriously impact quality of life for many years after middle-age. COPD is caused by long-term exposure to irritants such as smoke, smog, chemical fumes, and dust. So far we don't know the effects of long-term vaping of high concentrations of PG/VG/flavorings. But certainly there's some evidence to suggest that it's a respiratory irritant, which could contribute to COPD in the long run. So I would say for a non-smoker, it's not worth the risk. If you want to enjoy your old age, eat healthy, exercise, and breathe clean air!