Is Vaping Safer than Smoking? New Directions for Women Propylene glycol hi res stock photography and images Alamy Smoking vs vaping what are the key differences? Evapo 80.8% people believe that vapes are less harmful than cigarettes VAPE HK Propylene glycol and vegetable glycerin e cigarette aerosols impact mucociliary function and cause cytotoxicity in human airway epithelium Scientific Reports Studies show that the negative health effects of e cigarettes are like that of traditional cigarettes. A Parkview expert explains the dangerous combination of highly addictive nicotine and the chemicals in e liquid.