E cigarettes, or vapes, use a battery to heat a liquid containing nicotine and other substances into an aerosol. Vaping is the inhalation of this product. So, why should you avoid them? In E cigarettes Can Alter Airway Immune Defense Genes Respiratory Therapy Up in Vapor American Physiological Society Researchers find e cigarette use disrupts nasal microbiome UNC Gillings School of Global Public Health