Review of electronic cigarettes as tobacco cigarette substitutes: Their potential human health impact

Electronic cigarettes (ECs) are devised to deliver nicotine in a vapor rather than in smoke without tar. ECs are hence advertised as being safer than tobacco cigarette products as the chemical compounds inhaled in the former are believed to be fewer and less toxic than those of the latter. Hazardous chemicals (e.g., formaldehyde) are nonetheless found to be generated incidentally by contacting the heated wire (i.e., the oxidation of glycerol/glycol in e-liquid). Although the extent of their release varies by several variables (e.g., the type of e-liquid, puffing rate, and the battery voltage), their exposure may also contribute to negative health effects. As the use of ECs may be much safer than that of common tobacco products, the former can…