Electronic Cigarettes: A Short Review

Abstract

in water) and a vaporization chamber, which produce an aerosol that simulates the smoke of a cigarette ( fig. 1 ).Nicotine and other additives like flavorings and glycerol (purified vegetable glycerine) may be added in various concentrations to the liquid. No combustion is involved in the process and the 'smoke' produced is an aerosol of liquid particles, a 'mist' [1] .Advertised as a valid way to quit smoking real cigarettes, the e-cigarette has been the subject of much controversy but little experimental study. This review provides a brief overview of the current evidence on the ecigarette. Aerosol GenerationBesides water, the main ingredient of the e-liquid is usually propylene glycol (PG) in water. A mechanical sensor detects when the user inhales and it then triggers the microchip controlling the heater which raises the temperature in the vaporization chamber.As specified by the manufacturers, the temperatures in the vaporization chamber range from 40 to 65 ° C [1] . Recently, however, variable voltage devices gained popularity as they can increase the temperature of operation and the heater surface area in order to tune the vapor to the user's satisfaction. No reliable data could be found on the range of temperatures in these recent devices. The same uncertainty exists about the operating temperature in Key WordsElectronic cigarettes · Propylene glycol · Nicotine AbstractMarketed since 2004 as an alternative to nicotine delivery and advertised as a valid means to smoking cessation, the electronic (e)-cigarette has been the subject of much controversy but very little experimental study. This review provides a brief summary of the current knowledge of this product. Propylene glycol and glycerol, the main ingredients of the fluid that is vaporized, have proved to be harmless in the fog machines of the entertainment industry. However, in the case of the e-cigarette fluid, the composition is not properly labeled: additives like nicotine and flavors vary between and within brands and contamination with various chemicals has been detected. The short-term toxicity seems low, but the long-term toxicity is unknown. The usefulness of the e-cigarette in smoking cessation has still to be clinically established.

Electronic Cigarette (E-Cigarette) Using: Toxicological Aspects

“…The rate of inhalable aerosol concentration for stage fumes which also contains PG is 0.70 mg/ m 3 (34). The acceptable exposure limit was found to be 50 mg/m (28).…”

“…The main component of the e-cigarette liquid is usually PG dissolved in water. When the user inhales from e-cigarette, this is detected by the mechanical sensor and the heater that is controlled by a microchip is triggered (28). PG is an alcohol derivative that is also called propane-1,2-diol/1,2-dihydroxypropane/methyl glycol.…”

“…According to the FDA, the fume that contains PG and is produced by the smoke machine has been classified as safe. However, no study has yet been conducted on the long-term toxic effects of PG when inhaled through e-cigarette (28).…”

“…Contrary to this, it is widely used in food and chemical industries and it is not toxic. Absorbed glycerol is metabolized in the liver and is converted into carbon dioxide and water or glucose and glycogen (28). The TLV of PG and glycerol is 10 mg/m 3 at the end of 8-h exposure (33).…”

Hormonal contraception among electronic cigarette users and cardiovascular risk: a systematic review

“…However, among EC users, simultaneous use of cigarettes appears to be common [6]. Although ECs are often promoted as safer alternatives to cigarettes, data on health effects associated with their use are limited [7][8][9].…”