The e-cigarette industry is enjoying great success across the United States with over 10 percent of all American adults - an estimated 20 million people - currently vaping. Profits are high, with revenue from the vaping industry doubling in value from $1.75bn in 2013 to $3.5bn in only a two-year space of time.
Most e-cigarette users are either former or current smokers, with many taking a gamble on vaping being less detrimental to their health than traditional tobacco, simply because less is currently known about the new device.
But with research into e-cigarettes already struggling to keep up with new developments and changing statistics, how do consumers know which products to trust?
In terms of mechanics, the way an e-cigarette works is mostly straightforward. A battery-powered atomiser heats up a liquid mixture known as "juice", which is then transformed into vapour and then inhaled by the user. It is both the juice and the evolving vaping device that are creating health-related concerns for organisations like the Centers for Disease Control and Prevention (CDC) and researchers alike.
Monique Williams is a researcher at the University of California at Riverside and fears that the developments in the vaping world have not actually improved on any of the initial concerns - including finding heavy metal residue in the actual devices which are then easily inhaled into users' lungs.
"Inhalation of metals, especially things like tin, can cause stenosis, and that could constrict the bronchioles and the airways in the lungs," explains Williams.
The University of California at Riverside is also looking at discrepancies with nicotine labelling on a lot of the "juice" used in vaping. Researchers purchase juice samples at random from online vendors and then test the concentration of nicotine against what the labelling claims. The results are shocking.
"In a recent paper that we published, we found out that this specific sample was 59 percent higher in nicotine than the advertised label," says researcher Iliana Cordova, pointing to a random result in a long list of testing samples at the UC labs.
While vaping lobbyists continue to fight the notion that e-cigarettes and traditional tobacco are equal in their effects on peoples' health, researchers agree that until the longevity studies are executed, there can be no concrete evidence for or against these claims.
