E-cigarettes worse than traditional ones when it comes to addiction

Scientists have reported that much of the nicotine in e-cigarettes is the addictive form of the compound.

Although e-cigs don't burn tobacco, they heat and vaporise a liquid that contains nicotine, flavorings and other substances. Out of concern for the potential effects that inhaling this mixture could have on the health of young people, many states have banned their sale to minors.

Some experts have said that nicotine content could lead users to become addicted to e-cigs, or that it could even serve as a gateway to conventional cigarettes and other drugs.

But not all nicotine is created equal, and studies had yet to investigate what kind of nicotine was in the liquids. Out of three forms, scientists believe "free-base" nicotine is the only one that gets absorbed by the body, making it the most addictive kind.

Najat Saliba and colleagues tested commercial samples of liquids made for the devices and found that, by and large, the nicotine was in the most addictive form. They also determined that the concentration of nicotine varied and often didn't match the concentrations the labels claimed.

The research is published in ACS journal Chemical Research, Toxicology.