Although the market for e-cigarettes is booming, scientists and health agencies are still debating the extent of their health impacts. Basic questions remain: What chemicals are in the vapor cloud produced by e-cigarettes? And how does this vapor affect users and those around them?
A research team led by Hugo Destaillats, PhD, a chemist in the Indoor Environment Group at Lawrence Berkeley National Lab, is seeking the answers to these questions.
Destaillats and his colleagues have studied the complex chemical composition of vaping aerosols, the cloud of particles the devices emit. In one study, they quantified emissions from three e-liquids with various vaporizers, battery power settings and vaping habits — ranging from heavy to low puff duration and frequency.
The researchers found 31 potentially toxic substances in the vapors, including two not previously detected: propylene oxide in the e-liquids and glycidol in the vapors. Both of these compounds are considered probable carcinogens. They also determined that the base fluids used in vaping, propylene glycol and glycerin, can decompose when heated to produce acrolein, a powerful irritant.
However, the level of these toxins varied depending on the type of e-cigarette and how it was operated. For instance, toxic emissions rates were higher for e-cigarettes with a single heating coil compared to ones with double coils. Toxin levels also increased with the voltage used to power the device. And they rose with repeated use, presumably due to a buildup of residue within the device.
“We hope that one outcome of our research has been to provide useful information to manufacturers to help them improve the safety of their devices,” said Destaillats in a recent article in Analytical Scientist. .
In a follow-up study, the researchers assessed the health impact of firsthand and secondhand exposure to these vapor clouds under various typical use conditions. The integrated health damage from vaping for the various scenarios was lower than, or comparable to, the estimated damage from tobacco smoke, they concluded.
Given the countless unique e-liquid flavors and the on-going development of new devices, this research is difficult to generalize, they said, but they are concerned that more unidentified toxins exist.
Destaillats summarized in the article:
“Vaping is effectively a toxicological experiment being carried out with millions of people around the world.”
This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.
Scientists Talk Funny 
I find it terrifying that so many people are willing to inhale unknown compounds directly into their lungs, and that this became so widespread without adequate prior research or regulation. Thanks for the info.